Animal models of Aspergillus infection in preclinical trials

Document Sample
Animal models of Aspergillus infection in preclinical trials Powered By Docstoc
					Medical Mycology September 2006, 44, S119 ÁS126

Animal models of Aspergillus infection in preclinical trials,
diagnostics and pharmacodynamics: What can we learn
from them?
California Institute for Medical Research, San Jose, Department of Medicine, Division of Infectious Diseases, Santa Clara Valley
Medical Center, San Jose, and Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford
University, Stanford, California, USA

                                 Animal models of aspergillosis, particularly those studied in rodents, are an
                                 integral part of antifungal drug development. The capacity to control different
                                 variables is beneficial, allowing a well defined model system to be used to address
                                 various issues of efficacy with monotherapy, combinations, or immunotherapy.
                                 One beneficial aspect of the use of animal models is that they enable us to
                                 investigate novel indications of drugs prior to a clinical trial or where a clinical trial
                                 is impractical. Included in these types of studies is the testing of potentially
                                 preventative vaccines. Animal models also are useful for studying diagnostic assays,
                                 as well as pharmacology and toxicity. Thus, because of the ability of the best
                                 models to mimic human diseases, and our ability to infect genetically identical
                                 cohorts of the same age, sex, co-morbidities and risk factors, with an identical
                                 challenge inoculum at the same time, we are able to address issues in vivo that
                                 cannot be answered by in vitro tests. We also can have sufficient numbers of
                                 subjects for statistical analyses, can vary the severity of infection at will and can
                                 choose to terminate the experiments to enable using survival or clearance of
                                 residual infection as the efficacy end-point. Are these animal models predictive of
                                 clinical efficacy, pharmacology and toxicity of an antifungal drug? No single model
                                 should be relied upon, as different models of aspergillosis in mice or other animals
                                 sometimes show somewhat different results. However, the accumulated wealth of
                                 experience has demonstrated the utility of these models in predicting clinical
                                 efficacy, pharmacology and toxicity.
                                 Keywords         aspergillosis, animal models

Introduction                                                         the immune status of the host, what duration is desired
                                                                     for the course of disease and what outcome and end-
Animal models, particularly those studied in rodents,
                                                                     points will be examined. Thus, the model must be well-
are an integral part of antifungal drug development.
                                                                     defined, and the characteristics of a good model have
Various questions have to be addressed prior to the use
                                                                     been detailed previously [1 Á4].
of any single model for studies of antifungal drugs.
                                                                        Animal models have both strengths and weaknesses
These include the type of disease being mimicked, such
                                                                     that are taken into consideration. Murine models can
as invasive pulmonary aspergillosis or systemic disease,
                                                                     be done affordably with sufficient numbers of animals
                                                                     included to obtain statistically relevant data, and there
                                                                     are numerous genetically defined strains available. Mice
Correspondence: Karl V. Clemons, Division of Infectious Diseases,
Santa Clara Valley Medical Center, 751 South Bascom Avenue, San
                                                                     require less specialized animal care and support facil-
Jose, CA 95128, USA. Tel: '/1 408 998 4557. Fax: '/1 408 998-2723.   ities and personnel. However, most murine models of
E-mail:                                             aspergillosis have the drawback of rapid and fulminant
– 2006 ISHAM                                                                                    DOI: 10.1080/13693780600871174
S120     Clemons & Stevens

disease progression, involvement of organs such as the           each showing good histopathologic correlation with
kidneys, which is often not seen clinically, and are             human disease [20,21].
difficult to use when repeated samplings of blood, for              Two primary parameters of efficacy are followed,
example, is desired from the same animal. In contrast,           survival and fungal burden in the tissues. Survival
rabbits are more expensive and require greater efforts           studies result in clear data sets, but ask much of a
from support and animal care personnel. Rabbit                   potential therapeutic. In addition, ethical questions
models do have the benefits of multiple sampling                 arise concerning the humane care and use of animals
from the same animals, better clinical evaluations and           for survival studies with most institutional committees
opportunity to obtain body fluids such as CSF that are           requiring euthanasia of the animals prior to death. The
not readily obtained from mice in sufficient quantity.           criteria for euthanasia must be evaluated carefully for
Thus, the choice of animal model will greatly depend             each animal, since subjective judgments made by the
on the types of studies needed.                                  investigators can skew the data by euthanizing animals
   The capacity to control different variables is bene-          too soon. These criteria need to be as quantitative as
ficial. Among the variables are strain of Aspergillus            possible, applied objectively from study to study to
fumigatus used, or the use of another species of                 ensure the accuracy of the data obtained from the
Aspergillus, inoculum size, immunosuppressive regi-              model, and the judgements on individual animals made
men, strain of mouse or other animal species, route              without knowledge of their study group, wherever
of infection, and route and duration of therapy. This            possible.
control allows a well defined model system to be used               Reduction of infectious burden can be a sensitive
to address various issues of efficacy with monotherapy,          parameter of efficacy, but the best method of determi-
combinations, immunotherapy, as well as investigate              nation for Aspergillus burdens in the tissues is con-
novel indications, and potentially preventative vaccines.        troversial. Some investigators choose a qPCR
In general, a great benefit of animal models of                  methodology or chitin assay, while others use CFU
aspergillosis is that therapeutics can be tried in a             determinations [7,22Á25]. Each method has benefits
variety of scenarios prior to a clinical trial or where a        and drawbacks. The assay of chitin in the tissues can be
clinical trial is impractical. Animal models also are            used as an indicator of fungal burden [24]. However,
useful for studying diagnostic assays, as well as                this is a tedious assay and does not indicate whether the
pharmacology and toxicity. Thus, we are able to                  organisms present were viable. More recently a qPCR
address issues in vivo that cannot be answered by in             assay has been developed and applied to the determi-
vitro tests. In addition to their use in the development         nation of Aspergillus burden in the tissues [22]. The
and testing of therapeutics, diagnostics and pharma-             need for specialized equipment and reagents for sample
cology, animal models of aspergillosis are used in               preparation are drawbacks for many laboratories and
studies of host-response and virulence. However, these           sending tissues samples to a commercial enterprise for
subjects are outside of the purview of this short review         the assay is cost-prohibitive in most cases. In compara-
and have been addressed elsewhere [1,5 Á8].                      tive studies, we demonstrated that drug efficacy of
                                                                 caspofungin and amphotericin B against CNS asper-
                                                                 gillosis could be demonstrated at a single time point
Animal models and evaluation parameters
                                                                 using either the qPCR or the CFU method [23]. The
Because no single model of aspergillosis can be relied           CFU method has the advantages of indicating viable
on to answer the many questions one asks in preclinical          organisms and is an assay that can be performed
studies or mimic the various disease progressions seen           readily by most laboratories. However, its level of
in all clinical cases of aspergillosis, it is necessary to use   sensitivity is less than that of the qPCR assay.
multiple models. In our laboratory we have standar-
dized three murine models of aspergillosis: systemic
                                                                 Surrogate and diagnostic markers
infection in noncompromised mice, cerebral infection
in pancytopenic mice and pulmonary infection in                  Surrogate markers of infection are much sought after
steroid-suppressed mice [9 Á11]. We use each of these            and have included radiographic imaging techniques
models to address specific questions. Other laboratories         applicable to pulmonary models in rabbits [1,7,8,16], as
have used inhalational murine models, and pulmonary              well as Aspergillus metabolites [26] and other clinical
or systemic models in rabbits and guinea pigs, as well as        parameters such as body weight and temperature. In
birds and insects [1 Á3,7,8,12 Á21]. More recently, two          addition, PCR methods for detection of Aspergillus
groups have reported the development of inhalational             DNA and assays for antigenemia (galactomannan and
models of invasive pulmonary aspergillosis in mice,              glucan) have been used to study disease progression, as
                                                                               – 2006 ISHAM, Medical Mycology, 44, S119 ÁS126
                                                                                   Animal models of Aspergillus infection   S121

well as for diagnostic purposes [26 Á31]. Rabbit studies     Aspergillus fumigatus have also proven to correlate
have shown that galactomannan assays were useful for         well with the clinical efficacy of the echinocandins,
diagnostic purposes and gave results similar to those        azoles and amphotericin B preparations [13,18,25,40 Á
from humans [7,27,29,32,33]. In each example men-            52]. In addition, a rat model of pulmonary aspergillosis
tioned, the utility of a particular assay is based on the    in granulocytopenic animals has demonstrated excel-
eventual correlation of animal data with clinical results.   lent efficacy of amphotericin B preparations when
Currently there are two commercial antigen assays            administered by inhalation of aerosolized drug
available, a glucan and a galactomannan assay kit, and       [53,54], while aerosolized itraconazole has proven
both show promise as useful diagnostic aids. However,        effective in a pulmonary murine model [55].
continued studies are needed on the clinical use of these       Although a vast majority of animal model studies use
tests to better determine standardized interpretive          A. fumigatus, one must be aware of the clinical
values and how the diagnostic results are best used [33].    epidemiology of all the causative agents. Possibly related
                                                             to more intensive immunosuppression and/or pro-
                                                             longed survival, though in the immunosuppressed state,
Preclinical therapeutic studies
                                                             and concurrent with the advent of new therapeutics,
A primary use of animal models of aspergillosis is           voriconazole and the echinocandins, there has been a
related to efficacy, safety and pharmacologic studies of     rise in the number of cases of aspergillosis due to other
antifungals, both new and licensed. The major question       species, particularly Aspergillus terreus [56 Á58]. Fatality
remains, ‘Are animal models predictive of how an             due to disease caused by A. terreus is high, and while
antifungal drug will work in humans with respect to          amphotericin B has been a mainstay of therapy for
clinical efficacy and safety?’. We have found the            aspergillosis until recently, this organism is frequently
systemic murine model using immunocompetent mice             resistant to amphotericin B in vitro. Little data is
has been predictive of clinical efficacy for azoles,         available for models of disease due to A. terreus [58].
echinocandins and amphotericin B preparations                In studies done several years ago we demonstrated that
[1,2,10,34 Á36].                                             saperconazole was superior to conventional amphoter-
   However, a single model cannot answer all efficacy        icin B for treatment in a murine model of systemic
questions and different models can give different            disease due to A. terreus [36]. More recently, a murine
results. As an example we found micafungin to be             model of systemic disease and a rabbit model of
highly efficacious in murine systemic and cerebral           pulmonary disease demonstrated the resistance of the
models of aspergillosis [34,37]. Using the systemic          organism in vivo to either conventional or liposomal
model a combination of micafungin and nikkomycin             amphotericin B treatment [59,60]; in the rabbit posaco-
Z had enhanced efficacy whereas the combination of           nazole and itraconazole were effective [60]; studies done
micafungin and conventional amphotericin B or itra-          in mice have shown the efficacy of micafungin versus
conazole showed no enhanced activity, but were not           A. terreus [61]. In addition, studies with Aspergillus
antagonistic. Similarly, in a cerebral model of aspergil-    flavus demonstrated a lack of correlation for in vitro
losis, we found the combination of micafungin or             susceptibility to itraconazole or amphotericin B and in
caspofungin and AmBisome to have no significantly            vivo efficacy [62]; similar results were obtained by this
enhanced activity [34,37]. The combination of Abelcet        group for A. fumigatus, while A. terreus resistance to
and caspofungin gave similar results in the CNS              amphotericin did correlate to in vivo results [63].
aspergillosis model [38]. In contrast, micafungin had           These types of data will be important in clinical
reduced activity and possible enhanced drug toxicity         decision-making in disease caused by this species, as it
with triamcinolone against pulmonary disease in ster-        is highly unlikely that a sufficiently large prospective
oid-suppressed mice [11]. Furthermore, in the pulmon-        clinical trial can be done. Thus, the species of Asper-
ary model the significantly enhanced activity of a           gillus causing disease is an important consideration
combination of micafungin and nikkomycin Z shown             and the results of studies with A. fumigatus may not
in the systemic model was not observed, and the              reflect drug efficacy against other species. This makes a
combination of micafungin and itraconazole showed            strong case for the development of additional models
antagonistic effects, with a reduction in efficacy by the    using other species of Aspergillus, which are relevant
combination [11]. Others have also found that what           clinically, albeit to a lesser extent currently, but also
works in one model may well not work in another when         require effective therapy [56 Á58,64 Á67].
testing the same drugs in different murine models [39].         A benefit of using models is the ability to examine
   Efficacy studies done in rabbit and guinea pig models     various antifungal combinations for potential enhance-
of invasive and pulmonary aspergillosis caused by            ment of efficacy or antagonisms [4]. We, and others,
– 2006 ISHAM, Medical Mycology, 44, S119 ÁS126
S122    Clemons & Stevens

have found conventional amphotericin B and itracona-        shown in selected preclinical data. Other studies have
zole or ketoconazole to show some antagonism in vivo        examined the drug interactions of itraconazole and
[3,68,69]. In a murine study, treatment with itracona-      cyclosporine [52], which are relevant clinically [78], as
zole prior to treatment with amphotericin B reduced         are interactions with phenytoin and rifampin [79]. The
efficacy [70]. In clinical practice, the effectiveness of   antifungal activity shown by several of the immuno-
combination therapy is not well established and             suppressants presents the interesting possibility of
combinations of amphotericin B and itraconazole             combining these with conventional therapy, and the
have primarily shown indifference, although sequential      use of animal models will further delineate this
therapy depends on the order of drug use. Amphoter-         potential [80].
icin B followed by itraconazole has been successful, but       The advent of immunomodulatory therapy, using
not when the drugs are given in the converse order [66].    cytokines such as interferon-g and colony stimulating
The correlation of results between animal studies and       factors in combination with conventional therapy, is
clinical observation in this instance are similar, yet      also of great interest. Relatively few model studies have
there may be differences in the result of the drug          been done, but results are encouraging [1,5,65,77,81 Á
interactions in vivo.                                       88]. However, the results of clinical trials on use of
   More recently, murine CNS and guinea pig pulmon-         CSFs have proven difficult to interpret.
ary disease studies have been published on the use of
voriconazole and liposomal amphotericin B [37,71]. In
                                                            The search for novel indications
both, the combination of voriconazole with liposomal
amphotericin B proved superior to monotherapy, and,         A true strength in the availability of different animal
in addition, sequential therapy of liposomal amphoter-      models of aspergillosis or any infectious disease is that
icin B followed by voriconazole also proved highly          of allowing therapeutic investigations into novel in-
effective [37,71].                                          dications or disease processes. For aspergillosis the
   An early echinocandin, cilofungin, showed antagon-       most common site of infection is pulmonary, with
ism with amphotericin B in a murine model of systemic       dissemination to other organs also occurring; other
aspergillosis [10]. However, micafungin and amphoter-       primary sites include keratitis and sinusitis. A very
icin B in combination showed positive interaction in        important site of infection for aspergillosis is the
our systemic aspergillosis studies [34]; trends toward      central nervous system, which is difficult to treat, and
significant enhancement of efficacy of micafungin or        in spite of therapy results in 90% fatality [89]. Effective
caspofungin in combination with AmBisome or ABLC            treatment is badly needed, whereas it would be
were found in murine CNS disease [37,38]. This is in        impractical to do a clinical trial. To address this, our
contrast to the results of Graybill et al . [39], who       laboratory has developed a murine model of central
reported liposomal amphotericin B and micafungin            nervous system [CNS] aspergillosis in pancytopenic
combinations effective in a systemic model of aspergil-     mice that allows us to examine new and different
losis, but ineffective in a model of pulmonary disease in   possible therapies.
steroid-suppressed mice.                                       We have used our model of CNS aspergillosis for
   Recently, the combination of micafungin and am-          monotherapy and combination therapy studies
photericin B were found to be superior to either drug       [23,37,38,90,91]. Among the azoles tested, posacona-
alone in a model of pulmonary infection done in             zole was highly effective resulting in significant en-
p47phox-/- chronic granulomatous disease mice [72].         hancement of efficacy by both survival and reduction
Also encouraging are the results of significantly           of infectious burden. Both itraconazole and voricona-
enhanced efficacy by low dose combination therapy           zole are effective at higher doses, but possibly less so
of Abelcet and caspofungin in a rat model of systemic       than posaconazole. Both micafungin and caspofungin
aspergillosis [73]. Similarly, combinations of an echi-     are highly effective in prolonging survival, but neither
nocandin and an azole have shown promise, as has the        results in cure. Of particular interest to us has been the
addition of G-CSF to conventional therapy [74 Á77].         examination of whether intravenous amphotericin B or
   Clinically, the use of combination therapy for           a lipid-carried amphotericin B formulation (AmBisome
aspergillosis was historically amphotericin B plus          or Abelcet) would be efficacious against CNS disease
5-flucytosine or rifampin with about 60% of patients        when administered intravenously. Our results indicate
showing improvement [66]. Even with the availability of     that lipid-carried amphotericin B is efficacious, but that
voriconazole and its improved therapeutic effects           even very high doses were not curative, with efficacy
against aspergillosis, combination therapy, with the        being reduced at doses above 15 mg/kg for AmBisome
addition of an echinocandin, may be desirable [32], as      [37,38]. Combinations of suboptimal dosages of AmBi-
                                                                          – 2006 ISHAM, Medical Mycology, 44, S119 ÁS126
                                                                                    Animal models of Aspergillus infection   S123

some or Abelcet and voriconazole proved highly              Conclusions
effective but again were not curative, whereas AmBi-
some or Abelcet in combination with an echinocandin         Overall, the use of animal models for various studies
showed nonsignificant improvements in efficacy and          provides us with useful information that has historically
were not antagonistic [37,38]. However, these enhanced      been shown to reflect what happens clinically. Their
efficacies again did not carry-over to the pulmonary        utility in pharmacologic and safety studies remains a
model of invasive aspergillosis in steroid-suppressed       primary function, for the results are predictive of
mice. Furthermore, we found that combination therapy        human responses. As our use of animal models of
in the CNS model using optimal dosages of each drug         aspergillosis becomes more sophisticated, our ability to
did not result in cure or any demonstrable improvement      improve patient care and clinical response will be
in efficacy. This latter point may be quite relevant        enhanced.
clinically as the costs associated with the new anti-
fungal agents are formidable and the ability to reduce      References
the amounts of drugs used could lower associated costs
[92].                                                        1 Clemons KV, Stevens DA. The contribution of animal models of
                                                               aspergillosis to understanding pathogenesis, therapy and viru-
   In addition to the murine model of CNS disease, a           lence. Med Mycol 2005; 43(Suppl. 1): S101 Á110.
rabbit model of keratitis has been studied in both           2 Stevens DA. Animal models in the evaluation of antifungal
efficacy and pharmacokinetic studies [15,93]. Further-         drugs. J Mycol Med 1996; 6(Suppl. I): 7 Á10.
more, a recent study of treatment of experimental            3 Polak A. Experimental models in antifungal chemotherapy.
fungal endophthalmitis showed efficacy for amphoter-           Mycoses 1998; 41: 1 Á30.
                                                             4 Clemons KV, Stevens DA. Animal models testing monotherapy
icin B, micafungin and voriconazole [94]. Models of            versus combination antifungal therapy: lessons learned and
ABPA will provide the basis for therapeutic studies for        future directions. Curr Opin Infect Dis 2006; 19: 360 Á364.
that disease manifestation [6,95]. Thus, use of highly       5 Clemons KV, Stevens DA. Immunomodulation of fungal infec-
specific models like those mentioned provide the basis         tions: do immunomodulators have a role in treating mycoses?
                                                               EOS Rivista Immunol Immunofarmacol 2002; 22: 29 Á32.
for trying specific clinical treatments where no clinical
                                                             6 Kurup VP, Grunig G. Animal models of allergic bronchopul-
trials can be readily performed.                               monary aspergillosis. Mycopathologia 2002; 153: 165 Á177.
                                                             7 Latge JP. Aspergillus fumigatus and aspergillosis. Clin Microbiol
                                                               Rev 1999; 12: 310 Á350.
                                                             8 Patterson TF. The future of animal models of invasive aspergil-
Pharmacological studies                                        losis. Med Mycol 2005; 43(Suppl. 1): S115 Á119.
                                                             9 Chiller TM, Luque JC, Sobel RA, et al . Development of a
Uninfected animals are used for the purposes of                murine model of cerebral aspergillosis. J Infect Dis 2002; 186:
studying pharmacological responses such as kinetics,           574 Á577.
tissue penetration and drug distribution, and dose-         10 Denning DW, Stevens DA. Efficacy of cilofungin alone and in
related damage to different target organs. Although            combination with amphotericin B in a murine model of
many pharmacodynamic studies have been done in                 disseminated aspergillosis. Antimicrob Agents Chemother 1991;
                                                               35: 1329 Á1333.
infected animals for antibacterials, few have been done     11 Clemons KV, Stevens DA. Efficacy of micafungin alone or in
for fungal infections. Various investigators have exam-        combination against experimental pulmonary aspergillosis. Med
ined the pharmacokinetics of antifungals, particularly         Mycol 2006; 44: 69 Á73.
in rabbits [47 Á51,73,96]. The contribution of pharma-      12 Dufour X, Kauffmann-Lacroix C, Goujon JM, et al . Experi-
codynamic studies for determining clinical dosing and          mental model of fungal sinusitis: a pilot study in rabbits. Ann
                                                               Otol Rhinol Laryngol 2005; 114: 167 Á172.
predicting outcome has been addressed in several            13 Kirkpatrick WR, McAtee RK, Fothergill AW, Rinaldi MG,
reviews, and to date most have been done using models          Patterson TF. Efficacy of voriconazole in a guinea pig model of
of Candida albicans infection [97 Á99]. These types of         disseminated invasive aspergillosis. Antimicrob Agents Che-
studies are extremely important in relation to the             mother 2000; 44: 2865 Á2868.
capacity to effect cure of infection, and the determina-    14 Lionakis MS, Kontoyiannis DP. Fruit flies as a minihost model
                                                               for studying drug activity and virulence in Aspergillus. Med
tion of whether the trade-off of efficacy versus damage        Mycol 2005; 43(Suppl. 1): S111 Á114.
to an organ is acceptable for aspergillosis. In a single    15 O’Day DM, Head WS, Robinson RD, Williams TE, Gedde S.
study, the ratio of Cmax: MEC (minimum effective               The evaluation of therapeutic responses in experimental kerato-
concentration) for caspofungin was found to be the             mycosis. Curr Eye Res 1992; 11: 35 Á44.
                                                            16 Walsh TJ, Garrett K, Feurerstein E, et al . Therapeutic monitor-
predictive parameter in a murine model of invasive
                                                               ing of experimental invasive pulmonary aspergillosis by ultrafast
pulmonary aspergillosis [100]. Additional studies of           computerized tomography, a novel, noninvasive method for
this type are sorely needed and correlation with clinical      measuring responses to antifungal therapy. Antimicrob Agents
outcome remains to be determined.                              Chemother 1995; 39: 1065 Á1069.

– 2006 ISHAM, Medical Mycology, 44, S119 ÁS126
S124     Clemons & Stevens

17 Schmidt A. Animal models of aspergillosis-also useful for                  aspergillosis. Antimicrob Agents Chemother 2003; 47: 1452 Á
   vaccination strategies? Mycoses 2002; 45: 38 Á40.                          1455.
18 Van Cutsem J, Van Gerven F, Janssen PA. Oral and parenteral           35   Clemons KV, Stevens DA. Comparative efficacies of four
   therapy with saperconazole (R 66905) of invasive aspergillosis in          amphotericin B formulations ÁFungizone, Amphotec (Ampho-
   normal and immunocompromised animals. Antimicrob Agents                    cil), AmBisome, and Abelcet Á against systemic murine asper-
   Chemother 1989; 33: 2063 Á2068.                                            gillosis. Antimicrob Agents Chemother 2004; 48: 1047 Á1050.
19 Kurup VP, Sheth NK. Experimental aspergillosis in rabbits.            36   Hanson LH, Clemons KV, Denning DW, Stevens DA. Efficacy
   Comp Immunol Microbiol Infect Dis 1981; 4: 161 Á174.                       of oral saperconazole in systemic murine aspergillosis. J Med Vet
20 Sheppard DC, Rieg G, Chiang LY, et al . Novel inhalational                 Mycol 1995; 33: 311 Á317.
   murine model of invasive pulmonary aspergillosis. Antimicrob          37   Clemons KV, Espiritu M, Parmar R, Stevens DA. Comparative
   Agents Chemother 2004; 48: 1908 Á1911.                                     efficacies of conventional amphotericin B, liposomal amphoter-
21 Steinbach WJ, Benjamin DK, Jr, Trasi SA, et al . Value of an               icin B (AmBisome), caspofungin, micafungin, and voriconazole
   inhalational model of invasive aspergillosis. Med Mycol 2004;              alone and in combination against experimental murine central
   42: 417 Á425.                                                              nervous system aspergillosis. Antimicrob Agents Chemother
22 Bowman JC, Abruzzo GK, Anderson JW, et al . Quantitative                   2005; 49: 4867 Á4875.
   PCR assay to measure Aspergillus fumigatus burden in a murine         38   Imai J, Singh G, Fernandez B, Clemons KV, Stevens DA.
   model of disseminated aspergillosis: demonstration of efficacy of           Efficacy of Abelcet and caspofungin, alone or in combination,
   caspofungin acetate. Antimicrob Agents Chemother 2001; 45:                 against CNS aspergillosis in a murine model. J Antimicrob
   3474 Á3481.                                                                Chemother 2005; 56: 166 Á171.
23 Singh G, Imai J, Clemons KV, Stevens DA. Efficacy of                   39   Graybill JR, Bocanegra R, Gonzalez GM, Najvar LK. Combi-
   caspofungin against central nervous system Aspergillus fumiga-             nation antifungal therapy of murine aspergillosis: liposomal
   tus infection in mice determined by TaqMan PCR and CFU                     amphotericin B and micafungin. J Antimicrob Chemother 2003;
   methods. Antimicrob Agents Chemother 2005; 49: 1369 Á1376.                 52: 656 Á662.
24 Balloy V, Huerre M, Latge JP, Chignard M. Differences in              40   Kirkpatrick WR, McAtee RK, Fothergill AW, et al . Efficacy of
   patterns of infection and inflammation for corticosteroid treat-            SCH56592 in a rabbit model of invasive aspergillosis. Antimicrob
   ment and chemotherapy in experimental invasive pulmonary                   Agents Chemother 2000; 44: 780 Á782.
   aspergillosis. Infect Immun 2005; 73: 494 Á503.                       41   Kirkpatrick WR, Perea S, Coco BJ, Patterson TF. Efficacy of
25 MacCallum DM, Whyte JA, Odds FC. Efficacy of caspofungin                    ravuconazole (BMS-207147) in a guinea pig model of dissemi-
   and voriconazole combinations in experimental aspergillosis.               nated aspergillosis. J Antimicrob Chemother 2002; 49: 353 Á357.
   Antimicrob Agents Chemother 2005; 49: 3697 Á3701.                     42   Patterson TF, Fothergill AW, Rinaldi MG. Efficacy of itracona-
26 Francis P, Lee JW, Hoffman A, et al . Efficacy of unilamellar               zole solution in a rabbit model of invasive aspergillosis.
   liposomal amphotericin B in treatment of pulmonary aspergil-               Antimicrob Agents Chemother 1993; 37: 2307 Á2310.
   losis in persistently granulocytopenic rabbits: the potential role    43   Patterson TF, George D, Ingersoll R, Miniter P, Andriole VT.
   of bronchoalveolar D-mannitol and serum galactomannan as                   Efficacy of SCH 39304 in treatment of experimental invasive
   markers of infection. J Infect Dis 1994; 169: 356 Á368.                    aspergillosis. Antimicrob Agents Chemother 1991; 35: 1985 Á
27 Dupont B, Huber M, Kim SJ, Bennett JE. Galactomannan                       1988.
   antigenemia and antigenuria in aspergillosis: studies in patients     44   Patterson TF, George D, Miniter P, Andriole VT. The role of
   and experimentally infected rabbits. J Infect Dis 1987; 155: 1 Á11.        fluconazole in the early treatment and prophylaxis of experi-
28 Loeffler J, Kloepfer K, Hebart H, et al . Polymerase chain                  mental invasive aspergillosis. J Infect Dis 1991; 164: 575 Á580.
   reaction detection of Aspergillus DNA in experimental models          45   Patterson TF, George D, Miniter P, Andriole VT. Saperconazole
   of invasive aspergillosis. J Infect Dis 2002; 185: 1203 Á1206.             therapy in a rabbit model of invasive aspergillosis. Antimicrob
29 Marr KA, Balajee SA, McLaughlin L, et al . Detection of                    Agents Chemother 1992; 36: 2681 Á2685.
   galactomannan antigenemia by enzyme immunoassay for the               46   Patterson TF, Miniter P, Andriole VT. Efficacy of fluconazole in
   diagnosis of invasive aspergillosis: variables that affect perfor-         experimental invasive aspergillosis. Rev Infect Dis 1990;
   mance. J Infect Dis 2004; 190: 641 Á649.                                   12(Suppl. 3): S281 Á285.
30 Becker MJ, de Marie S, Willemse D, Verbrugh HA, Bakker-               47   Petraitiene R, Petraitis V, Groll AH, et al . Antifungal activity
   Woudenberg IA. Quantitative galactomannan detection is super-              and pharmacokinetics of posaconazole (SCH 56592) in treat-
   ior to PCR in diagnosing and monitoring invasive pulmonary                 ment and prevention of experimental invasive pulmonary
   aspergillosis in an experimental rat model. J Clin Microbiol               aspergillosis: correlation with galactomannan antigenemia. Anti-
   2000; 38: 1434 Á1438.                                                      microb Agents Chemother 2001; 45: 857 Á869.
31 Hurst SF, Reyes GH, McLaughlin DW, Reiss E, Morrison CJ.              48   Petraitiene R, Petraitis V, Groll AH, et al . Antifungal efficacy of
   Comparison of commercial latex agglutination and sandwich                  caspofungin (MK-0991) in experimental pulmonary aspergillosis
   enzyme immunoassays with a competitive binding inhibition                  in persistently neutropenic rabbits: pharmacokinetics, drug
   enzyme immunoassay for detection of antigenemia and anti-                  disposition, and relationship to galactomannan antigenemia.
   genuria in a rabbit model of invasive aspergillosis. Clin Diagn            Antimicrob Agents Chemother 2002; 46: 12 Á23.
   Lab Immunol 2000; 7: 477 Á485.                                        49   Petraitiene R, Petraitis V, Lyman CA, et al . Efficacy, safety, and
32 Segal BH, Walsh TJ. Current approaches to diagnosis and                    plasma pharmacokinetics of escalating dosages of intravenously
   treatment of invasive aspergillosis. Am J Respir Crit Care Med             administered ravuconazole lysine phosphoester for treatment of
   2006; 173: 707 Á717.                                                       experimental pulmonary aspergillosis in persistently neutropenic
33 Verweij PE. Advances in diagnostic testing. Med Mycol 2005;                rabbits. Antimicrob Agents Chemother 2004; 48: 1188 Á1196.
   43(Suppl. 1): S121 Á124.                                              50   Petraitis V, Petraitiene R, Groll AH, et al . Antifungal efficacy,
34 Capilla Luque J, Clemons KV, Stevens DA. Efficacy of                        safety, and single-dose pharmacokinetics of LY303366, a novel
   micafungin alone or in combination against systemic murine                 echinocandin B, in experimental pulmonary aspergillosis in

                                                                                           – 2006 ISHAM, Medical Mycology, 44, S119 ÁS126
                                                                                                    Animal models of Aspergillus infection   S125

      persistently neutropenic rabbits. Antimicrob Agents Chemother         66 Steinbach WJ, Stevens DA, Denning DW. Combination and
      1998; 42: 2898 Á2905.                                                    sequential antifungal therapy for invasive aspergillosis: review
 51   Petraitis V, Petraitiene R, Groll AH, et al . Comparative                of published in vitro and in vivo interactions and 6281 clinical
      antifungal activities and plasma pharmacokinetics of micafungin          cases from 1966 to 2001. Clin Infect Dis 2003; 37(Suppl. 3):
      (FK463) against disseminated candidiasis and invasive pulmon-            S188 Á224.
      ary aspergillosis in persistently neutropenic rabbits. Antimicrob     67 Steinbach WJ, Stevens DA, Denning DW, Moss RB. Advances
      Agents Chemother 2002; 46: 1857 Á1869.                                   against aspergillosis. Clin Infect Dis 2003; 37(Suppl. 3): S155 Á
 52   Berenguer J, Ali NM, Allende MC, et al . Itraconazole for                156.
      experimental pulmonary aspergillosis: comparison with ampho-          68 Clemons KV, Martinez M, Stevens DA. Efficacy of itraconazole
      tericin B, interaction with cyclosporin A, and correlation               alone and in combination with amphotericin B against pulmon-
      between therapeutic response and itraconazole concentrations             ary aspergillosis. In: 4th Congress of the European Confederation
      in plasma. Antimicrob Agents Chemother 1994; 38: 1303 Á1308.             of Medical Mycology ; 1998; Glasgow, Scotland; 1998: abst. 153.
 53   Ruijgrok EJ, Fens MH, Bakker-Woudenberg IA, van Etten EW,             69 Schmitt HJ, Edwards F, Andrade J, Niki Y, Armstrong D.
      Vulto AG. Nebulization of four commercially available ampho-             Comparison of azoles against aspergilli in vitro and in an
      tericin B formulations in persistently granulocytopenic rats with        experimental model of pulmonary aspergillosis. Chemother
      invasive pulmonary aspergillosis: evidence for long-term biolo-          1992; 38: 118 Á126.
      gical activity. J Pharm Pharmacol 2005; 57: 1289 Á1295.               70 Lewis RE, Prince RA, Chi J, Kontoyiannis DP. Itraconazole
 54   Ruijgrok EJ, Vulto AG, Van Etten EW. Efficacy of aerosolized              preexposure attenuates the efficacy of subsequent amphotericin
      amphotericin B desoxycholate and liposomal amphotericin B in             B therapy in a murine model of acute invasive pulmonary
      the treatment of invasive pulmonary aspergillosis in severely            aspergillosis. Antimicrob Agents Chemother 2002; 46: 3208 Á
      immunocompromised rats. J Antimicrob Chemother 2001; 48:                 3214.
      89 Á95.                                                               71 Kirkpatrick WR, Coco BJ, Patterson TF. Sequential or combi-
 55   Hoeben BJ, Burgess DS, McConville JT, et al . In vivo efficacy of         nation antifungal therapy with voriconazole and liposomal
      aerosolized nanostructured itraconazole formulations for pre-            amphotericin B in a guinea pig model of invasive aspergillosis.
      vention of invasive pulmonary aspergillosis. Antimicrob Agents           Antimicrob Agents Chemother 2006; 50: 1567 Á1569.
      Chemother 2006; 50: 1552 Á1554.                                       72 Dennis CG, Greco WR, Brun Y, et al . Effect of amphotericin B
 56   Fridkin SK. The changing face of fungal infections in health care        and micafungin combination on survival, histopathology, and
      settings. Clin Infect Dis 2005; 41: 1455 Á1460.                          fungal burden in experimental aspergillosis in the p47phox-/-
 57   Steinbach WJ, Benjamin DK, Jr, Kontoyiannis DP, et al .                  mouse model of chronic granulomatous disease. Antimicrob
      Infections due to Aspergillus terreus : a multicenter retrospective      Agents Chemother 2006; 50: 422 Á427.
      analysis of 83 cases. Clin Infect Dis 2004; 39: 192 Á198.             73 Sivak O, Bartlett K, Risovic V, et al . Assessing the antifungal
 58   Steinbach WJ, Perfect JR, Schell WA, Walsh TJ, Benjamin DK,              activity and toxicity profile of amphotericin B lipid complex
      Jr. In vitro analyses, animal models, and 60 clinical cases              (ABLC; Abelcet) in combination with caspofungin in experi-
      of invasive Aspergillus terreus infection. Antimicrob Agents             mental systemic aspergillosis. J Pharm Sci 2004; 93: 1382 Á1389.
      Chemother 2004; 48: 3217 Á3225.                                       74 Kirkpatrick WR, Perea S, Coco BJ, Patterson TF. Efficacy of
 59   Dannaoui E, Borel E, Persat F, Piens MA, Picot S. Amphotericin           caspofungin alone and in combination with voriconazole in a
      B resistance of Aspergillus terreus in a murine model of                 guinea pig model of invasive aspergillosis. Antimicrob Agents
      disseminated aspergillosis. J Med Microbiol 2000; 49: 601 Á606.          Chemother 2002; 46: 2564 Á2568.
 60   Walsh TJ, Petraitis V, Petraitiene R, et al . Experimental            75 Petraitis V, Petraitiene R, Sarafandi AA, et al . Combination
      pulmonary aspergillosis due to Aspergillus terreus : pathogenesis        therapy in treatment of experimental pulmonary aspergillosis:
      and treatment of an emerging fungal pathogen resistant to                synergistic interaction between an antifungal triazole and an
      amphotericin B. J Infect Dis 2003; 188: 305 Á319.                        echinocandin. J Infect Dis 2003; 187: 1834 Á1843.
 61   Warn PA, Morrissey G, Morrissey J, Denning DW. Activity of            76 Schmitt HJ, Bernard EM, Edwards FF, Armstrong D. Combina-
      micafungin [FK463] against an itraconazole-resistant strain of           tion therapy in a model of pulmonary aspergillosis. Mycoses
      Aspergillus fumigatus and a strain of Aspergillus terreus demon-         1991; 34: 281 Á285.
      strating in vivo resistance to amphotericin B. J Antimicrob           77 Sionov E, Mendlovic S, Segal E. Experimental systemic murine
      Chemother 2003; 51: 913 Á919.                                            aspergillosis: treatment with polyene and caspofungin combina-
 62   Mosquera J, Warn PA, Morrissey J, et al . Susceptibility testing         tion and G-CSF. J Antimicrob Chemother 2005; 56: 594 Á597.
      of Aspergillus flavus : inoculum dependence with itraconazole          78 Kramer MR, Marshall SE, Denning DW, et al . Cyclosporine
      and lack of correlation between susceptibility to amphotericin B         and itraconazole interaction in heart and lung transplant
      in vitro and outcome in vivo. Antimicrob Agents Chemother 2001;          recipients. Ann Intern Med 1990; 113: 327 Á329.
      45: 1456 Á1462.                                                       79 Tucker RM, Denning DW, Hanson LH, et al . Interaction of
 63   Johnson EM, Oakley KL, Radford SA, et al . Lack of correlation           azoles with rifampin, phenytoin, and carbamazepine: in vitro
      of in vitro amphotericin B susceptibility testing with outcome in        and clinical observations. Clin Infect Dis 1992; 14: 165 Á174.
      a murine model of Aspergillus infection. J Antimicrob Chemother       80 Blankenship JR, Steinbach WJ, Perfect JR, Heitman J. Teaching
      2000; 45: 85 Á93.                                                        old drugs new tricks: reincarnating immunosuppressants as
 64   Denning DW, Stevens DA. Antifungal and surgical treatment of             antifungal drugs. Curr Opin Investig Drugs 2003; 4: 192 Á199.
      invasive aspergillosis: review of 2,121 published cases. Rev Infect   81 Nagai H, Guo J, Choi H, Kurup V. Interferon-gamma and tumor
      Dis 1990; 12: 1147 Á1201.                                                necrosis factor-alpha protect mice from invasive aspergillosis. J
 65   Steinbach WJ, Stevens DA. Review of newer antifungal and                 Infect Dis 1995; 172: 1554 Á1560.
      immunomodulatory strategies for invasive aspergillosis. Clin          82 Rex JH, Bennett JE, Gallin JI, et al . In vivo interferon-gamma
      Infect Dis 2003; 37(Suppl. 3): S157 Á187.                                therapy augments the in vitro ability of chronic granulomatous

– 2006 ISHAM, Medical Mycology, 44, S119 ÁS126
S126       Clemons & Stevens

     disease neutrophils to damage Aspergillus hyphae. J Infect Dis       92 Lewis JS, Boucher HW, Lubowski TJ, et al . Cost advantage of
     1991; 163: 849 Á852.                                                    voriconazole over amphotericin B deoxycholate for primary
83   Graybill JR, Bocanegra R, Najvar LK, Loebenberg D, Luther               treatment of invasive aspergillosis. Pharmacother 2005; 25: 839 Á
     MF. Granulocyte colony-stimulating factor and azole antifungal          846.
     therapy in murine aspergillosis: role of immune suppression.         93 O’Day DM, Head WS, Robinson RD, Williams TE, Wolff R.
     Antimicrob Agents Chemother 1998; 42: 2467 Á2473.                       Ocular pharmacokinetics of saperconazole in rabbits. A potential
84   Polak-Wyss A. Protective effect of human granulocyte colony-            agent against keratomycoses. Arch Ophthalmol 1992; 110: 550 Á
     stimulating factor (hG-CSF) on Cryptococcus and Aspergillus             554.
     infections in normal and immunosuppressed mice. Mycoses              94 Harrison JM, Glickman RD, Ballentine CS, et al . Retinal
     1991; 34: 205 Á215.                                                     function assessed by ERG before and after induction of ocular
85   Uchida K, Yamamoto Y, Klein TW, Friedman H, Yamaguchi H.                aspergillosis and treatment by the anti-fungal, micafungin, in
     Granulocyte-colony stimulating factor facilitates the restoration       rabbits. Doc Ophthalmol 2005; 110: 37 Á55.
     of resistance to opportunistic fungi in leukopenic mice. J Med       95 Hogaboam CM, Carpenter KJ, Schuh JM, et al . The therapeutic
     Vet Mycol 1992; 30: 293 Á300.                                           potential in targeting CCR5 and CXCR4 receptors in infectious
86   Kullberg BJ. Trends in immunotherapy of fungal infections. Eur          and allergic pulmonary disease. Pharmacol Ther 2005; 107: 314 Á
     J Clin Microbiol Infect Dis 1997; 16: 51 Á55.                           328.
87   Kullberg BJ, van’t Wout JW. Cytokines in the treatment of fungal     96 Groll AH, Walsh TJ. Posaconazole: clinical pharmacology and
     infections. Biother 1994; 7: 195 Á210.                                  potential for management of fungal infections. Expert Rev Anti
88   Stevens DA. Combination immunotherapy and antifungal                    Infect Ther 2005; 3: 467 Á487.
     chemotherapy. Clin Infect Dis 1998; 26: 1266 Á1269.                  97 Andes D. Clinical pharmacodynamics of antifungals. Infect Dis
89   Lutz JE, Stevens DA. Treatment of invasive aspergillosis. Intern        Clin North Am 2003; 17: 635 Á649.
     Med 1995; 16: 25 Á31.                                                98 Andes D. Pharmacokinetics and pharmacodynamics in the
90   Chiller TM, Sobel RA, Luque JC, Clemons KV, Stevens DA.                 development of antifungal compounds. Curr Opin Investig Drugs
     Efficacy of amphotericin B or itraconazole in a murine model of          2003; 4: 991 Á998.
     central nervous system Aspergillus infection. Antimicrob Agents      99 Andes D. Clinical utility of antifungal pharmacokinetics and
     Chemother 2003; 47: 813 Á815.                                           pharmacodynamics. Curr Opin Infect Dis 2004; 17: 533 Á540.
91   Imai JK, Singh G, Clemons KV, Stevens DA. Efficacy of                100 Wiederhold NP, Kontoyiannis DP, Chi J, et al . Pharmacody-
     posaconazole in a murine model of central nervous system                namics of caspofungin in a murine model of invasive pulmonary
     aspergillosis. Antimicrob Agents Chemother 2004; 48: 4063 Á             aspergillosis: evidence of concentration-dependent activity. J
     4066.                                                                   Infect Dis 2004; 190: 1464 Á1471.

                                                                                          – 2006 ISHAM, Medical Mycology, 44, S119 ÁS126

Shared By: