Infections and Psychiatric Diseases
Lecture Outline
Clinical and Epidemiologic Features of Schizophrenia and Bipolar Disorder Biology of Endogenous Retroviruses Role of Herpesviruses in Retroviral Transcription Clinical Epidemiology of Herpesvirus Infections and Psychiatric Diseases Clinical Trials of Antimicrobial Agents
Schizophrenia and the Clinical Laboratory Opportunities and Challenges
Opportunities
Common Disease (1% of American Population) Availability of more easily tolerated medications
Challenges
Rudimentary knowledge of disease pathogenesis No relevant animal models or cell lines No laboratory tests Minimal prediction of response to medication
Schizophrenia and Bipolar Disorder
Clinical Features
Schizophrenia
Positive Symptoms Hallucinations, Delusions, Disordered Thinking Negative Symptoms Withdrawal, Amotivation, Restricted Expressiveness Impairment in Cognitive and Social Functioning Lifetime prevalence ~ 1% worldwide Bipolar Disorder Mania Depression Variable degree of positive and negative symptoms Variable degree of cognitive impairment Lifetime prevalence ~0.5% worldwide
A Beautiful Mind Hollywood or Reality
A Beautiful Mind Hollywood vs Reality?
Reality
Onset of schizophrenia without clear cause Attractiveness of delusions Role of medication Disease “burn out” at later age
Hollywood
Delusions coinciding with creativity Shock therapy used at “high class” hospital Family support
Schizophrenia and Bipolar Disorder
Biological and Epidemiological Features
Lifelong illness with peak onset in early adulthood. Range of structural and functional brain abnormalities visible on fMRI and PET scans. Abnormal expression of brain receptors Dopamine Glutamate Massive social and economic consequences Available medications Control symptoms in many patients Have a high rate of side effects Do not appreciably alter the course of disease
Microbial Agents and Schizophrenia Epidemiological Findings
Specific Infectious Agent Perinatal Rubella (Brown et al, 2001; OR~3.5) Neonatal Enterovirus (Jones et al, 1998 OR~4) Maternal Herpesvirus (Buka 2001; OR~4) Possible Infectious Exposure Seasonality of Birth (Torrey at al, 1998; OR~2) Urban Birth (Mortenson et at, 1999, OR~2.5) Fever in Pregnancy (Torrey et al 2000, OR~3) Pre-eclampsia ( Dalman et al, 1999, OR~2.5) Case Reports
HIV Herpes Simplex Virus 1/2 Toxoplasma gondii
Genetics Of Schizophrenia and Bipolar Disorder
• Increased Incidence in Biological First Degree Relatives • General Population 1% • First Degree Relatives 7-9% • Monozygotic Twins 30% • Most individuals with schizophrenia do not have a first
•
•
degree relative with this disease. Genetic factors have a large relative risk but a small risk in the overall population (5%) Intensive search for genes using molecular methods • Multiple chromosomal regions of linkage • Single nucleotide polymorphisms of minor effect in selected populations (OR~2) • No genes of major effect in different populations
Complex Human Diseases
Beyond Koch and Mendel
Mendel-Human traits are determined by individual genes which function independently of other genes and of environmental influences
Koch-Many human diseases are caused by microbes which exert their effect independently of other microbes, environmental factors and genes
Microbial Agents and Human Disease Koch’s Postulates
Principles
Specific infectious agents cause clearly delineated disease states The diseases cannot exist without the specific agent Etiologic agents cause disease in animal models
Limitations
Shared pathways of response to infection Genetic determinants of response Individual variation in response to infection Limited animal models of complex human diseases
Complex Human Diseases Beyond Koch’s Postulates
Most common human diseases are caused by the interaction of environmental insults and susceptibility genes. Many of the susceptibility genes are diverse determinants of human response to environmental factors to infection. Informative laboratory methods for complex disorders have to address both genetic and environmental factors. Prevention or treatment of the infections may result in the effective treatment of complex disorders: Helicobacter-Peptic Ulcer HPV-Genital Cancer Chlamydia-Cardiac Disease?
Etiology of Complex Human Diseases Relative vs. Attributable Risk
Relative Risk-Chance of an individual with an exposure acquiring a disease relative to the general population Population Attributable Risk-Percentage of the population with a disease which can be attributed to a specific factor Diseases of single or limited etiologies-High relative and attributable risks
CFTR gene-Cystic Fibrosis HIV-Acquired Immunodeficiency Syndrome
Complex Human Diseases Factors with high relative risk may have low attributable risks if exposures are rare
Apoliprotein genes-Alzheimer’s Disease Maternal alcohol-Fetal malformations M tuberculosis-Lung Disease
Epidemiology of Schizophrenia Relative vs. Attributable Risk
Factor Relative Risk Affected Father 7.2 Affected Mother 9.3 Affected Sibling 7.0 Urban Birth 2.4 Winter Birth 1.1 No Factor 1.0
Mortenson et al, NEJM 340:603, 1999
Epidemiology of Schizophrenia Relative vs. Attributable Risk
Factor Relative Risk Affected Father 7.2 Affected Mother 9.3 (No affected parent) Affected Sibling 7.0 (No affected sibling) Urban Birth 2.4 Winter Birth 1.1 % Cases In Population 1.2% 2.4% 88.8% 2.2% 97.8% 32.9% 25%
Mortenson et al, NEJM 340:603, 1999
Epidemiology of Schizophrenia Relative vs. Attributable Risk
Risk Factor Population Attributable Risk Affected Parent 3.8% Affected Sibling 1.9% Affected Parent or Sibling 5.5% Place of Birth 34.6% Season of Birth 10.5% Place and Season of Birth 41.4% All Variables 46.6%
Mortenson et al, NEJM 340:603, 1999
Schizophrenia Working Hypotheses
Most cases of schizophrenia are the result of infections and other environmental insults occurring in genetically susceptible individuals before the onset of clinically apparent symptoms. Distinct gene-environmental interactions may be operant in different populations. Interactions do not follow Koch’s postulates. The role of specific infectious agents can be defined by clinical trials of anti-microbial chemotherapy.
Identification of Infections in Schizophrenia
Methods-Old and New
Analytic Methods
Differential Display PCR Library screening Microarrays Two-dimensional electrophoresis Enzyme immunoassays
Samples for Analysis
Brains collected by the Stanley Neuropathology Consortium Cerebrospinal fluids (CSF’s) from individuals with recent onset schizophrenia Blood samples from mothers of infants who developed schizophrenia in adult life.
Differential Display PCR
Brain from Individual with Schizophrenia (S) and Unaffected Control(U)
M S U S U S U M
HIV
Human Endogenous Retrovirus HERV-W
Endogenous Retroviruses
Borderland Between Viruses and Genes
Integrated Genomic Elements with Homology to Retroviruses Arising from Germ Line Integration of infectious viruses during evolution
All Primates Old World Monkeys Apes Humans Individuals
Endogenous Retroviruses
Borderland Between Viruses and Genes II
Dynamic Effects on Gene Function
Promoter control of adjacent genes- PLA2; Placental Genes Interaction with infectious agents- Herpesviruses, Toxoplasma Interaction with soluble mediators-Hormones; Cytokines
Functionality of viral proteins-Syncytin; amino acid transporters
Role in Human Disease
Diabetes- Superantigen activation Multiple Sclerosis- Glial cell function Autoimmune Arthritis- T cell activity Pre-Eclampsia- Aberrant Fusion of Trophoblasts
Endogenous Retroviruses
Activation and Transcription
Microbe Hormone Mediator
DNA
5’LTR Viral Proteins 3’LTR
Endogenous Retroviruses
Borderland Between Viruses and Genes
Integrated Genomic Elements with Homology to Retroviruses Arising from Germ Line Integration of infectious viruses during evolution
All Primates Old World Monkeys Apes Humans Individuals
K113
Herv-W
Endogenous Retroviral PCR CSFs:Schizophrenia and Controls
Scz
DNA Ctr
Herv-W
HERVw C1 A1 A2 A3 A4 A5 A6 GTTCAGGGATAGCCCCCATCTATTTGGCCAGGCATTAGCCCAAGACTTGAGTCAATTCTCATACCTGGACACTCTTGTCCTTCAG ---------------------------------------------------C--------------------------------------------------------------A---------------------------------------------------TG------------------------------A---------------------------------------------------TG----------------------------------C----------------C--G----------------------------G-----------A----------------------------T----------C--G---------------------------TG-----A------------------------------------------------------------------------------------------T------------CA---TA-------------------C--G---------------------------TG-
Herv-W Envelope Chromosomal Distribution
Herv-W and Amino Acid Transporters
Lavillette et al, J Virol Jul;76(13):6442-52.
ASCT1 HERV-W Receptor Brains of Cases and Controls
Schi zophr eni a B pol ar D sor der i i C r ol ont
Co n te n tra ti o n o f ASCT 1 Re c e p to r
5
P<.02
4
P<.005
3
P<.009
2
1
0
Ne u ro n
In te r-Ne u ro n
W h ite M a tte r
Cingulate Gyrus
Human Endogenous Retroviruses
Activation by HSV-1Perron et al J Gen Virol. 1993 Jan;74 ( Pt 1):65-72
.
Retrovirus
HSV-1
Reverse Transcriptase Activity
Cognitive Functioning and Antibodies to Infectious Agents Individuals with Schizophrenia (N=229)
Antibody Positive 80 Cognitive Score (RBANS Total) Antibody Negative
**
75
*
70
65
60
**p<.00001
*p<.009
HSV-1
Toxo
CMV
HSV-2
EBV
HHV-6
Infectious Agent (IgG Antibodies)
Cognitive Deficits In Individuals with Schizophrenia Relationship with Antibodies to HSV-1
HSV-1 Pos N=101 HSV-1 Neg N=128
Immediate Memory Concentration Language
*** *
Attention
Delayed Memory RBANS Total
50
*** p<.0001 **p<.001 * p<.009
**
* ***
55 60 65 70 75 80 85 90
Score(Mean+/-95% Confidence)
Cognitive Functioning
Association with HSV-1 Serostatus
HSV-1 Se ro p o s itiv e HSV-1 Se ro n e g a ti v e
1 00
RBANS T o ta l Sc o re
9 5 9 0 8 5 8 0 7 5 7 0 6 5 6 0
Sc h iz o p h re n ia Bi p o l a r Dis o rd e r
N= 2 2 9 Pr = 4 4 . 1 % N= 1 1 7 Pr = 4 1 . 9 %
Co n tro l
N= 6 7 Pr = 4 1 . 8 %
Cognitive Function in Schizophrenia and Bipolar Disorder
HSV-1 Antibodies and Quintile of Total Score
Sc h i z o p h re n i a Bi p o l a r Di s o rd e r N= 1 1 7 N= 2 2 9
Pro p o rtio n HSV-1 Se ro re a c tiv e
0. 0 8 0. 0 7 0. 0 6 0. 0 5 0. 0 4 0. 0 3 0. 0 2 0. 0 1 0. 0 0
< 2 0 th
2 0 -4 0
4 0 -6 0
6 0 -8 0
> 8 0 th
Percentile- Total Cognitive Score
Collaborative Perinatal Study Study Design
65,000 healthy mothers enrolled from 1957-1964 from 11 geographically diverse sites. Mothers followed closely during pregnancy. Neurocognitive and developmental testing during first 7 years of life. Primary outcomes cerebral palsy and mental retardation. Serum samples obtained from mothers during pregnancy and infants at birth (cord). Offspring identified with psychiatric diseases in 1990’s and matched to maternal and cord blood serum specimens.
Unselected offspring evaluated for abnormalities of pregnancy, birth, and child development.
Schizophrenia in Adult Life Infection During Fetal Development
6.00
4.80 Odds Ratio
3.60
2.40
1.20
0.00
CMV CMV Rub IgG IgM IgG Rub Toxo Toxo HSV1 HSV2 Herv IgM IgG IgM IgG IgG W
Effect of HERV-K and HSV-1 on Eclampsia and Mental Illness
Un a d ju s te d
Ad j s d f r ut o e Ra c e , SES
1 0 9 8
Odds Ratio
7 6 5 4 3 2 1 0
H v- K er H 1 SVH ERV- K HSV- 1 / . H v- K er H 1 SVH ERV- K HSV- 1 /
Ec l m i a ps a
M en t al I l ess n
Effect of Maternal HSV-2 on Pregnancy and Child Development
Unadjusted Adjusted for Race, SES
4.50 4.00
Odds Ratio
3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.00
Abnormal Speech
Low IQ
Abnormal Vision
Any Fetal Deaths Complication
Age 7-8
Perinatal
Valacyclovir Clinical Trial
Individuals with Schizophrenia
Enrollment of 66 patients with stable schizophrenia on standard medication given Valacyclovir 2 gm/day for 16 weeks Evaluation by the positive and negative symptom score (PANSS) Change in score correlated with viral antibody status at start of study
HSV1/2
CMV
Other
herpesviruses
Response to Valacyclovir HSV-1 Antibody Status
HSV-1 Seropositive
20
HSV-1 Seronegative
Per cen tag e Imp r o vem en t
20 15 10 5 0 -5 -1 0
Percentage Improvement
10
0
-1 0
2 4 8 12 16
2
4
8
12
16
Week of Valacyclovir
Week of Valacyclovir
Positive Symptoms
Total Symptoms
Response to Valacyclovir by CMV Status
Percentage Improvement
Positive Scale
30 20
Negative Scale
P<.006
20 10 10 0 0 -10 -10
2
4
8
12
16
2
4
8
12
16
Percentage Improvement
General Scale
20 20
Total Score
P<.02
10 10
P<.0005
0
0
-10
2
4
8
12
16
-10
2
4
8
12
16
CMV Seropositive
CMV Seronegative
Prevalence of Cytomegalovirus
Populations with Schizophrenia
Cologne-Untreated Cologne-Recent Onset- Treated Cologne-Control
Heidelberg-Recent Onset- Treated
Heidelberg-Control Baltimore-Stable Treated Baltimore-Control
0 10 20 30 40 50 60 70 80
Prevalence (%)
Effect of Valacyclovir on Schizophrenia
Possible Explanations
Statistical artifact ? p<.0005 with covariance for multiple factors Placebo effect? Improvement only in CMV seropositive subjects Improvement persists throughout treatment Non-viral effect of valacyclovir/acyclovir? Effect only in CMV seropositive individuals The replication of CMV contributes to the symptoms of schizophrenia in some individuals Possible role of an antigenically related herpesvirus?
Valacyclovir Treatment of Schizophrenia-Planned Trials
Placebo-control trials using encapsulated valacyclovir and placebo
Stable patients with schizophrenia Recent onset patients with schizophrenia Patients with bipolar disorder High-risk individuals with prodromal symptoms
Study supported by the Stanley Medical Research Institute, without support from the pharmaceutical industry.
Infections and Schizophrenia Conclusions
Recent onset schizophrenia is associated with:
Increased transcription of HERV-W Increased levels of antibodies to CMV
Past infection with HSV-1 is associated with cognitive impairment in individuals with stable schizophrenia and bipolar disorder, but not in unaffected controls. Maternal exposure to infectious agents is associated with an increased rate of schizophrenia in the offspring. The administration of valacyclovir can reduce symptoms in some individuals with stable schizophrenia. The continued evaluation of the role of the prevention and treatment of infection in the management of psychiatric diseases remains a high priority.
Microbial Agents and Schizophrenia
Acknowledgements
Johns Hopkins University Harvard University
Loraine Brando Frances Yee Vern Caruthers Inna Ruslanova Bogdana Krivogorsky Steve Buka Ming Tsuang
University of Heidelberg
Silke Bachmann Johannes Schroeder
Stanley Medical Research Institute
Michael Knable Maree Webster
Karolinska Institute
Håkan Karlsson
University of Cologne
F Markus Leweke
Sheppard Pratt Hospital
John Boronow Catherine Stallings