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Antiphospholipid Syndrome Prof. Dr. Suchitra N. Pandit MD, DNBE, DFP, FRCOG, FICOG, B.Pharm Consultant Obstetrician & Gynaecologist Kokilaben Dhirubhai Hospital, Mumbai ,India Clinical secretary –MOGS, Vice President - FOGSI (2008-09) Chairperson -Young Talent promotion committee FOGSI (2003-07) Antiphospholipid ( APLA ) syndrome Antiphospholipid syndrome (Hughes syndrome) is a disorder of immune system ,characterised by excessive clotting of blood ,thrombocytopenia & /or adverse pregnancy outcomes Body recognizes negatively charged phospholipids on cell membrane as foreign & produces antibodies against them leading to an acquired autoimmune thrombophilia Patients have laboratory evidence for antibodies ( IgG, IgM or IgA ) against phospholipids or phospholipid- binding protein cofactors in their blood How many types of APLA syndromes are there A.) One B.) two C.) Three D.) Four Antiphospholipid antibody syndrome (APLA) Primary antiphospholipid syndrome (PAPS) - when APS occurs in the absence of any other related disease (LA, ACL antibodies in patient’s serum). Secondary antiphospholipid syndrome - when APS coexists with other diseases such as SLE I In catastrophic APLA (rare ), APS leads to rapid organ failure due to generalised thrombosis & a high risk of death Other rare antibodies to phosphotidyl ethanolamine & phosphotidylserine are also associated with it Thrombophilic defects either acquired or inherited Thrombophilia - tendency to thrombosis Lupus anticoagulant Acquired APLA antibodies Anticardiolipin antibodies Myeloprolipherative diseases Malignancy Paroxysmal nocturnal Haemoglobinuria Nephrotic syndrome Inherited Hyperhomocysteinemia (C677T) mutation Factor V Leiden mutation (A506G) mutation Mutation in prothrombin ( G 20210 A) Prothrombin II (PTII) mutation Protein S deficiency Protein C deficiency All these conditions should be investigated for APLA except : A.) Early onset severe preeclampsia B.) Arterial or venous thrombosis C.) Unexplained fetal growth restriction D.) Gestational Diabetes Primary antiphospholipid antibody syndrome Presentation may be totally asymptomatic or in a classical manner : Various clinical presentations : Recurrent pregnancy loss Unexplained second or third trimester loss Early onset severe preeclampsia Arterial or venous thrombosis Unexplained fetal growth restriction Prolonged coagulation studies Autoimmune diseases Cardiac valvular diseases Neurological disorders Thrombocytopenia Diagnosis of APLA Challenging !!! Due to fluctuating titers of the antibodies, Lack of agreement between laboratories concerning standardization of the assays Debates among researchers & clinicians concerning which antibodies to measure. Which is not an APLA antibody ? A.) Anti Ro B.) Lupus Anticoagulant (LAC) C.) Anticardiolipin Antibodies (ACL) D.) Anti insulin antibodies Which are the Antibodies Lupus Anticoagulant (LAC) Anticardiolipin Antibodies (ACL) Anti Beta 2 glycoprotein antibodies Other antibodies Lupus anticoagulant ( LAC) LAC is characterized by a prolonged partial thromboplastin time & paradoxically the so-called ‘anticoagulant’ is a powerful thrombotic agent in vivo Higher thrombotic potential than ACL when present alone LAC interferes with platelet function, causing aggregation & thrombosis & also interferes with endothelial function, causing procoagulant activation & thrombosis Prevalence of LAC in low risk population is < 1% Bad obstetric history - 9.1% Early pre eclampsia - 16%, Abruption - 33% Systemic lupus erythematosus - 34% Patient typically has a prolonged APTT that does not correct in 80:20 mixture with normal human plasma Prolonged Dilute Russel viper venom time (DRVVT), Kaolin clotting test (KCT),(TDT/DTT) or prothombin time Due to heterogeneous nature of LA ,minimum of 2 tests required, 6 weeks apart & should be positive each time showing persistent positivity to confirm diagnosis of APLA Caution : patients with transient positive tests (due to infection etc) can be diagnosed as positive. Lupus anticoagulant (LAC) Prolongation of which of these tests is most sensitive for LAC ? A.) Activated partial thromboplastin B.) Dilute Russel Viper venom C.) Kaolin clotting time D.) Partial Thrombin time Anticardiolipin Antibodies Were thought to react against cardiolipin but it is now thought to interact with B2GP1 85% of APS pts have both LA & aCL These can be detected using an (ELISA) Screens for the presence of β2 glycoprotein 1 dependent anticardiolipin antibodies (ACA) A low platelet count & positivity for antibodies against β2-glycoprotein 1 or phosphatidylserine may also be observed in a positive diagnosis Anti Beta 2 GP1 Discovered after LA & ACL Found without other two in 11% of APS pts & commonly with others. Binds to B2GP1 disrupting f(x) B2GP1 has anticoagulant activity through the inhibition of the conversion of prothrombin- thrombin, regulation of protein S, & /or activation of platelets. Sapporo criteria International Consensus Conference held in Sapporo (’98) Clinical criteria of ( APAS ) Thrombosis, one or more confirmed episodes of venous, arterial, or small vessels disease ‘ Coexisting inherited or acquired thrombotic risk factors are not reasons for excluding patients from a diagnosis of APS trials.’ Sapporo Criteria (updated) Pregnancy criteria : One or more unexplained fetal deaths > 10 wks of pregnancy One or more preeclampsia / eclampsia or placental insufficiencies occurring before 34 weeks . Three or more unexplained consecutive spontaneous abortions < 10 weeks Laboratory criteria LAC defined by a functional, clot-based assay (ISTH guidelines) ACL (IgG or IgM) antibody Anti-b2 glycoprotein I ,IgG or IgM antibody Miyakis, et al., J. Thromb. Haemost.,2006; 4: 295-306. The International Consensus Statement Definite CAPS diagnosis requires: Vascular thrombosis in three or more organs or tissues & development of manifestations simultaneously or in < a week & small vessel thrombosis in at least one organ or tissue Lab. confirmation of presence of aPL Some serological tests for syphilis may be positive in aPL- positive patients if it is positive) although more specific tests for syphilis that use recombinant antigens are negative Transient elevations common. Elevations common in autoimmune disease & infections ex. HIV, Hep C, syphilis Principal pathogenic mechanisms mediated by APL Interference with Protein C/S pathway a.) Soluble coagulation inhibition; factors fibrinolysis inhibition Induction of a pro-adhesive, pro- inflammatory & pro-coagulant b.) Coagulation cells: endothelial phenotype ; induction of a procoagulant phenotype in monocytes Interference with : Reduction of proliferation & differentiation; a.) Trophoblast cells: Gonadotrophin secretion impairment Pregnancy losses classified as : Occult (preclinical or chemical) pregnancy loss prior to missed menses. (40% of implantation embryos) Early pregnancy loss before 12 wk. (13%) Late pregnancy loss after 12 wk. (1%) Causes of pregnancy loss Chromosomal Environmental 55% of occult & early losses hormonal 5% of recurrent losses. anatomical Immunological 45% of early losses 95% of late losses Aneuploidy Aneuploid fetus risk in women > 35yr. age 1/80 Inherent risk of fetal loss after amniocentesis 1/200 Standard of care is to offer genetic amniocentesis for all pregnant women older than 35 years What is Recurrent pregnancy loss ? What actually causes it ? Definition A recurrent pregnancy loss (RPL) is 3 or more consecutive, spontaneous pregnancy losses, under 20 week gestation from the last menstrual period by the same partner. Primary recurrent pregnancy loss" refers to couples that have never had a live birth “Secondary RPL" refers to those who have had repetitive losses following a successful pregnancy Pregnancy loss in the APLA syndrome - A possible thrombogenic mechanism Levels of annexin V, a phospholipid-binding protein with potent anticoagulant activity, are markedly reduced on placental villi from women with APLA APL antibodies reduce the levels of annexin V & accelerate the coagulation of plasma on cultured trophoblasts & endothelial cells. Reduced annexin V levels on vascular cells may be an important mechanism of thrombosis & pregnancy loss in APLA syndrome. Jacob Rand, Xiao-Xuan Wu, H. Andree, CJ. Lockwood, Seth Guller, J Scher, Peter Harpel, -N Engl J Med ; 337:1630-1631, 1997 Pregnancy loss in autoimmune connective tissue disorders (CTDs) Adverse outcomes like IUGR, prematurity, recurrent pregnancy loss & stillbirth are common Systemic lupus erythematosus (SLE) is prototype , others are rheumatoid arthritis, scleroderma, Behcet’s disease & Sjogren’s syndrome Recent studies show anti-Ro/SSA antibody as a possible factor for unexplained pregnancy loss in SLE. Antibody is directed against cellular ribonucleoprotein complexes which is present in serum of > 10% pts of CTDs. It is associated with neonatal lupus & congenital heart block showing passively acquired autoimmunity How do you proceed ? Interview the couple together History of the case is very important Clinical examination Investigations as per the history Reassurance & counselling Treatment plan : Drugs, maternal & fetal surveillance , dealing with complications Timely referral to a tertiary centre Special Investigations LAC tested by prolonged coagulation time (inhibition of phospholipids) APTT , KCT , TTIT Most accurate - Dilute russel viper venom test (DRVVT) ACL - ELISA - IgG (GPL) IgM (MPL) IgG/ IgM isotypes of anticardiolipin & antiphosphotidyl serine antibodies In c/o low titres-repeat after 6-8wks (can revert to normal) Transient low titres can be found in viral fever If autoimmune disorders are suspected ANA, anti –nDNA, antiSm, anti-Ro/SSA antibody, anti La (SSP) So how does one manage the drug treatment in pregnancy ? General guidelines for anticoagulation in Pregnancy with APS leading to recurrent pregnancy loss Very controversial issue ! Commonly used Drugs • Steroids : Reduces ACA, normalises prolongation of invitro coagulation • Complications : ? perinatal outcome preterm labour, preeclampsia • Low dose Aspirin (LDA) : Selective inhibition of Thromboxane A2 No effect on PGI2 • Azathioprine • Warfarin Which is the commonly used drug for APLA ? A.) Progesterone B.) Folic acid C.) Low dose Aspirin D.) RU- 486 Unfractionated Heparin (UFH) Potentiates complex formation with AT III + factor VII A XII A & thrombin Complications : Reduces platelet bleeding & B.M.D. Low molecular weight Heparin (LMWH) Once daily dose, less monitoring Lesser osteopenia, does not cross placenta Cost factor !! Trials Heparin vs Aspirin + prednisolone Live birth 75% Pre-eclampsia, preterm delivery more in latter group L.S. + LDA Vs Heparin + LDA (n=20) No placebo Large multicentric trials needed Cowchock et al .1994 Randomised controlled trial of LDA versus LDA plus heparin in pregnant women with APS 90 women with APS were randomized into two groups with 1st group receiving 75mg of LDA & 2nd group LDA & Heparin 5000u subcut, every 12 hourly Outcomes measured were number of live births & miscarriages LDA group had 19 live births & 26 miscarriages LDA + heparin group had 32 live births & 13 miscarriages Significant (p=0.01) improvement in outcomes with heparin R. Rai, H.Cohen et al..,BMJ. (1997 ) Antiphospolipid antibodies Presence of Antiphosholipid antibodies may cause recurrent pregnancy loss Are antibodies directly responsible ? Should all women with APA be treated ? How do you treat a women with positive APLA ? Controversies surrounding treatment for pregnancy loss Evidence-based medicine (EBM) has not succeeded in giving patients & physicians the data they need to choose (or not choose) a therapy in the field of pregnancy loss Women with APLA are advised to take LDA & to start LMWH Rx after pregnancy is diagnosed (80% success) In case of H/o thrombotic symptoms, Warfarin is used as anticoagulant .Maintain INR between 3.0 - 4.0. Patients with APLA have minor elevations of PT & are difficult to manage with warfarin. During pregnancy, LMWH & LDA are preferred to Warfarin (teratogenic effects ) If previous H/o thrombosis use LMWH in therapeutic doses throughout pregnancy :dose 1mg/kg subcut. If UFH is used dose is 10,000 u 12 hourly Since APLA reacts with phospholipids both aPTT & PT can be affected. If UFH used to anticoagulate patients with APLA monitor heparin levels ( 0.35 - 0.70 anti-Xa units 6 hours post injectiont ). With LMWH , monitoring is easier : predictable dosing & anticoagulant effect . Measure LMW heparin levels in these patients for long term Rx (0.7 - 1.0 anti-Xa units) Perform prothrombin & proconvertin times ("P&P") to follow anticoagulation. Being less dependent on phospholipids & one can monitor therapy. If miscarriage occurs with heparin & aspirin & there is a pregnancy again IVIG can be tried (RCT did not show benefit) In refractory cases plasmapheresis may be used ACCP Guidelines : Pregnancy & APL Manifestation Recommendation Grade Antiphospholipid antibody; Surveillance, or mini-dose heparin, or 2C no prior VTE or pregnancy prophylactic LMWH, & /or aspirin loss Antiphospholipid antibody; Adjusted dose UFH or LMWH, plus 1C prior thrombotic event low-dose aspirin. - Bates, et al., Chest, 2004; 126: 627S - 644S Can pregnancy outcome be improved ? Management of pregnant women Surveillance depends on past obstetric history LDA preconception & LDA + LMWH has 80% success rate for treatment of APLA ( Feinberg et al,’ 97 ). Refer preferably to a tertiary centre with a neonatal backup Team effort including an obstetrician , hematologist, physician, & neonatologist Vigilant monitoring B.P, platelets, complement levels , renal function test (to asses target organ damage ) Care of the fetus Surveillance depends on past obstetric history 1st trim U.S.G : viability & dating , nuchal & nasal bone U.S.G at 19 weeks & serial scans with doppler for early diagnosis of IUGR & waveform abnormalites Inj Betamethasone 2 doses for enhancing lung maturity Timely delivery in a centre with a good neonatal backup Future Possibilities PAPRE warfarin intensity PRECLUDE primary prevention More frequent use of LMWH, IVIG What to do with the patient with APLA but no thrombotic manifestations ? Although some of these patients are at risk, especially those with SLE, many will never develop thrombosis The current recommendation would be to do very careful search for thrombosis. Brain MRI in patients with SLE & in patients with any neurological symptom If this work-up is negative follow the patient very closely Does immunosuppression work ? APLA seems like an autoimmune disease, but immunosuppression does not prevent recurrent thrombosis, fetal loss, or neurological syndromes & so no role in the Rx of thrombotic APLA In"catastrophic APLA" plasmapheresis may play a crucial role. Low intensity anticoagulation with warfarin appears to be mostly effective in APLA (except patients with venous thrombosis) Many patients will fail low intensity warfarin & need more aggressive anticoagulation. Heparin anticoagulation appears more effective. Arterial Thrombosis: Warfarin to an INR of 2.0 - 3.0 Venous Thrombosis: Warfarin to an INR of 3.0 - 3.5. Patients who "break through" warfarin should receive heparin. Inherited Thrombophilia Inherited Thrombophilia Three important inherited thrombophilias : • Mutation in factor V Leiden causing resistance to activated protein C (responsible of 20–30% of venous thromboembolism events.) • Mutation in prothrombin (guanine 20210 adenine ) • Mutation in methylene tetrahydrofolate reductase (MTHFR) (cytosine 677 thymine (C677T) ) This is responsible for reduced MTHFR activity & is most frequent cause of mild hyperhomocysteinemia & is found in 5–15% of the population. Factor V Leiden (A506G) mutation Present in 3-8% of the general population , (heterozygotes) have a seven fold increased risk for thrombosis whereas homozygotes have an eighty fold increase. It has been linked with an increased risk for venous thromboembolism due to resistance to activated protein C & is responsible of 20–30% of venous thromboembolism events Protein S deficiency Protein S deficiency (PSD), present in up to 2% of general population. Found in approximately 15% of individuals with a DVT or PE . Found in 6% of women with obstetrical complications including a relatively high risk for stillbirth. MTHFR (C677T) mutation A homozygous (MTHFR) mutation, present in 1-4% of the general population, is associated with a three fold increased risk for DVT or PE, as well as preeclampsia & placental abruption. MTHFR (C677T) mutation Responsible for reduced MTHFR activity results in decreased synthesis of 5-methyltetrahydrofolate, the primary methyl donor in the conversion of homocysteine to methionine & the resulting increase in plasma homocysteine concentrations ( Hyperhomocysteinemia ) is a risk factor for thrombosis Dietary restriction of folate & vitamin B12 remains the most common cause. Prothrombin (G20210A) mutation A change of G to A at position 20210 in prothrombin (prothrombin 20210A) elevates baseline prothrombin levels & thrombin formation. Unexplained recurrent miscarriage In about half the women in the research studies, no cause could be found, so no specific treatment could be given. However, this group responded very well to a programme which removed as many stress factors as possible from their lives, resulting in an 80% success rate with the subsequent pregnancy Psychological support can improve outcome between the higher areas of the mind & the delicately balanced hormonal system Women with unexplained recurrent miscarriage have an excellent prognosis for future pregnancy outcome without pharmacological intervention if offered supportive care alone in the setting of a dedicated early pregnancy assessment unit. After all these investigations 50% of recurrent aborters will have no abnormalities & these should be attributed to chromosomal defect in the conceptus. Conclusion In cases of adverse pregnancy outcomes APLA should be kept in mind Detailed history & tailor investigations Couple should be counselled together . The only intervention to have demonstrated benefit is serial ultrasound scans in early months of pregnancy. Referral to a tertiary unit as multidisciplinary management is needed for patients with APLA / Thrombophillia Psychological support Education & reassurance has an important role to play Thromboprophylaxis for previous thromboembolic episode Risk categoryp Risk factors Prophylaxis High risk -Prev. TED ANC:s/c UH or -Prev TED+APLA LMWH TED (thromboembolic -Prev TED+ family history Intrapartum:s/c UH disease) of TED or LMWH -Recurrent TED Post partum:s/c UH -TED in current preg. or LMWH for 3-7 days f/b UH or LMWH or warfarin for 3-7 days Low risk One prev TED (No other ANC: g odd risk factors) Intrapartum or post partum:as above Diagnosis of APLA can be challenging, due to fluctuating titers of the antibodies, a lack of agreement between laboratories concerning standardization of the assays, and debates among researchers and clinicians concerning which antibodies to measure. Although multiple APLAs might eventually be considered pathologic to pregnancies, anti-cardiolipin, anti- phosphotidylserine, and the 'lupus anticoagulant' are generally believed to be culprits when identified in women with pregnancy losses. Rx APLA syndrome generally requires daily baby aspirin prior to conception & the use of baby aspirin & heparin as soon as pregnancy is diagnosed One recently published study demonstrated an 80% success rate for treatment of APLA by this approach. The 20% failure rate is likely accounted for in large part by genetically-abnormal losses. More aggressive treatment of APLA occasionally involves the use of human intravenous immunoglobulin. This is an expensive therapy that has less clear-cut efficacy demonstrated. The use of empiric intravenous immunoglobulin should generally be discouraged, and is not endorsed by the American College of Obstetricans and Gynecologists.
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