LAUSR

Catastrophic antiphospholipid syndrome (CAPS) is an uncommon, often fatal, variant of the antiphospholipid syndrome (APS) that defined as multiorgan thrombosis affecting three and more organs confirmed by histopathology of small vessel occlusions in at least one organ or tissue. The development of CAPS in pregnancy poses many diagnostic challenges as a result of its overlap with other obstetric TMA syndromes. Because of the high associated mortality rate, prompt recognition and treatment are paramount. Some studies have shown that complement activation contributes in antiphospholipid antibodies (aPL) mediated thrombosis in CAPS. Short treatment with eculizumab can result in a rapid improvement of pts with TMAs other than aHUS with persisted hematological and renal symptoms worsened despite treatment of the TMA-inducing condition. Aims: Analysis of renal involvement, course and outcomes of obstetric CAPS From 2016 to 2019 we observed 11 pts aged 19 - 38 years with CAPS, occurred during pregnancy (from 16 to 40 weeks) or postpartum period. Only 1 patient had a diagnosis of APS with SLE before pregnancy. 5 out of 11 pts had the first pregnancy, 6 pts already had a history of pregnancy, but all previous pregnancies were failed: miscarriage or antenatal death of the fetus. Preeclampsia (PE) and/or HELLP syndrome, surgical intervention in combination with obstetric complications (bleeding, manual separation of the placenta, Сaesarean delivery, etc.) preceded CAPS manifestation in all pts. Moreover, in 1 patient with SLE, secondary APS and triple aPL positivity, HELLP syndrome developed very early stage of 16 weeks. In all cases, aPL circulation was detected (anti-cardiolipin antibodies and/or anti-beta-2-glycoprotein-1, lupus anticoagulant). All pts (100%) had complete MAHA (microangiopathic hemolysis): hemoglobin level 73,0 ± 19,2 g/l, LDH level 1066,7 ± 1056,7 U/l, schizocytosis), thrombocytopenia (122,0±157,9х10µL) and multi-organ failure (MOF): kidney damage (81%, 9 of 11), liver (63%, 7 of 18), gastrointestinal tract, heart, lungs, central nervous system - 55% (6 of 11), skin (gangrene 1-9%). A feature of kidney involvement was the development of AKI (mean creatinine level 207,6 ±140,3 mg/dl, oliguria or anuria) not all pts (9 of 11), in 2 case was observed only minimnal urinary syndrome without increasing sCr. All pts underwent traditional treatment, including plasma exchange and/or plasma infusions+corticosteroids+anticoagulants, which was effective in 6 out of 11 pts. In the 2 most severe plasma-resistant cases complement-blocking treatment with eculizumab was prescribed, with rapid positive dynamics was observed: the relief of MOF, hematological parameters normalization after the first infusion and recovery of kidney function by the end of the induction course. Favorable outcome with complete normalization of lab parameters and clinical improvement with kidney function normalization was achieved in 8 of 11 women. In 1 patient chronic kidney disease (CKD) stages 3B has occurred as outcome of AKI. 2 pts died despite ongoing therapy with PT + ST+IG+AC from progressive multiple organ failure. 1. Сomplicated obstetric history in patients with acute obstetric TMA requires mandatory exception of CAPS 2. Proven role of complement system involvement in the pathogenesis of CAPS gives a reason for the complement-blocking therapy appointment in severe postpartum TMA, which increases the patients' chance of recovery.