S3D:6 Microangiopathic manifestations of the primary antiphospholipid syndrome

Abstract

Objective Thrombotic microangiopathy (TMA) is a relatively rare but severe vascular complication of antiphospholipid syndrome (APS) and may involve any organ. It’s crucial for prompt diagnosis and early intervention, while the clinical features and outcomes of patients with TMA in APS is quite scant. The aim of this study was to investigate characteristics of primary APS with TMA patients. Patients and methods One handred and twelve priamry APS patients who attended in Peking Union Medical College Hospital from January 2004 to December 2016 were enrolled. Patients were subdivided into two groups: PAPS with TMA and PAPS without TMA. Demographic data, clinical characteristics, laboratory features and treatment were retrospectively collected. Bivariate statistical analysis and logistical regression test were performed to compare the discrepancy between the two groups. Survival rates were studied by Kaplan-Meier method, and COX proportional hazard model was adopted to perform the analysis of predicting factors for mortality. Results Twenty-one patients with TMA were indentified, presenting in 18.8% of all PAPS patients. Both groups were similar with respect to age of onset, gender, clinical course and pregnancy morbidity. However, the frequency of anti-b2-glycoprotein I antibodies (anti-b2GPI) (66.7% vs 33.0%, p=0.004) was significantly higher in the TMA group than the non-TMA group. In addition, thrombocytopenia (85.7% Vs 54.9% p=0.007) and elevated high-sensitivity C-reactive protein (hsCRP) (71.4% Vs 54.9% p=0.007) were observed more frequently among TMA group. In multivariate analysis, only thrombocytopenia (OR=4.055, 95% CI: 1.006 to 16.345, p=0.049), hsCRP elevation (OR=6.789, 95% CI: 2.018 to 22.840, p=0.002) and positivity for anti-b2GPI (OR=4.723, 95% CI: 1.409 to 15.830, p=0.012) were independent risk factors for the occurrence of TMA in PAPS patients. The overall 1, 3, and 5 year survival rate of PAPS with TMA was 69.2%, 60.6% and 50.5% respectively; while 90.4%, 88.2%, and 88.2% in APS patients without TMA (p Conclusion Microangiopathic antiphospholipid syndromes should be an independent subset with mainly small vessels involved and worse prognosis, compared with classic APS.