SAT0212 OBSTETRIC AND THROMBOTIC ANTIPHOSPHOLIPID SYNDROME: SIMILAR ANTIBODIES BUT DIFFERENT PHENOTYPES?
Authors: H. Jiang, Y. Zhao, C. H. Wang, J. Zhao
Journal: Annals of the Rheumatic Diseases (2020)

Background: Several studies showed two main clinical phenotypes of antiphospholipid syndrome which could be independent, but only a few data contrast features between these two groups. Objectives: To investigate whether obstetric and thrombotic manifestations of APS are independent subtypes. Methods: This was a single center prospective study from the PUMCH database of primary antiphospholipid syndrome followed for over 4years. Comparing demographic data, laboratory tests, pregnancy morbidity and thrombotic events during follow-up between IoAPS (isolated obstetric APS) and ItAPS (isolated thrombotic APS). Results: A total of 244 patients was registered in PUMCH primary APS cohorts, 157(64.34%) were female patients. In female patients, 44(28.03%) were diagnosed with IoAPS, 42(26.75%) were ItAPS. Demography showed patients in ItAPS group were older than IoAPS group (40 vs 33, p&lt;0.001), presented more cardiovascular risks(33.33% vs 6.8%, p&lt;0.01), neurological disorders (23.8% vs2.3%,p&lt;0.01) and thrombocytopenia (47.6%vs 20.5%,p&lt;0.01). Antibody profiles had no difference in triple positivity, double positivity and partial single positivity (ACL, LA), but presence of single anti-β2GPI positivity showed significant difference between IoAPS and ItAPS (59.09% vs 38.1%, p&lt;0.05). Significant difference was presented in homocysteine(Median) between IoAPS and ItAPS (9.9 vs 11.5, p&lt;0.05), not in inflammatory markers. During 49.5 (Median) months follow-up of ItAPS group, patients got 90 pregnancies, 5 abortions but weren’t fulfilled with the diagnosis criteria of pregnancy morbidity. No thrombotic event occurred during 48.5(Median) months follow-up time in IoAPS group. Conclusion: IoAPS and ItAPS shared similar antibody profile, but presented isolated clinical complications, different demographic features and maintained independent manifestation during follow-up, indicating the underlying pathogeneses are different. References: [1]Meroni P L, Borghi M O, Grossi C, et al. Obstetric and vascular antiphospholipid syndrome: same antibodies but different diseases?[J]. Nat Rev Rheumatol, 2018, 14(7): 433-440 Table1. Demographic characteristics IoAPS(n=44) ItAPS(n=42) P-value Age, years, Median (Q1-Q3) 33 (30.00, 36.00) 40(33.75, 55.25) .00 B.M.I. Median (Q1-Q3) 22.86 (20.70,24.45) 23.52 (21.44, 27.70) .10 Flow-up time, month, Median (Q1-Q3) 48.50 (36.00,77.00) 49.50 (23.00,103.75) .44 Smoke (n%) 1(2.27) 0(0) 1.00 Cardiovascular risk factors (n%) 3 (6.82) 14 (33.33) .00 Coronary heart disease 0(0) 2(4.76) .24 Hypertension 1(2.27) 5(11.90) .11 Obesity 2(4.55) 9(21.43) .03 Diabetes mellitus 0(0) 0(0) Complications (n%) 16 (36.36) 30 (71.43) .00 Kidney diseases 2(4.55) 3(7.14) .67 Thrombocytopenia 9(20.45) 20(47.62) .01 Neurological Disorders 1(2.27) 10(23.81) .00 Stroke 0(0) 8(19.05) .00 Non stroke CNS manifestations 1(2.27) 2(4.76) .61 Valvular heart diseases 4(9.09) 2(4.76) .68 Failed pregnancy during follow-up (%) 116/154(75.32) 5/90(5.56) .00 Thrombosis during follow-up (n%) 0(0) 4(9.52) .05 Table 2. Laboratory tests IoAPS(n=44) ItAPS(n=42) P-value Antibody categories Triple positive (n%) ACL+β2GPI+LA 11(25.00) 15(35.71) .35 Double positive (n%) 7(15.90) 11(26.19) .29 LA+ACL 0(0) 1(2.38) .49 LA+anti-β2GPI 2(4.55) 3(7.14) .67 ACL+anti-β2GPI 5(11.36) 7(16.67) .55 Single positive (n%) 26(59.10) 16(38.10) .04 ACL 1(2.27) 1(2.38) 1.00 anti-β2GPI 23(52.27) 10(23.81) .01 LA 2(4.55) 5(11.90) .26 Negative after treatment 4(9.09) 1(2.38) .36 ESR 10(6, 27) 9(4, 16) .06 CRP 1.03(0.56, 3.85) 1.11(0.43, 3.18) .63 HCY 9.9(8.10, 12.10) 11.5 (9.30, 14.65) .04 * aCL: anticardiolipin antibodies; anti-β2-GPI: anti-β2 glycoprotein I antibodies; LA: lupus anticoagulant; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; HCY: homocysteine. Acknowledgments: The authors thank Department of Rheumatology in Peking Union Medical College Hospital for support with statistics. Disclosure of Interests: None declared