Ruyu Liang1, Ranran Yao2, Ziye Wang3, Wenwen Pei2, Renge Liang3 and Chun Li4, 1Peking University, XiCheng, China, 2Peking University, Beijing, China, 3Peking University People's Hospital, Beijing, China, 4Peking University People’s Hospital, Beijing, China
Background/Purpose: There is a lack of serum markers to differentiate thrombotic APS (tAPS) and obstetric APS (oAPS). Neutrophil extracellular traps (NETs) are involved in the pathogenesis of antiphospholipid syndrome (APS). This study aims to evaluate the difference of NETs markers between tAPS and oAPS.
Methods: A total of 253 adult patients diagnosed APS and fulfilled Sydney criteria were recruited from the Department of Rheumatology and Immunology at Peking University People's Hospital. Demographic characteristics and clinical features of patients were recorded. Serum concentrations of aPLs, MPO-DNA complexes, cell-free DNA and calprotectin were measured. Results are shown as mean±SD. The results were analyzed by independent t tests, Mann-Whitney U test, and chi-square tests as appropriate.
Results: In comparison to those with oAPS, patients with tAPS had older age (46.89±17.69 vs. 36.95±8.88 years, P< 0.001), higher rate of cardiovascular risk (at least one positive of smoke, coronary heart disease, hypertension, obesity, diabetes, and hyperlipidemia) (65.63% vs. 36.56%, P < 0.001), and lower lymphocyte count (1.51±0.74 vs. 1.77±0.69 109/L, P < 0.05) and neutrophil-to-lymphocyte ratio (4.11±3.89 vs. 3.07±2.17 109/L, P < 0.05). Both lupus anticoagulant (61.72% vs. 29.63%, P < 0.001), and anti-cardiolipin (61.90% vs. 30.95%, P < 0.001) positivity were higher in patients with tAPS, and there was no significant difference in anti-β2GPI positivity. Compared with oAPS patients, tAPS patients had higher concentration of MPO-DNA complex [1107.77(689.90, 2107.62) vs. 583.62(313.78, 1498.41), ng/ml, P < 0.01) but lower calprotectin (21.22(20.40, 22.60) vs. 22.85(21.43, 24.19), ng/ml P < 0.05), but there was no significant difference in cell-free DNA level in two groups.
Conclusion: Our data suggest that patients with tAPS had higher level of MPO-DNA complex but lower calprotectin, and higher lupus anticoagulant and anti-cardiolipin. It is worth further research distinct mechanisms of pathogenesis.
Fig 1. Patients with tAPS had higher level of MPO-DNA complex (A) but lower calprotectin (B). There was no significant difference in cell-free DNA level (C). *P < 0.05, ***P < 0.001 Data are presented as the mean ± SD.
R. Liang: None; R. Yao: None; Z. Wang: None; W. Pei: None; R. Liang: None; C. Li: None.