Influencing factors of thrombosis besides antiphospholipid antibodies in patients with antiphospholipid syndrome

Abstract

Objective: To identify the influencing factors of thrombosis besides antiphospholipid antibodies in patients with antiphospholipid syndrome (APS). Methods: The 169 patients diagnosed with APS were enrolled according to the current APS classification criteria from January 2003 to August 2017 in Peking University People's Hospital. There were 23 males and 146 females with a mean age of (41±15) years. Antiphospholipid antibodies, including anticardiolipin (aCL), anti-β2glycoprotein-1 (β2GP1) antibodies and antibodies to the phosphatidylserine-prothrombin complex (aPS/PT), were determined by enzyme-linked immunosorbent assay (ELISA) methods. Lupus anticoagulant (LA) was identified using the STA Compact coagulation testing system. The differences of clinical and laboratory characteristics between patients with and without thrombosis were analyzed (100 cases and 69 cases, respectively). The influencing factors for thrombosis in patients with APS were determined using binary logistic regression. Results: Compared with patients without thrombosis, patients with thrombosis were older and had a longer disease duration ((45±17) years vs (35±9) years and M(Q1, Q3) 12.0(3.8, 84.0) months vs 48.0(12.0, 108.0) months, both P<0.05). The percentage of male, primary APS, smoking, low blood platelet count, hypertension, and diabetes in patients with thrombosis were significantly higher than those in patients without thrombosis (all P<0.05). Similarly, the rates of antinuclear antibodies positive, aCL positive, aPS/PT-IgM positive, and aPS/PT-IgG positive in patients with thrombosis were significantly higher than those in patients without thrombosis (all P<0.05). The levels of D-dimer in patients with thrombosis were significantly higher than that in patients without thrombosis (P<0.05). There was significant difference in global anti-phospholipid syndrome score (GAPSS) between patients with and without thrombosis (P<0.05). The GAPSS score was also significantly higher in patients with arterial thrombosis than that in patients with venous thrombosis (P<0.05). Smoking and D-dimer levels were independent influencing factors for thrombosis in patients with APS (smoking: OR=11.222, 95%CI:1.119-112.544, P=0.040, D-dimer levels: OR=1.002, 95%CI: 1.000-1.003, P=0.037). Conclusions: Thrombotic APS patients are older and have a longer suffering duration, a higher ratio of male, primary APS, smoking, hypertension, lower blood platelet count, diabetes, higher GAPSS scale, and higher D-dimer levels. Smoking and D-Dimer levels may be independent risk factors for thrombosis in patients with APS.