The association between thrombocytopenia and clinical and laboratory characteristics in antiphospho-lipid syndrome / 中华风湿病学杂志

ABSTRACT

Objective:To analyze the association between thrombocytopenia and clinical manifestations in patients with antiphospholipid syndrome (APS), and the significance of adding thrombocytopenia to the classification criteria of APS.Methods:One hundred and sixty one APS patients admitted to Peking University People's Hospital from January 2003 to August 2017 were retrospectively analyzed. Clinical and laboratory data were compared between patients with and without thrombocytopenia. Chi-square test, Fisher's exact test and t test were used for statistical analysis. Results:Among 161 APS patients, 48 patients (29.8%) were primary APS and 113 patients (70.2%) were secondary APS. Ninety-one patients (56.5%) experienced thrombocytopenia, while 62 patients (38.5%) had thrombocytopenia as the initial symptom. Among primary APS patients, compared with patients without thrombocytopenia, the prevalence of thrombosis was significantly lower in patients with thrombocytopenia (40.0% vs 69.6%, χ2=4.218, P=0.040), especially venous thrombosis (20.0% vs 47.8%, χ2=4.174, P=0.041). Among secondary APS patients, compared with patients without thrombocyt-openia, the prevalence of thrombosis, arterial thrombosis (21.2% vs 42.6%, χ2=5.944, P=0.015) and venous thrombosis (22.7% vs 51.1%, χ2=9.753, P=0.002) was significantly lower in patients with thrombocytopenia (43.9% vs 80.9%, χ2=15.496, P<0.01). As for laboratory findings, primary APS patients with thrombocytopenia showed a higher proportion of positive aCL findings (80.0% vs 52.2%, χ2=4.174, P=0.041), while secondary APS patients with thrombocytopenia experienced more leukopenia (25.8% vs 10.6%, χ2=4.002, P=0.045), lower complement C3 levels (78.7% vs 44.4%, χ2=13.205, P<0.01) and complement C4 levels (74.6% vs 46.7%, χ2=8.485, P=0.004). The proportion of patients fulfilling 1988, 1989, 1999 and 2006 APS classification criteria in our cohort was 88.2%, 87.0%, 64.0% and 70.8%, respectively. Inclusion of thrombocytopenia into 2006 criteria improved the proportion to 96.3%. Conclusion:The prevalence of thrombosis in APS patients with thrombocytopenia is significantly low. Thrombocytopenia is an important clinical manifestation of APS which can improve the diagnostic accuracy of APS.