The objective of the work was to study the manifestations of antiphospholipid syndrome (APS) in the Chinese population, and evaluate the ability of lupus anticoagulant (LAC) assays to identify APS.Methods:
Consecutive patients with APS from 2012 to 2015 in our hospital were recruited, strictly following the Sydney revised Sapporo criteria for APS classification. Meanwhile, in the LAC-positive population, LAC normalized ratios obtained from diluted Russell viper venom time (DRVVT) and silica clotting time (SCT) assays were compared between patients with and without APS.Results:
One hundred and seventeen patients with defined APS comprised 86 women and 31 men with a mean age of 38 years (range 9-78 years), 38 (32.5%) of them had systemic lupus erythematosus. The prevalence of arterial thrombosis, venous thrombosis and obstetric complications were 46.2%, 25.6% and 30.8%, respectively. LAC was detected in 105 patients (89.7%), anti-β2-glycoprotein I antibodies (aβ2GPI) in 88 (75.2%) and anticardiolipin antibodies in 41 (35.0%). In 353 patients with persistent LAC, the receiver operator characteristic (ROC) curve for APS prediction defined the best cut-off value for DRVVT normalized ratio as 1.61 with 73.7% specificity and 72.6% sensitivity. For SCT, the normalized ratio was 1.91 with 70.8% specificity and 56.5% sensitivity.Conclusions:
A high prevalence of arterial thrombosis and LAC-positive result was noted in Chinese patients with APS, and an appropriate threshold for LAC normalized ratios could help to discriminate APS from non-APS patients in the LAC-positive population.