The sera of 69 Chinese patients with systemic lupus erythematosus were tested for the presence of lupus anticoagulant (LA) by a panel of laboratory tests: Kaolin clotting time (KCT), dilute Russell viper venom time (DRVVT) and platelet neutralization procedure (PNP). The prevalence of LA varied among the 3 tests (10–19%), and was 10% when LA was considered present if either KCT or DRVVT and the PNP were positive. Concordance was fair between KCT and PNP, but was poor for DRVVT with either of the other 2 tests.
Only 2 of our lupus patients had a history of thrombo-embolic disease, and neither were serologically positive for LA. The incidence of thrombo-embolic diseases and that of LA were both too low in this group of Chinese lupus patients for their association to be evaluated.