Here we present a case report of three familial primary antiphospholipid syndrome (PAPS) patients from Malaysia. The three familial patients comprised two females and one male with a mean age of 26.3 years. The first diagnosis was made between 2005 and 2009, and all patients demonstrated deep vein thrombosis, high levels of IgM and IgG anticardiolipin antibodies, and received warfarin treatment international normalized ratio (INR) 2.0-3.0. The patients ceased to show clinical symptoms after treatment. Recently (August 2014), we investigated whether the levels of antiphospholipid antibodies remained elevated, and we found that seronegativity occurred in the patients. We suspect that prolonged anticoagulant treatment might be one of the causes of reduced levels of antiphospholipid antibodies in these familial PAPS patients.
Keywords: Primary antiphospholipid syndrome; antiphospholipid antibodies; deep vein thrombosis.