DIFFERENCES IN FUNCTIONAL-ACTIVITY OF ANTICARDIOLIPIN ANTIBODIES FROMPATIENTS WITH SYPHILIS AND THOSE WITH ANTIPHOSPHOLIPID SYNDROME

Anticardiolipin antibodies are produced both in patients with the anti phospholipid syndrome (APS) and in patients with syphilis, but lupus a nticoagulant activity has been reported only for the former group. To understand these differences, affinity-purified immunoglobulin G antic ardiolipin antibodies from APS (n = 11) and syphilis (n = 5) patients were compared. Only the antibodies from the APS group inhibited prothr ombin conversion to thrombin and cross-reacted with phosphatidylserine . These findings may enable better definition of the phospholipid epit opes involved in the hemostatic abnormalities of APS.