Occurrence of anti-prothrombin and anti-beta(2)-glycoprotein I antibodies in patients with history of thrombosis

New evidence indicates that antibodies to beta(2)-glycoprotein I (anti-beta (2)GPI) or to human prothrombin (anti-II)(ar to both of these) are specific markers of the antiphospholipid syndrome (APS). They have been mainly asso ciated with thrombotic complications In patients with APS, However, some st udies have reported that elevated levels of anti-II, but not of anti-beta(2 )GPI, imply a risk of venous thrombosis (VT) or arterial thrombosis (AT) in subjects with no previous thrombosis and no antiphospholipid antibodies (a PL) by ELISA. The present study included 180 patients with a history of thr ombosis, 83 of them without aPL (group I) and the remaining 97 diagnosed as having APS (group II). Anti-beta(2)GPI was found in only 1 of the 83 patie nts from group I but was found in approximately 50% of those from group II (P < .0001). In contrast, positive anti-II was detected with a high prevale nce in patients from group I (VT, 22.6%; AT, 26.7%) and in those from group II (VT, 37.5%; AT, 14.6%). No statistical differences were found in the pr evalence of anti-II between the two groups of patients. On the other hand, such a difference was significant when compared with results in a normal gr oup (1/67, 1.4%, P < .0001). These data indicate that anti-ii occurs freque ntly in patients with previous thrombosis either with or without lupus anti coagulant activity. Accordingly testing of anti-II might be clinically usef ul in the evaluation for thrombophilia.