Antibodies to prothrombin, factor V, and beta(2)-glycoprotein I and vascular access thrombosis

We studied 88 hemodialysis patients for the presence of antibodies to human factor II (hFII), bovine factor V (bFV), and human beta (2)-glycoprotein I (beta (2)GPI). Forty-one patients had elevated anti-hFII antibodies, 17 ha d elevated anti-bFV antibodies, and 9 had elevated anti-beta (2)GPI antibod ies. Fifty-two patients had elevated antibodies to one or more protein. Pat ients with PTFE grafts had elevated antibodies most frequently (21 [75%] vs . 20 fistulas [45%; p = 0.016 compared with PTFE] and 11 tunneled catheters [68.8%]). Twelve of 13 patients (92.3%) with PTFE grafts and thrombosis ha d elevated antibody levels, compared with 9 of 15 without thrombosis (60%; p = 0.049). The number of thromboses and mean thrombosis rates were signifi cantly higher in PTFE patients with antibodies (1.24 vs. 0.14 thromboses, p < 0.01; 42.67 vs. 6.44 thromboses/100 patient years, p < 0.05). When analy zed individually, thrombotic complications occurred more frequently in pati ents with PTFE grafts and elevated anti-bFV antibodies (p = 0.016), but did not correlate with anti-hFII or anti-beta (2)GPI antibodies. Thrombotic co mplications did not correlate with elevated antibody levels in patients wit h AV fistulas or cuffed catheters. In conclusion, hemodialysis patients wit h PTFE grafts frequently have elevated antibodies to FII, FV, and beta (2)G PI, and the presence of elevated antibody levels to one or more of these pr oteins is associated with an increased thrombotic risk. Further studies are necessary to determine whether limiting exposure to bovine thrombin prepar ations will decrease the incidence of these antibodies and PTFE graft throm bosis.