Procoagulant effect of the OKT3 monoclonal antibody: involvement of tumor necrosis factor

Procoagulant effect of the OKT3 monoclonal antibody: Involvement of tumor necrosis factor. We recently observed that the prophylactic administration of high doses of OKT3 monoclonal antibody (MoAb) in cadaveric renal transplantation favors the development of thromboses of the grafts' main vessels and of thrombotic microangiopathies. These clinical observations led us to perform sequential determinations of plasma levels of prothrombin fragment 1 and 2 (F 1 + 2) and fibrin degradation products (FDP) after the first injection of 5 or 10mg OKT3 given as prophylaxis in kidney transplant recipients. The values observed have been compared with those of kidney transplant recipients not treated with OKT3. F 1 + 2 levels peaked four hours after the first injection of 5mg OKT3 (mean ± SEM: 4.82 ± 0.73 vs. 1.75 ± 0.37 nmol/liter in controls, P