Effect of leukopenia induced by cyclophosphamide on the initial stage of arterial thrombosis in mice.

Abstract Introduction Leukocytes are found in organizing thrombi and are associated with thrombus growth. However, their role in the initial stage of thrombus formation is not well known. We investigated the role of leukocytes in the early stage of arterial thrombosis by inducing leukopenia. Methods In this double-blind, randomized, placebo-controlled study, 72 Institute of Cancer Research mice were randomly treated with intraperitoneal 100 mg/kg cyclophosphamide or normal saline. The primary outcome was time to occlusion after FeCl3 treatment. We also compared thrombus size, histological composition, and association with peripheral blood cell counts between cyclophosphamide and control groups. Results Cyclophosphamide treatment significantly decreased leukocyte counts by 82.8% compared to placebo (P  Conclusions Cyclophosphamide-induced leukopenia attenuated thrombus formation during the early stage of arterial thrombosis. Our findings suggest the potential role of leukocytes in the initial stage of arterial thrombosis.