Factor V deficiency in Philadelphia-positive chronic myelogenous leukemia

Abstract

Factor V deficiency has been identifed in 8 of 8 patients 7-20 yr of age, with Philadelphia-positive (Ph1 +) chronic myelogenous leukemia (CML). In these 8 patients, factor V deficiency was not due to hepatic dysfunction, factor V inhibitors, or disseminated intravascular coagulation. In 3 patients, factor V activity rose 10%-12% (0.10-0.12 U/ml) after the infusion of 28-31 ml/kg body weight of fresh frozen plasma (FFP). The rise persisted less than 14 hr. The mean measured postinfusion rise in factor V was 18% of the expected rise calculated from the volume of FFP infused in the patients' plasma volume. In 4 patients, a small transient rise in factor V activity occurred after splenectomy or plateletpheresis. Factor V deficiency was completely corrected after a marked reduction in bone marrow cellularity in 2 patients with Ph1 + CML treated with extensive chemotherapy, total body irradiation, and bone marrow transplantation. Factor V deficiency was retrospectively observed in 6 of 20 patients, ages 20-80 yr, with Ph1 + CML and 3 of 6 patients with other myeloproliferative disorders. The factor V deficiency appears to be associated with the large myeloid-megakaryocytic cell mass characteristic of CML and other myeloproliferative disorders.