Factor XI deficiency diagnosed following use of adalimumab.

Adalimumab is a drug used in the treatment of refractory psoriasis. We present a case of a 55-year-old male patient who developed petechiae and purpura after the ninth dose of adalimumab therapy. The results of laboratory investigations revealed factor XI (F.XI) deficiency. It should be recognized that F XI deficiency may develop in patients using long-term adalimumab, leading to increased risk of bleeding.

L-Asparaginase-induced coagulopathy during therapy of acute lymphocytic leukemia.

L-Asparaginase-induced coagulation abnormalities were observed in all patients receivng this drug. All patients studied demonstrated low factor IX and fibrinogen levels and most (75%) had low levels of factor XI. Disturbances in other factors were much less frequent. Despite the presence of markedly abnormal coagulation studies, clinical bleeding was not observed.

The effect of L-asparaginase of plasma coagulation factors in acute lymphoblastic leukemia.

Serial coagulation studies were performed in 26 pediatric patients with acute lymphoblastic leukemia during initial induction therapy with vincristine, prednisone, and L-asparaginase. Prolongation of screening coagulation tests was frequent: prothrombin time (in 16 of 26 patients), partial thromboplastin time (23/26) and thrombin time (21/26). In all 26 patients fibrinogen levels fell below .20 g/100 ml and 16 had levels below .10 g/100 ml. Sixteen patients had plasma coagulation factor assays performed. In these 16 patients, Factor XI was less than 40% in 14 and Factor XI was less than 70% in 9, with only a few scattered low levels of other factors. There were no clinical bleeding episodes. Coagulation abnormalities returned to normal at the completion of L-asparaginase therapy while the patients remained on vincristine and prednisone.