Search

In Reply.— We appreciate and, in general, agree with the comments of Ashenhurst and her colleagues, but we believe several specific additional comments are worthy. In the adult population, the use of cryoprecipitate for replacement therapy of hemophilia-A patients undergoing surgery is cumbersome, and the dosage of factor VIII is difficult to regulate. In another report, we recommended that adequate replacement therapy sufficient to produce surgical hemostasis in the adult population is ten to 12 bags of cryoprecipitate every 12 hours. Assuming the average adult weighs 70 kg, and an average of 100 units of factor VIII per bag, the patient's factor VIII level would be raised to a maximum factor VIII level of 30% to 40% each 12 hours. In our experience, the biologic half-life of factor VIII is about 12 hours, and following the above regimen, the level of factor VIII could easily drop to 15% to 20%

Immune hemolytic anemia is a recognized complication of the use of factor VIII concentrates. Hemolysis is obscured often by the presence of active bleeding. Where hemolysis has been demonstrated, red blood cell (RBC) destruction has been attributed to anti-A antibodies found in the transfused material. We present two episodes of hemolysis associated with the use of factor VIII concentrate. In the first, a high titer of "immune" anti-A (1:256) was present in the factor VIII. In the second, the patient's RBCs were group B, and the hemolysis was caused by anti-B antibody in the factor VIII concentrate. In addition, the antibody titer in the material that was received was much lower than previously described. The RBC destruction presumably occurred because of the massive dosage of factor VIII concentrate administered in order to overcome a factor VIII inhibitor. ( Arch Intern Med 136:1018-1020, 1976)