Recurrent acute hepatitis following the use of factor VIII concentrates.

During a 3-yr period, a patient with hemophilia A experienced 5 episodes of acute hepatitis within 7-16 days following 5 separate infusions of factor VIII (FVIII) concentrates. Although the exact mechanism of the recurrent hepatitis remains unclear, these episodes most likely represented repeated allergic reactions to an antigenic protein derived from the FVIII concentrates. Although no evidence was found for a specific humoral immune response to FVIII in the circulation of the patient, an isolated cellular immune response was suggested by the finding of in vitro lymphocyte stimulation in response to the FVIII concentrate. This unusual type of posttransfusion hepatitis must be added to the list of adverse responses to FVIII concentrates.