Cause and frequency of posttransfusion hepatitis after open-heart surgery.

A total of 1476 patients who underwent open-heart surgery between 1986 and 1988 participated in a prospective study examining posttransfusion hepatitis. They received a total of 8327 units of whole blood, packed erythrocytes, or fresh frozen plasma. The aminotransferase activities were measured preoperatively and 1, 2, 3, 4, 6, 9, 12, and 24 weeks after the operation. Thirty-four patients in all (2.3% of the transfused patients) developed posttransfusion hepatitis, which could be identified as hepatitis B in 1 patient and hepatitis C in 14 patients. No cause for posttransfusion hepatitis could be found in 19 cases (hepatitis of unknown origin). Hepatitis C became chronic in 5 patients. In contrast to hepatitis C, the 19 patients with hepatitis of unknown origin all showed a milder clinical course with lower maximal aminotransferase activities and a shorter duration of the hepatitis. A chronic course was not observed among them. The cause of hepatitis of unknown origin is discussed.