ANTI-HCV IN POSTTRANSFUSION HEPATITIS - DEDUCTIONS FROM A PROSPECTIVE-STUDY

Stored sera from 52 patients who developed post-transfusion hepatitis (PTH) during a prospective study of PTH in Toronto in 1984/85, sera from 111 donors whose blood was transfused into these patients and sera from 50 patients with chronic active hepatitis with a remote history of blood transfusion were tested for anti-HCV. In patients with PTH seroconversion occurred relatively early. Ten converted in less than 14 weeks after transfusion. Only three of the 34 patients (9%) whose hepatitis resolved developed anti-HCV compared to 11 of 18 (61%) whose hepatitis became chronic. Patients who seroconverted had higher alanine aminotransferase (ALT) values during the phase of acute hepatitis than those who did not seroconvert. Most of the patients who developed PTH received blood that was negative for anti-HCV. Four donors whose blood was positive for anti-HCV transmitted hepatitis. Three of the patients developed anti-HCV and chronic hepatitis. One of the recipients did not seroconvert and the hepatitis resolved. Forty-two of the 50 patients (84%) with chronic hepatitis and a remote history of blood transfusion were positive for anti-HCV. We conclude that anti-HCV-positive donors may transmit hepatitis C; that if anti-HCV is diagnostic of hepatitis C, most cases of acute PTH are either not due to hepatitis C or may represent cases of hepatitis C in which the anti-HCV test was undetectable. On the other hand, most cases of PTH which progress to chronic hepatitis are caused by HCV. The presence and persistence of anti-HCV is an indicator of chronic disease but an asymptomatic viremic state without detectable anti-HCV in the serum may exist which is capable of transmitting hepatitis. Anti-HCV testing may detect a subgroup of donors who transmit hepatitis C with a tendency to develop chronic disease. This fact alone suggests that introduction of anti-HCV testing of blood donors will make the national blood supply much safer.