Prevention of posttransfusion hepatitis B and C by screening for antibody to hepatitis C virus and antibody to HBcAg

Abstract

Screening of blood donors by testing for antibody to HBcAg and antibody to hepatitis C virus is commonly done. However, the applicability of these screening tests may vary depending on the prevalence of hepatitis B virus and hepatitis C virus infection in various populations. We have therefore prospectively evaluated 158 adult patients who received blood or blood products during open‐heart surgery in Hong Kong to compare the efficacy of various serological screening tests in the prevention of posttransfusion hepatitis. Serum from five (0.5%) donors was positive for antibody to hepatitis C virus by second‐generation enzyme immunoassay; in two, optical‐density readings in enzyme immunoassay were greater than 2.0, but only one was positive for hepatitis C virus RNA by reverse transcription–polymerase chain reaction. The latter donor was also positive for antibody to HBcAg and had elevated serum ALT activity. The recipient of a unit of this donor's blood was the only one in whom posttransfusion hepatitis C developed (0.1% per unit transfused). Screening with antibody to hepatitis C virus was more specific than that with antibody to HBcAg or ALT in excluding donors from transmitting hepatitis C (99.6%, 79.4% and 98.8%, respectively). Both the sensitivity and negative predictive value of screening for antibody to hepatitis C virus were 100%, but the positive predictive value was only 20%. Forty‐five blood recipients were considered susceptible to hepatitis B virus infection because testing for hepatitis B serology in serum (HBsAg, antibody to HBsAg and antibody to HBcAg) was negative before being transfused. Asymptomatic hepatitis B seroconversion developed in three (6.7%) recipients (1.1% per unit transfused). One was transiently positive for HBsAg, and all three became positive for antibody to HBsAg and antibody to HBcAg during follow‐up. One patient received a unit of blood that was positive for antibody to HBcAg and hepatitis B virus DNA by polymerase chain reaction. The second patient received a unit of blood with antibody to HBcAg but negative for hepatitis B virus DNA. The blood administered to the third patient was negative for hepatitis B markers, including hepatitis B virus DNA by polymerase chain reaction. Exclusion of donors with isolated antibody to HBcAg had the highest sensitivity and specificity for prevention of posttransfusion hepatitis B (66.7% and 96.1%, respectively). This approach yielded a positive predictive value of 16.7% and a negative predictive value of 99.6%. Antibody to hepatitis C virus should be screened in all blood donors to minimize the risk of posttransfusion hepatitis C. In hepatitis B virus–endemic areas, further reduction of the risk of posttransfusion hepatitis B with blood from HBsAg‐negative volunteer donors is difficult. Our data suggest that excluding donors with isolated antibody to HBcAg may be the most effective approach. (HEPATOLOGY 1993;18:1045‐1049). Copyright © 1993 American Association for the Study of Liver Diseases