Safety of the blood supply. Surrogate testing and transmission of hepatitis C in patients after massive transfusion.

Abstract

To define a risk profile for post-transfusion hepatitis C in patients receiving massive transfusion. Hepatitis C accounts for more than 90% of post-transfusion hepatitis. Two-hundred twenty-one of 8,765 consecutive trauma admissions to a Level I trauma center received more than 20 units of erythrocytes. Sixty-nine survivors had positive viral serologic tests at least 1 year after transfusion. Surrogate testing for hepatitis C using alanine aminotransferase (ALT) levels and antibodies to hepatitis B core antigen (Core) began in October 1986 and January 1987, respectively. Donor blood for group 1 (pre-ALT/Core) was transfused before surrogate screening was introduced. Donor blood for group 2 (post-ALT/Core) was transfused after surrogate screening. Sixty-nine patients received blood products from 4,987 donors (mean, 72.3 units of exposure). No patient tested positive for antibodies to hepatitis B surface antigen, human immunodeficiency virus, or human T-lymphotrophic virus type 1. However 23.2% tested positive for hepatitis C virus (HCV) as measured by a second-generation enzyme immunoassay (HCV 2.0) and a recombinant immunoblot assay (RIBA), and 21.7% tested positive by HCV 1.0. Antibodies to Core were found in 8.7% of patients. The risk for post-transfusion hepatitis C per unit of exposure is estimated to be 1.52% group 1 (pre-ALT/Core) and 0.239% for group 2 (post-ALT/Core). The introduction of ALT/Core donor screening by a blood bank reduced the incidence of post-transfusion hepatitis C by 84%. The risk for post-transfusion hepatitis C depends on units of exposure, screening techniques, and prevalence of hepatitis C in the donor population. In our community, the risk for post-transfusion hepatitis C is less than 0.2% per unit of exposure. The population of massively transfused patients may serve as our effective resource for monitoring the safety of the blood supply.