Cold activation of complement as a marker of hepatitis c viremia in sera from blood donors

Abstract Sera from 49,088 blood donors were tested for markers of hepatitis C virus (HCV) infection and decreased hemolytic activity after they had been stored at 4°C for 24 h, a phenomenon known as the cold activation of complement. Antibody to HCV (anti-HCV) was detected in 315 (0.64%) units, of which 181 (57%) were positive for HCV RNA. The cold activation of complement was detected in 170 (0.35%) units, and HCV RNA was detected in 140 (82%) of them. Thus, the cold activation of complement was observed in 140 (77%) of 181 blood units with HCV RNA. The close association of HCV viremia with the cold activation of complement would be useful as a surrogate test in preventing post-transfusion HCV infection in developing areas where antiHCV assays are not easily performed.