A radioimmunoassay was used to detect antibodies to hepatitis C
virus (anti-HCV) in 154 patients with haemophilia. Prevalence of
anti-HCV was associated with exposure to clotting factor
concentrates. 76 of 129 (59%) who had received factor VIII or IX
had anti-HCV: 42 of 55 (76%) who required over 10 000 units of
concentrate annually had anti-HCV, compared with 34 of 74 (46%)
who required less, and 0 of 25 patients who had never received
concentrates. Anti-HCV were significantly more common in
patients seropositive for antibodies against human
immunodeficiency virus (anti-HIV) or with markers of previous
hepatitis B infection than in those without anti-HIV or
hepatitis B markers (88% vs 39% and 75% vs 46%, respectively). 5
of 23 (22%) haemophiliacs treated only with heated concentrates
had anti-HCV compared with 71 of 106 (67%) patients who received
unmodified products. 35 patients with chronic liver disease
underwent liver biopsy: histological examination showed features
associated with post-transfusion hepat