Five hundred consecutive healthy blood donors were tested for serum alanine aminotransferase (ALT) and 44 (8.8%) had increased levels. Donors with and without raised ALT were compared in several aspects but only weight (expressed as percentage of ideal body weight) and sex differed significantly (119.1 ± 14.5 and 106.3 ± 12.8%, respectively; p<0.001 and males 97.7 and 77.1%, respectively; p<0.01). The 44 donors with raised ALT were followed up and in 13 out of 15 donors with persistently raised ALT without obvious reason, a liver biopsy was performed. Ten donors had various degrees of liver steatosis, 2 had normal liver morphology and in 1 donor chronic hepatitis could not be ruled out. If ALT screening is introduced as a surrogate test for non-A, non-B hepatitis in Swedish blood donors, we suggest that a correction for overweight must be considered in order to minimize donor loss.

Seventy-three Swedish blood donors (52 men, 21 women; median age 36 years) repeatedly reactive for hepatitis C antibodies (anti-HCV C-100-3) were tested with a second-generation (2^nd-gen) anti-HCV Elisa and a 4-band recombinant immunoblot assay (RIBA 2). These results were correlated to serum alanine aminotransferase (S-ALAT), liver morphology and viremia as detected by ‘nested’ polymerase chain reaction (PCR) based on primers from a 5'-noncoding sequence of the HCV genome. Thirty-five of 46 (76%) donors with positive 2^nd-gen Elisa tests confirmed by RIBA 2 were PCR positive whereof 27 had histological findings compatible with chronic persistent hepatitis (CPH) and 7 had chronic active hepatitis (CAH). Ten of 56 (18%) 2^nd-gen Elisa-positive donors were RIBA 2 negative (or indeterminate) and none of these had chronic hepatitis nor were PCR positive. Seventeen of 73 (23%) donors were 1^st-gen Elisa positive but 2^nd-gen Elisa negative. All of these were PCR negative and only 1 (6%) had chronic hepatitis (CPH). An elevated S-ALAT level (reference <0.7 µkat/1) was found in 26 2^nd-gen Elisa and RIBA 2-positive donors of which 18 had CPH and 7 had CAH and all 25 were PCR positive. A normal S-ALAT level was found in 9 of 34 (26%) donors with chronic hepatitis (all had CPH) and positive PCR. We have found that blood donors with positive 2^nd-gen anti-HCV Elisa tests confirmed by RIBA-2 and especially with a concomitant elevated S-ALAT are highly likely to be viremic as demonstrated by PCR and to have chronic hepatitis.