The RIBA-HCV second-generation assay is geared to detect antibodies reactive with a series of recombinant HCV antigens in a slot blot format. Test results are interpreted on the basis 1+ band intensity. A band with visibly lower response than Control Level l is considered negative; an intensity scale of 0 to 4+ is applied (see TABLE A-6). Valid test results for HCV-RIBA are:

POSITIVE - Strongly suggests that the EIA screening result was specific. Physician follow-up of living donors, including monitoring of ALT activity, is recommended.

INDETERMINATE - At the present time, indeterminate RIBA results should be interpreted as positive.

NEGATIVE - This result in a donor with normal ALT activity is indicative of a false positive screening test result for antibodies to HCV. Further follow up is not recommended.