HCV Ab RIBA: Sensitivity and Specificity

Introduction: None written. Excerpt from the entry in Hepatitis C:
RIBA (recombinant immunoblot assay), vs HCV PCR

RIBA is not intended to be used as a screening test but rather as a confirmatory test. In addition, note that there are 3 outcomes of RIBA: positive (>= 2 antigens reactivity), intermediate (1 antigen reactive), or negative. Intermediate RIBA does carry a higher PPV than negative but lower than a positive test.