Hepatitis C Viral RNA, Genotype, LiPA

The HCV LiPA genotype assay can detect all 6 major HCV genotypes (1–6) and HCV subtypes 1a and 1b. If the banding pattern does not sufficiently differentiate between subtypes within genotype 1, only the genotype may be reported (for example "genotype 1").

The HCV LiPA genotype assay usually requires a minimum viral load of 300 IU/mL to obtain a genotype. Since many of our viral load assays have a much lower limit of quantitation, it is possible for the patient to have a detectable viral load (below 300 IU/mL) and no genotype result.

Not necessarily. The HCV LiPA genotype assay is performed by analyzing banding patterns that are indicative of the genotype. Two regions of the genome are assessed: the 5¢untranslated region (UTR). Some genotype 6 subtypes have the same banding pattern as genotype 1. Therefore, the core region is used to differentiate type 1 from type 6. If the core region banding pattern is not conclusive, we report a type 1 but cannot rule out genotype 6.

This indicates that banding patterns indicative of both HCV subtype 1a and genotype 2 were present. This test result is consistent with HCV coinfection.

The LiPA genotype test is designed to detect all 6 major HCV genotypes. The NS3a, NS5a, and NS5b genotype tests, on the other hand, detect mutations associated with drug resistance; they are limited to individuals infected with HCV genotype 1 or genotypes 1 and 3 in the case of NS5a and are not intended for determining HCV subtype. The Hepatitis C Viral RNA, Genotype, LiPA should be performed before ordering a drug resistance test.

The AASLD and IDSA recommendations for testing, managing, and treating HCV may be found at https://www.hcvguidelines.org/.