Objective: To evaluate the HCV genotype distribution in subjects affected by cryoglobulinemia in order to verify its possible role in the pathogenesis of the disease and to provide the clinician with a useful datum for therapy.
Methods: Nested PCR with universal and type-specific primers was used for the genotyping.
Results: Genotype I (1a) was never present in cryoglobulinemia, while it was present in 7 (4.3%) patients with chronic hepatopathy and in 4 (10.8%) asymptomatic patients. Type II (1b) was present in 28 (58.3%) and in 8 (47.1%) cryoglobulinemic patients with and without hepatopathy, respectively, in 106 (64.6%) patients with chronic hepatitis; in one patient with acute hepatitis; and in 14 (37.9%) asymptomatic patients. Type III (2a) was present in 2 (4.2%) and 2 (11.8%) cryoglobulinemic patients with and without hepatopathy, respectively; in 1 (0.6%) patient with chronic hepatopathy; and in 2 (5.4%) asymptomatic subjects. Type IV (2b) was present in 1 (2.1%) and in 2 (11.8%) cryoglobulinemic patients with and without hepatopathy, respectively; in 5 (3%) patients with chronic hepatopathy; and in 1 (2.7%) asymptomatic subject. Coinfections were present in 42 cases: 6 (12.5%) cryoglobulinemia with hepatopathy, 4 (23.5%) cryoglobulinemia without hepatopathy, 25 (15.3%) chronic hepatopathy, and in 7 (18.9%) asymptomatic subjects. For 41 (15.4%) strains typing was not possible. Eight of the "untypable" strains and 3 strains from patients with coinfection proved to belong to a new genotype.
Conclusions: Genotype II (1b) was the most frequent in patients with and without cryoglobulinemia; genotype I (1a) was absent in all 65 patients with cryoglobulinemia, in whom, however, as in the subjects without cryoglobulinemia, all the other genotypes could be found. An interferon-resistant genotype characterized by an elevated homology with Simmonds' type 2c (rare genotype) was present.