ObjectiveTo detect the relationships between the genotype of hepatitis C virus(HCV) and severity of the disease, expression of immunocompetent cells in patients with chronic hepatitis C(CHC).

MethodsFrom June 2017 to July 2018, 169 Tibetan CHC patients were selected as the study objects(CHC group), and 170 Tibetan healthly examinees in Qinghai were selected as the control group.The levels of HCV-RNA in all cases were detected using PCR fluorescence probe, the PCR reverse hybridization was used to detect the HCV genotyping, and the levels of serum interferon-γ(INF-γ) and interleukin-4(IL-4) were measured by enzyme-linked immunosorbent assay(ELISA).The relationships between the genotype distribution, and disease severity, serum levels of INF-γ and IL-4;and between disease severity, and levels of INF-γ and IL-4 were analyzed.

ResultsCompared with the control group, the positive rate of HCV-RNA and serum level of IL-4 increased, and the serum level of INF-γ decreased in CHC group(P < 0.01).The positive rates of HCV-RNA in severe chronic hepatitis group and acute hepatitis group were higher than that in mild and moderate chronic hepatitis group(P<0.05).The differences of the positive rates of HCV-RNA among different genotypes and different severity of CHC were statistically significant(P < 0.01).Compared with the HCV genotype 1a, the serum levels of INF-γ in patients with genotype 2a and 3b increased(P < 0.01).Compared with the HCV genotype 1b, the serum level of INF-γ increased(P < 0.01), and the serum level of IL-4 level decreased in genotype 2a(P < 0.01).The serum level of INF-γ in genotype 3b decreased compared with the genotype 2a(P<0.05).The differences of the serum levels of INF-γ and IL-4 among different severity of CHC were statistically significant(P < 0.01).There was no statistical significance in the levels of INF-γ between mild and moderate group, and between moderate and severe group(P>0.05).The serum level of INF-γ in the mild group was higher than that in severe group, it decreased gradually in moderate group, severe group and acute group, and the differences of which were statistically significant(P < 0.01).The serum level of IL-4 increased gradually in the mild group, moderate group, severe group and acute group, and the differences of which were statistically significant(P < 0.01).

ConclusionsFour subtypes of HCV(1a, 1b, 2a and 3b) are detected in Tibetan patients with hepatitis C in Qinghai area, the proportions of 1b and 2a are high.The genotype 1b is closely related to the severity of the disease, the level of INF-γ decreases, and the level of IL-4 increases.