Concerns related to CCR5 gene delta 32 mutation role in hepatitis B virus infection

STUDY OBJECTIVE: A literature review to analyze potential evidence regarding the influence of Δ32 CCR5 gene mutation on resistance to/clinical recovery from HBV infection

METHODS: Literature search, covering the period 1996-2017, was performed using Medline. Comparative between-studies analysis was conducted with regard to reliability as well as statistical and clinical significance of results

RESULTS: Data on the influence of Δ32 CCR5 mutation on the course of HBV infection are sparse and results obtained in various scientific studies are not consistent. As the example, heterozygosity for CCR5/CCR5Δ32 in healthy Iranian blood donors was greater than in cases with chronic HBV infection; in the American study on Caucasian subjects who had been infected with HBV CCR5 Δ32 reduced the risk of developing a persistent HBV infection by nearly half. Conversely, the Indian study revealed that heterozygosity for CCR5/CCR5Δ32 was more often present in patients with chronic hepatitis B than in healthy controls. However, there were some methodological errors found in previously published studies such as limited sample size and/or incorrect selection of controls; this could influence the fact that results were not heterogeneous

CONCLUSIONS: The evidence for potential association of CCR5 gene Δ32 mutation on HBV infection in regard to the resistance to HBV infection or recovery from an HBV infection are insufficient. Previously conducted studies presented the lack of results’ consistency, possibly due to between-population differences in the context of genetic determinants, ethnic and geographical origin, as well as methodological errors. There is an urgent need to conduct further, methodologically correct studies on larger populations from different regions, including Polish subjects