Distribution of hepatitis C virus genotypes among hemodialysis patients in Tehran--a multicenter study.

Hepatitis C virus has substantial heterogeneity of genotypes throughout the world. The aim of this study was to determine the frequency of HCV genotypes, risk factors and clinical implications in cases of hemodialysis living in Tehran. A total of 155 patients treated by hemodialysis, who had been identified to be anti-HCV positive at 45 medical centers in Tehran, were enrolled. Genotyping was using restriction fragment length polymorphism (RFLP) on HCV-RNA positive samples. HCV-RNA was detected in 66 (42.6%) patients. Genotyping of HCV-RNA positive serum samples demonstrated that subtypes 3a and 1a were predominant accounting for 30.3 and 28.8%, respectively. The distribution of other HCV genotypes showed genotype 1b, 18.2%; genotype 4, 16.7%; mixed genotypes 1a and 1b, 3%; and genotype 3b, 3%. Genotype 2 was not detected in this study. Statistically significant differences were identified between HCV infected and non-HCV infected patients regarding history of hemodialysis unit changes more than two times (P = 0.01), and history of hemodialysis for more than 20 years (P = 0.02). However, blood transfusion, mean duration of hemodialysis therapy and the history of solid organ transplantation did not differ between these two groups. This study indicates that the dominant HCV genotypes among patients treated by hemodialysis living in Tehran were 3a and 1a, and considering previous reports from the general population, genotype 4 was strongly associated with hemodialysis. The duration of treatment by hemodialysis and, in turn, more hemodialysis unit changes will lead to more frequent HCV infections.