Distribution of IL28B Genotypes in Iranian Patients with Chronic Hepatitis C and Healthy Individuals

Abstract

BackgroundIL28B polymorphism is recognized as one of the most prominent predictors of hepatitis C spontaneous and treatment-induced clearance. Interestingly, the favorable genotypes of IL28B are found to be more frequent in Asian ethnicity than Caucasian and African populations, respectively. A few studies reported that there is a mysterious association between the IL28B polymorphism and the hepatitis C virus (HCV) genotype in patients with chronic hepatitis C but they did not give any reason for this phenomenon.ObjectivesThe foremost purpose of this study was to compare the distribution of IL28B genotypes between Iranian healthy individuals and patients with chronic hepatitis C.Patients and MethodsIn this study, 921 patients with chronic hepatitis C and 142 healthy individuals were included. The IL28B rs12979860 and rs8099917 polymorphisms were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.ResultsThe frequency of IL28B rs12979860 CC, CT, and TT genotypes in chronic hepatitis C patients was 38%, 48.8%, and 13.2% and in healthy individuals was 43.7%, 48.6%, and 7.7%. Also, the frequency of IL28B rs8099917 TT, GT, and GG genotypes in chronic hepatitis C patients was 58.3%, 37.1%, and 4.6% and in healthy individuals was 64.1%, 32.4% and 3.5%. The differences in the distribution of IL28B rs12979860 and rs8099917 genotypes between patients with chronic hepatitis C and healthy individuals were not statistically significant. When we compared the distribution of IL28B genotypes between the healthy group and the HCV infected patients by HCV genotype, we found 9.8% higher frequency of rs12979860 CC genotype in the healthy individuals than HCV genotype 1 infected patients (P = 0.03) however there was no significant difference in the distribution of rs12979860 genotypes between the healthy and HCV genotype 3 infected groups (P = 0.46).ConclusionsIt seems that the impact of IL28B polymorphism on the spontaneous clearance of HCV genotype 1 is more prominent than HCV genotype 3 which results in the observation of higher rs12979860 C allele frequency in chronic hepatitis C patients with HCV genotype 3 than HCV genotype 1.

The Role of Polymorphisms Near IFNL3 Gene as Predictors of Residual HCV RNA in Buffy Coat after Successful Antiviral Therapy

“…The distribution of polymorphisms near IFNL3 in the current study was the same as the previous studies (28,29) in Iranian patients with HCV infection. Based on our observations, polymorphisms near IFNL3 were associated with persistence of HCV RNA in BC samples of patients with SVR.…”

Genetic Variation in Interleukin-28B and Response to Peg-IFNα-2a/RBV Combination Therapy in Patients with Hepatitis C Virus Infection

“…On the other hand, because the most studied patients were infected with HCV genotype 1b, this polymorphism was analyzed separately in these participants. The genotype frequencies of rs12979860 polymorphisms in these patients with CC, CT, and TT genotypes were 33.3%, 58.3%, and 8.3%, respectively, which are close to the corresponding frequencies in Iranian and Turkish patients (26)(27)(28).…”

Interleukin 28B Genetic Polymorphism and Spontaneous Recovery from Hepatitis B Virus Infection in an Iranian Azeri Population

“…On the other hand, rs12979860CT is the most common genotype reported by studies from Turkey (24,25), similar to the current results from Iranian Azeri-Turk population. However, this similarity is not restricted to inhabitants of Azerbaijan province yet are reported from other parts of Iran as well (19,26). Fewer data are available about polymorphism in rs8099917, and comparable to the current results; rs8099917TT is the most common (13,14,20).…”

“…For rs12979860, the primer sequences were 5'-GCG GAA GGA GCA GTT GCG CT -3' (Rs12-F) and 5'-GGG GCT TTG CTG GGG GAG TG -3' (Rs-12-R). For rs8099917, the oligonucleotide primers were 5'-CCC ACT TCT GGA ACA AAT CGT CCC -3' (Rs80-F) and 5'-TCT CCT CCC CAA GTC AGG CAA CC -3' (Rs80-F) (19).…”