Correlation between genetic variations and serum level of interleukin 28B with virus genotypes and disease progression in chronic hepatitis C virus infection

Recent studies have demonstrated that polymorphisms near the interleukin-28B (IL-28B) gene could predict the response to Peg-IFN-a/RBV combination therapy in HCV-infected patients. The aim of the study was to correlate the serum level of IL28B in HCV-infected patients with virus genotype/subgenotype and disease progression. IL28B serum level was detected and variations at five single nucleotide polymorphisms (SNPs) in IL28B gene region were genotyped and analyzed. The variation of IL28B genetic polymorphisms was found to be strongly associated with HCV infection when healthy control group was compared to HCV-infected patients with all P values <0.0001. Functional analysis revealed that subjects carrying rs8099917-GG genotype had higher serum level of IL28B than those with GT or TT genotypes (P = 0.04). Also, patients who were presented with cirrhosis (Cirr) only or with cirrhosis plus hepatocellular carcinoma (Cirr+HCC) had higher levels of serum IL28B when compared to chronic HCV-infected patients (P = 0.005 and 0.003, resp.). No significant association was found when serum levels of IL28B were compared to virus genotypes/subgenotypes. This study indicates that variation at SNP rs8099917 could predict the serum levels of IL28B in HCV-infected patients. Furthermore, IL28B serum level may serve as a useful marker for the development of HCV-associated sequelae.

Genetic variation at -1878 (rs2596542) in MICA gene region is associated with chronic hepatitis B virus infection in Saudi Arabian patients

MHC class I polypeptide-related chain A (MICA), mapping to 6p21.33, belongs to the non-classical class I family and its expression is induced by several stress factors including viral infection. A recent genome-wide association study has identified a single nucleotide polymorphism (SNP) of MICA, rs2596542 to be significantly associated with hepatitis C-induced hepatocellular carcinoma (HCC) in a Japanese population. Therefore, this study aims to investigate whether the SNP rs2596542 plays any role in hepatitis B virus (HBV) sero-clearance or in the development of complications associated with chronic HBV such as cirrhosis and/or HCC. TaqMan genotyping assay was used to identify the association of the SNP among 584 normal healthy controls and 777 HBV-infected patients. The patient group was further categorized into inactive carriers (Group I), active carriers (Group II), cirrhosis (Group III) and cirrhosis-HCC (Group IV). Variation at this SNP was found to be significantly more frequent in control subjects than in patients (OR = 0.852; 95% C.I. = 0.730-0.994; p = 0.0415). Also, the SNP was found to have a highly significant association when the inactive carriers were compared to the rest of the patients (OR = 1.308; 95% C.I. = 1.058-1.617; p = 0.0130). The TT genotype was found to occur more frequently among active HBV carriers (groups II, III and IV) when compared to inactive HBV carriers, thus suggesting that the rs2596542-T may be recessively associated with an active HBV infection. However, no significant association was observed in the case of HBV-related cirrhosis or HCC. These findings indicate that the MICA rs2596542 has a significant role in HBV infection.

IL28B polymorphisms predict the virological response to standard therapy in patients with chronic hepatitis C virus genotype 4 infection

Background

Genome-wide association studies have recently revealed that several single-nucleotide polymorphisms (SNPs) in the interleukin (IL) 28B genes can predict the sustained virological response (SVR) to pegylated interferon-α2a/b plus ribavirin in hepatitis C virus (HCV)-genotype 1 patients. However, data for patients infected with HCV genotype 4 (HCV-G4) are limited.

Aim

We analyzed the association of IL28B SNPs (hematological, biochemical, virological, and pathological factors) with SVR in the HCV-G4 monoinfected cohort of patients.

Patients and methods

One hundred twenty-nine treatment-naïve HCV-G4 patients undergoing treatment were recruited from three tertiary care centers in Saudi Arabia. Five IL28B SNPs (rs12979860, rs12980275, rs8105790, rs8099917, and rs72486680) were identified by polymerase chain reaction and DNA sequencing. SVR was statistically correlated with various clinical, histopathological, virological, and genetic parameters.

Results

SVR was significantly associated with the CC and AA alleles of rs12979860 (p = 0.008) and rs12980275 (p = 0.004), respectively. Moreover, albumin levels (p = 0.002) and platelet count (p = 0.039) showed significant differences in the SVR and No SVR groups. On multivariate analysis, the CC allele of rs12979860 (OR, 2.89; 95 % CI 1.6–6.2, p = 0.006) and albumin levels (OR, 1.2; 95 % CI 1.1–1.4, p = 0.001) independently predicted SVR.

Conclusions

IL28B polymorphism (CC allele of rs12979860) predicts the sustained response to antiviral therapy in HCV-G4.

Electronic supplementary material

The online version of this article (doi:10.1007/s12072-013-9421-8) contains supplementary material, which is available to authorized users.

Toll-like receptor 3 polymorphism and its association with hepatitis B virus infection in Saudi Arabian patients

Hepatitis B virus (HBV) is the major causative agent of chronic liver complications including cirrhosis and hepatocellular carcinoma (HCC). Individuals infected with HBV show a wide spectrum of disease manifestations ranging from asymptomatic carriers to HCC. TLR3 is part of the innate immune system that recognizes double-stranded RNA (dsRNA) and provides early immune response to exogenous antigens. The genetic polymorphisms such as single nucleotide polymorphisms (SNPs) in the TLR3 could be considered as factors for the susceptibility to viral pathogens including HBV. Due to lack of knowledge on the role of TLR3 polymorphisms in HBV infection, this study investigated the distribution of nine SNPs in the TLR3 gene and its association with Saudi Arabian patients infected with HBV. A total of 707 patients and 600 uninfected controls were examined for different parameters including the nine SNPs (rs5743311, rs5743312, rs1879026, rs5743313, rs5743314, rs5743315, rs111611328, rs78726532 and a newly identified SNP located at position 184322913 of chr4). The association analysis confirmed that only one SNP, rs1879026 (G/T), showed a significant difference (P = 0.0480; OR = 0.809, 95% CI = 0.655-0.999) in the distribution between HBV carriers and uninfected controls. While, the rest of the SNPs showed no significant association with regards to HBV infection or in the progression to cirrhosis of the liver and HCC. Furthermore, haplotype analysis revealed that one haplotype GCGA (rs1879026, rs5743313, rs5743314, and rs5743315, respectively), was associated significantly with HBV infection in this population. These findings indicate that genetic variations in the TLR3 gene could affect the outcome of HBV infection among Saudis.

Role of single nucleotide polymorphisms of KIF1B gene in HBV-associated viral hepatitis

BACKGROUND/AIM

Kinesin family member 1B (KIF1B) gene resides in the chromosomal region 1p36.22 and has been reported to have frequent deletions in a variety of human cancers. A recent genome wide association study (GWAS) study conducted on a Chinese population has reported the involvement of a KIF1B genetic variant in Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). This study aims to investigate the significance of KIF1B genetic variations in HBV-associated hepatitis in patients of Saudi Arabian ethnicity.

METHODS

TaqMan genotyping assay was used to investigate the association of three SNPs (rs17401966, rs12734551, and rs3748578) in 584 normal healthy controls and 660 HBV-infected patients. The patients were categorized into inactive carriers (Case I), active carriers (Case II), Cirrhosis (Case III) and Cirrhosis-HCC (Case IV) sub-groups.

RESULTS

Since SNPs rs12734551 and rs3748578 are in strong linkage disequilibrium (LD) with rs17401966, only results for the latter SNP are reported. Therefore, the allele frequency of rs17401966 among HBV-infected patients and healthy controls were comparable and therefore, no significant association was observed (P=0.2811, Odds Ratio (OR) 0.897). A similar analysis was performed among the different sub-groups in order to determine whether KIF1B SNPs were associated with the advancement of the disease. No significant differences were observed in any of the comparisons performed.

CONCLUSION

Polymorphisms at KIF1B gene locus investigated in this study showed no significant association with HBV infection or with HBV-associated diseases such as liver cirrhosis or HCC.

RANTES gene polymorphisms (-403G>A and -28C>G) associated with hepatitis B virus infection in a Saudi population

Besides the host immune response, genetic and environmental factors play crucial roles in the manifestation of hepatitis B virus (HBV) infection. "Regulated on activation normal T-cell expressed and secreted" factor (RANTES) plays a vital role in CD4(+), CD8(+) T-lymphocyte and dendritic cell activation and proliferation in inflammation. Single nucleotide polymorphisms (SNPs) in the RANTES gene are associated with several viral and non-viral diseases. Association studies have invariably indicated a lack of association between RANTES gene SNPs and HBV infection in ethnic populations, even though RANTES gene SNPs exhibit distinct ethnic distributions. Despite the high prevalence of HBV infections in Saudi Arabia, no studies have been made concerning a possible relationship between RANTES gene polymorphisms and susceptibility to and progression of HBV infection. We examined -403G>A and -28C>G RANTES gene variants in 473 healthy controls and 484 HBV patients in ethnic Saudi populations. Significant differences were found in the genotype and allele distributions of the SNPs between the controls and the HBV patients. Both SNPs were significantly linked to viral clearance in these subjects. Our data demonstrate for the first time in a Saudi population, a relationship between the RANTES gene polymorphisms and the clinical course of HBV infection and underscore the importance of evaluating the genetic background of the affected individual to determine how it may affect disease progression.

Pan-valvular annular calcification in Takayasu's arteritis: report of 3 cases

Takayasu's arteritis is a chronic inflammatory arteriopathy. It mainly affects the aortic arch and its main branches. The aortic valve annulus and coronary and pulmonary arteries are rarely affected. Mitral and tricuspid annular calcification were not reported previously. We identified mitral annular calcification by using transthoracic echocardiography in 3 patients with Takayasu's arteritis, in whom none had any of the reported causes of mitral annular calcification. Two of them had concomitant tricuspid and aortic annular calcification.