Hamad I. Al-Ashgar

Association between HLA Variations and Chronic Hepatitis B Virus Infection in Saudi Arabian Patients

Hepatitis B virus (HBV) infection is a leading cause of liver diseases including cirrhosis and hepatocellular carcinoma. Human leukocyte antigens (HLAs) play an important role in the regulation of immune response against infectious organisms, including HBV. Recently, several genome-wide association (GWAS) studies have shown that genetic variations in HLA genes influence disease progression in HBV infection. The aim of this study was to investigate the role of HLA genetic polymorphisms and their possible role in HBV infection in Saudi Arabian patients. Variations in HLA genes were screened in 1672 subjects who were divided according to their clinical status into six categories as follows; clearance group, inactive carriers, active carriers, cirrhosis, hepatocellular carcinoma (HCC) patients and uninfected healthy controls. Three single nucleotide polymorphisms (SNPs) belonged to HLA-DQ region (rs2856718, rs7453920 and rs9275572) and two SNPs belonged to HLA-DP (rs3077 and rs9277535) were studied. The SNPs were genotyped by PCR-based DNA sequencing (rs2856718) and allele specific TaqMan genotyping assays (rs3077, rs7453920, rs9277535 and rs9275572). The results showed that rs2856718, rs3077, rs9277535 and rs9275572 were associated with HBV infection (p = 0.0003, OR = 1.351, CI = 1.147–1.591; p = 0.041, OR = 1.20, CI = 1.007–1.43; p = 0.045, OR = 1.198, CI = 1.004–1.43 and p = 0.0018, OR = 0.776, CI = 0.662–0.910, respectively). However, allele frequency of rs2856718, rs7453920 and rs9275572 were found more in chronically infected patients when compared to clearance group infection (p = 0.0001, OR = 1.462, CI = 1.204–1.776; p = 0.0178, OR = 1.267, CI = 1.042–1.540 and p = 0.010, OR = 0.776, CI = 0.639–0.942, respectively). No association was found when polymorphisms in HLA genes were compared in active carriers versus cirrhosis/HCC patients. In conclusion, these results suggest that variations in HLA genes could affect susceptibility to and clearance of HBV infection in Saudi Arabian patients.

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. J. Med. Virol. 84:1353–1359, 2012.

Safety and efficacy of peginterferon-α2a plus ribavirin treatment in renal transplant recipients with chronic hepatitis C.

BACKGROUND & AIMS Interferon (IFN)-based therapy in chronic hepatitis C virus (HCV)-infected renal transplant (RT) recipients has been associated with a high risk of acute allograft rejection (AAR) and poor efficacy. We assessed the safety and efficacy of PegIFNα-2a and ribavirin (RBV) combination therapy in HCV-infected RT recipients. METHODS Thirty-two adult RT recipients of >12-month duration, infected with HCV genotypes 1 (62.5%) and 4 (37.5%), and significant fibrosis (Metavir ≥ F2) were recruited in an open-label trial with PegIFNα-2a 135-180 μg/week, plus RBV 200-1200 mg/day for 48 weeks, based on the estimated glomerular filtration rate. Safety assessments were performed weekly for 4 weeks, 2-weekly for 8 weeks, and 6-weekly for 36 weeks. Study end points were sustained virologic response (SVR) or development of AAR. Allograft biopsies were performed for 20% increase in creatinine from pretreatment levels, or optionally at week 12 on surveillance protocol. Renal safety was compared with matched untreated historical controls (n=31). RESULTS None of the treated patients showed AAR when biopsied for raised creatinine (12.5%) or during surveillance (37.5%), with incremental and sustained creatinine increases occurring in 6.3% of treated patients and 16.1% of untreated controls (p=0.148), by week 72 assessment. Mean pretreatment and end-of-assessment creatinine in treated patients remained similar (106.8 ± 32.0 vs. 113.4 ± 62.8, respectively; p=0.140), while levels increased significantly in the controls (106.6 ± 35.6 vs. 142.5 ± 93.0, respectively; p=0.013). Rapid, early virologic response (EVR) and SVR occurred in 12.5%, 56.3%, and 37.5% of cases, respectively. SVR was similar in both genotypes (p=1.000). PegIFN and RBV dose reductions were required in 34.4% and 78.1%, respectively; discontinuation was required in 12.5%. Binary logistic regression identified only EVR (OR, 20.4; 95% CI: 2.2-192.6; p=0.008) as an independent predictor of SVR. CONCLUSIONS PegIFN/RBV therapy is not associated with AAR in RT recipients at low risk for rejection but has modest efficacy in the treatment of HCV.

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.

Diagnostic Utility of Impedance-pH Monitoring in Refractory Non-erosive Reflux Disease

Background/Aims Approximately one-third of non-erosive reflux disease (NERD) patients are refractory to proton pump inhibitors (PPI) and face a therapeutic challenge. Therefore, it is important to differentiate between pathological and non-pathological reflux utilizing multichannel intraluminal impedance-pH (MII-pH) to analyze symptom-reflux association and diagnose true NERD versus hyper-sensitive esophagus (HE) and functional heartburn (FH). Herein, we evaluated the diagnostic yield of MII-pH in refractory NERD and sub-classified it based on quantity and quality of acid/non-acid reflux and reflux-symptom association. Methods Sixty symptomatic NERD patients on twice daily PPI for > 2 months were prospectively evaluated by MII-pH. Distal and proximal refluxes, bolus exposure time (BET), esophageal acid exposure time, symptom index (SI) and symptom association probability (SAP) were measured. Results Thirty-two (53%) patients had BET > 1.4% (MII-pH positive-true NERD), while 28 (47%) had BET < 1.4% (MII-pH negative NERD) where SI and SAP were negative in 15/60 (25%; categorized as FH) and SI or SAP were positive in 13/60 (22%; identified as HE). Thirty-eight (63%) patients reported significant SI or SAP parameters where > 80% of symptoms were associated with non-acid reflux. The number of distal refluxes in true NERD versus FH or HE were significantly different, but not between FH and HE. Conclusions Approximately 60% of refractory PPI NERD patients had positive reflux-symptom association, primarily due to non-acid reflux. Nearly half of NERD patients on PPI had normal MII-pH monitoring, sub-divided further into FH and HE equally.

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.

Relationship of interferon-γ-inducible protein-10 kDa with viral response in patients with various heterogeneities of hepatitis C virus genotype-4

Introduction The role of serum interferon-&ggr;-inducible protein-10 kDa (IP-10) level in the treatment of chronic hepatitis C genotype-4 (HCV-4) and its various subtypes remains unknown. We aimed to study the impact of pretreatment IP-10 levels on the sustained viral response (SVR) in HCV-4 patients (n=64) undergoing peginterferon &agr;-2a/ribavirin therapy. Patients and methods Pretreatment IP-10 levels and HCV-4 subtypes (4a=48.4%, 4d=39%, others=12.5%) were measured and correlated with treatment responses. Variables significantly associated with SVR on univariate analysis were included in a multivariate logistic regression model. Results Patients with SVR had lower pretreatment IP-10 levels (462.4±282.7 vs. 840.1±490.6 pg/ml; P=0.002), but the levels were not significantly different in those with a rapid (P=0.245) or an early viral response (P=0.221). IP-10 levels were similar across all subtypes. The pretreatment level was significantly lower in subtype 4d patients with SVR (465.9±349.1) compared with non-SVR patients (904.9±532.1; P<0.001), but not when compared with genotype 4a patients (564.7±288.9 vs. 658.6±374.9, respectively; P=0.330). IP-10 levels [odds ratio (OR), 0.998; 95% confidence interval (CI): 0.996–0.999; P=0.006], low viremia (OR, 8.852; 95% CI: 1.244–63.03; P=0.029), and early viral response (OR, 4.162; 95% CI: 1.023–16.94; P=0.046) were independent predictors of SVR. Receiver operating characteristic curve analysis identified a threshold IP-10 level of 359 pg/ml (area under receiver operating characteristic curve, 0.737; sensitivity, 81.8%; specificity, 45.2; positive predictive value, 43.9%; negative predictive value, 82.6%) for SVR. Conclusion Pretreatment serum IP-10 level is a predictor for SVR in HCV-4-infected patients. The baseline IP-10 level is significantly lower in responders among HCV genotype-4d patients as compared with 4a patients.

The epidemic dynamics of hepatitis C virus subtypes 4a and 4d in Saudi Arabia

The relatedness between viral variants sampled at different locations through time can provide information pertinent to public health that cannot readily be obtained through standard surveillance methods. Here, we use virus genetic data to identify the transmission dynamics that drive the hepatitis C virus subtypes 4a (HCV4a) and 4d (HCV4d) epidemics in Saudi Arabia. We use a comprehensive dataset of newly generated and publicly available sequence data to infer the HCV4a and HCV4d evolutionary histories in a Bayesian statistical framework. We also introduce a novel analytical method for an objective assessment of the migration intensity between locations. We find that international host mobility patterns dominate over within country spread in shaping the Saudi Arabia HCV4a epidemic, while this may be different for the HCV4d epidemic. This indicates that the subtypes 4a and 4d burden can be most effectively reduced by combining the prioritized screening and treatment of Egyptian immigrants with domestic prevention campaigns. Our results highlight that the joint investigation of evolutionary and epidemiological processes can provide valuable public health information, even in the absence of extensive metadata information.

The association of toll-like receptor 4 polymorphism with hepatitis C virus infection in Saudi Arabian patients.

Hepatitis C virus (HCV) is a single stranded RNA virus. It affects millions of people worldwide and is considered as a leading cause of liver diseases including cirrhosis and hepatocellular carcinoma. A recent study reported that TLR4 gene polymorphisms are good prognostic predictors and are associated with protection from liver fibrosis among Caucasians. This study aims to investigate the implication of genetic polymorphisms of TLR4 gene on the HCV infection in Saudi Arabian patients. Two SNPs in the TLR4 gene, rs4986790 (A/G) and rs4986791 (C/T), were genotyped in 450 HCV patients and 600 uninfected controls. The association analysis confirmed that both SNPs showed a significant difference in their distribution between HCV-infected patients and uninfected control subjects (P < 0.0001; OR = 0.404, 95% CI = 0.281–0.581) and (P < 0.0001; OR = 0.298, 95% CI = 0.201–0.443), respectively. More importantly, haplotype analysis revealed that four haplotypes, AC, GT, GC, and AT (rs4986790, rs4986791), were significantly associated with HCV infection when compared with control subjects. One haplotype AC was more prominently found when chronic HCV-infected patients were compared with cirrhosis/HCC patients (frequency = 94.7% and P = 0.04). Both TLR4 SNPs under investigation were found to be significantly implicated with HCV-infection among Saudi Arabian population.

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.