Ahmed A. Al-Qahtani

Enteric viruses in pediatric diarrhea in Saudi Arabia

Between September 1st, 2002 and August 31st, 2003, a panel of 1,000 stool samples was collected from patients presenting with diarrhea in the three major urban centers of Saudi Arabia; Riyadh, Mecca, and Jeddah. Each sample was tested for rotavirus, and astrovirus by ELISA, G and P type was determined for all rotaviruses. Adenoviruses were sought by hexon‐specific PCR and identified by RFLP. A subset of 253 samples was also tested for norovirus by ELISA. Data were analyzed for seasonality of infection, patient nationality and likelihood of hospitalization. Although the overall incidence of rotavirus identification in acute diarrheal stool continued to decline, this was still the virus identified most commonly (6%). Norovirus accounted for 3.5%, astrovirus, 1.9% and adenovirus, 1.4%. Type G9 rotavirus was found to be present (and already common) in 2003, predating its first reported identification in the country in 2004. Most of the virus infections (and most of the G9 detections) occurred in April, the month following the occurrence of the Hajj in the study year. Although most viruses were spread equally in the population, rotaviruses were significantly more common in non‐Saudis than in Saudi citizens. Overall the data are consistent with an increase in all virus infections following al Hajj and the potential introduction of novel strains (such as the G9 rotaviruses) by pilgrims. Hospitalization was significantly associated only with norovirus infections. J. Med. Virol. 80:1919–1929, 2008.

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.

Reactive oxygen species-mediated DNA damage and apoptosis in human skin epidermal cells after exposure to nickel nanoparticles.

Nickel nanoparticles (NiNPs) are increasingly used in various applications due to their unique properties. However, there is little information concerning the toxicity of NiNPs in the human skin cell (A431). The present study was designed to investigate the cytotoxicity, apoptosis, and DNA damage due to NiNPs in A431 cells. A cellular proliferative capacity test showed that NiNPs induce significant cytotoxicity in a dose- and time-dependent manner. NiNPs were also found to induce oxidative stress evidenced by the generation of reactive oxygen species (ROS) and depletion of glutathione (GSH). Further, co-treatment with the antioxidant N-acetylcysteine (NAC) mitigated the ROS generation due to NiNPs, suggesting the potential mechanism of oxidative stress. NiNPs also induced significant elevation of lipid peroxidation, catalase, and superoxide dismutase and caspase-3 activity in A431 cells. In addition, NAC suppressed NiNP-induced caspase-3 activity. DNA fragmentation analysis using the comet assay showed that the NiNPs cause genotoxicity in a dose- and time-dependent manner. Therefore, the study points out the capability of the NiNPs to induce oxidative stress resulting in apoptosis and genotoxicity. This study warrants more careful assessment of NiNPs before their industrial applications.

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.

Molecular detection of hepatitis B, hepatitis C, and torque teno viruses in drug users in Saudi Arabia.

Injecting drug users are at increased risk of infection with hepatitis viruses and blood‐borne pathogens. The aim of this study was to examine HBV, HCV, HDV, and TTV infections in Saudi drug users (N = 344). Extraction of nucleic acid from serum, reverse‐transcription, amplification of viral nucleic acids, and HBV and HCV genotyping were done using established techniques. Of the analyzed samples, 41 (12%) contained detectable HBV DNA, 131 (38%) contained detectable HCV RNA, and 174 (51%) had detectable TTV DNA. The predominant HBV genotype was found to be genotype D and the predominant HCV genotype was found to be genotype 1b. All the samples were negative for HDV. Twelve samples (3.5%) were found to contain mixed HBV and HCV genomes, 24 samples (7%) were found to contain mixed HBV and TTV genomes, 82 samples (24%) were found to contain mixed HCV and TTV genomes, and 9 samples (2.6%) were found to contain mixed HBV, HCV, and TTV genomes. Identification of various infections in drug users will help the control of these infections in this group as well as in the community. J. Med. Virol. 81:1343–1347, 2009.

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.

Integrative and comparative genomics analysis of early hepatocellular carcinoma differentiated from liver regeneration in young and old

BackgroundHepatocellular carcinoma (HCC) is the third-leading cause of cancer-related deaths worldwide. It is often diagnosed at an advanced stage, and hence typically has a poor prognosis. To identify distinct molecular mechanisms for early HCC we developed a rat model of liver regeneration post-hepatectomy, as well as liver cells undergoing malignant transformation and compared them to normal liver using a microarray approach. Subsequently, we performed cross-species comparative analysis coupled with copy number alterations (CNA) of independent early human HCC microarray studies to facilitate the identification of critical regulatory modules conserved across species.ResultsWe identified 35 signature genes conserved across species, and shared among different types of early human HCCs. Over 70% of signature genes were cancer-related, and more than 50% of the conserved genes were mapped to human genomic CNA regions. Functional annotation revealed genes already implicated in HCC, as well as novel genes which were not previously reported in liver tumors. A subset of differentially expressed genes was validated using quantitative RT-PCR. Concordance was also confirmed for a significant number of genes and pathways in five independent validation microarray datasets. Our results indicated alterations in a number of cancer related pathways, including p53, p38 MAPK, ERK/MAPK, PI3K/AKT, and TGF-β signaling pathways, and potential critical regulatory role of MYC, ERBB2, HNF4A, and SMAD3 for early HCC transformation.ConclusionsThe integrative analysis of transcriptional deregulation, genomic CNA and comparative cross species analysis brings new insights into the molecular profile of early hepatoma formation. This approach may lead to robust biomarkers for the detection of early human HCC.

Zika virus: a new pandemic threat

Zika virus (ZIKV) is an emerging arbovirus of the Flaviviridae family and is related to dengue, Chikungunya, West Nile, yellow fever, and Japanese encephalitis viruses. ZIKV was first discovered in Uganda in 1947. Different species of mosquito from the Aedes genus, mainly A. aegypti and A. albopictus are the vectors responsible for ZIKV infection in humans. It is also reported that ZIKV is transmitted congenitally, sexually, and through blood donation. Until recently, ZIKV outbreaks were sporadic and self-limiting. The first large epidemic was reported from Yap Island in 2007 followed by an outbreak of Zika fever in French Polynesia in 2013. Brazil is the epicenter of the current ZIKV epidemic which is rapidly spreading across the Americas. ZIKV infection remained relatively less studied in view of its low case numbers, and low clinical impact relative to other arboviruses. However, all this is set to change with its rapid spread in the Western hemisphere and suspected complications particularly microcephaly in newborn babies with ZIKV infected mothers. ZIKV is expected to substantially add to both short-term and long-term economic burden of the effected countries. Due to the large number of people travelling across the borders and some reported cases of transmission of ZIKV via contaminated blood, screening and identification of asymptomatic infected individuals are important.

Discriminant value of serum HBV DNA levels as predictors of liver fibrosis in chronic hepatitis B

Summary.  Current guidelines recommend antiviral therapy in chronic hepatitis B (HBV) patients with significant histological disease. We aimed to compare histological fibrosis (METAVIR, ≥F2) in patients with HBV DNA ≥20 000 IU/mL vs≥2000 IU/mL and identify predictors of fibrosis. We performed prospective liver biopsies on 203 HBeAg‐negative patients in four groups: Group I (n = 55): HBV DNA ≥20 000 IU/mL and persistently elevated alanine aminotransferase (ALT) levels (PEALT; >40 U/L); Group II (n = 34): HBV DNA ≥20 000 IU/mL and persistently normal ALT (PNALT); Group III (n = 40): HBV DNA <20 000 IU/mL and PEALT; and Group IV (n = 74): HBV DNA <20 000 IU/mL, and PNALT. We reanalysed all groups in relation to updated cut‐off for treatable viremia (2000 IU/mL). Genotype D was detected in 86% of patients. Hepatic fibrosis ≥F2 was detected in 72.7%, 52.9%, 57.5% and 18.9% in Groups I–IV, respectively (P < 0.0001). Except in Group II with a trend for lower ≥F2 fibrosis (P = 0.067), there was no significant difference by using HBV DNA cut‐off 20 000 vs 2000 IU/mL. Multivariate logistic regression analysis identified study Group IV (OR, 0.0276; CI: 0.088–0.868; P = 0.0276) and milder (A0–1) necroinflammatory grade (OR, 0.135; CI: 0.063–0.287; P < 0.0001) as independent predictors of ≥F2 fibrosis. The specificity, positive and negative predictive values for PEALT in detection of ≥F2 fibrosis for viremia ≥2000 IU/mL (80%, 69% and 65%, respectively) or ≥20 000 IU/mL (86%, 73% and 63%, respectively) were similar, with a marginal gain in sensitivity (51%vs 42%, respectively). Significant fibrosis is prevalent in a large proportion of HBeAg‐negative patients with high viremia and persistently normal ALT. Lower HBV DNA cut‐offs could be adopted with marginal gains in fibrosis detection and without loss of diagnostic accuracy.