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Introduction and Objectives: Two clusters of the subgenotype F1b (basal and cosmopolitan) have recently been described. The basal cluster has been associated with the early occurrence of hepatocellular carcinoma in chronically infected patients from Alaska and Peru. In Argentina, where the cosmopolitan cluster is the most prevalent, this relationship has not been observed. In the course of chronic hepatitis B infection, mutations occur in different regions. In particular, mutations in the basal core promoter (BCP) and the preC/C regions are associated with HBe-antigen (HBeAg) seroconversion, an event related to the severity of chronic HBV infection. This study aimed to determine the HBeAg status and to characterize the molecular mutation patterns associated with HBeAg seroconversion in both subgenotype F1b clusters. Materials and Methods: Serum samples from 68 patients with subgenotype F1b chronic hepatitis B infection were analyzed. The BCP and pC/C regions were amplified and sequenced. Results: Twenty-one samples belonged to the basal cluster and 47 to the cosmopolitan cluster. No differences in age or gender were observed between the cases of both clusters. The basal cluster samples showed a lower frequency of positivity for HBeAg (38.1 vs. 57.4 %). In HBeAg negative samples, the basal cluster showed significantly higher rates of A1762T/G1764A (92.3 vs. 50.0, p:0.013) and G1896A (92.3 vs. 20.0,

Background: The quantitative hepatitis B surface antigen (qHBsAg) threshold of 1,000 IU/ml has been proposed to distinguish HBeAg-negative chronic infections from HBeAg-negative chronic hepatitis, to assess risk of liver disease progression, and to predict HBsAg clearance. There is evidence that qHBsAg vary significantly among genotypes, however, there is scarce data on genotype F, the most prevalent in Latin America. Aims: To analyze the impact of HBV genotype F on qHBsAg inpatients with HBeAg-negative chronic infection and to describe clinical and virological outcomes. Methods: HBV-DNA and qHBsAg serum levels of 141 patients with HBeAg-negative chronic infection were correlated with HBV genotype, who were followed for 10.6±7.4 years. Results: The overall genotype distribution was as follows: F 46.8%, D 26.1%, A 25.2%, and B 0.7% and C 0.7%. While no impact of the HBV genotype on HBV DNA levels was observed, qHBsAg differed significantly among genotypes (p3.0 Log10IU/ml, no cases of advanced liver disease or hepatocellular carcinoma were observed at the end of follow-up. Conclusions: This study provides new insights into the impact of HBV genotypes on serum HBsAg levels, emphasizing the need to implement genotype-specific cut-off to achieve diagnostic certainty in the identification of HBeAg-negative chronic infection and the risk of liver disease progression, particularly on infections with genotypes A and F. Moreover, HBsAg serum levels can became a reliable biomarker to predict HBsAg clearance.

Background: Hepatitis B virus (HBV) has been classified into 10 genotypes (A-I) and numerous subgenotypes (SGTs). There is growing evidence that HBV genotypes (GTs) influence clinical outcomes, HBeAg seroconversion rates, severity of liver disease, and response to interferon therapy. However, there is a paucity of data regarding their distinctive biological characteristics, in particular for GTF, the most prevalent in Latin America. Aim: To investigate the impact of HBV genotypes on HBV-DNA levels and viral antigen expression. Materials and Methods: Full-length HBV genomes representing GTs A-D and SGTs F1b and F4 were transfected in Huh7 cell line. Secreted HBeAg and intra and extracellular HBsAg were quantified by EIA. HBV-DNA was analyzed by real-time PCR. Results: Marked differences were observed in HBV replicative capacity as well as HBeAg and HBsAg antigen expression across genotypes (Table 1). GTC secreted significantly higher levels of HBeAg in relation to the other GTs. GTD showed lower HBsAg extracellular levels than all other GTs, while GTA showed the highest HBsAg intracellular levels. Finally, SGTs F1b and F4 showed significantly lower HBV-DNA levels. Regarding the ratio of extra and intracellular HBsAg, GTs A and D showed the lower ratios compared to SGTs F1b and F4, while SGTs F1b and F4 showed the highest HBsAg/HBV-DNA ratio. Discussion: This study provides new insights into the impact of HBV genotypes on HBV antigen expression and HBV-DNA levels. The uneven expression of antigens, as well as their intracellular accumulation, could be associated with the role of genotypes in pathogenesis. Likewise, the extracellular levels of HBsAg and the replication rate might have implications in immunopathogenesis as well as in the exhaustion of the host's immune system. The virus-cell interaction in different genotypes deserves further study to understand its role in the pathogenesis of HBV infection.

HIV-1 is characterized by its ability to mutate and recombine even at polymerase (pol) gene. However, pol-gene diversity is limited due to functional constraints. The aim of this study was to characterize longitudinally, by next-generation sequencing (NGS), HIV-1 variants based on pol-gene sequences, at intra- and inter-host level, from acute/early to chronic stages of infection, in the absence of antiretroviral therapy. Ten men who have sex with men (MSM) were recruited during primary infection and yearly followed for five years. Even after a maximum of a five-year follow-up period, the phylogenetic analysis of HIV-1 pol-gene sequences showed a host-defined structured pattern, with a predominance of purifying selection forces during the follow-up. MSM had been acutely infected by different HIV-1 variants mainly ascribed to pure subtype B, or BF recombinant variants and showed different genetic mosaicism patterns that last until the chronic stage, representing a major challenge for prevention strategies.

Hydroxysteroid 17-#x03B2; dehydrogenase 13 (HSD17B13) is a lipid droplet-associated protein; its gene-encoding variants affect the chronic liver diseases, including nonalcoholic fatty liver disease (NAFLD). To estimate the effect of rs72613567, a splice variant with an adenine insertion (A-INS), on NAFLD susceptibility and severity, we performed a case-control study with 609 individuals. We investigated the effect of carrying the A-INS allele in 356 patients with biopsy-proven disease and explored the relationship between rs72613567 genotypes and the hepatic transcriptome. The A-INS allele protected against NAFLD [odds ratio (OR) per adenine allele = 0.667; 95#x0025; CI, 0.486−0.916; P = 0.012]; this effect was nonsignificant when logistic regression analysis included BMI. The A-INS allele protected against nonalcoholic steatohepatitis (NASH) (OR = 0.612; 95#x0025; CI, 0.388−0.964; P = 0.033), ballooning degeneration (OR = 0.474; 95#x0025; CI, 0.267−0.842; P = 0.01), lobular inflammation (OR = 0.475; 95#x0025; CI, 0.275−0.821; P = 0.007), and fibrosis (OR = 0.590; 95#x0025; CI, 0.361−0.965; P = 0.035). In patients carrying A-INS, HSD17B13 levels decreased proportionally to allele dosage. Whole-transcriptome genotype profiling showed overrepresented immune response-related pathways. Thus, the rs72613567 A-INS allele reduces the risk of NASH and progressive liver damage and may become a therapeutic target.

We report on the presence of a rare nonsense mutation (rs149847328, p.Arg227Ter) in the glucokinase regulator (GCKR) gene in an adult patient with nonalcoholic fatty liver disease (NAFLD), morbid obesity, and type 2 diabetes; this patient developed a progressive histological form of the disease. Analysis of paired (5 years apart) liver biopsies (at baseline and follow‐up) showed progression of simple steatosis to severe nonalcoholic steatohepatitis and cirrhosis. Study design involved an initial exploration that consisted of deep sequencing of 14 chromosomal regions in 96 individuals (64 of whom were patients with NAFLD who were diagnosed by liver biopsy that showed the full spectrum of histological severity). We further performed a replication study to explore the presence of rs149847328 that included a sample of 517 unrelated individuals in a case‐control study (n = 390), including patients who were morbidly obese (n = 127). Exploration of sequence variation by next‐generation sequencing of exons, exon–intron boundaries, and 5′ and 3′ untranslated regions of 14 genomic loci that encode metabolic enzymes of the tricarboxylic acid cycle revealed the presence of heterozygosity for the p.Arg227Ter mutation, the frequency of which is 0.0003963 (4:10,000; Exome Aggregation Consortium database). GCKR protein expression was markedly decreased in the liver of the affected patient compared with patients with NAFLD who carry the wild‐type allele. Sequencing of the same 14 genomic loci in 95 individuals failed to reveal the rare mutation. The rarity of p.Arg227Ter was confirmed in a more extensive screening. Conclusion: While rare variants/mutations are difficult to detect in even reasonably large samples (frequency of the mutant allele of p.Arg227Ter was ~1:1,000 in our data set), the presence of this mutation should be suspected as potentially associated with NAFLD, particularly in young adults at the extreme of histological phenotypes. Hepatology Communications 2018;2:1030‐1036)

This study aimed to assess the prevalence of natural resistance-associated substitutions (RASs) to NS3, NS5A and NS5B inhibitors in 86 genotype 1 Hepatitis C Virus (HCV)-infected patients from Buenos Aires, Argentina, and to determine their effect on therapy outcome. Additionally, virological, clinical and host genetic factors were explored as predictors of the presence of baseline RASs. NS3 RASs (39.2%) were more prevalent than NS5A RASs (25%) and NS5B RASs (8.9%). In the three regions, the frequencies of RASs were significantly higher in HCV-1b than in HCV-1a. The prevalence of Y93H, L159F and Q80K were 1.3%, 6.3% and 2.5%, respectively. IFNL3 CC genotype was identified as an independent predictor of the presence of baseline RASs in NS5A and NS3 genes (p = 0.0005 and p = 0.01, respectively). Sustained virologic response was achieved by 93.3% of the patients after receiving direct-acting antivirals (DAAs), although 48.7% of them showed baseline RASs related to the DAA-regimen. Notably, the prevalence of clinically relevant RASs in the three genes was lower than that observed around the world. The baseline presence of RASs in both subtypes did not appear to affect therapy outcome. These results support the need to evaluate resistance patterns in each particular country since RASs´ prevalence significantly vary worldwide.

Aim: To evaluate the effects of ribavirin on cytokine production of recall antigen and PHA-stimulated PBMC obtained from healthy individuals.Materials and methods: PBMC were challenged with tetanus toxoid (5μg/mL) and PHA (10 μmL) in absence or presence of ribavirin at different concentrations (1, 10 and 100 (μM). Parallel sets of wells containing PBMC exposed to medium alone were used as negative controls. On day 3 after initiation of the cultures, IL-2, IFN-γ, IL-4, IL-10, TNF-α content were determined in supernatants of PBMC from the different individuals.Results: The effects of ribavirin on cytokine released by human PBMC in response to PHA and TT showed a great variation among individuals. No significant changes were observed between 1-10μ M concentrations in the production of TNF-α, IFN-γ and IL-10 by both PHA and TT-stimulated PBMC. Ribavirin inhibited TNF-α, IFN-γ, and IL-10 in both PHA and TT-stimulated PBMC at 100 μM (p

In order to assess Hepatitis B Virus genotype (g) and subgenotype (sg) implications in the course of infection, 234 HBsAg positive patients in different infection stages were characterized (66 acute infections, 63 HBeAg positive chronic infections and 105 anti-HBe positive chronic infections).Overall, sgA2 (17.9%), gD (20.9%), sgF1b (34.2%) and sgF4 (19.7%) were the most prevalent. Subgenotype F1b was overrepresented in acute and chronic HBeAg infections (56.1%), whereas gD was the most frequent (40.0%) in anti-HBe positive chronic infections. Among chronic infections, HBeAg positivity rates were 50.0, 12.5, 62.8 and 35.3% for sgA2, gD, sgF1b and sgF4, respectively (p

The intrahepatic cholestasis of pregnancy (ICP) is a multifactorial liver disorder which pathogenesis involves the interplay among abnormal bile acid (BA) levels, sex hormones, environmental factors, and genetic susceptibility. The dynamic nature of ICP that usually resolves soon after delivery suggests the possibility that its pathobiology is under epigenetic modulation. We explored the status of white blood peripheral cells-DNA methylation of CpG-enriched sites at the promoter of targeted genes (FXR/NR1H4, PXR/NR1I2, NR1I3, ESR1, and ABCC2) in a sample of 88 ICP patients and 173 healthy pregnant women in the third trimester of their pregnancies. CpG dinucleotides at the gene promoter of nuclear receptors subfamily 1 members and ABCC2 transporter were highly methylated during healthy pregnancy. We observed significant differences at the distal (-1890) and proximal promoter (-358) CpG sites of the FXR/NR1H4 and at the distal PXR/NR1I2 (-1224) promoter, which were consistently less methylated in ICP cases when compared with controls. In addition, we observed that methylation at FXR/NR1H4-1890 and PXR/NR1I2-1224 promoter sites was highly and positively correlated with BA profiling, particularly, conjugated BAs. Conversely, methylation level at the proximal FXR/NR1H4-358 CpG site was significantly and negatively correlated with the primary cholic and secondary deoxycholic acid. In vitro exploration showed that epiallopregnanolone sulfate, a reported FXR inhibitor, regulates the transcriptional activity of FXR/NR1H4 but seems to be not involved in the methylation changes. In conclusion, the identification of epigenetic marks in target genes provides a basis for the understanding of adverse liver-related pregnancy outcomes, including ICP.