Comprehensive Evolutionary Analysis of Complete Epstein-Barr Virus Genomes from Argentina and Other Geographies.

The sequence variability of the Epstein-Barr virus has been extensively studied throughout previous years in isolates from various geographic regions and consequent variations at both genetic and genomic levels have been described. However, isolates from South America were underrepresented in these studies. Here, we sequenced 15 complete EBV genomes that we analyzed together with publicly available raw NGS data for 199 EBV isolates from other parts of the globe by means of a custom-built bioinformatic pipeline. The phylogenetic relations of the genomes, the geographic structure and variability of the data set, and the evolution rates for the whole genome and each gene were assessed. The present work contributes to overcoming the scarcity of complete EBV genomes from South America and is the most comprehensive geography-related variability study, which involved determining the actual contribution of each EBV gene to the geographic segregation of the entire genome. Moreover, to the best of our knowledge, we established for the first time the evolution rate for the entire EBV genome based on a host-virus codivergence-independent assumption and assessed their evolution rates on a gene-by-gene basis, which were related to the encoded protein function. Considering the evolution of dsDNA viruses with a codivergence-independent approach may lay the basis for future research on EBV evolution. The exhaustive bioinformatic analysis performed on this new dataset allowed us to draw a novel set of conclusions regarding the genome evolution of EBV.

Hepatic lymphocytes involved in the pathogenesis of pediatric and adult non-alcoholic fatty liver disease.

The immune response is critical in NAFLD pathogenesis, but the liver infiltrate's composition and the role of each T cell population is still up for debate. To characterize liver pathogenesis in pediatric and adult cases, frequency and localization of immune cell populations [Cytotoxic T Lymphocytes (CD8+), T helper Lymphocytes (CD4+), Regulatory T lymphocytes (Foxp3+) and Th17 (IL-17A+)] were evaluated. In portal/periportal (P/P) tracts, both age groups displayed a similar proportion of CD8+ and CD4+ lymphocytes. However, comparable Foxp3+ and IL-17A+ cell frequencies were observed in pediatric cases, meanwhile, in adults Foxp3+ was higher than IL-17A+ cells. Interestingly, IL-17A+ lymphocytes seemed to be nearly exclusive of P/P area in both age groups. In intralobular areas, both pediatric and adult cases showed CD8+ lymphocytes predominance with lower frequencies of CD4+ lymphocytes followed by Foxp3+ . Severe inflammation was associated with higher intralobular Foxp3+ lymphocytes (p = 0.026) in children, and lower P/P Foxp3+ and higher IL-17A+ lymphocytes in adults. All cases with fibrosis ≥ 2 displayed P/P low Foxp3+ and high IL-17A+ lymphocyte counts. Pediatric cases with worse steatosis showed high P/P CD4+ (p = 0.023) and intralobular CD8+ (p = 0.027) and CD4+ cells (p = 0.012). In NAFLD cases, the lymphocyte liver infiltrate composition differs between histological areas. Treg and Th17 balance seems to condition damage progression, denoting their important role in pathogenesis.

Serum apoptosis markers related to liver damage in chronic hepatitis C: sFas as a marker of advanced fibrosis in children and adults while M30 of severe steatosis only in children.

BACKGROUND: Liver biopsy represents the gold standard for evaluating damage and progression in patients with chronic hepatitis C (CHC); however, developing noninvasive tests that can predict liver injury represents a growing medical need. Considering that hepatocyte apoptosis plays a role in CHC pathogenesis; the aim of our study was to evaluate the presence of different apoptosis markers that correlate with liver injury in a cohort of pediatric and adult patients with CHC. METHODS: Liver biopsies and concomitant serum samples from 22 pediatric and 22 adult patients with CHC were analyzed. Histological parameters were evaluated. In serum samples soluble Fas (sFas), caspase activity and caspase-generated neoepitope of the CK-18 proteolytic fragment (M30) were measured. RESULTS: sFas was associated with fibrosis severity in pediatric (significant fibrosis p = 0.03, advanced fibrosis p = 0.01) and adult patients (advanced fibrosis p = 0.02). M30 levels were elevated in pediatric patients with severe steatosis (p = 0.01) while in adults no relation with any histological variable was observed. Caspase activity levels were higher in pediatric samples with significant fibrosis (p = 0.03) and they were associated with hepatitis severity (p = 0.04) in adult patients. The diagnostic accuracy evaluation demonstrated only a good performance for sFas to evaluate advanced fibrosis both in children (AUROC: 0.812) and adults (AUROC: 0.800) as well as for M30 to determine steatosis severity in children (AUROC: 0.833). CONCLUSIONS: Serum sFas could be considered a possible marker of advanced fibrosis both in pediatric and adult patient with CHC as well as M30 might be a good predictor of steatosis severity in children.

The role of innate cells is coupled to a Th1-polarized immune response in pediatric nonalcoholic steatohepatitis.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a chronic inflammatory liver disease influenced by risk factors for the metabolic syndrome. In adult patients, NASH is associated with an altered phenotype and functionality of peripheral immune cells, the recruitment of leukocytes and intrahepatic activation, and an exacerbated production of reactive oxygen species (ROS) and cytokines. It remains unclear if the previously described differences between pediatric and adult nonalcoholic fatty liver diseases also reflect differences in their pathogenesis. AIMS: We aimed to investigate the phenotype and functionality of circulating immune cells and the potential contribution of liver infiltrating leukocytes to the immunological imbalance in pediatric NASH. RESULTS: By a real-time PCR-based analysis of cytokines and immunohistochemical staining of liver biopsies, we demonstrated that the hepatic microenvironment is dominated by interferon-gamma (IFN-γ) but not interleukin-4 and is infiltrated by a higher number of CD8(+) cells in pediatric NASH. The number of infiltrating neutrophils positively correlated with ROS generation by peripheral polymorphonuclear cells. By a flow cytometric analysis of peripheral blood lymphocytes, a distinctive increase in CD8(+) CD45RO and CD8(+) CD45RA subpopulations and an increased production of IFN-γ by CD4(+) and CD8(+) cells were shown. The production of ROS following PMA stimulation was augmented in circulating neutrophils but not in monocytes. CONCLUSION: In sum, the distinctive phenotype and functionality of infiltrating and circulating cells suggest that the role of innate cells is coupled to a Th1-polarized immune response in pediatric NASH.

Neonatal cholestasis in congenital pituitary hormone deficiency and isolated hypocortisolism: characterization of liver dysfunction and follow-up / Colestase neonatal na deficiência congênita de hormônio hipofisário e hipocortisolismo isolado: caracterização da disfunção hepática e acompanhamento

INTRODUCTION: Neonatal cholestasis due to endocrine diseases is infrequent and poorly reco-gnized. Referral to the pediatric endocrinologist is delayed. OBJECTIVE: We characterized cholestasis in infants with congenital pituitary hormone deficiencies (CPHD), and its resolution after hormone replacement therapy (HRT). SUBJECTS AND METHODS: Sixteen patients (12 males) were included; eleven with CPHD, and five with isolated central hypocortisolism. RESULTS: Onset of cholestasis occurred at a median age of 18 days of life (range 2-120). Ten and nine patients had elevated transaminases and γGT, respectively. Referral to the endocrinologist occurred at 32 days (range 1 - 72). Remission of cholestasis occurred at a median age of 65 days, whereas liver enzymes occurred at 90 days. In our cohort isolated, hypocortisolism was a transient disorder. CONCLUSION: Cholestasis due to hormonal deficiencies completely resolved upon introduction of HRT. Isolated hypocortisolism may be a transient cause of cholestasis that needs to be re-evaluated after remission of cholestasis.

INTRODUÇÃO: A colestase neonatal causada por doenças endócrinas é pouco frequente e reconhecida. Existe um atraso no encaminhamento dos pacientes a um endocrinologista pediátrico. OBJETIVO: Caracterizamos a colestase em recém-nascidos com deficiências congênitas de hormônio hipofisário (DCHH) e sua resolução após a terapia de reposição hormonal (TRH). SUJEITOS E MÉTODOS: Dezesseis pacientes (12 do sexo masculino) foram incluídos; sete com DCHH, e cinco com hipocortisolismo central isolado. RESULTADOS: O início da colestase ocorreu aos 18 dias de vida (variação 2-120). Dez e nove pacientes apresentaram elevação das transaminases e γGT, respectivamente. A consulta com um endocrinologista aconteceu aos 32 dias (variação 1-72). A remissão da colestase ocorreu em uma idade mediana de 65 dias, enquanto a remissão das enzimas hepáticas aconteceu aos 90 dias. Na coorte isolada, o hipocortisolismo foi uma desordem transitória. CONCLUSÃO: A colestase causada por deficiências hormonais foi completamente resolvida após a introdução da TRH. O hipocortisolismo pode ser uma causa transitória da colestase e precisa ser reavaliado após a remissão da colestase.

Neonatal cholestasis in congenital pituitary hormone deficiency and isolated hypocortisolism: characterization of liver dysfunction and follow-up.

INTRODUCTION: Neonatal cholestasis due to endocrine diseases is infrequent and poorly recognized. Referral to the pediatric endocrinologist is delayed. OBJECTIVE: We characterized cholestasis in infants with congenital pituitary hormone deficiencies (CPHD), and its resolution after hormone replacement therapy (HRT). SUBJECTS AND METHODS: Sixteen patients (12 males) were included; eleven with CPHD, and five with isolated central hypocortisolism. RESULTS: Onset of cholestasis occurred at a median age of 18 days of life (range 2-120). Ten and nine patients had elevated transaminases and γGT, respectively. Referral to the endocrinologist occurred at 32 days (range 1 - 72). Remission of cholestasis occurred at a median age of 65 days, whereas liver enzymes occurred at 90 days. In our cohort isolated, hypocortisolism was a transient disorder. CONCLUSION: Cholestasis due to hormonal deficiencies completely resolved upon introduction of HRT. Isolated hypocortisolism may be a transient cause of cholestasis that needs to be re-evaluated after remission of cholestasis.

Naturally occurring hepatitis B virus (HBV) variants with primary resistance to antiviral therapy and S-mutants with potential primary resistance to adefovir in Argentina.

Hepatitis B virus (HBV) variants may either emerge in patients with chronic hepatitis B (CHB) as a result of positive selection pressure exerted by their own immune response, or during therapy with nucleos(t)ide analogues (NAs). Naturally occurring HBV variants with primary antiviral resistance are rarely observed. The aim of this study was to retrospectively analyze the (eventual) circulation of HBV variants with natural resistance to NAs currently used as therapy for CHB in Argentina. This study reports 13 cases of CHB-infected patients with natural antiviral resistance to at least one NA. Five of them were also carriers of S-variants that might escape the humoral immune system recognition with potential resistance to adefovir. In addition to the already reported A2 HBV subgenotype association to NAs natural resistance, E and F genotypes association to such resistance is described for the first time. These findings suggest that sequence analysis of the HBV reverse transcriptase might be an essential tool before starting antiviral therapy, in order to choose the proper NAs for optimizing the therapeutic management of chronically infected patients. Moreover, the circulation and transmission of S-mutants with resistance to such antiviral drugs should be of public health concern as they may represent an additional risk for the community.

The most severe forms of type I autoimmune hepatitis are associated with genetically determined levels of TGF-beta1.

We previously reported that paediatric (PAH) and adult (AAH) forms of type I autoimmune hepatitis (AH) have different HLA-associations and clinical outcome. In the present study we investigated the role of TGF-beta1 genetic polymorphisms in the different outcome of PAH and AAH. We found a significant increase of "high producer" 25GG genotype in PAH and 10CC in AAH. Low inflammation and low fibrosis in AAH was associated with the increase of codon 10CC (high producer) and codon 25CC (low producer) genotypes. The analysis in AAH of the two positions-haplotypes revealed that combined presence of 25GG and 10CC seems to neutralize the 10CC effect which remained in AAH having the 10CC(+)-25GG(-) haplotype. Altogether these results may explain, at least partially, the different clinical outcome of AAH and PAH.

Apoptosis markers in liver biopsy of nonalcoholic steatohepatitis in pediatric patients.

The natural history of pediatric nonalcoholic steatohepatitis is still unknown; however, there are differences between adult and pediatric presentation. Apoptosis may play an important role in pathophysiologic pathways involved in liver damage and progression. Our aim was to detect early apoptosis markers, activated caspase-3 and cleaved cytokeratin-18, in hepatocytes and to correlate their presence with clinical, serologic, and histologic characteristics in pediatric nonalcoholic steatohepatitis. Twenty-five pediatric nonalcoholic steatohepatitis liver biopsies were evaluated by immunohistochemistry for presence of activated caspase-3 and cleaved cytokeratin-18. Biopsy specimens were semiquantitatively graded for activity (steatosis, inflammation, and ballooning) and fibrosis. Records were reviewed for serum aspartate aminotransferase, alanine aminotransferase, cholesterol, triglycerides, and body mass index, which was elevated in 92% of cases. Serum aspartate aminotransferase and alanine aminotransferase were elevated in 32% and 68% of cases, respectively. Sixty percent of biopsies exhibited lobular steatosis grade 3, 84% lobular inflammatory activity grade 1, 72% ballooning grade 1, and 76% fibrosis stage 3. Cleaved cytokeratin-18 was associated with milder fibrosis (P = .02) and inflammation (P = .07), although there was no association with steatosis grade. Activated caspase-3 detection was also associated with low inflammatory grade (P = .03) but not with fibrosis and steatosis. This study reveals interesting differential features concerning nonalcoholic steatohepatitis histologic characteristics and apoptosis markers compared with adult cases. Because, in this pediatric series, apoptosis seemed to be an early event in the cascade of liver injury steps, it would be useful to consider caspase inhibitors as potential therapeutic strategies to prevent liver damage progression.