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.

Changing Etiologies and Prognostic Factors in Pediatric Acute Liver Failure.

After the implementation of universal hepatitis A virus vaccination in Argentina, the outcome of pediatric acute liver failure (PALF) remains unknown. We aimed to identify variables associated with the risk of liver transplantation (LT) or death and to determine the causes and short-term outcomes of PALF in Argentina. We retrospectively included 135 patients with PALF listed for LT between 2007 and 2016. Patients with autoimmune hepatitis (AIH), Wilson's disease (WD), or inborn errors of metabolism (IEM) were classified as PALF-chronic liver disease (CLD), and others were classified as "pure" PALF. A logistic regression model was developed to identify factors independently associated with death or need of LT and risk stratification. The most common etiologies were indeterminate (52%), AIH (23%), WD (6%), and IEM (6%). Overall, transplant-free survival was 35%, whereas 50% of the patients underwent LT and 15% died on the waiting list. The 3-month risk of LT or death was significantly higher among patients with pure PALF compared with PALF-CLD (76.5% versus 42.5%; relative risk, 1.8 [1.3-2.5]; P < 0.001), and 3 risk factors were independently associated with worse outcome: international normalized ratio (INR) ≥3.5 (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.3-7.2]), bilirubin ≥17 mg/dL (OR, 4.4; 95% CI, 1.9-10.3]), and pure PALF (OR, 3.8; 95% CI, 1.6-8.9). Patients were identified by the number of risk factors: Patients with 0, 1, or ≥2 risk factors presented a 3-month risk of worse outcome of 17.6%, 36.6%, and 82%, respectively. In conclusion, although lacking external validation, this simple risk-staging model might help stratify patients with different transplant-free survival rates and may contribute to establishing the optimal timing for LT.

Guías de Vacunación en Huéspedes Especiales / Guidelines for the Vaccination of Special Hosts

Los niños con alteración de su sistema inmunológico son más vulnerables ante las infecciones que el resto de la población. Una de las formas de protegerlos de infecciones graves es a través de la vacunación, deben ser correctamente evaluados al planear los esquemas a fin de establecer los riesgos vs. los beneficios que implican inmunizarlos. El rol del médico pediatra y del médico especialista trabajando en equipo es fundamental, para que puedan beneficiarse con vacunas y esquemas especiales que requieran por su patología de base. Una protección óptima de estos pacientes incluye además la adecuada inmunización de los convivientes y del equipo médico tratante. La inmunización de los huéspedes especiales es una situación clínica compleja que requiere un análisis exhaustivo personalizado en cada caso, debido a las diferentes características de estos pacientes con enfermedades crónicas y/o inmunosuprimidos, los diversos grupos y muchos tipos de terapias inmunosupresoras que se están desarrollando y utilizando en un número cada vez mayor. Es fundamental el trabajo en equipo del médico especialista y el pediatra de cabecera para lograr el mejor control de las enfermedades inmunoprevenibles en estos pacientes de tan alta complejidad

Children with weakened immune systems are more vulnerable to infections than the rest of the population. One of the ways to protect them against serious infections is vaccination; they must be correctly evaluated when planning schedules in order to define the risks versus the benefits involved by their immunization. The role of pediatricians and medical specialists working as a team is fundamental, so that patients can benefit from vaccines and special schedules that they may require due to their underlying pathologies. Optimal protection of these patients also includes the adequate immunization of household members and their treating medical teams. The immunization of special hosts is a complex clinical situation that requires an exhaustive personalized case-by-case analysis, due to the different characteristics of these patients who have chronic diseases and / or are immunosuppressed, the various groups and many types of immunosuppressive therapies that are being developed and increasingly used. The teamwork of specialists and family pediatricians is essential to achieve the best control of immuno-preventable diseases in these highly complex patients

Liver disease and dyslipidemia as a manifestation of lysosomal acid lipase deficiency (LAL-D). Clinical and diagnostic aspects, and a new treatment. An update. / Enfermedad hepática y dislipemia como manifestación de deficiencia de lipasa acida lisosomal (LAL-D). Aspectos clínicos, diagnósticos y nuevo tratamiento. Actualización.

Lysosomal acid lipase deficiency (LAL-D) is still a little recognized genetic disease with significant morbidity and mortality in children and adults. This document provides guidance on when to suspect LAL-D and how to diagnose it. It is recommended to add lysosomal acid lipase deficiency to the List of differential diagnoses of sepsis, oncological diseases, storage diseases, persistent diarrhea, chronic malnutrition, and hemophagocytic lymphohistiocytosis. It should also be considered in young patients with dyslipidemia and atherosclerosis as well as diseases associated with fatty liver and/or hepatomegaly. LAL-D should be suspected in patients with hepatomegaly, hyperlipidemia and /or elevated transaminases found during routine checks or testing for other conditions, and in patients with cryptogenic cirrhosis. At present, there is the option of a specific enzyme replacement treatment.

La deficiencia de lipasa ácida lisosomal es una enfermedad genética aún poco reconocida, con significativa morbimortalidad en niños y en adultos. Esta guía orienta sobre cuándo sospechar la enfermedady cómo diagnosticarla. Serecomienda agregar la deficiencia de lipasa ácida lisosomal a la lista de diagnósticos diferenciales de las sepsis, enfermedades oncológicas, enfermedades de depósito, diarrea prolongada y desnutrición crónica y linfohistiocitosis hemofagocítica. Asimismo, se sugiere considerarla en pacientes jóvenes con dislipemia y arterioesclerosis y en enfermedades que ocurran con hígado graso y/o hepatomegalia. La hepatomegalia, hiperlipidemia y/o elevación de las transaminasas en ocasión de controles de rutina o de otras afecciones deberían hacer sospechar la deficiencia de lipasa ácida lisosomal, al igual que en pacientes con cirrosis criptogénica. Hoy existe la opción de un tratamiento de remplazo enzimático específico.

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.

Management of hepatitis C virus infection in childhood.

Infection with hepatitis C virus (HCV) is a worldwide health problem with more than 170 million infected individuals. In children, since 1992 almost all infections occurred through vertical transmission from an infected mother to her newborn infant. Natural history of HCV infection in children is not yet well defined, most children are asymptomatic and may remain so for decades. Most infected individuals (60-80%), regardless of their age at infection, become chronically infected with HCV. Spontaneous resolution in children appears to be infrequent. Positive HCV antibody implicate that patient has been exposed to the virus (EIA test). To discriminate between active or resolved HCV viral infection it is necessary to perform HCV RNA (PCR). Liver biopsy assess degree of liver injury and exclude concurrent diseases. HCV chronic infection is slow progressive in childhood. Progression of fibrosis seems to be a function of infection duration. Treatment objective is clearance of HCVRNA. IFNa is recognized as the drug approved for hepatitis C treatment in pediatric population. Combination therapy with IFNa or pegylated IFNa plus ribavirin is recently approved by US FDA and EMEA and clinical trials are in progress.

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.

High sustained virologic response rates in children with chronic hepatitis C receiving peginterferon alfa-2b plus ribavirin.

BACKGROUND & AIMS: Pegylated interferon (PEG-IFN) alfa-2b plus ribavirin (RBV) is the standard of care for adults with chronic hepatitis C but was not approved for the treatment of children at the time of this study. The aim of this study was to evaluate the efficacy and safety of PEG-IFN alfa-2b plus RBV in children. METHODS: Children and adolescents ages 3-17 years were treated with PEG-IFN alfa-2b (60microg/m(2)/week) plus RBV (15mg/kg/day). The duration of therapy was 24 weeks for genotype (G) 2 and G3 patients with low viral load (<600,000IU/ml) and 48 weeks for G1, G4, and G3 with high viral load (>or=600,000IU/ml). The primary end point was sustained virologic response (SVR), defined as undetectable hepatitis C virus (HCV) RNA 24 weeks after completion of therapy. RESULTS: SVR was attained by 70 (65%) children. Genotype was the main predictor of response: G1, 53%; G2/3, 93%; G4, 80%. SVRs were similar in younger and older children. Baseline viral load was the main predictor of response in the G1 cohort. No new safety signals were identified, and adverse events (AEs) were generally mild or moderate in severity. Dose was modified because of AEs in 25% of children; 1 child discontinued because of an AE (thrombocytopenia). No serious AEs related to study drugs were reported. CONCLUSION: Therapy with PEG-IFN alfa-2b plus RBV in children and adolescents with chronic hepatitis C offers favorable efficacy, reduced injection frequency, and an acceptable safety profile.

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.