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.

The simultaneous high expression of Vα24, IFN-γ and FoxP3 characterizes the liver of children with type I autoimmune hepatitis.

The immunopathogenesis of type I autoimmune hepatitis (AIH-I) might involve the deregulation of different cellular processes. Here, we investigated the liver expression of selected cytokines and genes of regulatory cell populations in children both at diagnosis and during biochemical remission following immunosuppressive treatment (AIH-Ir). We found a higher Vα24, IFN-γ, FoxP3, IL-27p28, IL-12p40 and IL-21 expression at diagnosis as well as a positive correlation between IL-21 and transaminase levels. Interestingly, only IFN-γ and FoxP3 were decreased in AIH-Ir. An "AIH-I phenotype" (high Vα24, IFN-γ and FoxP3 expression at diagnosis) was observed in only 5 out of 22 AIH-Ir patients but not in controls. These results indicate a local deregulation of the innate and adaptive immune responses with an increased transcriptional activity of immunoregulatory cells at diagnosis. In addition, IL-21 is highlighted as a mediator of liver injury. AIH-Ir is characterized by a partial reversal of the deregulated response.

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.

Simultaneous expression of Th1 cytokines and IL-4 confers severe characteristics to type I autoimmune hepatitis in children.

To investigate the immunopathogenic mechanisms of type I autoimmune hepatitis in children, we analyzed by quantitative or semiquantitative reverse transcription-polymerase chain reaction the expression of cytokines interferon (IFN)-gamma, interleukin (IL)-12p40, IL-18, IL-4, IL-10, and IL-12R beta 2. In addition, liver and peripheral blood was collected to investigate the expression of the natural killer T (NKT) cell marker V alpha 24. The presence of NKT cells in hepatic lesions were also identified by immunohistochemistry. The analysis was performed on liver biopsies from 25 children with type I autoimmune hepatitis. As disease controls, we included six children with hepatitis C virus-related chronic hepatitis and nine control livers. The expression of IFN-gamma and IL-12p40 was not detected in controls but was clearly upregulated in pathologic biopsies. In addition, these samples showed an increased expression of IL-18 (p = 0.0003), IL-4 (p = 0.0055), and IL-12R beta 2 (p = 0.007). Western blot analysis confirmed the expression of IL-12p40 and IL-18. However, for IL-18, we detected only the immature biologically inactive polypeptide. The V alpha 24 transcripts were found increased in the liver (p = 0.0007) where V alpha 24(+) cells were also localized, but decreased in peripheral blood mononuclear cells (p = 0.041). In addition to a type I immune response, NKT cells might play a substantial role in the pathogenesis of type I autoimmune hepatitis in children.

Caracterización genotípica de la infección por el virus de hepatitis C en niños / Genotype characterization of hepatitis C virus infection in children

Hepatitis C virus (HCV) infection in children was assessed by RT-nested PCR of the 5untranslated region (5UTR) of the viral genome combined with virus genotyping, performed by restriction fragment length polymorphism (RFLP). We analysed HCV infection in 64 children and in 9 HCV chronically infected mothers corresponding to 10 of them. Thirty two children were positive for serum HCV RNA as determined by RT-nested PCR. The viremia was analysed in consecutive samples of 25 children. Nine children (36 per cent) were always positive for HCV RNA, in 5 (20 per cent) a positive RT-nested PCR turned negative in subsequent samples, other 9 (36 per cent) showed alternating RT-nested PCR results and in 2 (8 per cent) the RT-nested PCR turned positive after an initial negative result. The HCV genotype distribution was studied in 27/32 children and in 9 mothers, and it was similar to that reported in the literature for adult and pediatric patients in our country. Genotype 1 was predominant in our population. HCV genotype did not change in the same patient during the time of this study. HCV genotype was the same in mother-infant pairs. We could not establish a correlation between HCV genotype and vertical transmission of HCV. This study will be helpful to further analyze HCV behavior during pediatric infection and the hosts response in the initial stages of it. (Au)

Caracterización genotípica de la infección por el virus de hepatitis C en niños / Genotype characterization of hepatitis C virus infection in children

Hepatitis C virus (HCV) infection in children was assessed by RT-nested PCR of the 5'untranslated region (5'UTR) of the viral genome combined with virus genotyping, performed by restriction fragment length polymorphism (RFLP). We analysed HCV infection in 64 children and in 9 HCV chronically infected mothers corresponding to 10 of them. Thirty two children were positive for serum HCV RNA as determined by RT-nested PCR. The viremia was analysed in consecutive samples of 25 children. Nine children (36 per cent) were always positive for HCV RNA, in 5 (20 per cent) a positive RT-nested PCR turned negative in subsequent samples, other 9 (36 per cent) showed alternating RT-nested PCR results and in 2 (8 per cent) the RT-nested PCR turned positive after an initial negative result. The HCV genotype distribution was studied in 27/32 children and in 9 mothers, and it was similar to that reported in the literature for adult and pediatric patients in our country. Genotype 1 was predominant in our population. HCV genotype did not change in the same patient during the time of this study. HCV genotype was the same in mother-infant pairs. We could not establish a correlation between HCV genotype and vertical transmission of HCV. This study will be helpful to further analyze HCV behavior during pediatric infection and the host's response in the initial stages of it.

Genomic and phylogenetic analysis of hapatitis C virus strains from Argentina

HCV genomic characterization was performed by nucleotide sequence analysis (n=50) combined with restriction fragment length polymorphism (RFLP) of the 5UTR region in 82 isolates coresponding to different Argentine groups. Genotype 1 was detected in 70.7 percent of the samples (58 out of 82), genotype 2 in 21.9 percent (18 of 82) and genotypes 3 in the remaining 6 sera (7.3 percent). HCV ib subtype contributed with 35.3 percent to the whole population studied (29 of 82) and was detected in 6 out of 21 sporadic cases. Besides their epidemiological significance, these results should be taken into account when future vaccines are considered on the basis of geographical HCV genotypic prevalence. (AU)

Genomic and phylogenetic analysis of hapatitis C virus strains from Argentina

HCV genomic characterization was performed by nucleotide sequence analysis (n=50) combined with restriction fragment length polymorphism (RFLP) of the 5'UTR region in 82 isolates coresponding to different Argentine groups. Genotype 1 was detected in 70.7 percent of the samples (58 out of 82), genotype 2 in 21.9 percent (18 of 82) and genotypes 3 in the remaining 6 sera (7.3 percent). HCV ib subtype contributed with 35.3 percent to the whole population studied (29 of 82) and was detected in 6 out of 21 sporadic cases. Besides their epidemiological significance, these results should be taken into account when future vaccines are considered on the basis of geographical HCV genotypic prevalence.