RESUMO
OBJECTIVES: To ascertain a molecular genetic diagnosis for subjects with neonatal/infantile intrahepatic cholestasis (NIIC) by the use of next-generation sequencing (NGS) and to perform a genotype-phenotype correlation. STUDY DESIGN: We recruited Japanese subjects with NIIC who had no definitive molecular genetic diagnosis. We developed a diagnostic custom panel of 18 genes, and the amplicon library was sequenced via NGS. We then compared clinical data between the molecular genetically confirmed subjects with NIIC. RESULTS: We analyzed 109 patients with NIIC ("genetic cholestasis," 31 subjects; "unknown with complications" such as prematurity, 46 subjects; "unknown without complications," 32 subjects), and a molecular genetic diagnosis was made for 28 subjects (26%). The rate of positive molecular genetic diagnosis in each category was 22 of 31 (71%) for the "genetic cholestasis" group, 2 of 46 (4.3%) for the "unknown with complications" group, and 4 of 32 (12.5%) for the "unknown without complications" group. The grouping of the molecular diagnoses in the group with genetic cholestasis was as follows: 12 with Alagille syndrome, 5 with neonatal Dubin-Johnson syndrome, 5 with neonatal intrahepatic cholestasis caused by citrin deficiency, and 6 with progressive familial intrahepatic cholestasis or benign recurrent intrahepatic cholestasis with low gamma-glutamyl transpeptidase levels. Several clinical datasets, including age of onset, direct bilirubin, and aminotransferases, were significantly different between the disorders confirmed using molecular genetic diagnosis. CONCLUSION: Targeted NGS can be used for molecular genetic diagnosis in subjects with NIIC. Clinical diagnosis should be accordingly redefined in the view of molecular genetic findings.
Assuntos
Colestase Intra-Hepática/diagnóstico , Colestase Intra-Hepática/genética , Sequenciamento de Nucleotídeos em Larga Escala , Síndrome de Alagille/diagnóstico , Síndrome de Alagille/genética , Bilirrubina/sangue , Proteínas de Ligação ao Cálcio/deficiência , Aberrações Cromossômicas , Éxons , Feminino , Deleção de Genes , Estudos de Associação Genética , Genômica , Humanos , Lactente , Recém-Nascido , Japão , Icterícia Idiopática Crônica/diagnóstico , Icterícia Idiopática Crônica/genética , Masculino , Biologia Molecular , Transportadores de Ânions Orgânicos/deficiência , gama-Glutamiltransferase/genéticaRESUMO
BACKGROUND/AIMS: The knowledge of molecular mechanisms determining drug pharmacokinetics in pathological states is relevant for the development of new therapeutic approaches. This study was undertaken to evaluate the cortical renal blood flow (cRBF) and the renal protein expression of the organic anion transporters (OAT1 and OAT3) in association with the elimination of organic anions in an early stage of renal ischemia-reperfusion. METHODS: Ischemic acute renal failure (ARF) was induced in adult male Wistar rats by occlusion of both renal pedicles during 60 min, followed by 60 min of reperfusion (ARF group). Pair-fed sham-operated rats served as controls. The renal protein expression of OAT1 and OAT3 was evaluated by immunohistochemistry techniques and by Western blotting in renal cortex homogenates and in basolateral plasma membranes. A pharmacokinetic study of p-aminohippurate (PAH, a prototypical organic anion) was performed. cRBF was determined using fluorescent microspheres. RESULTS: ARF rats displayed a significant decrease in systemic clearance and in renal excretion of PAH. OAT1 and OAT3 protein abundance showed a statistically significant reduction both in homogenates and in basolateral plasma membranes from ARF rats. Immunohistochemical studies confirmed the changes in the cortical renal expression of these transporters. ARF animals also showed a decrease in cRBF. CONCLUSIONS: The decrease in PAH elimination observed in an early stage of renal ischemia-reperfusion in male Wistar rats might be explained by the sum of the lower OAT1 and OAT3 expression in renal basolateral plasma membranes plus the decrease in cRBF. These findings might have significant implications in the development of novel pharmacological strategies to be applied in the initial stages of ischemic ARF.
Assuntos
Membrana Celular/fisiologia , Córtex Renal/irrigação sanguínea , Córtex Renal/metabolismo , Proteínas de Membrana Transportadoras/fisiologia , Transportadores de Ânions Orgânicos/metabolismo , Circulação Renal/fisiologia , Traumatismo por Reperfusão/metabolismo , Injúria Renal Aguda/genética , Injúria Renal Aguda/metabolismo , Animais , Membrana Celular/genética , Masculino , Proteínas de Membrana Transportadoras/deficiência , Proteínas de Membrana Transportadoras/genética , Transportadores de Ânions Orgânicos/deficiência , Transportadores de Ânions Orgânicos/genética , Ratos , Ratos Wistar , Traumatismo por Reperfusão/genéticaRESUMO
OBJECTIVES: To explore the prevalence of hepatic steatosis and neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) in Taiwanese infants with idiopathic intrahepatic cholestasis. STUDY DESIGN: The liver specimens from 69 infants with idiopathic intrahepatic cholestasis were reviewed (1993-2004); 11 of them (14.7%) had hepatic steatosis. Six patients with hepatic steatosis participated in the genetic study for the SLC25A13 gene under parental consent. RESULTS: Infants with cholestasis and hepatic steatosis had lower aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels than those with cholestasis alone. Three of the six infants in the genetic study had homozygous 851del4 mutation; for the others, homozygous 1638ins23 mutation, compound heterozygous 851del4/IVS6+5G-->A mutation, and heterozygous IVS6+5G-->A mutation were found for each one. Eleven of the total 12 alleles (91.7%) were demonstrated to have SLC25A13 gene mutations. CONCLUSIONS: Metabolic and genetic studies for NICCD should be performed in Asian infants with idiopathic intrahepatic cholestasis and hepatic steatosis. The 851del4 mutation on the SLC25A13 gene accounts for the major genotype expression of patients with NICCD in Taiwan.