RESUMO
INTRODUCTION AND AIM: Natural Killer (NK) cells play an important role in innate immune response to viral infections and their high proportion is situated in the liver. The aim of this study was to analyze possible relation between the expression of NK cell receptors and varied intensity of liver lesions in chronic hepatitis C (CHC) in children. MATERIAL AND METHODS: Study included 105 children with CHC - 54 boys and 51 girls, age 13.62 ± 3.48 years. Blood specimens were taken at the day of the liver biopsy. Histological evaluation was performed according to METAVIR scoring system. Circulating NK cells were evaluated by flow cytometry. The results were shown as a proportion of cells expressing evaluated receptor and its' mean fluorescent intensity (MFI). RESULTS: In 58 children with CHC (55.2%) significant liver fibrosis was observed ( ≥F2). Higher proportion of cells expressing CD158e inhibitory receptors was observed in the group of children with ALT > 2UNL (21.11 ± 14.60 vs. 12.22 ± 8.99%; p = 0.037). While higher proportion of cells expressing inhibitory CD158b receptor was observed in children with significant fibrosis (F ≥ 2) compared to minimal fibrosis (F < 2) - (34.14 ± 12.44 vs. 27.48 ± 8.71%; p = 0.049). Children with advanced fibrosis (F ≥ 3) had higher MFI of NK cell CD 158b receptor than children with fibrosis scored F < 3 - (5344.20 ± 3407.49 vs. 2979.67 ± 1190.64; p = 0.049). Proportion of NK cells expressing CD158b was found a predictor of significant fibrosis in univariate analysis - [OR 1.065; 95%CI (1.07-1.15); p = 0.046]. CONCLUSIONS: Higher proportion of NK cells expressing inhibitory CD158b and CD158e receptors is associated with significant liver injury.
Assuntos
Hepatite C Crônica/imunologia , Hepatite C Crônica/patologia , Cirrose Hepática/imunologia , Cirrose Hepática/patologia , Fígado/patologia , Células T Matadoras Naturais/imunologia , Receptores KIR2DL3/sangue , Receptores KIR3DL1/sangue , Adolescente , Fatores Etários , Biomarcadores/sangue , Biópsia , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Feminino , Citometria de Fluxo , Hepacivirus/patogenicidade , Hepatite C Crônica/sangue , Hepatite C Crônica/virologia , Interações Hospedeiro-Patógeno , Humanos , Fígado/virologia , Cirrose Hepática/sangue , Cirrose Hepática/virologia , Masculino , Análise Multivariada , Células T Matadoras Naturais/virologia , Razão de Chances , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
BACKGROUND: During the early phases of a hepatitis C virus (HCV) infection, NK cell activation appears to be critical to the induction of adaptive immune responses that have the potential of clearing the infection. This study aimed to investigate the phenotype and function of NK cells in chronic HCV (CHC) patients, particularly patients who cleared HCV infections spontaneously (SR-HCV). MATERIAL AND METHODS: Peripheral blood NK cells were compared between 36 CHC patients, 12 SR-HCV patients, and 14 healthy controls (HC). The phenotype and function of NK cells were characterized by flow cytometry. In addition, the potential associations between the frequency of NK cell subsets and ALT, AST and HCV viral loads were also analyzed. RESULTS: Our data revealed that the population of CD3-CD56+ NK cells was significantly decreased in CHC and SR-HCV patients compared to levels in HC (P = 0.031, P = 0.014). Interestingly, we found that the levels of the CD158b inhibitory receptor were higher in CHC patients compared to levels observed in HCand SR-HCV subjects (P = 0.018, P = 0.036). In addition, the percentages of the activation receptors NKp30 and NKp46 were significantly decreased in CHC and SR-HCV patients compared to their expression levels in HC (P < 0.05). Moreover, the frequencies of inducible CD107a (but not IFN-γ-secreting) NK cellsfrom both CHC and SR-HCV patients were significantly lower than frequencies observed in controls (P = 0.018, P = 0.027). CONCLUSION: Our data indicated that the higher frequency of inhibitory NK cells combined with fewer activated NK cells may be associated with HCV-related chronic inflammation involved in CHC pathogenesis.