Enhanced production of IFN-γ and age associated alterations in CD4+ and CD8+ peripheral subsets in non alcoholic steatohepatitis

INZAUGARAT MARIA EUGENIA; BAZ PLÁCIDA; BILLORDO LUIS ARIEL; CHERÑAVSKY ALEJANDRA C

Berlín

Encuentro; 6th. Annual Meeting of the European Association for the Study of the Liver; 2011

European Association for the Study of the Liver

Children and adults have different histological features associated with nonalcoholic steatohepatitis (NASH). We have previously demonstrated an altered CD8+ but not CD4+ peripheral subsets in pediatric [Ped] NASH. We aimed to expand the analysis to adults and to characterize the functionality of CD4 and CD8 by measuring intracellular production of IFNγ and IL-4. Also to investigate whether histological distinction with age extends to pathophysiology of NASH. Methods: 12 Ped (< 18y) and 12 adults [Ad] ( > 18y) with NASH(N), obese individuals (O) without hepatic damage (15 OPed, 6 OAd) and 30 healthy controls(14 Ped ,16 Ad) were studied. Peripheral blood mononuclear cells (PBMC) obtained by Ficoll-Hypaque were co stained with anti-CD4 or -CD8 PerCP and anti-CD45RO or -CD45RA FITC and analyzed by flow cytometry. For intracellular detection, PBMC were stimulated with PMA/Ionomycin/brefeldin and stained with anti-CD4 or -CD8/-IFNγ or IL4 mAbs. Kruskal-Wallis and Mann-Whitney tests were performed. Results: In NASH Ped, total CD4+ subpopulation is decreased (pc= 0.039 and 0.012 vs. Co and OPed); while CD8+ did not differ. A higher % of γ-IFN producing cells was seen in NASH and OPed (CD4+: pc= 0.03 and pc= 0.029, vs. Co; CD8+: pc= 0.03 and pc= 0.015; vs. Co). In NASH Ad, not only total CD4+ subpopulation is increased(pc=0.006, vs. Co) but also memory subpopulation is larger (pc=0.006 and pc< 0.050, vs. Co and OAd) and, reciprocally, CD4+CD45RA+ subpopulation is smaller (pc=0.024 and pc< 0.050; vs. Co and OAd). NASHAd show larger % of CD8+memory cells(pc=0.030 and pc< 0.050; vs. Co and OAd) and a reciprocally smaller % of CD8+naïve cells (pc< 0.001 and pc< 0.050; vs. Co and OAd). CD4+IFN-γ+ subpopulation is larger in NASH(pc=0.031; vs. Co) whereas CD8+IFN-γ+ is larger in NASH and OAd(p=0.035 and p< 0.050; vs.Co). No differences were found for CD4+IL-4+ subpopulation neither among groups nor with age. Conclusions: The composition of peripheral CD8+ and CD4+ subsets is altered in adults with NASH. Circulating cytotoxic effectors as well as the differentiation towards Th1 are associated with NASH and obesity independently from hepatic injury.