Role and clinical significance of imbalanced Th17/CD4+CD25+ regulatory T lymphocytes in children with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the changes in Th17 cells and CD4+CD25+regulatory T lym-phocytes ( Treg) as well as transcription factors and cytokines relating to them in children with Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH) and to analyze their role and clinical significance. Methods Thirty-two children with newly diagnosed EBV-associated HLH in the Hematology/Oncology Department of Zhengzhou Children′s Hospital from January 2012 to December 2016 were enrolled in this study. Thirty healthy children taking physical examination in the same hospital in the corresponding period were recruited as controls. Percentages of Th17 and Treg cells in peripheral blood T lymphocytes were detected by flow cytometry. Expression of RORγt and Foxp3 at mRNA level in peripheral blood mononuclear cells was detected by real-time PCR. Levels of IL-6, IL-17, IL-10 and TGF-β1 in serum samples were measured by ELISA. Results Compared with the control group, the EBV-associated HLH group showed in-creased percentage of Th17 cells [(1. 09±0. 43)％ vs (0. 39±0. 19)％, P<0. 05] and enhanced expres-sion of RORγt at mRNA level [(1. 41±0. 37) vs (0. 67±0. 13), P<0. 05], but decreased percentage of Treg cells [(3. 66±1. 13)％ vs (6. 80±1. 15)％, P<0. 05] and inhibited expression of Foxp3 at mRNA level [(15. 97±5. 11) vs (30. 23±4. 95), P<0. 05]. All of the above mentioned changes were reversed af-ter treatment (P<0. 05). Serum levels of IL-6 and IL-17 of EBV-associated HLH group were higher than those of control group, while serum levels of IL-10 and TGF-β1 were lower (P<0. 05). Conclusion Im-balanced Th17/Treg cells might play an important role in the pathogenesis of EBV-associated HLH. Cyto-kines relating to the maintenance of Th17/Treg cell balance could be used as indicators of disease develop-ment.