Study of the correlation between the percentage of iNKT cells and the ratio of IFN-γ/IL-4 in patients with rheumatoid arthritis / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the alterations of invariant nature killer T( iNKT) cells in peripheral blood samples from patients with rheumatoid arthritis ( RA) and to clarify the correlation between the percentage of iNKT cells and the ratio of IFN-γ/IL-4 in order to further understand the significance of iNKT cells in the development of RA.Methods Peripheral blood mononuclear cells ( PBMCs) were isola-ted from 70 patients with RA and 40 healthy subjects.Among them, thirty patients in the stage of inactive RA were involved in a follow-up study.Fluorescence activated cell sorting ( FACS) was used to detect the percentage of iNKT cells.PBMCs were cultured in vitro for analysis of cytokine production.The dynamic changes of iNKT cells in percentages were analyzed by FACS.MILLIPLEX MAP Human Cytokine/Chemo-kine kit was used to measure the secretion of IFN-γand IL-4 in serum samples and culture media of PBMCs. The expression of IFN-γand IL-4 in iNKT cells at mRNA level were analyzed by RT-PCR.Results Com-pared with the healthy subjects, the patients with active RA showed the delayed proliferation of iNKT cells and the decreased percentages and proliferation rates of iNKT cells (P0.05).The ratios of IFN-γ/IL-4 in serum samples and culture media of PBMCs were increased in patients with active RA as compared with those in patients with inactive RA and healthy subjects (P0.05).Compared with healthy subjects and patients with inactive RA, patients with active RA showed increased transcriptional level of IFN-γand decreased transcriptional level of IL-4.No significant differences with the expression of IFN-γand IL-4 in iNKT cells at mRNA level were observed between healthy subjects and patients with inactive RA.The per-centage of iNKT cells was negatively related to the IFN-γ/IL-4 ratio in patients with RA (P<0.05).Con-clusion Decreased percentage and impaired function of iNKT cells were detected in patients with RA. iNKT cells were closely related to the development and disease activity of RA.