Effect Of Serum 25-hydroxyvitamin D Level On T Cell Related Factors In Maintenance Hemodialysis Patients

Objective To investigate the T cells differentiation and cytokines expression in different serum 25-hydroxyvitamin D?25?OH?D?levels patients,the T cell differentiation and cytokine results after treatment with activated vitamin D in the SHPT patients,and patients' clinical manifestation.Methods 57 patients on chronic HD over 3 months were enrolled during the period from January 1^st,2016 to June 30^th,2017 in our hospital.Patients with systemic infection,malignancy,taking immunosuppressive medication and activated vitamin D or analogues in the past 3 months were all excluded.The peripheral blood mononuclear cells?PBMCs?and sera were collected while mid-week predialysis.The PBMCs were cultured and stimulated by mitogens in different time points.Then the T cells were triplely stained by surface and intracellular cytokine markers and the differentiation was analyzed by flow cytometry.The 25?OH?D level in the sera was detected by enzyme-linked immunosorbent assay?ELISA?.The Th1?interleukin?IL?-2 and interferon?IFN?-??and Th2?IL-4 and IL-5?cytokine levels in the sera and culture supernatants were also evaluated by enzyme-linked immunosorbent assay?ELISA?methods.In the SHPT patients,we prescribed the different dosage of activated vitamin D?Calcijex^?,Abbott.?according to the NKF K/DOQI guideline for 3 months.Repeated previous cell culture and ELISA exam were done after 3 months.Patients' outcome and clinical condition were followed and analyzed during the study period.Results We divided the patients into 2 groups?vitamin D deficiency?VDD?:<20 ng/ml in vitamin D and non-vitamin D deficiency?NVDD?:?20 ng/ml in vitamin D?according to their 25?OH?D level.In the VDD group,the Th2 cytokine?IL-4 and IL-5?were lower in the sera,the Th1cytokine?IL-2 and IFN-??were higher and Th2 cytokine?IL-4 and IL-5?were lower in the culture supernatant.Besides,the T cell differentiation was towards to Th1 type in the VDD group,but Th2 type in the NVDD group.The T cell differentiation was not influenced by biochemistry examinations,such as albumin,hematocrit,calcium,phosphate,creatinine or dialysis vintage.After treatment with activated vitamin D in the SHPT patients,we found no significant difference in the serum iPTH and 25?OH?D level.However,the level in Th1 cytokines was decreased and that of Th2 cytokines were both increased in the sera and the culture supernatant.The T cell differentiation was also more towards to Th2 phenotype than Th1 phenotype.The mortality cases were found with prevalent Th1 cell differentiation and vitamin D deficiency.Conclusion T-cell differentiation is only correlated with serum25?OH?D level.The higher vitamin D in the sera,the more prevalent in Th2 cytokines and Th2 differentiation are found.Treatment with activated vitamin D also influences the T cell differentiation and cytokines expression in the SHPT patients.Because Th2 cell has the anti-inflammatory effect,activated vitamin D treatment may not only have therapeutic potential for secondary hyperparathyroidism,but also can improve the immune response in the chronic HD patients.