Measurement of recent thymic output function in uremia patients who underwent maintenance hemodialysis

Objective To determine the recent thymic output of naive T cells in patients with uremia who underwent maintenance hemodialysis(MHD). Methods Fifteen consecutive patients with uremia were recruited from Affiliated Oncology Hospital of Zhengzhou University between October 2010 and October 2011 and were subjected to detection of T cell receptor excision DNA circles(TRECs) in peripheral blood mononuclear cells(PBMCs) prior to and after MHD via real-time polymerase chain reaction(TaqMan).And the level of TRECs was calculated based on the positive rate of CD3+T cells in peripheral blood.The peripheral blood drawn from 10 age-matched healthy individuals served as normal control. Results Prior to initial dialysis,15 patients who underwent MHD were found to have considerably lower level of TREC[(0.48±0.39)copies/1000 PBMCs and(1.03±0.57)copies/1000 CD3+T cells;P=0.0014 and 0.0067,respectively] as compared with normal controls.Higher between-subject variation in peripheral blood TREC [(0.41±0.36)copies/1000 PBMCs and(1.33±1.46)copies/1000 CD3+T cells;P=0.0008 and 0.019,respectively] was shown at months 2 to 6 after MHD yet these levels remained remarkably lower than that of normal controls.The difference with pre-treatment level did not yield statistical difference(P0.05). Conclusion Patients who underwent MHD are featured by markedly impaired recent thymic output naive T cell immunity prior to initial dialysis and at months 2 to 6 thereafter.Low recent thymic output function may contribute to cellular immunity defect.