The Homestasis Of Regulatory T Cells In Patients With Acute Coronary Syndrome

Objective: To investigate the subsets and apoptosis of regulatory T cells (Treg) in patients with acute coronary syndrome based on our previous studies.Methods: A total of 109 subjects were enrolled in our study, including 18 patients with st-elevation myocardial infarction (STEAMI), 64 patients with NSTACS (including NSTEAMI and UA), 12 patients with chronic stable angina (CSA)and 15 patients with chest pain syndrome (CPS ). The peripherial lymphocytes were isolated using gradient-density confriguration. The ration of CD4~+CD25~+CD127-CD45RO~+ -CD45RA- memory Treg (mTreg), CD4~+CD25~+CD127-CD45RO-CD45RA~+ naive Treg (nTreg) , CD4~+CD25~+CD127-CD45RO-CD45RA~+TCD31~+ recent thymic emigrants-naive Treg (RTE-nTreg)and AnnexinⅤ~+7-AAD-CD4~+CD25~+CD127- in CD4~+CD25~+CD127-total Treg were analyzed using flow cytometry. 12 cases with ACS, 12 cases with CSA and 12 cases with CPS were also included and CD4~+CD25high Treg were purified by magnetic activated cell sorting (MACS), and T-cell receptor excision circles (TREC) in the purifed Treg were determined by realtime-PCR.Results: The frequencies of mTreg and nTreg in total Treg were comparable among the STEAMI, NSTACS, CSA and CPS group. In contrast, the frequency of RTE-nTreg in total nTreg significantly decreased in both STEAMI group (16.91±7.90) and NSTACS group (20.39±10.31) compared to CSA group (29.78±9.86) and CPS group (31.54±10.52) (p<0.01). The frequency of apoptotic Treg in total Treg increased in the group of STEAMI group (18.42±10.93) and NSTACS group (16.24±9.67) increased compared with CSA group (12.76±6.52) and CPS group (11.38±4.85) , but the differences were not significant (STEAMI vs CSA, p=0.122; STEAMI vs CPS, p=0.068; NSTACS vs CSA, p=0.235; NSTACS vs CPS, p=0.170). The copies of TREC were also markedly lower in the ACS group (1.06±0.48) than in the CSA group (1.98±0.69) and CPS group (2.26±0.98) (p<0.05).Conclusion: Our data demonstrated that the frequency of RTE-nTreg in total Treg and the the copies of TREC in purified Treg significantly decreased in STEAMI and NSTACS patients compared to CSA and CPS patients, suggesting that Treg homeostatis was disturbed in patients with ACS.