The Expression Of CD4~+ CD25~+ Foxp3~+ Treg In Newly Diagnosed Type 2 Diabetic Patients

CD4+ CD25+Treg cells, which have the function of immune suppression and immune anergy, are a group of cells involved in the maintenance of immune tolerance. Foxp3 is not only a specific cell marker of Treg,but also the specific functional protein of Treg. The expression of FOXP3 is the"switch"of regulatory T cell function. It was reported that the number or function of Treg is abnormal in patients with autoimmune diabetes. Lots of clinical studies suggested that many organs of type 2 diabetes patients suffered autoimmune damage. Therefore, we suspect that CD4+CD25+Foxp3+Treg may play a role in the occurrence and development of type 2 diabetes.Objective:To investigate the frequence of CD4+CD25+Foxp3+Treg in type 2 diabetes and the relationship with islet function,early-phase secretion and insulin resistance.Methods:We selected 18 newly diagnosed type 2 diabetes in our hospital(dating from September 2009 to March 2010), who were diagnosed less than 1 year, including 14 males and 4 females, 40.89±10.71 years old. They must fit the following standard: (1) the diagnose and typing standard made in 1999 by WHO; (2)all the objects didn't have acute or chronic infections, cancer, autoimmune disease, diabetic ketoacidosis, hyperosmolar state, diabetic retinopathy, diabetic nephropathy and other chronic complications of diabetes mellitus. (3)hadn't taken immuno- suppressive agents, aspirin, peroxisome proliferator-activated receptor-γagonist, lipid-lowering drugs, and any hypoglycemic agents(including insulin) one month before hospitalization. Body height, weight were measured in all of the selected objects and then we calculated the body mass index (BMI): BMI =height/weight2.All subjects were fasted for more than 8 hours, and got the venous blood at the next morning. Separating the serum to detect the fasting glucose (FPG), fasting insulin(FINS), triglyceride(TG), total cholesterol(TC), glycosylated hemoglobin(HbA1c), at the same time, taking 4-6ml of blood with EDTA anticoagulant tubes to detect the frequence of CD4+CD25+Foxp3+regulatory T cells by flow cytometry; after eating a steamed bread(100 gram), got the venous blood for postprandial 30min blood glucose and postprandial 30min insulin. According to the FPG and FINS, insulin resistance index was calculated by homeostasis model, HOMA-IR=[FINS(mU/L)×FPG (mmol/L)]/22.5. According to body mass index, the patients were divided into two groups: non-obese group and obese group. we chose 18 heathy medical workers in our hospital as control group whose body mass index are in the normal range, including 12 males and 6 females, 42.28±8.54 years old. Taking 4-6ml of blood with EDTA anticoagulant tubes from the control group to detect the frequence of CD4+CD25+Foxp3+regulatory T cells by flow cytometry.Results:(1) The percentage of CD4+CD25+Foxp3+ Treg is significantly reduced in the case group than the control group (P<0.01)(2) There was no significant difference between obese group and non-obese group in the percentage of CD4+CD25+Foxp3+Treg (P>0.05)(3) In obese group, HOMA-IR was negatively correlated with the percentage of Treg, the spearman coefficient was-0.91667, P<0.01.Conclusion:(1) The percentage of CD4+CD25+Foxp3+Treg in the newly diagnosed type 2 diabetic patients was precipitously decreased. Therefore, the newly diagnosed T2DM patients may suffer autoimmune regulatory disfunction.(2) In obese T2DM group, the percentage of Treg is negatively correlated with HOMA-IR. To increase the expression of Treg may improve insulin resistance in newly diagnosed type 2 diabetes patients with obesity.(3) Cellular immune function disorders exsists in T2DM. Therefore, the ultimate goal of immunotherapy is to achieve balance between effector T cells and regulatory T cells. Not only does it benefit to blood sugar control, but also it can reduce the incidence of infection and delay disease progression.