老年糖尿病患者血清胰岛自身抗体检测的意义

Significance of detection of serum autoantibodies to pancreatic islet cells in elderly patients with diabetes

目的 研究老年糖尿病患者血清胰岛自身抗体与临床表现的关系。方法 观察老年糖尿病住院患者的临床、生化特征及血清C肽、胰岛细胞抗体 (ICA)、谷氨酸脱羧酶抗体 (GADA)、蛋白酪氨酸磷酸酶抗体(IA 2A)水平。结果 临床初诊为 2型糖尿病、年龄在 6 0岁以上的 4 15例老年患者中 ,13.4 9%有 1种以上抗体阳性。将患者按血清抗体阳性或阴性分组 ,与抗体阴性组相比 ,抗体阳性组的体重指数 (BMI)低 ,空腹及餐后 2h血清C肽水平较低 ,其中接受胰岛素治疗者比例较高 ,在病程中发生酮症者较多。进一步按不同抗体亚组分析 ,在GADA及IA 2A抗体阳性亚组中C肽水平降低更趋明显。结论 部分老年糖尿病患者血清出现胰岛特异性抗体 ,提示糖尿病的发生与自身免疫反应有关 ,GADA及IA 2A阳性者胰岛功能衰退更明显。

Objective To investigate the relevance of serum islet autoantibodies and clinical characteristics in elderly patients with diabetes. Methods The general clinical and biochemical characteristics were investigated in a group of hospitalized elderly diabetic patients. The serum antibodies to glutamic acid decarboxylase (GADA), islet cell cytoplasmic antigens (ICA),or protein tyrosine phosphatase (IA 2A) were determined by immunofluorescence method or commercial kits.Results Among the 415 patients diagnosed as type 2 diabetes and aged more than 60 years, 13.49% showed at least one positive serum antibody. According to their serum antibodies, property the patients were divided into two groups: group with positive antibody and group with negative antibody. The patients with positive antibody showed lower BMI, fasting and 2 h postprandial C peptide levels, among these, those receiving insulin treatment before having more frequent ketosis during the course of diabetes had higher level as compared with those patients with negative antibody. To analyse the subgroups of patients with different antibodies, we found that those with positive GADA and IA 2A had more significant decrease of Cpeptide.Conclusion In some of the elderly diabetic patients specific positive serum antibodies to islet cells are present. This suggests the development of diabetes is relevant to autoimmune reaction. Patients with positive serum GADA and IA 2A would expect more significant deteriorating pancreatic β islet cell function.