胰岛素自身抗体影响胰岛素测定及作用的临床及试验分析二例报道

Clinical and experimental analysis of the insulin autoantibody interference on clinical features and real-time insulin determination:Two cases report

目的分析IAA(+)、FIns>300μU/ml的2例T2DM患者,明确IAA对胰岛素测定及作用的影响。方法以零胰岛素标准品稀释血清测定直接胰岛素,聚乙二醇沉淀法检测游离胰岛素,酸解法检测总胰岛素,采用相同方法同步处理IAA(-)的高胰岛素血症患者血清并作为对照,比较试验组和对照组血清直接胰岛素、游离胰岛素和总胰岛素水平。结果两患者直接胰岛素水平分别为15144.0、4563.2μU/ml,去除IAA干扰后,两患者游离胰岛素、总胰岛素水平均降低,且游离胰岛素低于总胰岛素水平。同法检测IAA(-)的高胰岛素血症患者,其直接胰岛素、游离胰岛素、总胰岛素水平基本一致。结论 T2DM患者应用外源胰岛素后可诱导机体产生IAA,导致血胰岛素测定值假性增高,并干扰胰岛素作用,引起重度IR或自发性低血糖。

Objective To analyze the reason of the extremely high serum insulin in two T2 DM patients,whose IAA were positive but one developed＂extreme insulin resistance＂（IAA that combines free insulin makes it ineffective）,another developed daytime hyperglycemia and nighttime hyperglycemia（free insulin is released from Ag/Ab complex）.Methods Firstly,we diluted the serum with zero-insulin standard solution and determined the direct insulin.Secondly,mixing PEG with serum and centrifugation of precipitation were performed,then we determined the free insulin.Thirdly,after treating the serum with acid solution,we determined the total insulin.Results The direct insulin concentrations of two patients were 15144.0,4563.2μU/ml respectively.Compared with the direct insulin concentrations,the free insulin and total insulin were decreased significantly after the removal of IAA-Ab/Ag complex precipitation interference.For normal control,no such phenomenon was observed.Conclusion IAA interference induced by exogenous insulin leads to ＂false insulin resistance＂（Ag/Ab complex）related hyperglycemia and Ag/Ab complex-released free insulin related hypoglycemia during insulin treatment.