Demonstration of anti-"a-component" antibody--a possible means to differentiate patients with auto-antibodies to endogenous insulin from insulin-treated patients.
The presence of anti-"a-component" antibody was examined in sera of 4 groups of patients with or without anti-insulin antibody, using 125I-a-component and the polyethylene glycol precipitation method. 125I-a-component crossreacted with insulin antibody. This cross-reactivity was abolished after preincubation of these sera with monocomponent insulin. The specificanti-"a-component" antibody could be estimated in this procedure. After preincubation with monocomponent insulin, significant binding of 125I-a-component was demonstrated in sera of most patients treated with ordinary commercial insulin, but not in sera of 2 hypoglycemic patients suspected of an insulin autoimmune syndrome. Some cases treated with commercial insulin for less than one year and all cases treated with monocomponent insulin for 7-10 months did not have significant anti-"a-component" antibody. The test for the presence of anti-"a-component" antibody is not definitive but if positive it differentiates "auto-antibodies" from the antibodies produced by injections of commercial insulin.
D000818:Animals; D000906:Antibodies / Q000032:analysis*; D001323:Autoantibodies / Q000032:analysis*; D001327:Autoimmune Diseases / Q000175:diagnosis; D011232:Chemical Precipitation; D003429:Cross Reactions; D003920:Diabetes Mellitus / Q000276:immunology; D004285:Dogs; D004340:Drug Contamination; D005260:Female; D007003:Hypoglycemia / Q000276:immunology; D007328:Insulin / Q000009:adverse effects; D007330:Insulin Antibodies / Q000032:analysis*; D008297:Male; D008722:Methods; D011863:Radioimmunoassay
D000906:Antibodies; D001323:Autoantibodies; D007328:Insulin; D007330:Insulin Antibodies