NO ASSOCIATION BETWEEN ANTI-BOVINE SERUM-ALBUMIN ANTIBODIES AND ISLET-CELL REACTIVE ANTIBODIES IN NEWLY-DIAGNOSED TYPE-I DIABETIC-PATIENTS

Serological findings have suggested that antibodies (Ab) to bovine ser um albumin (BSA-Ab) are associated with type 1 diabetes mellitus. The aim of our study was to evaluate a competitive fluid-phase radioimmuno assay for detecting BSA-Ab using different incubation times and to stu dy a possible association of these BSA-antibodies with autoantibodies (AAb) frequently detected in type 1 diabetic patients. For the overnig ht incubation time, there was an enormous overlap in the [I-125]BSA bi nding by serum samples between 52 newly diagnosed type 1 diabetic pati ents (mean [I-125]BSA binding 23.6 +/- 17.4%) and 54 healthy blood don ors (mean [I-125]BSA binding 10.2 +/- 15.7%). By an incubation time of only 3 min the BSA-antibody prevalence was found to be 15.4% (8/52) f or type 1 diabetic patients and 3.7% (2/54) for control subjects, Howe ver, there was no association between BSA-Ab and type 1 diabetes-assoc iated antibodies as cytoplasmic islet cell antibodies (ICA), or glutam ate decarboxylase autoantibodies. Our results confirm that (i) BSA-Ab occur more frequently in newly diagnosed type 1 diabetic patients comp ared with a healthy control group and (ii) that the BSA-Ab detected by the fluid-phase radioimmunoassay with an incubation time of 3 min are more disease-associated than the [I-125]BSA binding after an overnigh t incubation, The competitive BSA-Ab fluid-phase radioimmunoassay desc ribed is a simple and rapid method to detect antibodies specifically r eactive with BSA. It is suggested that the humoral immune reactivity t o BSA in type 1 diabetic patients probably reflects an unspecific defe ct of the immune system and gives no additionally diagnostic value abo ut the type 1 diabetes.