AUTOIMMUNE HYPOGLYCEMIA SYNDROME DUE TO S PECIFIC ANTI-HUMAN INSULIN-ANTIBODIES

A 33 year old woman with episodes of severe hypoglycemia is presented. The studies showed anti-insulin antibodies and variable C-peptide lev els. Circulating insulin measured after acid-ethanol extraction, was o f 1,600 uU/ml and shown to be human insulin after characterization by HLPC. Specific anti-human insulin antibodies were of high affinity (Ka (1): 6.20 x 10(10) M(.1); Ka(2), 2.42 x 10(9) M(-1)). A small cross-re active porcine and bovine antibody subpopulation was also detected (Ig G, light k type chain). Plasmapheresis was undertaken when symptoms we re spontaneously declining and turned antibody title negative. Prolong ed folkow-up showed no relapse of this syndrome.