[Prevalence and clinical meaning of insulin-specific IgE antibodies].

Systemic and local reactions to insulins in patients affected by insulin-dependent diabetes are uncommon but may be life threatening. Both systemic and local adverse reactions to therapy may be managed by different therapeutic schemes. The availability of human (DNA recombinant) insulin raised hopes that this be the choice treatment for allergic complications. However, controlled studies showed that reaginic (IgE) antibodies are directed to common insulin determinants and not to heterologus protein contaminants. Therefore we investigated in 62 patients undergoing insulin therapy, prevalence and clinical significance of the detection of specific IgE to insulin. Furthermore, we searched for a relationship between atopic status and the presence of antiinsulin IgE. In our study prevalence of specific IgE to insulin was 16.1%. We showed a correlation between clinical symptoms and the presence of specific IgE to insulin, when these antibodies are of an elevated class (R.A.S.T. class 2 or more). When specific IgE were present we detected antibodies to all insulines (bovine, porcine and human) thus confirming that specific IgE are directed to a common antigenic determinant. Finally, we couldn't find a relationship between atopic status and the presence of reaginic antibodies to insulin.