Insulin allergy: differences in the binding of porcine, bovine, and human insulins with anti-insulin IgE.

We investigated in vitro binding of insulins of various species sources (bovine, porcine, and human) with anti-insulin reaginic immunoglobulins (IgE) in 10 patients with systemic insulin allergy and in 5 nonallergic but insulin-resistant cases. Anti-insulin IgE had a higher avidity for bovine compared with porcine insulin in both groups. Avidity for bovine insulin was also significantly higher compared with human or desalanine porcine insulin in the insulin-allergic patients. These observations provide a rationale for using porcine insulin in the treatment of systemic insulin allergy.