An investigation of possible immunologic reactions to human serum albumin used as a stabilizer in allergy extracts.

Two hundred fifteen patients who had received allergy immunotherapy for at least 1 year with an extract preparation containing 0.03% human serum albumin (HSA) were tested for evidence of an immunologic reaction to HSA by immediate skin testing. Sera from 39 of these subjects and from control subjects were studied in a microtiter enzyme-linked immunosorbent assay for anti-HSA antibodies. The 39 subjects' sera were examined by immunoelectrophoretic analysis for evidence of "tailing albumin" indicative of HSA bound to immunoglobulins. All studies were negative. We conclude that in these patients HSA-containing allergy extracts used in immunotherapy failed to induce the production of specific antibodies against HSA. This suggests that HSA was a safe extract stabilizing agent for allergy extracts in these representative allergic patients.