Is there a role for immunoblots in the diagnosis of latex allergy? Inter-method comparison of in vitro and in vivo IgE assays in spina bifida patients

Background: The best diagnostic method for latex allergy is still controver sial. This investigation was designed to evaluate the diagnostic efficiency of immunoblotting in comparison with established ipl vitro and in vivo tes t systems. Methods: A total of 108 spina bifida patients were investigated by question naire and skin prick test (SPT). Specific serum IgE to latex was analyzed b y the Pharmacia CAP FEIA immunoassay, DPC AlaSTAT microplate immunoassay, a nd DPC AlaBLOT immunoblot. Patients were regarded as latex allergic if they reacted positively to challenge by the late?: glove wearing test. Results: Thirty-four patients reacted positively to challenge. The sensitiv ity rates were 97% (SPT), 94% (immunoblot, CAP), 74% (AlaSTAT), and 35% (cl inical history). The specificity rates were 92%, (clinical history), 88% (A laSTAT), 77% (SPT), 76% (CAP), and 69% (immunoblot). If two methods were co mbined. efficiency rates were highest for SPT combined with CAP (sensitivit y 94%, specificity 82%), with AlaSTAT (sensitivity 74%, specificity 92%), o r with immunoblot (sensitivity 91%, specificity 84%). The sera of challenge -positive patients recognized more immunoblot bands than challenge-negative patients, and the severity of symptoms correlated with the number of recog nized bands. Conclusions: The diagnostic efficiency of immunoblotting is not superior to that of SPT. However, immunoblotting may serve as an additional tool to in crease slightly the specificity of SPT and specific serum IgE tests.