A comparison of electrochemiluminescence and flow cytometry for the detection of natural latex-specific human immunoglobulin E.

In vitro correlates of type 1 hypersensitivity to natural latex (NL) proteins continue to be limited by both sensitivity and specificity. Methods which have detection limits in the picogram range, namely, radioallergosorbent assays (RAST) and enzyme-linked immunosorbent assays (ELISA), are inadequate for the identification of NL hypersensitivity in certain at-risk groups, such as health care workers. A flow cytometry assay (FCA), previously shown to be comparable to RAST and ELISA in the identification of NL-sensitized pediatric patients with spina bifida, was compared with electrochemiluminescence (ECL) in the evaluation of pediatric patients with spina bifida and NL-sensitized adult health care workers. As with RAST and ELISA, ECL is capable of detecting picogram amounts of specific analyte. The ECL assay detected NL-specific immunoglobulin E (NL-IgE) in three of six health care workers with strong histories of NL hypersensitivity. All six patients were negative by FCA. Further, 2 of 11 spina bifida patients found to be NL-IgE negative by FCA were NL-IgE positive by ECL. These findings suggest that in sensitivity the ECL assay is an improvement over the FCA for the identification of NL-sensitive individuals.