Immediate-type allergic reactions to natural rubber latex are characterized by the appearance of circulating latex allergen-specific immunoglobulin E (sIgE) antibodies. In addition to taking the patient history and clinical testing, diagnosis of latex allergy is routinely based on the determination of sIgE to latex. Since latex allergy can have serious consequences, an accurate diagnosis is very important.

In this study, we examined the clinical performance of a new latex sIgE test (CLA system, Hitachi Chemical Diagnostics) by comparing its results to other laboratory tests for sIgE (CAP-Pharmacia/Microplate (MP) and Immulite 2000 (I2K)-Diagnostic Products Corporation), to skin prick testing, and to the results of the challenge test with a latex-containing glove. The study population involved 30 latex-allergic patients, 6 latex-sensitized individuals without symptoms and 16 controls.

The sensitivity to detect latex-allergic patients of the various in vitro tests for latex sIgE ranged from 0.57 (DPC-MP), 0.6 (CLA), 0.7 (CAP) to 0.73 (DPC-I2K). The highest specificity was 0.86 (CLA and DPC-MP) compared to 0.73 (CAP and DPC-I2K). The comparable values for sensitivity and specificity of the skin prick test with latex extract were 0.73 and 1.0. None of the tests gave a positive result with any of the 16 control individuals.

Laboratory testing for sIgE is an important part of the diagnostic work-up of latex-allergic patients. The new latex sIgE test provided on the already established CLA system shows good sensitivity and specificity in latex allergy and can be considered as a valuable tool for laboratory diagnosis in the future.