Skin prick test reactivity to recombinant latex allergens

Background: Allergy to latex has become a serious and increasingly common h ealth problem, particularly for healthcare workers and patients who undergo frequent surgical procedures. Testing for latex allergy currently involves in vitro tests and skin prick testing using crude preparations of natural rubber latex (NRL). To date, 10 latex proteins have received designation as allergens (Hev b 1 to Hev b 10) and, except for Hev b 4, have been cloned as recombinant proteins. Our aim was to compare the skin prick test (SPT) r eactivity of six recombinant latex allergens with SPT reactivity to natural rubber latex proteins in known latex-allergic individuals. Methods: Six re combinant proteins were expressed in Escherichia coli, and tested as the in tact fusion proteins (Hev b 2, 5, 6, 8) or as purified proteins (Hev b 3 an d 7). SPT with the six recombinant latex allergens was performed using 10-f old serial dilutions on 31 latex-allergic subjects to determine the level o f reactivity to each recombinant allergen. Latex-specific IgE was determine d using the AlaSTAT assay. Results All six recombinant allergens were react ive by SPT in at least 1 latex-allergic patient but not in any of the contr ol patients. The frequency of sensitization to the various recombinant alle rgens was similar to previous studies using the native proteins isolated fr om NRL. The minimal level of protein for a positive skin test was 70 pg/ml for NRL and 1 ng/ml for one recombinant allergen (Hev b 7). In our patients , the use of a combination of recombinant latex allergens Hev b 5, 6 and 7 diagnosed latex allergy with 93% sensitivity and 100% specificity. Conclusi on: Recombinant latex allergens are clinically reactive, can be produced in a standardized manner, and could potentially provide safe, sensitive and s pecific reagents for the diagnosis of latex allergy. Copyright (C) 2000 S. Karger AG, Basel.