Skin Prick Test Reactivity to Recombinant Latex Allergens

Abstract

Background: Allergy to latex has become a serious and increasingly common health 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) reactivity of six recombinant latex allergens with SPT reactivity to natural rubber latex proteins in known latex-allergic individuals. Methods: Six recombinant proteins were expressed in Escherichia coli, and tested as the intact fusion proteins (Hev b 2, 5, 6, 8) or as purified proteins (Hev b 3 and 7). SPT with the six recombinant latex allergens was performed using 10-fold serial dilutions on 31 latex-allergic subjects to determine the level of reactivity to each recombinant allergen. Latex-specific IgE was determined using the AlaSTAT assay. Results: All six recombinant allergens were reactive by SPT in at least 1 latex-allergic patient but not in any of the control patients. The frequency of sensitization to the various recombinant allergens was similar to previous studies using the native proteins isolated from 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. Conclusion: Recombinant latex allergens are clinically reactive, can be produced in a standardized manner, and could potentially provide safe, sensitive and specific reagents for the diagnosis of latex allergy.

Hypoallergenic Variants of the Major Latex Allergen Hev b 6.01 Retaining Human T Lymphocyte Reactivity

“…Hev b 6.01 and the other major latex glove allergen Hev b 5, are important triggers of occupational asthma and allergy (36,38). The association of Hev b 6.01 sensitization with the development of latex-fruit syndrome further emphasizes the importance of this allergen and the desirability of a safe and effective desensitizing vaccine.…”

“…As monosensitization to Hev b 6.01 is uncommon (38), any potential immunotherapy preparation would require the use of more than one hypoallergenic recombinant latex allergen or derived synthetic peptide. Hev b 5 and Hev b 6.01, particularly the Hev b 6.02 domain, are the two major allergens for individuals sensitized by latex glove use and these Ags should be targeted in a latex immunotherapy "vaccine" for this patient group (44).…”

Allergic Rhinitis and its Impact on Asthma (ARIA) 2008*

“…Recombinant DNA technology allows the production of pure biochemically characterized proteins. Skin tests with recombinant allergens were available in the 1990s for pollens (1199), molds such as Aspergillus (1200), mites (1201,1202), venoms (1203,1204) or latex (1205). Skin tests with recombinant and natural allergens have a similar value (1206)(1207)(1208)(1209)(1210) if the recombinant allergens have been well selected and represent all or most epitopes of the natural allergen (1211)(1212)(1213)(1214).…”

<i>Hevea brasiliensis</i> Latex Allergens: Current Panel and Clinical Relevance

“…Yagami et al [24] described that the carbohydrate structures of Hev b 2 were the major IgE-binding epitopes. Based on these findings, it is not surprising that in one study performed with a recombinant Hev b 2 expressed in E. coli only 7% positive responses were detectable in SPTs [25]. Nor did Raulf-Heimsoth et al [26] observe any responses to their recombinant Hev b 2.…”