Measurement of natural rubber latex allergen levels in medical gloves by allergen‐specific IgE‐ELISA inhibition, RAST inhibition, and skin prick test

Abstract

Exposure to natural rubber latex (NRL) medical gloves poses risks to patients sensitized to NRL and to users of protective gloves. Previous studies have shown that extractable allergen levels of the gloves vary widely. Since most of the available laboratory methods of NRL allergen measurement lack adequate validation, we wanted to evaluate the performance of a recently developed competitive IgE-ELISA-inhibition method in relation to the skin prick test (SPT) and RAST inhibition, as well as to extractable protein quantification and an immunochemical latex antigen assay (LEAP). Twenty samples of surgical (n = 14) and examination gloves (n = 6), covering > 90% of medical gloves marketed in Finland in 1994-5, were collected by the Finnish National Research and Development Centre for Welfare and Health, coded, extracted, and analyzed by the five methods. The IgE-ELISA inhibition correlated highly significantly with SPT (r = 0.94) and RAST inhibition (r = 0.96). Likewise, ELISA inhibition and RAST inhibition showed highly significant correlation (P = 0.96, P < 0.0001 in all three instances). Protein quantification by a modified Lowry method also correlated highly significantly with SPT (r = 0.80), RAST inhibition (r = 0.82), and ELISA inhibition (r = 0.81, P < 0.0001 in all three instances). Clearly weaker correlation, though statistically significant (r = 0.48, P = 0.03), was found between SPT and the LEAP assay. An NRL standard preparation was assigned an arbitrary content of 100,000 allergen units (AU) per ml. In relation to this standard, the NRL allergen level was considered low (< 10 AU/ml) in 11, moderate (10-100 AU/ml) in two, and high (> 100 AU/ml) in seven of the 20 glove brands analyzed. In conclusion, the results of a novel IgE-ELISA-inhibition method of measuring NRL allergen levels in medical gloves correlated highly significantly with those of SPT. The ELISA method was found to be sensitive, reproducible, technically easy, inexpensive, and suitable for the analysis of large numbers of NRL products. The results of extensive market surveys in 1994 and 1995, communicated to the medical community in Finland, appear to have had a clear effect in moving glove purchasing policies toward the use of low-allergen gloves.

The Major Conformational IgE-binding Epitopes of Hevein (Hev b6.02) Are Identified by a Novel Chimera-based Allergen Epitope Mapping Strategy

“…Hevein has been found to elute in large quantities from NRL products (5). The importance of hevein as a latex allergen is supported by the findings that Ͼ70% of latexallergic patients have hevein IgE antibodies (6) and that hevein elicits positive skin prick test reactions in the great majority of latex-allergic patients (1). Hevein is therefore a useful tool in the diagnosis of latex allergy as well as a potential candidate for immunotherapy.…”

“…In particular, health care workers (up to 17%) and children with a history of multiple surgeries (up to 60%) are reported to be sensitized to NRL products (1,2). Although several NRL allergens have recently been characterized at the molecular level, consensus exists that hevein (Hev b6.02) is one of the most important NRL allergens (3,4).…”

“…Natural rubber latex (NRL) 1 allergy has become increasingly common during the last decade, and a large proportion of the general population is regularly exposed to NRL. In particular, health care workers (up to 17%) and children with a history of multiple surgeries (up to 60%) are reported to be sensitized to NRL products (1,2).…”

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

“…Accurate diagnosis of latex allergy, whenever possible in a component-resolved way, is of great importance for the development and application of any specific immunotherapy. At present, the skin prick test (SPT) is considered the most reliable test for the diagnosis of latex allergy [12,13,14]. It is in this context that we review the current status of knowledge about the thirteen officially accepted latex allergens (www.allergen.org) and present available data on their frequency of recognition or reactivity in different study populations.…”

Occupational Allergy to Latex among Loom Tuners in a Textile Factory

“…The in vitro determination of specific IgE antibodies to whole latex is not always associated with clinically relevant protein sensitivity. A correct diagnosis is therefore dependent on the use of well-characterised purified allergens and, where appropriate, investigation of the allergenic material in question [6,7,8,9,10]. Once sensitised to latex, patients may experience symptoms such as itchy eyes, runny nose, sneezing, wheezing, coughing, asthma, itchy skin and urticaria and even anaphylaxis [11, 12].…”