Latex allergy: review of recent advances

Opportunities and obstacles in translating evidence to policy in occupational asthma

PURPOSE

Occupational asthma (OA), a common respiratory disorder in Western countries, is caused by exposures at the workplace. It is part of a broader definition of work-related asthma (WRA) that also includes pre-existing asthma aggravated by substances present in the workplace environment, and it is potentially preventable. The purpose of this paper is to illustrate preventive measures for occupational asthma by case studies.

METHODS

In three case studies we discuss preventive measures that have been associated with reductions in incidence of occupational asthma from natural rubber latex and from diisocyanates as supported by published literature. We also discuss challenges in relation to asthma from cleaning products in healthcare work.

RESULTS AND CONCLUSIONS

Several preventive measures have been associated with reduction in incidence of occupational asthma from natural rubber latex and from diisocyanates, and may provide lessons for prevention of other causes of occupational asthma. Cleaning products remain an unresolved problem at present with respect to asthma risks but potential measures include the use of safer products and safer applications such as avoidance of spray products, use of occupational hygiene methods such as improving local ventilation, and when appropriate, the use of personal protective devices.

Latex immunotherapy: state of the art

OBJECTIVE

Latex allergy remains a significant problem, especially among certain professional categories, and specific immunotherapy has been suggested as a suitable therapeutic option. The objective of the this article is to review the available literature on clinical trials of specific immunotherapy in latex allergy.

DATA SOURCES

Literature databases (PubMed, Embase, Google Scholar) were searched for latex immunotherapy clinical trials.

STUDY SELECTIONS

Clinical trials (either open or randomized controlled) using subcutaneous or sublingual immunotherapy with latex extracts were selected. Only articles published in English in peer-reviewed journals were considered. Case reports quoted in the clinical trials were also described, when pertinent.

RESULTS

Eleven clinical trials (3 with subcutaneous and 8 with sublingual immunotherapy) were identified. Two of the 3 randomized trials of subcutaneous immunotherapy reported some benefit in adults but a remarkable occurrence of side effects. Concerning sublingual immunotherapy (SLIT), there were 6 randomized placebo-controlled (1 in children), 1 randomized open, and 1 open trials. All but 1 trial reported positive results, and the safety profile was overall superior to injection immunotherapy. The overall quality of the study was moderate, and the number of subjects studied was low.

CONCLUSION

Although guidelines do not consider allergy to latex as an accepted indication to desensitization, SLIT can be offered, in addition to symptomatic treatment, to selected patients, when avoidance measures are not feasible or effective.

New diagnostic classification of allergic skin disorders

PURPOSE OF REVIEW

To highlight the importance of one common nomenclature for allergic skin disorders.

RECENT FINDINGS

Diseases are best defined on the pathophysiological mechanisms underlying the symptoms. Although the mechanisms behind what is sometimes unfortunately referred to as 'atopic eczema' or 'atopic dermatitis' have been quite well understood for 30 years the present terms used are confusing. Over the years more than 20 different names have been used.

SUMMARY

Doctors, scientists and patients in the field of allergy must use one and the same terminology for allergic diseases or the result will be confusion. Diagnosis, prevention, treatment, patient advice, environmental relations, and the search for genetic markers are examples of areas that will be hampered by conflicting results. Strong efforts should be invested into broadly implementing the European Academy of Allergology and Clinical Immunology (EAACI) revised nomenclature for allergy.

Recent developments in latex allergy

PURPOSE OF REVIEW

Immediate allergic reactions to natural rubber latex continue to be an important medical and occupational health problem. In this review we focus on progress made in understanding the significance of occupational exposure and epidemiology, risk groups, diagnosis and prevention of natural rubber latex allergy. We also discuss methods aimed at quantification of clinically relevant natural rubber latex allergens and studies on B-cell epitopes of major natural rubber latex allergens.

RECENT FINDINGS

Prospective studies have been published focusing on the prevention of natural rubber latex allergy. Efforts to identify and characterize new natural rubber latex allergens were continued in several research groups. The use of purified allergens or proteins produced by recombinant DNA technology was assessed in studies aimed at improving the diagnosis of natural rubber latex allergy as well as in developing quantitative methods for the measurement of specific natural rubber latex allergens. For the first time, conformational immunoglobulin E epitopes were identified in a major natural rubber latex allergen, hevein, using a novel chimera-based allergen epitope mapping strategy.

SUMMARY

Measures taken in health care to reduce exposure to natural rubber latex products seem to be effective in reducing the number of new sensitizations. A few new minor natural rubber latex allergens, probably important in allergen cross reactions, were identified, and some nonmedical natural rubber latex products were found to be potentially dangerous to natural rubber latex-allergic patients. Sensitive and specific immunoassays for quantification of clinically relevant natural rubber latex allergens in manufactured products were developed in some laboratories. These assays may eventually replace the nonspecific total protein measurement, currently advocated by health authorities in the indirect estimation of allergen amounts in natural rubber latex products. Knowledge about conformational immunoglobulin-binding B-cell epitopes of major allergens is expected to be helpful in designing optimal reagents to specific immunotherapy.