Cockroach allergy and allergen-specific immunotherapy in asthma

Abstract

Purpose of review To provide a summary and discussion of cockroach allergy and clinical trials of cockroach allergen immunotherapy. Recent findings Cockroach allergen exposure among sensitized children is increasingly recognized as a key factor contributing to asthma morbidity. Recent trials suggest that cockroach immunotherapy has promise as a treatment strategy with studies demonstrating immunomodulatory and clinical effects. However, a few obstacles need to be overcome to realize the full potential of this treatment modality as cockroach allergic patients often exhibit complex sensitization patterns to multiple cockroach-associated proteins and an immunodominant allergen has not been identified. These factors have made it difficult to produce standardized cockroach allergen extracts that are potent and provide the broad allergen profiles needed for optimal treatment. There have been important advances in the identification and cloning of cockroach allergens and several strategies are being developed to provide therapeutic cockroach allergen products with enhanced clinical efficacy. Summary Allergen immunotherapy has the capability of modulating the immune response to cockroach allergen and has potential as a valuable treatment modality. Further studies of the clinical efficacy along with the development of improved therapeutic products are needed to advance our knowledge and realize the full potential of this promising therapy.

New Insights into Cockroach Allergens

“…A limited number of clinical trials using cockroach allergen extracts showed improvement in both immunological and clinical parameters [59,117] (Table 2). Kang et al in 1988 reported in a small number of patients (n = 11) that immunotherapy with cockroach extract resulted in improvement of immunological and clinical parameters after five years of treatment [118].…”

“…The pediatric SLIT study (n = 99) revealed significant differences in IgE, IgG, and IgG4 responses between both active groups and the placebo group but no consistent differences between the high- and low-dose groups. The SCIT adult study (n = 10) found that the treatment resulted in significant changes from baseline in cockroach IgE, IgG4, and blocking antibody levels [117]. No further clinical trials conducted with cockroach extracts have been reported.…”

Cockroach allergen exposure and risk of asthma

“…Thus, it is essential to have the standardized cockroach extracts with reliable potency and contents for the diagnosis of cockroach allergy. Similarly, cockroach immunotherapy for cockroach allergy holds promise as a treatment strategy with immune-modulatory and clinical effects in a limited number of trials (22-25), but the lack of standardized cockroach extracts limit their potential to provide optimal clinical efficacy to patients. Thus, further works are needed to identify major allergenic components in cockroach and clone immunodominant cockroach allergens in order to provide therapeutic cockroach allergen products with enhanced clinical efficacy.…”

Inner-city asthma

“…However, the utility of immunotherapy and its effect on allergic asthma has been disputed [47][48][49]. The clinical effectiveness of immunotherapy with cockroach and mouse extracts for asthma or allergic rhinitis has been investigated in only a limited number of studies [50][51][52]. This has prompted the National Institute of Allergy and Infectious Diseases to develop cockroach and mouse extract immunotherapy protocols, with the intent to develop new therapies for cockroach and mouse allergy.…”