Will sublingual immunotherapy with cockroach allergen work in the inner city?
Published Online: November 4, 2013
The combination of cockroach allergy and cockroach exposure is one of the most important factors contributing to the high morbidity seen in inner-city children with asthma. One of the major initiatives of the NIAID-sponsored Inner City Asthma Consortium (ICAC) has been to develop treatment strategies which target cockroach allergy as a way to improve asthma outcomes in this population. Sublingual immunotherapy (SLIT) has been the focus of this program because of the growing body of literature supporting its efficacy and safety profile.
In a recent article in The Journal of Allergy & Clinical Immunology (JACI), Wood et al. describe four pilot clinical trials designed to gather preliminary data on cockroach immunotherapy: 1) an open label 2-week study to assess the safety of cockroach SLIT in adults and children; 2) a randomized, double-blind 6-month study of cockroach SLIT versus placebo in adults; 3) a randomized, double-blind 3-month study of two doses of cockroach SLIT versus placebo in children; and 4) an open-label 6-month safety study of cockroach subcutaneous immunotherapy (SCIT) in adults. In the last three studies, the researchers collected blood at multiple study visits to measure changes in certain markers of the response to treatment (IgE, IgG, IgG4, and blocking antibodies).
No safety concerns were raised in any of the studies. The researchers found increases in the blood biomarkers of adults and children receiving active immunotherapy compared to placebo in the two SLIT studies; however, those increases were modest and less than anticipated. Because SLIT must be taken daily at home, not all participants received all their doses, which may have been one reason for the lack of response. Much larger responses to treatment were seen in the adult SCIT study.
The researchers concluded that the administration of cockroach allergen by SCIT is immunologically more active than SLIT, especially with regard to IgG4 and blocking antibody responses. They suggest that SCIT is likely to be a better option for cockroach immunotherapy in the inner-city population.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.