SAN DIEGO-Sublingual immunotherapy (SLIT) is effective in controlling allergic symptoms in a preliminary patient cohort, according to a study presented April 27 at the Combined Otolaryngology Spring Meeting. Offered as part of the American Rhinologic Society program, the study looked at SLIT as an alternative to traditional subcutaneous immunotherapy (SCIT), which has resulted in several documented deaths and raised safety concerns.
Presenter Sarah K. Wise, MD, rhinology fellow and clinical instructor at the Medical University of South Carolina in Charleston, told the audience that SLIT is routinely performed in Europe but has not been as popular as SCIT in the United States, in spite of reports of a shorter escalation period, few cases of systemic reactions, and easy administration by patients at home. Although the World Health Organization and the European Academy of Allergology and Clinical Immunology concluded in 1998 that SLIT is a viable alternative to SCIT, it has not yet been approved by the US Food and Drug Administration.
Although worldwide studies have shown decreased allergy symptom scores, reduction in allergy medication use, improved quality of life, decreased bronchodilator use, decreased frequency of asthma exacerbations, and increased FEV1 and peak expiratory flow, US studies assessing the efficacy of SLIT are lacking, Dr. Wise said.
Structure of the Study
In the South Carolina study, patients with seasonal and perennial allergic rhinitis and/or allergic fungal sinusitis (five males and 10 females) with appropriate allergen reactivity on skin testing were given the option to pursue immunotherapy by traditional SCIT or by SLIT. Patients choosing SLIT completed the Mini-Rhinoconjunctivitis Quality of Life Questionnaire (mRQLQ), a 14-item forced-choice Likert-type questionnaire, at baseline and during SLIT maintenance therapy. Patients typically reached maintenance therapy in five weeks.
Dr. Wise said that maintenance mRQLQ showed statistically significant improvement in 12 of 14 domains, including impact on regular and recreational activities, sleep, nose rubbing and nose blowing, stuffy nose and runny nose, itchy eyes, sore eyes, watery eyes, thirst, and tiredness. Additionally, total RQLQ score showed statistically significant improvement (p = 0.001) as early as six weeks after initiation of therapy. Baseline total mRQLQ score of 27.8 decreased to 12.6 during maintenance. Maintenance mRQLQ was assessed at a mean of 2.9 months, with a range of five weeks to seven months.
Safety and Efficacy
One of the biggest arguments for SLIT is its safety profile, Dr. Wise told COSM participants, noting few reports of systemic reactions, as compared to SCIT systemic reaction rates of 0.5% to 5.6%. The typical side effects of SLIT, she said, are oral itching, stomachache, and nausea, with very rare withdrawal rates from SLIT studies for adverse reactions.