Journal of Clinical and Diagnostic Research (Apr 2012)
A Prospective Quasi-Experimental Study on the Effect of Sub-Lingual Immunotherapy with Multiple Allergens in Allergic Bronchial Asthma
Abstract
Background: Sub-lingual immunotherapy (SLIT) has been introduced as a disease modifying agent for allergic bronchial asthma in many countries and currently practicing in India. Aims: To assess the outcome of adding multiple-allergen sublingual immunotherapy with rescue medicines in patients having allergic bronchial asthma and to document adverse events, if any. Settings and Design: This was a clinic-based prospective quasiexperimental study. Methods and Material: Patients giving consent to receive multiple-allergen SLIT and rescue medicines formed the experimental group (Group A) while patients who did not give consent to SLIT but wished to have only rescue medicines formed the comparison group (Group B). Follow-up was done up to three years. Initially 703 patients were in Group A and 313 in Group B. However, around 647 patients in Group A and 282 in Group B completed the study for three years. Statistical Analysis: Unpaired t- test was used to compare the difference between the mean symptom and medication scores in Group A and Group B, before intervention and at the end of the study. Paired t- test was applied to compare the mean scores before and after intervention for each group separately. Results: Mean symptom scores of the two groups did not vary significantly before intervention but found to be significant at the end third year [8.60 (SD 3.92) v 14.73 (SD 4.42), P<0.001). In both groups mean symptom scores decreased from the baseline but it differed significantly in Group A only [15.46 (SD 4.88) v 8.60 (SD 3.92), P<0.001]. The mean medication scores between the two groups also differed significantly at the end of the third year [1.60 (SD 0.31) v 2.98 (SD 0.44), P<0.001)]. The scores also decreased in both the groups from the baseline, but significantly only in Group A [3.10 (SD 0.50) v 1.60 (SD 0.31), P<0.001]. Around 6.4% (45/703) patients receiving SLIT complained of mouth and throat irritation and about 3.7% (26/703) complained of mild vomiting. It can be concluded that long term sub-lingual immunotherapy in addition to rescue medicines significantly improves both symptom and medication scores with a high degree of safety.
