Immunotherapy with depigmented glutaraldehyde-polymerized extracts: changes in quality of life

Immunotherapy (IT) with modified allergens reduces allergic rhinitis (AR) symptoms and medications requirements. Improvement of quality of life (QOL) is a key point in the treatment of AR. The aim of this study was to provide evidence of changes related to the patient's QOL (well-being) induced by a modified (depigmented glutaraldehyde-polymerized) therapeutic vaccine and of its safety.

Fifty-three patients with a well-documented clinical history of seasonal AR sensitized to Dactylis glomerata and Olea europaea pollens were included in a randomized clinical trial. Twenty-five patients (Group-A) received a mixture of D. glomerata and O. europaea pollen extracts and 28 patients received placebo (group-C). Any adverse event was recorded and graded in accordance with EAACI guidelines. RQLQ was recorded before the treatment (pollen season 2000) and after 1 year of treatment (pollen season 2001). Dose-response skin prick test with each allergen extract was conducted at baseline and at the end of the study.

Each patient received 17 injections during this period. All patients completed the trial and no systemic adverse reactions were recorded. Symptom scores (P<0.001) and medication requirements (P<0.001) were significantly reduced in the IT group during the pollen season. This patient group also experienced greater and statistically significant improvement in overall RQLQ score and in five of the seven domains, all of them surpassing the threshold of 'minimal important difference' of 0.5 points.

Results of this study provided evidence that IT with depigmented, glutaraldehyde-modified allergen extracts was well-tolerated and added beneficial effects to AR treatment in pollen allergic patients eliciting an improvement in QOL enough to justify a change in the patient's treatment.