Assessment of short-term changes induced by a Dermatophagoides pteronyssinus extract on asthmatic patients. Randomised, double-blind, placebo-controlled trial.

BACKGROUND: Once the optimal dose is reached, subcutaneous immunotherapy [SCIT] with mite extract is capable of reducing symptoms and the need for rescue medication. OBJECTIVE: To assess the capacity of a subcutaneous extract of mites [D. pteronyssinus] to bring about a reduction in concomitant medication as well as in vivo and in vitro changes in just 2-3 months of treatment in patients with allergic asthma. METHODS: A total of 45 patients with persistent mild-moderate allergic asthma due to sensitisation to D. pteronyssinus were included in a multi-centre, double-blind, placebo-controlled trial. Length of treatment was 4 months. After a period for adjusting medication in order to classify asthma severity appropriately, patients were commenced on treatment of 400 or 800 g/day of budesonide as concomitant medication. RESULTS: After 4 months of treatment there were no significant changes in the budesonide dose between the active group and the placebo group. In the active group there was a significant difference between active and placebo group in sIgG4 [p=.0003], as well as a significant increase in the cutaneous tolerance index [2.81, CI 95%: 1.29 - 7.48, which was significant with a Confidence Interval of 95%]. These changes were not observed in the placebo group. CONCLUSION: After just 4 months of treatment, SCIT was capable of inducing in vivo and in vitro changes, but these changes were not reflected in improved clinical outcome within the first 4 months of therapy.

Systemic tolerability of specific subcutaneous immunotherapy with index-of-reactivity-standardized allergen extracts administered using clustered regimens: a retrospective, observational, multicenter study.

BACKGROUND: Subcutaneous immunotherapy is an etiological therapy for certain IgE-mediated diseases. It is usually administered in 2 phases: induction and maintenance. Administration in clustered schedules during the induction phase may be a valid alternative to reach the maintenance dose early if the treatment is well tolerated. OBJECTIVES: To compare the tolerability of different clustered schedules in subcutaneous immunotherapy with standardized allergen extracts administered and to identify factors associated with increased risk of systemic reactions (SRs). METHODS: Retrospective, observational, multicenter study in patients with allergic respiratory disease. RESULTS: Data from 1,147 patients were collected. Thirty-nine patients (3.4%) experienced 42 SRs (0.6% of doses). According to the European Academy of Allergy and Clinical Immunology SR grading system, there were 7 grade 0 reactions (16.7%), 26 grade 1 reactions (61.9%), 8 grade 2 reactions (19.0%), and 1 grade 3 reaction (2.4%). There were no grade 4 SRs (anaphylactic shock). We observed a higher risk of SRs in patients who received an initial dose higher than 0.3 index of reactivity (IR); only 2 reactions occurred after administration of the initial dose of the regimen, both with 0.4 IR. The remainder appeared in subsequent injections, although never with a dose lower than 0.35 IR. CONCLUSIONS: Clustered regimens with IR-standardized extracts are an alternative to classic immunotherapy thanks to their low incidence of SRs compared with other rapid regimens during the induction phase. The ideal clustered regimen should start at an initial dose no greater than 0.35 IR to minimize the incidence of SRs.