Allergen immunotherapy (AIT) with mould extracts has been performed for many years but the final demonstration of its clinical efficacy is still missing, due to the small number of studies and their inconsistent results.
To systematically review efficacy and safety of AIT for the treatment of respiratory allergies to moulds.
The primary outcomes were safety and reduction of symptoms (Symptom Score, SS) and medication use (Medication Score, MS) in patients treated with AIT compared to controls. The strength of the evidence was graded based on the risk of bias, consistency and magnitude of effect, according to the GRADE Working Group\'s guide.
Medline, Web of Science and the Cochrane Library (through September 2017) supplemented with manual searches of reference lists.
Randomized studies of intervention comparing AIT to placebo/pharmacotherapy. Studies not reporting on our outcome of interest or without a control population were excluded.
Nine studies (168 children, 99 adults; median sample size, 27) met the inclusion criteria. The risk of bias was moderate-to-high in all but one study. Low strength evidence supports the assumption that AIT is effective in reducing symptoms and medication use, with only four of nine studies reporting higher benefit of AIT vs. comparators. The highest benefit of AIT compared to pharmacotherapy/placebo was reported in studies with a longer follow-up (SMD for MS from -3.96 to -3.97 in favour of AIT) and low risk of bias (VAS for SS: 66.3 ± 13 in AIT group; 186.6 ± 39 in comparators; P < 0.05). No difference was reported with respect to study sample size, route of administration, age of participants. Generalised adverse reactions were reported in 12.5% of participants treated with sublingual immunotherapy, and 37.2% of participants treated with subcutaneous immunotherapy.
Low strength evidence suggests that mould AIT is efficacious for the treatment of respiratory allergies. High-quality studies with an adequate sample size are needed.