Efficiency and safety of oral immunotherapy protocols in peanut allergy. Pilot study on 51 patients.

Background. - Peanut allergy (PA) is persistent and severe, so that therapeutical trials using oral immunotherapy (OIT) are in the spotlight. The primary objective of this pilot study conducted from 2007 to 2009 is the evaluation of the efficiency and the safety of this procedure. Methods. - Fifty-one subjects aged 2 to 20 years with persistent PA documented by DBPCFC are enrolled. Doses of roasted peanut powder are weighted in the hospital. The duration of the escalation phase is 17 or 34 weeks according to the severity of PA and the threshold of reactivity. The final dose is 12 grams per week. Controls at specified times are carried out by prick-test and specific IgE to peanut. Adverse reactions (AR) are studied and risk factors are searched out. Results. - Forty-eight subjects completed the escalation phase. The duration was extended in two cases. 18 patients have been controlled after six months of the maintenance phase. The global efficiency is estimated at 92.1%. A decrease of prick-tests and an increase of specific IgEs are observed at the end of the escalation phase and evolve conversely six months later. AR occur during both phases, benign in 84% of cases, serious in 16%. They characterize 36.8% patients of group 1, 53.1% of patients in group 2 (0.26% and 0.48% of doses respectively). The relationship of RI with a lower basal threshold is confirmed: 763 +/- 363 mg versus 1988 +/- 1995 mg (p < 0.05). Risk factors are aspirin, exercise sunbathe, viral gastroenteritis, pollinosis, discontinuation of daily doses, intake in decubitus. Eighty-eight percent of RI remain still unpredictable. Conclusions. - These results show a benefit of OIT and lead to propose further trials. The duration of the daily dose maintenance and the optimal dose have to be monitored by the immunological profile of IgEs and IgG4s to recombinant peanut major allergens. (C) 2010 Elsevier Masson SAS. All rights reserved.