FARE representatives and many FARE-funded researchers are in Atlanta this weekend for the annual meeting of the American Academy of Allergy, Asthma & Immunology. Over 800 studies published by more than 3000 authors are being presented at AAAAI 2017. Thousands of allergists, immunologists, allied health professionals, research scientists and others are attending.
Sunday’s presentations included immunotherapy research funded in part by FARE. We are proud of our role in promoting hope for new treatments to all those managing food allergy, and we are grateful to the food allergy community for the research funding they make possible through their generous donations to FARE. Here are summaries of two oral immunotherapy studies that received FARE support.
Forty-six patients aged 4 to 23 years underwent a series of double-blind placebo-controlled food challenges to determine the safety and effectiveness of wheat oral immunotherapy at low and high doses.
More than half of patients (12 of 23) treated with up to 1445 mg of high-gluten wheat-flour OIT for one year passed a 4443-mg wheat protein challenge, compared to zero placebo-treated patients. Skin prick tests and wheat-specific serum IgE levels did not differ significantly between the two groups, but levels of wheat-specific serum IgG4 antibodies that appear to promote allergen tolerance were much higher in the group undergoing active treatment.
Following the challenge, the placebo group crossed over to treatment and began a year of wheat OIT up to a higher daily dose, 3870 mg. The treatment group continued a second year of wheat OIT up to a lower daily dose, 2035 mg. Each group was then challenged again.
After two years, 30 percent of the low-dose patients (7 of 23) tolerated a 7443-mg dose and were considered desensitized. Eight to ten weeks after wheat OIT was stopped, 3 of 23 patients (13 percent) showed sustained unresponsiveness by again passing a 7443-mg challenge.
At the one-year mark, two-thirds of the 21 high-dose patients passed a 4443-mg challenge, and 57 percent were desensitized (median dose 7443 mg). Compared to their own baseline levels prior to OIT, crossover patients had much higher levels of wheat-specific serum IgG4 after one year of treatment. However, IgG4 levels after one year of low-dose or high-dose treatment did not show significant differences.
Successfully consumed doses were not significantly different between the low-dose and high-dose groups. Of more than 21,000 doses of wheat protein consumed, 10 resulted in reactions treated with epinephrine. Adverse reactions did not differ significantly between the low-dose and high-dose groups. Ten participants dropped out over the course of the trial.
Investigators at University of Arkansas for Medical Sciences and Arkansas Children’s Hospital treated patients with allergy to walnut and another tree nut. The study assessed whether long-term walnut oral immunotherapy could desensitize the patients (median age 9 years) to both walnut and their other tree nut allergen (the “test tree nut”), namely pecan, cashew, hazelnut, or pistachio.
After completing 38 weeks of blind, placebo-controlled treatment, participants received 142 weeks of open-label walnut OIT. Nine* patients then had oral food challenges to walnut and their test tree nut. Seven of the nine patients (78 percent) passed both challenges, tolerating 5000-mg doses of walnut protein and test tree nut protein. The remaining two patients were desensitized to walnut but not to their test tree nut. Further evidence that walnut OIT had favorably shifted immune function in these patients includes significant increases in blood serum levels of allergen-specific IgG4 antibodies and significantly smaller skin prick test wheals.
When the seven walnut-desensitized/test tree nut-desensitized patients were challenged again four weeks after discontinuing walnut OIT, four (57 percent) remained unresponsive to 5000-mg doses of both walnut and the test tree nut. The study is currently ongoing with additional subjects.
*After the abstract went to press (see link above), a ninth patient completed the post-OIT challenges.
Stay tuned to our blog for more updates from the AAAAI meeting.