Many patients are turning to oral immunotherapy (OIT) to treat their food allergies. OIT is a treatment — conducted under the supervision of a trained medical professional — where an allergic individual is fed an increasing amount of an allergen with the goal of increasing the threshold that will trigger a reaction to that allergen.
Individuals are often treated with OIT for food allergies one at a time, although some allergists will treat patients with multi-allergen OIT thus addressing multiple food allergies at the same time.
According to Healio, a study presented at this year’s ACAAI Annual Scientific Meeting in November shows there is a trade-off involved in multi-allergen OIT: although it may reduce treatment time, that reduction comes at a cost of more epinephrine use vs single allergen OIT.
Said E Katherine Larson, a physician assistant at Aspire Allergy & Sinus, during her presentation:
Multiple studies have shown oral immunotherapy … a food allergen desensitization process, to be effective and improve the quality of life for food-allergic patients. However, there is a paucity of data concerning multi-allergen OIT where patients treat multiple allergens concurrently.
To address that paucity, Larson and her colleagues conducted a study of 169 patients being treated with single-allergen OIT and 147 with multi-allergen OIT.
The muti-allergen cohort had a greater proportion of participants with multiple food allergies (100% vs 45.6%), a history of asthma (44.2% vs 33.1%), a history of allergic rhinitis (69.4% vs 55.6%), and a history of reactions to one of the treatment foods (95.2% vs 88.8%).
Differences in mean baseline-specific IgE totals were statistically relevant as well, with 49.76 kU/L for the multi-allergen cohort and 37.86 kU/L for the single-allergen cohort.
According to the study, 85.2% of those in the single-allergen cohort and 80.3% in the multi-allergen cohort completed their therapy, which did not represent any statistical difference.
“However, there was a statistical difference in epinephrine use rates between the two cohorts, with a 6.5% epinephrine use rate in the single-allergen cohort vs. 15.7% in the multi-allergen cohort,” said Larson.
There was also a meaningful statistical difference in mean days to completion of OIT, with the single-allergen cohort taking 290 days and the multi-allergen cohort taking 311.
“However, multi-allergen OIT still results in an overall time reduction compared to single-allergen OIT due to avoidance of multiple rounds of treatment,” reported Larson.
The researchers compared epinephrine use between the cohorts using three separate logistic regression models. In the first — which did not control for differences between the groups — patients comprising the multi-allergen cohort were 2.66 times more likely to use epinephrine. In the second — using comorbidity controls — the multi-allergen cohort was 2.21 times more likely to use epinephrine. The third model added baseline testing and reaction history controls.
“The odds ratio drops to 1.63 in model three, and the difference in epinephrine use rates between the cohorts is no longer statistically significant,” said Larson.
As noted by Larson, the study was limited by its small sample size, significant differences between cohorts, and its clinical nature which reduced standardization of its protocol.
“A randomized controlled trial would solve many of the issues concerning this study,” said Larson, adding that clinicians can still conclude that multi-allergen OIT is as effective as single-allergen OIT while saving treatment time overall.
“However, clinicians should approach multi-allergen OIT using shared decision-making with patients, highlighting the possibility of increased epinephrine use with multi-allergen OIT,” she concluded.