FCAAIA Notes: If you have been following this blog over the years (or search it now), you know that I have posted many articles about oral immunotherapy (OIT) to food. This study looked at the feasibility of OIT to wheat. The researchers found that desensitization to wheat is possible. However, only about ½-2/3 of the study participants tolerated a dose of about 4.4 grams (about 1 ½ slices of bread. More were able to tolerate larger amounts than before the study.
The flip side of this success is the high reaction rate. More than 10% had mostly mild reactions. So we have to ask, how many had accidental ingestions with symptoms after their diagnosis but before they entered the study? I raise a question I have asked before, “Just because we CAN do OIT to food, SHOULD we do OIT to food?”
I am sure this question will come up again and future research may provide safer methods of desensitization. For now for it to be tried at all, I would reserve it for the most allergic patients who continue to have accidental ingestions with significant symptoms (who probably ought to be more diligent about their avoidance too!).
Lower and high doses of vital wheat gluten oral immunotherapy induced desensitization in the majority of children after one year of treatment, according to results from a double-blind, placebo-controlled study of more than 40 children.
Following two years of lower dose vital wheat gluten oral immunotherapy, 30% of children achieved desensitization — defined as a successfully consumed dose of 4,443 mg wheat protein, reported Anna H. Nowak-Wegrzyn MD, PhD, of Mount Sinai’s Icahn School of Medicine in New York City.
Additionally, 13% of patients were able to tolerate gluten even after 8 to 10 weeks off therapy, she stated during her oral presentation at the annual American Academy of Allergy, Asthma, and Immunology meeting.
However, Nowak-Wegrzyn also noted that lower and high doses of vital wheat gluten oral immunotherapy were not significantly different regarding the successfully consumed dose, or the last dose taken without experiencing any symptoms.
Panel moderator Roland Solensky, MD, FCAAIA, of the Corvallis Clinic in Oregon, commented that “wheat is sort of novel” in terms of immunotherapy.
“The study results were not as promising as with other foods. The percent of people in which the immunotherapy worked, but as soon as they stopped they will revert back, was higher in wheat than with other foods like eggs and nuts,” he explained to MedPage Today.”
Study co-author Hugh A. Sampson, MD, also of Mount Sinai, addressed the importance of wheat gluten oral immunotherapy during a press event on Sunday: “Wheat allergy is common in young children. The majority outgrow the allergy but the subgroup that retain it have fairly severe reactions when they have accidental ingestions, and trying to avoid wheat in the American diet is difficult.”
“The idea [of the study] is that they should have sufficient protection to prevent them from having anaphylactic reaction” after accidental small exposures, he said.
Nowak-Wegrzyn and colleagues randomized 46 children with wheat allergies to receive active oral immunotherapy with high-gluten, wheat flour or placebo, a commercially available cornstarch. Median age of participants was 8.7 years and 78% were male. Wheat skin prick test results were similar between placebo and active treatment at baseline (4.6 mm versus 3.4 mm).
Exclusion criteria included children with conditions that were considered to increase risk for anaphylaxis or interfere with treatment for anaphylaxis, recent immunomodulatory treatments, and active eosinophilic gastrointestinal disease in the past two years.
Doses escalated every two weeks for 44 weeks, with a maximum dose of 1,445 mg wheat protein for at least eight weeks of maintenance. After one year, the placebo crossed over to active treatment for 52 weeks, with a maximum dose of 3,870 mg wheat protein. During that time, the active cohort continued on maintenance, with a maximum dose of 2,035 mg wheat protein.
Wheat protein doses of 373 mg or greater were provided in pre-measured capsules and packets, while smaller doses were provided via bulk powder measured at home with special scoops.
Nowak-Wegrzyn and her team found that at year one, 52.2% of those taking a lower dose wheat oral immunotherapy, compared with 0% on placebo, achieved a successfully consumed dose (4,443 mg versus 143 mg at pre-treatment baseline, P<0.0001).
At crossover after year one, 14 out of 21 (66.7%) high-dose crossover subjects reached a successfully consumed dose greater than 4,443 mg wheat protein and 12 out of 21 (57.1%) were desensitized, with a median successfully consumed dose of 7,443 mg.
Among those in vital wheat gluten oral immunotherapy, median-year-1-sIgG4 was greater than placebo: wheat (22.0 versus 3.05 mgA/L, P=0.0005), omega-5-gliadin (7.34 versus 0.62 mgA/L, P=0.0001).
Additionally, year one successfully consumed dose correlated with year one wheat (rho statistic 0.56, P=0.0002) and omega-5-gliadin-sIgG4 (0.49, P= 0.002), Nowak-Wegrzyn reported.
Regarding safety, Sampson noted that of more than 20,000 active doses given, 11.2% were associated with some form of symptom — most of them being mild, such as stomach aches and nausea. A few children (0.05%) received epinephrine.
Looking forward, Sampson commented that he “hopes someone will take up the torch,” but acknowledged that future studies would be very expensive.
“This is the point where we have to get industry involved,” he stated.
Solensky agreed, noting that while “the results were not as promising as with other foods, they warrant future research.”