Bit by bit, treatment cuts back peanut allergy
UNC-CHAPEL HILL (US) — In a possible new remedy for peanut allergies, patients hold liquids containing increasing amounts of peanut powder under their tongues.
Peanuts are one of the most common triggers of severe food-induced allergic reactions, which can be fatal, and the prevalence of peanut allergy is increasing. However, there is currently no clinical treatment available for peanut allergy other than strict dietary elimination and, in cases of accidental ingestion, injections of epinephrine.
But a new multicenter clinical trial shows promise for sublingual immunotherapy (SLIT), in which the patients first hold the liquid under the tongue for two minutes and then swallow it.
“These results are encouraging,” says Wesley Burks, professor and chair of the department of pediatrics in the University of North Carolina School of Medicine.
“The immune response was stronger than we thought it might be, and the side effects of this treatment were relatively small. However, the magnitude of the therapeutic effect was somewhat less than we had anticipated. That’s an issue we plan to address in future studies.”
In the study, 40 people with peanut allergy, ages 12 to 37 years, were randomized to receive daily peanut or placebo SLIT. All were given a baseline oral food challenge of up to 2 grams of peanut powder to test how much peanut powder they could consume without symptoms.
After 44 weeks, all were given a second oral food challenge. Those who were able to consume either 5 grams, or at least 10-fold more peanut powder than their baseline amount, were considered to be responders (i.e., desensitized to peanut).
At 44 weeks, 70 percent of those who received peanut SLIT were responders, compared to 15 percent of those receiving placebo. Among the peanut-SLIT responders, the median amount of peanut powder they could successfully consume increased from 3.5 to 496 milligrams. After 68 weeks, that amount increased significantly, to 996 milligrams.
Of 10,855 peanut doses given through week 44 of the study, 63.1 percent were symptom-free. When oral/pharyngeal symptoms were excluded from the analysis, 95.2 percent of doses were symptom-free.
The study, published in Journal of Allergy and Clinical Immunology, concludes that peanut SLIT safely induced desensitization in a majority of participants compared to placebo, and that longer duration of therapy led to significant increases in the amount of peanut powder people could safely consume.
However, Burks cautions, this is not a treatment that people should try on their own. For now it’s a treatment that should only be given by medical professionals in a carefully monitored clinical trial, he says.
Study participants were recruited from five US sites: New York, New York; Baltimore, Maryland; Little Rock, Arkansas; Denver, Colorado; and Durham, North Carolina.
Study co-authors include researchers from National Jewish Health in Denver, Colorado, University of Arkansas for Medical Sciences and Arkansas Children’s Hospital, Johns Hopkins University School of Medicine, Mount Sinai School of Medicine, the EMMES Corp. in Rockville, Maryland, and the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH).
The NIAID and the NIH’s National Center for Research Resources funded the study.
Source: UNC-Chapel Hill