January 7, 2013
New Therapy Points To Potential Cure For Peanut Allergy
Alan McStravick for redOrbit.com - Your Universe Online
Peanuts are one of the most common triggers of severe food-induced allergic reactions. In many instances, this reaction can even be fatal. Add to that recent studies showing that the overall prevalence of peanut allergies has been steadily on the rise, not to mention the fact that the danger of this allergy is magnified by the fact there is currently no clinical treatment for its sufferers short of strict dietary abstinence.
A new study in this month´s issue of the Journal of Allergy and Clinical Immunology may shed new light on a possible treatment for individuals afflicted with this harsh allergy. Lead authors of the study, David M. Fleischer of the National Jewish Health in Denver, and Wesley Burks, the Curnen Distinguished Professor and Chair of the Department of Pediatrics at the University of North Carolina School of Medicine, have been working with a new treatment plan that could help to eradicate the allergy in adolescents to middle aged adults.
The new therapy underwent clinical trials at multiple centers to account for any geographic or procedural anomalies. By utilizing sublingual immunotherapy (SLIT), a treatment where patients are given gradually increasing daily doses of a liquid containing peanut powder, the researchers were able to slowly desensitize the patients´ allergic response to peanuts.
The study participants included 40 individuals between the ages of 12 and 37. The researchers began by administering a baseline oral food challenge of up to 2 grams of peanut powder to test how much peanut powder the subjects could consume before they started to experience symptoms of their allergy. Each participant was asked to hold the liquid peanut mixture under their tongue for 2 minutes before swallowing it. After administration of the baseline SLIT, the patients were then randomized to receive either a daily regimen of peanut powder or a placebo.
A second oral food challenge was then administered after 44 weeks of the clinical trial. Participants who were able to consume 5 grams, or a 10-fold increase in peanut powder compared to their initial baseline results were considered ℠responders´, or in layman´s terms, desensitized to their peanut allergy. It was at the 44-week mark that researchers discovered that a full 70 percent of those who had received the steadily increasing doses of peanut SLIT were responders. This was a marked difference to the 15 percent of placebo SLIT participants who were designated as responders. All told, the median amount of peanut powder that could be ingested increased from 3.5 to a staggering 496 milligrams in patients who had received the peanut SLIT treatment. Continuing the study to week 68 saw that figure increase further to 996 milligrams.
At week 44, the research team had administered 10,855 peanut doses to the participants. A full 63.1 percent of these patients were found to be symptom-free at this point. Taking into account an exclusion of minor oral/pharyngeal symptoms from the team´s analysis showed that 95.2 percent of the participants could be considered symptom-free.
"These results are encouraging," Burks said. "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."
Due to the inherent danger of peanut allergies, Burks is quick to caution that individuals should not attempt to bring about desensitization to this allergy on their own. For now, he says, it´s a treatment that should only be given by medical professionals in a carefully monitored clinical trial.
That said, Fleischer and Burk contend that their study shows that peanut SLIT can safely and effectively induce desensitization in a majority of participants when compared to a placebo SLIT. They also contend that the longer duration of the therapy can lead to significant increases in the amount of peanut powder that people with peanut allergies can safely consume.
The researchers believe, however, that SLIT could eventually become an important therapy in helping to protect individuals with peanut allergies from harmful and even fatal reactions due to accidental ingestion of peanuts or peanut-related products.
The study was sponsored by the National Institutes of Health (NIH).