Peanut allergy is the most common cause of severe and fatal allergic reactions related to food; it affects 0.5-1.4% of children in high-income nations. The only way to avoid the problem is to avoid eating foods containing peanuts. Even then, many individuals suffer accidental reactions when they unknowingly consume a food product that contains peanuts or peanut oil. A new study has reported success in decreasing the allergic response—a move that could be lifesaving. The study was published online on January 30 in the journal The Lancet by researchers affiliated with the Cambridge University Hospitals, Cambridge, UK.
The study authors noted that some small studies have suggested that peanut oral immunotherapy might be effective for the treatment of peanut allergy. Therefore, thy conducted a study to determine whether oral immunotherapy could desensitize children with allergy to peanuts. The study group comprised 99 children, aged 7 to 16 years, with varying severity of peanut allergy. The children were randomly assigned to either a treatment or control group. For six months, the treatment group received gradually increasing doses of peanut protein; the initial dose was 2 milligrams and the final dose was 800 milligrams. After six months, in the second phase of the study, the control group received the gradually increasing doses of peanut protein.
The primary outcome measure was desensitization, determined by a negative peanut challenge (1,400 mg protein) at six months (first phase). Control participants underwent OIT during the second phase, with subsequent DBPCFC. A scientific analysis was conducted after six months to compare the proportion of children who became desensitized to peanut protein between the active and control group at the end of the first phase.
The investigators found that desensitization occurred for 24 of 39 (62%) children in the treatment group and none of the control group after the first phase. In addition, 84% of the treatment group tolerated daily ingestion of 800 mg protein (comparable to five peanuts). The average increase in peanut threshold after oral immunotherapy was 1,345 mg (range: 45-1,400 mg). After the second phase, 54% of the children tolerated the 1,400 mg challenge (comparable to ten peanuts) and 91% tolerated daily ingestion of 800 mg protein. In addition, quality-of-life scores improved after oral immunotherapy. For most children, the side-effects were mild. The most common side-effect was gastrointestinal symptoms (31 children with nausea, 31 with vomiting, and one with diarrhea). The second most common side-effect was oral pruritus (inflammation of the mouth) after 6.3% of doses (76 children) and wheeze after 0.41% of doses (21 children). Intramuscular adrenaline was used after 0.01% of doses in one child.
The researchers concluded that oral immunotherapy successfully resulted in desensitization for most children within the study population and with peanut allergy of any degree of severity; thus, a clinically meaningful increase in peanut threshold occurred among the study group. Quality of life improved after intervention; furthermore, there was a good safety profile. Immunological changes (laboratory studies) corresponded with clinical desensitization. The recommended that further studies among larger and different groups should be conducted. They noted that oral immunotherapy was effective and well tolerated in the study group; however, they cautioned that oral immunotherapy should not be done in non-specialist settings.