Investigators Propose New Food Allergy Trial for Pediatric Allergy Patients

W. Wouter de Weger, MD

Investigators from The Netherlands proposed a diagnostic clinical trial that measured the accuracy of both open and double-blind placebo-controlled food challenges, the latter of which had been considered the “gold standard” of food challenges according to investigators.

To their knowledge, there had been no studies performed that compared the 2 methods.

The trial they proposed would be called the Allergy Diagnosed by Open or Double Blind Food challenge (ALDORADO), and would determine food allergies in pediatric populations.

Though generally effective, double-blind placebo-controlled food challenges have been considered costly, time- and resource intensive procedures.

Investigators led by W. Wouter de Weger, MD, Department of Pediatrics, Martini Hospital, Groningen, hypothesized that the structural implementation of open food challenges would be supported if research demonstrated their comparability to the double-blind placebo-controlled food challenge.

As such, the investigators performed a literature review to investigate the diagnostic accuracy of oral food challenges in comparison with the traditional methods employed, as well as define the parameters of the ALDORADO trial.

Ethical Concerns and Parental Involvement

Initially, Weger and colleagues performed Pubmed searches to retrieve papers discussing the methodology of oral food challenges (OFC).

According to investigators, OFCs had been used to expose suspected food allergic children to potential allergens since 1976.

Additionally, 19 parents of children with proven or suspected food allergy were interviewed and asked for their opinions on a potential study involving OFCs.

All parents interviewed understood the relevance of the study and were aware of the necessity to perform an OFC to draw firm conclusions about a suspected food allergy. However, they mentioned that they and their child would likely be anxious to perform a second OFC in case severe objective symptoms or discomfort occurred during the first OFC.

Only 2 previous studied had previously compared OFCs and double-blind placebo-controlled food challenges, though specificity and sensitivity of the former could not be analyzed in 1 study.

The ALDORADO Trial

Given the parent input and methodological considerations acquired by investigators, the proposed ALDORADO trial would be designed to test the hypothesis that the open food challenge outcome is comparableto the standards set by the double-blind placebo-controlled food challenge.

Participants would undergo a double-blind placebo-controlled food challenge as well as an open food challenge in accordance with EAACI guidelines.

The former would last for 2 days, and the latter would conclude in 1 day.

Each method would consist of a maximum of 7 steps and have a mandatory 30 minute waiting time between each allergen dose.

Additionally, the double-blind placebo-controlled food challenge outcome would be kept blinded until the end of the last open food challenge, and parents would be instructed not to introduce the food into their child’s diet until the last test had been performed.

In the event of an anaphylactic reaction, participation in the study would be terminated to avoid any harm.

The primary outcome measure would be the difference in the proportion of positive outcomes of the DBPCFC and the open food challenge.

The secondary outcome measures would be analyzed: OFCs with negative and/or inconclusive outcome, eliciting dose and stopping dose, occurrence, and severity of symptoms on all challenge days as well as the percentage of false positive reactions.

In their closing statement, Weger and colleagues believed their proposed trial could be used to address what they considered a “challenging research question”, and stressed that “there is an urgent need to investigate the diagnostic accuracy of different oral food challenge protocols.”

The study, “The dilemma of open or double-blind food challenges in diagnosing food allergy in children: design of the ALDORADO trial,” was published online in Pediatric Allergy and Immunology.