Is specific oral tolerance induction with foods an option in allergic children?

Allergists are talking informally about reports of success in clinical trials employing specific oral tolerance induction (SOTI), also know as "oral immunotherapy," as treatment for food allergy. But where are the published reports?

Fisher et al. (Arch Dis Child 2010, doi:10.1136/adc.2009.172460) looked for those clinical trials reports and ran a meta-analysis to see if SOTI is more effective than avoidance for inducing tolerance. The authors’ pivotal criteria for inclusion in the analysis are double-blind oral food challenge before and after treatment.

Fisher and colleagues found only 3 studies that met all inclusion criteria. All three studies found SOTI significantly better than avoidance/placebo for inducing tolerance. However, one study used the endpoint “any tolerance” rather than food challenge-demonstrated tolerance; reanalysis of the published raw data by Fisher et al did not distinguish SOTI from avoidance for that study.

Editors’ note: 2 of the 3 studies were published in the JACI and can be accessed free of charge from http://www.jacionline.org/article/PIIS0091674907020003/fulltext and http://www.jacionline.org/article/PIIS0091674908017259/fulltext.

The three studies comprised only 127 children, which led the authors to comment that a type II error may account for the overall lack of significance to the results. Two studies that reported significance for SOTI did not measure persistence of tolerance over time, which was measured in the 3rd study for which the authors’ reanalysis found no significant difference.

Fisher et al conclude that SOTI cannot be recommended for routine clinical practice for IgE-mediated food allergy treatment yet. They suggest that future, larger trials need to assess persistence of tolerance over time as well as cost-effectiveness and safety.

Tell us what you think. Please feel free to post your own comments and/or predictions below. Topics and articles that you think would be of interest in our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.

Rhinitis and asthma increase the risk of days off work

Allergic rhinitis imposes a substantial economic burden on society, with indirect costs of productivity loss that are larger than the direct healthcare costs. All studies carried out in allergic rhinitis combine to indicate that patients with this disease have an impaired work performance. However, it has not been known whether allergic rhinitis can induce days off work and how its impact compares to asthma.

In a large occupational cohort study recently published online by Kauppi et al. (Respiratory Medicine 2010, doi:10.1016/j.rmed.2010.05.006), the risk of absenteeism due to illness (sick leave) associated with allergic rhinitis with or without asthma was examined in Finland. The study population of over 48,000 subjects was drawn from government employees in 10 towns and 21 public hospitals who consented to link their employer’s sick leave records to a survey they completed on allergic rhinitis and asthma. The study periods were 2000-2002 and 2004 and the survey collected information for the previous calendar year.

Overall, subjects with rhinitis took an average of 3.1 sick days/person/year more than the comparison group, while subjects with asthma took 9.4 days more, and subjects with both took 9.7 additional sick days.

To our knowledge this is the first prospective longitudinal study reporting sickness absences in public sector employees with allergic rhinitis, asthma or both. This study found an increased risk of sickness absences for those employees who reported physician-diagnosed self-reported allergic rhinitis, asthma or both of these conditions combined.

Tell us what you think. Please feel free to post your own comments and/or predictions below. Topics and articles that you think would be of interest for our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.

U.S. Department of Transportation considers peanut restrictions on flights

Peanut allergy is one of the most common food allergies and trace amounts can cause threatening symptoms and even death in the most sensitized patients. The U.S. Department of Transportation (DOT) has announced that it will be gathering feedback regarding whether to restrict, or even ban, the serving of peanuts on commercial flights in the U.S. According to an article from the Associated Press (AP), the DOT will be consulting "allergy sufferers, medical experts, the food industry and the public." Supporters of regulations such as these feel that they will reduce fears and the potential of harm for Americans who suffer from a peanut allergy. Opponents, such as peanut farmers and food packagers, feel that such restrictions would be "overreaching" and "unfair."

According to the AP article, the DOT previously considered mandating peanut-free zones on airliners in 1998, but dropped these plans following a "hostile response" from Congress, which threatened to cut its budget. The article also notes that several airlines, including Continental, United, US Airways and JetBlue, have voluntarily stopped serving packaged peanuts.

The proposals regarding peanuts are part of a longer set of proposed protections for travelers. According to the DOT, three options are being considered: completely banning the serving of peanuts, prohibiting peanuts only requested in advance by a passenger, or requiring a "peanut-free zone" when asked for by a passenger. Quoted in the AP article, DOT spokesman Bill Mosely says, "We're just asking for comment on whether we should do any of these three things... We may not do any of them."

On the other hand, the article also quotes Martin Kanan, CEO of the King Nut Companies, which provides the peanuts served on most U.S. flights: "The peanut is such a great snack and such an American snack... What's next? Is it banning peanuts in ballparks?" Armond Morris, a peanut farmer in Georgia, is also quoted: "The peanut industry feels like we're being picked on... If we're going to go targeting food products, maybe we just need to ban all food" on planes.

Comments on the proposal can be submitted at www.regulations.gov, using docket number DOT-OST-2010-0140.

Bone mineral density impaired in children receiving continuous inhaled corticosteroids

Reduced growth induced by inhaled corticosteroid (ICS) use in children with asthma has been, and continues to be, a focus for researchers. Most of the research has been of short duration, and reported no significant differences observed between ICS-treated children and children treated with non-steroidal therapies, such as nedocromil. Moreover, bone mineral density has never been measured in a trial.

The recent online publication by Turpeinen et al. (Pediatric Research 2010, doi: 10.1203/PDR.0b013e69e36), at Helsinki University Hospital, presents findings from the first long-term controlled trial to address the clinical impact of ICS therapy on bone mineral density (BMD). The authors conduct an 18-month blinded randomized trial with three parallel treatment arms: 1) step down, high to moderate budesonide, followed by low-dose maintainace for 12 months; 2) step down, high to moderate budesonide, followed by placebo for a year, with PRN budesonide for worsening; and 3) disodium cromoglycate (DSCG) for all 18 months.

Turpeinen et al. find that BMD was significantly decreased across any BUD treatment as compared to DSCG treatment after 6 months, but more in the continuous BUD group. The difference between all three treatment groups was significant after 12 and 18 months, by pairwise comparison. Overall, all subjects had increased BMD and height across the duration of the study, with the BUD treatment group having the smallest incremental change. They conclude by suggesting that height could be used clinically to monitor ICS effects on bone.

Tell us what you think. Please feel free to post your own comments and/or predictions below. Topics and articles that you think would be of interest in our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.

Can a chip help to diagnose food allergies?

Demonstrating clinical food allergy is a double-edged sword; on the one hand, the least risky approach, using skin testing results and specific IgE levels, is allergen-specific, but problematic for sensitivity assessment. On the other, oral food challenge is very sensitive, but is high risk for the subject and has a significant utilization burden.

Research out of MIT, led by J. Christopher Love, PhD, and his team, might hold the solution. Love and his colleagues have produced a microarray chip capable of assessing cytokine production from single leukocytes. The chip is covered in subnanoliter microwells, and is capable of quantitative measure of cytokine secretion by a single cell activated by antigen using a process called microengraving. The chip has much greater sensitivity to the numbers and intensities of responses by stimulated immune cells and can detect up to 4 different cytokines secreted by a single activated cell. Their research is presented in the journal Lab on a Chip.

So how does this help food allergy diagnosis? Love and his team are collaborating with the Children’s Hospital in Boston to correlate cytokine production with allergic response in children receiving oral immunotherapy for milk allergy. In addition, the chip will be used to characterize cytokine production during the desensitization period.

Tell us what you think. Please feel free to post your own comments and/or predictions below. Topics and articles that you think would be of interest in our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.