OrAAAA: While I am sure that most folks
have heard of the LEAP study by now, can you tell us exactly what the study
is and what the goals of the research were/are?
Dr. Stukus: LEAP was designed to
study whether onset of peanut allergy could be prevented through early
introduction. It has been known that food allergies have been on the rise for
10+ years and that some groups (ie, Israeli infants) do not have as high rate
of allergy as others. Many hypotheses, but few answers. Most recent research
has focused on treatment of existing food allergy…LEAP was born to try and
approach prevention. They recruited over 600 infants all 4-11 months old in
the United Kingdom between 2006-09 who ALL had a history of severe eczema and
egg allergy. This was a high risk group, more likely to develop peanut
allergy compared with other children. Each child underwent skin prick test to
peanut AND physician supervised oral challenge. 10% had too + of a skin test
to proceed and 13% failed food challenge and could also not proceed (great
reasons to NOT try this at home). They were separated into skin test negative
and mildly positive (1-4 mm wheal), then randomized to either eat peanut
snack (Bamba) 3 times/week for 4 years vs. complete avoidance. Primary
outcome was development of peanut allergy at 5 years of age, determined by
oral challenge. It was not 100% successful, as 2% of skin test neg and 11% of
mild positive skin test still developed peanut allergy even by eating it
regularly. There was, however, a 86% reduction in peanut allergy for negative
skin test and 70% reduction in mildly positive skin test between those that
ate vs. those that avoided peanut. Pretty remarkable.
OrAAAA: There have been lots of
concerns expressed about the design of this study. Also, several
members of the food allergy community have expressed concerns about funding
sources for this research (and the possibility that they could influence
results). Can you talk to us about the design of this study?
Dr. Stukus: The assessment of eligibility/safety for inclusion and outcome
measures were as good as it gets (in my opinion). They really did a great job
of using a good, consistent protocol and excellent assessment of allergy
(gold standard = oral food challenge). In regards to bias from funding
source, full disclosures are made by all authors involved, considered by the
journal that publishes the article, and these authors went the extra mile as
they have made ALL of their results available for the world to see and
conduct their own analyses. This study is not subject to additional bias from
funding more so than any other study ever conducted through funding. The peer
reviewed process on the path to publication is rigorous for a reason.
OrAAAA: To clarify, was there any part of the research that included a double-blind? I see
the most questions surfacing around how an allergy was diagnosed at the
oral challenge (which was, admittedly, different than the initial
criteria), and, depending on the criteria used, potentially having
influence if the researcher and patient were aware?
Dr. Stukus: Yes, excellent point. Every challenge at 5 years of age was double
blind, placebo controlled. As clean as you can possibly make it.
OrAAAA: There has been quite a bit of
feedback about the results of this research, particularly from parents of
food allergic children. What do you think is causing much of this push
back? Do you think the widespread publicity of this research has had a
positive or negative impact?
Dr. Stukus: Great question – some of
it was anticipated, but a lot was more of a surprise. This was as big as it
gets in regards to publicity. Major journal publication coordinated to the
minute with the presentation of results at the preeminent international
allergy conference followed immediately by a press conference with major news
organizations…I’ve never seen anything like this! I think the publicity has
hurt the impact based upon the terrible headlines that misinterpret the study
results. Let’s face it, many subsequent opinions by ill informed individuals
have been based only upon reading some of these headlines, all designed
solely to get more clicks or readers. (Yes, I’m frustrated by this).
In regards to push back,
I think that this is hard news for the millions of individuals living with
food allergy as this has nothing to do with treatment or a cure. Not to mention
that dietary recommendations have changed dramatically over the last 15
years, so parents who followed the advice of the ‘experts’ and avoided peanut
are now hearing that they may have been able to prevent their child’s peanut
allergy. Tough news to swallow. There’s a lot more to it than that, but could
easily be perceived that way.
OrAAAA: Can you talk to us about some
of the limitations of this study?
Dr. Stukus: Major limitation is the
infants studied – predominantly white and all had eczema and egg allergy. No
inclusion of other food allergies, history of wheezing, or older children.
Makes it tough to extrapolate results to other populations.
OrAAAA: There are some parents who have
said that this seems like (for lack of a better phrase) OIT before the
fact. Is there any truth to that?
Dr. Stukus: I see why it appears
that way, but this is very different. OIT is administered to people who have
a known history of allergic reaction to a food. It is essentially a
desensitization procedure. The LEAP study did not include anyone who had
peanut allergy – in fact, reactions were exclusion criteria. This was not a
desensitization as allergy never existed. It was truly prevention, as best as
can tell.
OrAAAA: There has been discussion of
next steps for this research Can you explain these? Will the study be
repeated? Different countries? Cultures? Races/ethnicities? Health
backgrounds?
Dr. Stukus: I have no doubt that
these results will now need to be replicated in other countries and all
matter of backgrounds. Next steps for the authors is the LEAP-On study,
during which the children who did not develop allergy will now avoid peanut
for 12 months and then undergo repeat challenge – this is to better
understand underlying mechanisms and better determine true prevention.
OrAAAA: Assuming the results can be
replicated, what do you see the practical application of this research
looking like?
Dr. Stukus: Assuming similar
findings in other cohorts, this will dramatically change feeding guidelines
and approach by allergists. I believe, as with any study/procedure, that
children will need to be carefully selected. This should NOT be done at home
– to reiterate, every single child in this study underwent BOTH skin prick
and oral challenge to ensure safety. I envision a renewed approach to testing
at risk infants early and then consideration for more early introduction of
peanut and other allergenic foods.
OrAAAA: Should parents do
anything different at this time?
Dr. Stukus: If your child already
has peanut allergy, or is older than 12 months of age, the short answer is
no. This does not change anything for these children, unfortunately. If your
child has risk factors for development of peanut allergy (strong family
history, eczema, other food allergy), then I would discuss with their
allergist who may now consider skin test and oral challenge followed by
putting into the diet.
OrAAAA: Do you believe that this
research may eventually be able to be applied to other allergens?
Dr. Stukus: Eventually, yes. It’s
only a matter of time.
OrAAAA: What do you want people
to take away from this research?
Dr. Stukus: We still understand very
little about all of the factors involved in the development of food allergy,
natural history, and treatment. This is a landmark study unlike any other
that offers some insight into actual steps we can take to try and prevent
peanut allergy from ever developing for infants at risk. Treatment for those
living with food allergies is everyone’s wish, but if we could prevent it in
the first place, that would be revolutionary.
OrAAAA: There has been
discussion about whether children who are not at high risk for developing an
allergy should be avoiding allergens in infancy. Is there research that
supports giving or withholding allergens? Is there an ideal window? Does this
change if a sibling has an allergy?
Dr. Stukus: Revamping of the
guidelines by the American Academy of Pediatrics in 2008 acknowledged that
there is insufficient evidence to suggest prolonged avoidance of major food
allergens in low risk infants would prevent the development of allergic
diseases. Not much research done to support giving it early (until now), but
it is generally thought to be very safe and that there is a small window of
opportunity to promote tolerance through early introduction (before 12 months
old) whereas the old feeling was avoidance prevented allergy. Truth be told,
for the 90% of people that do not have food allergies, it won’t matter when
they eat foods for the first time.
Sibling with peanut
allergy is a risk factor; many recommend skin prick or blood IgE for younger
sibling before giving peanut.
OrAAAA: There are lots of confused
parents asking for help understanding these results. For many of us, we ate peanut products while pregnant and
breastfeeding. Is this insufficient to provide protection?
Dr. Stukus: Without a doubt, there
is ZERO evidence that indicates that any parent caused their child to develop
food allergy through their own dietary habits during pregnancy or
breastfeeding. In fact, some research shows the opposite effect – the more
you eat, the better it is. Unfortunately, this is not 100%. There is still so
much we don’t understand. It is likely a very complicated combination of
inherited genes and early life exposures (not just with food, also
microorganisms in our gut and respiratory tract) that determine who does and
does not develop food allergy.
I tell parents every
chance I get that “It’s not your fault”. Way too much guilt for something
that is so far outside of anyone’s control.
OrAAAA: It seems that the media
coverage has caused much of the message of the research to get lost. Is
there anything else that you feel that parents should know that may have been
missed in the chaos of the press coverage?
Dr. Stukus: I agree – it’s so
important to read past the headlines. This was one study about possible
PREVENTION of peanut allergy in young infants at risk who did not already
have peanut allergy. Anyone who claims that this now allows for fewer
safeguards in schools for children with peanut allergy, or that this now
allows people with peanut allergy to start eating peanut…or that parents
created peanut allergy in their children by refusing to give it to them
simply does not understand what this research shows.
|
A giant thanks to Dr. Stukus for taking the time to answer the questions from our readers!
Dr.
Stukus is an Assistant Professor of Pediatrics in the Section of
Allergy/Immunology at Nationwide Children's Hospital, in Columbus Ohio.
In addition to his interest
in caring for families with food allergies and other allergic
conditions, he also serves as Director of the Complex Asthma Clinic. He
currently serves as the Chair of the Medical Advisory Team for Kids with
Food Allergies and sits on the Board of Directors
for the Asthma and Allergy Foundation of America. He previously
completed his pediatric residency at Nationwide Children's Hospital and
his fellowship in Allergy/Immunology at the Cleveland Clinic Foundation.
You can follow him on twitter @AllergyKidsDoc.
