Contradictory skin test and ImmunoCAP results–which is better?

This question comes up in my office almost everyday….should I do skin testing or blood work?  As you can see from the response of national experts, it depends.  There is NO test that can boast 100% accuracy to predict whether or not you will react to a food.  In fact, the gold standard if you will, is still the oral food challenge.  Here is some food for thought (really, do you have to pun)

  1. Clinical history is very important in determining food allergy.  If you can eat a food without difficulty breathing, rash, or hives, you are most likely not allergic.  You may have a positive test, but that only means you’ve had previous exposure to the food.
  2. I will often obtain both skin testing and ImmunoCap (blood work) to clarify the presence of IgE-mediated allergy. If both tests are negative, you may have an adverse reaction to a food, not the severe life-threatening anaphylaxis.  Very important distinction!
  3. If in doubt, a food challenge is always a procedure to consider.  Here’s why.
  4. Sometimes the food in question just isn’t worth the trouble to challenge.  No one says you have to eat strawberries!
  5. If you challenge peanuts for example, in the doctor’s office and experience anaphylaxis, better there than at home.  Epinephrine is more readily available and in many cases, IV access and full resuscitation is available within minutes of your reaction. 
  6. This is another reason why a single test or treating allergy without experience is not a good idea.  Read the link below and tell me just how complicated things can become!

Contradictory skin test and ImmunoCAP results.

#allergy, #anaphylaxis, #food, #immunocap, #immunoglobulin-e

Allergenicity of Shea nut/Shea butter

So you have peanut or tree nut allergy and wonder about Shea butter?  Here’s your answer–it’s safe!

This web site has a catchy tune to go along with the picture.

This web site has a catchy tune to go along with the picture.

This type of butter does grow on trees! In Africa no less.

This type of butter does grow on trees! In Africa no less.

Allergenicity of Shea nut/Shea butter.

#shea-butter

Blood work can be a problem

Normally, I like to include lab studies for evaluation of patients with chronic infections.  It’s very important to find out if your body can make the right amount of antibodies to fight infection.  But…there’s always the exception.  In this case, IgA can be absent from your bloodstream and not cause a problem because it’s gone.  In short, I call this asymptomatic IgA deficiency (you should see the long version).  The link below comes from the American Academy of Allergy, Asthma, and Immunology–good stuff and easy to understand if you’re interested.

Low IgA with elevated IgE in a relatively asymptomatic.

#american-academy-of-allergy-asthma-immunology, #selective-immunoglobulin-a-deficiency

You’ll Be the Hit of the Party!

Oh, if I only knew of a more interesting subject for MY next cocktail party.  When kids’ drama, and the latest neighborhood gossip just won’t do, try your luck at the newest asthma mediation! 

A special thanks to Reuters for their excellent reporting…my comments will be in RED.

Medscape Medical News from the American Thoracic Society (ATS) 2013 International Conference

Regeneron, Sanofi Asthma Drug Seen as Potential Game Changer

By Ransdell Pierson

(Reuters) – A new type of asthma drug meant to attack the underlying causes of the respiratory disease slashed episodes by 87% in a mid-stage trial, making it a potential game changer for patients with moderate to severe disease, researchers said on Tuesday.

Slashing episodes by 50% is pretty dramatic, much less results of 87%.  Too good to be true always lurks in the background with medical studies.  Am I cynical?  Unfortunately, I’ve been burned by too many drugs, gadgets, and the next best nutritional supplement to accept this news without a grain of salt.

“Overall, these are the most exciting data we’ve seen in asthma in 20 years,” said Dr. Sally Wenzel, lead investigator for the 104-patient study of dupilumab, an injectable treatment being developed by Regeneron Pharmaceuticals Inc and French drugmaker Sanofi.

The drug also met all its secondary goals, such as improving symptoms and lung function and reducing the need for standard drugs called beta agonists.

Although far larger trials will be needed to confirm findings from the “proof of concept” study, researchers expressed optimism. They noted that dupilumab has also shown the ability to tame atopic dermatitis or severe eczema.

The medicine, if approved, could hold promise for patients with moderate to severe persistent asthma that is not well controlled by standard drugs.

“We have been treating asthma with sort of Band-Aid therapies that didn’t get at the underlying causes,” Dr. Wenzel said in an interview, adding that dupilumab could be an important step in going to the root of the problem. 

The Holy Grail in more ways than one!

The Holy Grail in more ways than one!

The drug works by simultaneously blocking proteins that have been linked to inflammation, interleukin-4 (IL-4) and interleukin-13 (IL-13).

Dr. Wenzel, director of the Asthma Institute at the University of Pittsburgh, said other drugmakers have tested medicines that block one or both of the proteins, but without success.

The trial recruited patients with high levels of eosinophils. Such patients were deemed likely to benefit from treatment.

This new form of medication, called monoclonal antibodies, targets single molecules to avoid the side effects of steroids.  Our prototype for asthma is Omalizumab or Xolair which just celebrated its 10th year out in the market.  Other than Xolair, I’m limited to using steroids for severe asthma.  😦

All patients initially stayed on their standard asthma treatments, meaning medium-to-high doses of inhaled glucocorticoids, as well as long-acting beta agonists. But patients gradually tapered off on those drugs and were no longer taking either of them after nine weeks.

Throughout the Phase IIa trial, half the patients also received weekly injections of dupilumab, while half received placebo injections.

After the ninth week, about 25% of those on placebos had experienced exacerbations, i.e., the need to take a beta agonist, a decrease in lung function, the need for an oral or inhaled corticosteroid, or admission to the hospital or emergency room for worsening asthma.

“By end of the trial, after 12 weeks, 44% of those in the placebo group had exacerbations, compared with 5% of those on dupilumab,” Dr. Wenzel said.

That represented an overall 87% reduction in exacerbations, which Dr. Wenzel said was highly statistically significant.

She said dupilumab was well tolerated, with side effects similar to placebo. But she cautioned that longer trials are needed to fully assess the drug.

Regeneron and Sanofi said standard drugs are unable to control asthma well in 10% to 20% of patients. They estimate that inflammation caused by Th2 cells – the type of inflammation among patients they tested – plays a role in half of those moderate to severe cases and affects as many as 2.5 million people in the United States and up to 30 million worldwide.

Dupilumab has also shown strong hints of safety and effectiveness in two early-stage trials that involved 67 patients with atopic dermatitis. Larger studies are slated to begin later this year.

Atopic dermatitis is inherited and involves patches of highly itchy skin on any part of the body. Patients, many of whom also have asthma and hay fever, have compared the sensation to having unending poison ivy.

“This asthma data and the data we already have in atopic dermatitis really raises the possibility the scientific community has finally hit upon the key pathway across all these allergic diseases,” George Yancopoulos, Regeneron’s research chief, said in an interview.

And there you have it….next time don’t be stuck with boring conversation about the weather, talk about Dupilumab!

#asthma, #omalizumab, #regeneron

American College of Allergy news tidbit…

One over-active gene has been implicated in 20-30 percent of patients with childhood asthma, according to a study in Science Translational Medicine. The gene, according to authors, interrupts the synthesis of lipid molecules sphingolipids, which are part of cell membranes found throughout the body. Reduced sphingolipids was clearly linked to bronchial hyper-reactivity, unrelated to allergens or inflammation, according to the researchers, from New York-Presbyterian Hospital/Weill Cornell Medical Center, Columbia University Medical Center and SUNY Downstate Medical Center.

Here is the full citation—>Sci Transl Med. 2013 May 22;5(186):186ra67. doi: 10.1126/scitranslmed.3005765.

Impaired sphingolipid synthesis in the respiratory tract induces airway
hyperreactivity.

Worgall TS, Veerappan A, Sung B, Kim BI, Weiner E, Bholah R, Silver RB, Jiang XC,
Worgall S.

Department of Pathology and Cell Biology, Columbia University, New York, NY
10032, USA.

Asthma is a clinically heterogeneous genetic disease, and its pathogenesis is
incompletely understood. Genome-wide association studies link orosomucoid-like 3
(ORMDL3), a member of the ORM gene family, to nonallergic childhood-onset asthma.
Orm proteins negatively regulate sphingolipid (SL) synthesis by acting as
homeostatic regulators of serine palmitoyl-CoA transferase (SPT), the
rate-limiting enzyme of de novo SL synthesis, but it is not known how SPT
activity or SL synthesis is related to asthma. The present study analyzes the
effect of decreased de novo SL synthesis in the lung on airway reactivity after
administration of myriocin, an inhibitor of SPT, and in SPT heterozygous knockout
mice. We show that, in both models, decreased de novo SL synthesis increases
bronchial reactivity in the absence of inflammation. Decreased SPT activity
affected intracellular magnesium homeostasis and altered the bronchial
sensitivity to magnesium. This functionally links decreased de novo SL synthesis
to asthma and so identifies this metabolic pathway as a potential target for
therapeutic interventions.

#asthma

Shots Aren’t the Only Choice for Treating Your Allergies

Novel Routes for Allergen Immunotherapy

Safety, Efficacy and Mode of Action

Philippe Moingeon; Laurent Mascarell

Immunotherapy. 2012;4(2):201-212. © 2012 Future Medicine Ltd.

I DON’T like shots!  And who does?  But alas, if you have to get shots for your allergies, they better be worth the fuss.  Allergen immunotherapy is the only curative treatment of IgE-mediated type I respiratory allergies. Subcutaneous immunotherapy (SCIT) is used as a reference therapy and has transformed allergic treatments; it improves symptoms (asthma and rhinitis) as well as the quality of life of patients. SCIT requires repetitive administration and carries the risk of severe systemic adverse effects, including anaphylaxis. I have modified the schedule of SCIT by rapidly advancing to MONTHLY shots, which makes a big difference on compliance and convenience.  Continue reading

#allergen-immunotherapy, #allergy, #scit

Who says you can’t clean house?

Home cleaning advice.