This summary was compiled from the tweets posted by @MatthewBowdish, an allergist/immunologist, who attended the 2012 Western Society of Allergy, Asthma and Immunology (WSAAI) meeting. The tweets were labeled #WSAAI. The text was edited and modified by me.
Eosinophilic esophagitis (EoE)
Dr. Seema Aceves discussed eosinophilic esophagitis (immunological and clinical spectrum):
Eosinophilic Esophagitis (EoE) first described in 1977 by Dobbins. EoE big picture: Antigen swallowed or inhaled causes inflammation with subsequent remodeling, fibrosis and clinical symptoms.
EoE is “very much a disease of Caucasian males”.
How do you define EoE?
Clinicopathologic diagnosis is based on more than 15 eosinophils/hpf. As peak eosinophil counts increase, the probability of dysphagia also increases.
Genetics of EoE
The single most dysregulated gene in EoE is Eotaxin-3.
Increased IL15 is seen in EoE and is associated with iNKT cells. IL5/IL13 is also very important in EoE. There is an increased TSLP expression.
TGFb1 and IL13 induce periostin that increases trafficking via cell adhesion (feedback loop for inflammation).
Mast cells in esophageal smooth muscle make TGFb1 in EoE.
Smooth muscle dysfunction is a big deal in EoE - it was shown on lab reports but also correlates with clinical symptoms.
There are many potential subtypes in EoE: acid-induced, allergic, fibrotic (TGFb). There are age-related, familial, gender and ethnic differences.
Clinical features of EoE
Dysphagia most common presenting symptom in EoE. Anorexia and early satiety are the two main symptoms that can distinguish EoE from GERD patients.
Atypical EoE symptoms may include cough, hoarseness, post-tussive emesis, "anaphylaxis" to every food.
Diagnosis of EoE
Grossly seen are furrows, rings, strictures with friable mucosa, but 25% of patients can have normal appearing esophagus (with abnormal biopsy results).
EoE histologic features include expanded basal zone due to active proliferation of eosinophils that are often degranulated.
At least 4 biopsies in children and 5 biopsies in adults from two levels are required in order not to miss EoE diagnosis.
Clinicopathologic diagnosis is based on more than 15 eosinophils/hpf. As peak eosinophil counts increase, the probability of dysphagia also increases. Patients with higher eosinophil levels have lower QOL and increased hospitalizations.
Eosinophilic Esophagitis (click here to enlarge the image):
Tests for food sensitization
Skin prick testing is the preferred way to identify food sensitization. Food patch testing (APT) can be helpful with delayed/cellular hypersensitivity aspect of EoE.
There are imperfections with EoE testing: SPT/sIgE look for immediate hypersensitivity. We don’t know what a positive APT tells us. New studies are needed for standardization and validation of testing modalities.
Treatment of EoE
You may see a transient PPI response in acid-induced EoE. Children with eosinophilic esophagitis (EoE) treated with PPIs show an improvement in symptoms despite persistent eosinophilic inflammation. PPI treatment may be useful maintenance therapy in children with EoE (Annals of Allergy&Immunology, 2012).
Almost 80% of EoE patients will relapse if you take drug away or add a food back they're allergic to.
Six food elimination diet
Six food elimination diet is important in EoE therapy (egg, milk, peanut, wheat, seafood, soy). Common EoE foods include: rice, rye, wheat, barley, oat, milk, egg, soy, chicken, beef, potato.
The most effective treatment regimen for histologic resolution of EoE is elemental formula (the response is in the 90-96% range).
At least a third of EoE will not adhere to elimination diet. Most children with EoE will have to avoid some foods “forever” and cannot reintroduce them.
Food OIT and EoE
There is onset of new EoE with oral desensitization trials for food allergy. This raises long-term issues with OIT. When you do SLIT for pollens or OIT for foods, you can drive EoE.
Topical and systemic steroids work well equally for EoE but systemic steroids have much higher adverse effects, of course.
Patients need to wait 30 minutes after swallowed fluticasone, so they don't wash away the medication.
Oral viscous budesonide (OVB) works in up to 80% of patients. This figure shows Seema's EoE treatment algorithm: http://yfrog.com/nw84byzqj
Anti-IL5 antibodies decrease eosinophils but symptoms often continue, especially in adults. Anti-IgE doesn't seem to work for EoE but studies limited.
SCIT stands for subcutaneous immunotherapy (a.k.a. allergy shots). There is no strong published data supporting the use SCIT for enviornmentals and eosinophilic esophagitis (EoE) (a poster from the 2011 AAAAI meeting suggested in might help).
This summary was compiled from some of the tweets posted by @MatthewBowdish . The tweets were labeled #WSAAI and they reached more than 3,000 people. I would strongly encourage you to post updates on Twitter from the CME conferences that you are planning to attend in the future. Here is how to do it: Twitter for Physicians: How to use Twitter to keep track of the latest news and scientific meetings, and share information with colleagues and patients.
Disclaimer: The text was edited, modified, and added to by me.