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IgE Casein/IgE β-Lactoglobulin in Gastrointestinal Phenotype of Cow's Milk Allergy
Monday, March 7, 2016
South Exhibit Hall H (Convention Center)
Victor Matheu, MD, PhD, Paloma Poza-Guedes, MD, Inmaculada Sanchez-Machin, MD, Yvelise Barrios, MD PhD, Andres Franco, MD, Ruperto Gonzlez Prez
Rationale: The prevalence of phenotype of IgE-mediated food allergy with exclusively gastrointestinal (g-i) symptoms is increasing.

Methods: A retrospective study of pediatric patients with a diagnosis of food reaction to cow’s milk (CM) and only g-i symptoms (COLIVAC study) such as discomfort, abdominal cramps, constipation or intermittent diarrhea more than 1 h after intake of a CM glass. Skin prick test (SPT) with extracts of CM proteins (CMP) (Stallergenes,France) and in vitro specific IgE (sIgE) (limit detection of 0.1 kU/L, Phadia, Sweden) were determined. Study was approved by Regional Ethics Committee (CHUNSC:24/14).

Results: Thirty nine children complaining exclusively g-i symptoms (median age; 5 y-o) were studied. The most important symptom was abdominal cramps in 35 patients (90%); discomfort or abdominal distention (n=30; 75%), diarrhea (n=10; 25%) and constipation (n=5; 12%). SPT with commercial extracts were positive in only 40% (n=16). IgA anti-transglutaminase antibodies were absent in all patients. Average of tgE was 288 UI/ml. sIgE against casein was 1.74 kU/l; α-lactoalbumin 0.83 kU/l and β-lactoglobulin 4.14 kU/l. Average of IgE levels to whole cow’s milk were of 0.78 kU/l. Interestingly, the quotient sIgE casein/sIgE β-lactoglobulin in these patients was always lower than 1 (average 0.43)

Conclusions: β-lactoglobulin was the dominant protein in IgE response in patients with gastrointestinal phenotype of food allergy with cow’s milk. This profile has a differentiated profile with less total IgE, less specific IgE to CM and lower SPT diameter compared to anaphylaxis phenotype.