title: Role of specific IgE to β-lactoglobulin in the gastrointestinal phenotype of cow's milk allergy.
abstract: BACKGROUND
  The prevalence of many phenotypes of food allergy is increasing. Specific gastrointestinal (GI) phenotype of food allergy (GI allergy) is also increasing but it is difficult to know the prevalence because of many entities. METHODS AND RESULTS: A 1 year retrospective study of pediatric patients complaining exclusively gastrointestinal symptoms after cow's milk consumption and at least one positive specific IgE (sIgE) to cow's milk (CM) proteins (CMP) was done (n = 39). The most prevalent symptom was abdominal cramps in 35 patients (90 %), discomfort or abdominal distention in 30 patients (75 %), diarrhea in 10 patients (25 %) and constipation in 5 patients (12 %). IgA anti-transglutaminase antibodies were absent and lactose intolerance was ruled out in all patients. Average of total IgE on this group was 288 UI/ml. sIgE against β-lactoglobulin was the dominant with an average of 4.14 kU/l. sIgE to casein (CAS), which is the dominant protein in systemic anaphylaxis was 1.74 kU/l; sIgE to α-lactoalbumin, the other whey protein, was 0.83 kU/l and sIgE levels to CM were 0.78 kU/l. The quotient sIgE CAS/sIgE β-lactoglobulin in these patients was always lower than 1. Patients experienced an improvement of their symptoms after a CM free diet. An open oral challenge with CM did mimic their initial symptoms in all patients. However, the open oral challenge with dairy products was well tolerated.
  
  
  CONCLUSIONS
  Patients with a specific phenotype of GI allergy with CM have specific IgE against β-lactoglobulin, as a dominant sIgE. These patients could beneficiate of a diet with dairy products.
authors.affiliation: Consulta de Alergia Infantil, Unidad de Alergología-Norte, Hospital del Tórax/Ofra, CHUNSC, Sta. Cruz de Tenerife, 38320 Spain.
authors.forename: Paloma
authors.initials: P
authors.lastname: Poza-Guedes
authors.affiliation: Immunology, Hospital Universitario de Canarias, La Laguna, Spain.
authors.forename: Yvelise
authors.initials: Y
authors.lastname: Barrios
authors.affiliation: Consulta de Alergia Infantil, Unidad de Alergología-Norte, Hospital del Tórax/Ofra, CHUNSC, Sta. Cruz de Tenerife, 38320 Spain.
authors.forename: Ruperto
authors.initials: R
authors.lastname: González-Pérez
authors.affiliation: Consulta de Alergia Infantil, Unidad de Alergología-Norte, Hospital del Tórax/Ofra, CHUNSC, Sta. Cruz de Tenerife, 38320 Spain ; Unidad Alergología-Norte, Hospital Tórax, CHUNSC, Sta Cruz de Tenerife, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Sánchez-Machín
authors.affiliation: Immunology, Hospital Universitario de Canarias, La Laguna, Spain.
authors.forename: Andres
authors.initials: A
authors.lastname: Franco
authors.affiliation: Consulta de Alergia Infantil, Unidad de Alergología-Norte, Hospital del Tórax/Ofra, CHUNSC, Sta. Cruz de Tenerife, 38320 Spain.
authors.forename: Víctor
authors.initials: V
authors.lastname: Matheu
keywords: Anaphylaxis; Casein; Cow’s milk allergy; Food allergy; Gastrointestinal allergy; IgE-mediated allergy; Specific IgE; β-lactoglobulin