The role of specific IgE antibodies in infants with cow milk protein allergy

Abstract

Objectives This article aims to evaluate the role of lactoglobulin-specific IgE and lactalbumin-specific IgE in cow milk allergy. Background Allergy to cow milk is the most common food allergy in infants and young children. Symptoms of milk allergy reaction can range from mild symptoms such as hives, to severe symptoms, such as anaphylaxis. The allergy is most likely to persist in children who have high levels of cow milk antibodies in their blood. The aim of this study is to assess the value of lactalbumin-specific IgE and lactoglobulin-specific IgE in the diagnosis of cow milk protein allergy. Participants and methods This study was carried out on 70 participants classified into the following groups: group 1: it included 50 infants with suspected cow milk protein allergy, who were diagnosed with chronic diarrhea with a history of recent introduction of cow milk and a positive elimination test. Group 2: it included 20 age-matched and sex-matched apparently healthy participants. Their ages ranged between 8 and 18 months. All individuals included in this study were subjected to full history taking, clinical examination, complete blood count, and determination of serum total IgE, lactoglobulin-specific and lactalbumin-specific IgE which was carried out using the enzyme-linked immunosorbent assay technique. Results The diagnostic accuracy of lactoglobulin IgE in the diagnosis of cow milk protein allergy was 84%, with sensitivity of 78%, specificity of 100%, positive predictive value of 100%, and a negative predictive value of 65% at the cutoff point of 0.345 IU/ml. The diagnostic accuracy of lactoalbumin IgE in the diagnosis of cow milk protein allergy was 83%, with sensitivity of 84%, specificity of 80%, positive predictive value of 91%, and negative predictive value of 67% at the cutoff point of 0.335 IU/ml. Conclusion Lactalbumin-specific and lactoglobulin-specific IgE assays are important in the diagnosis of cow milk protein allergy and their combination may give better diagnostic accuracy than the total IgE assay.