1 - Serviço de Imunoalergologia, Hospital Pulido Valente, Centro Hospitalar Lisboa Norte, E.P.E.;
2 - Serviço de Imunoalergologia, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central E.P.E.;
3 - Departamento de Fisiopatologia, CEDOC, Faculdade de Ciências Médicas, Universidade Nova de Lisboa;
4 - Departamento de Pediatria, Faculdade de Ciências Médicas, Universidade Nova de Lisboa.
- EAACI Congress 2012, Genebra, 16-20 de Junho 2012 (Poster).
Background: Cow's milk (CM) allergy diagnosis is classically established based on a detailed medical history followed by skin prick tests, laboratory tests and oral food challenge (OFC). OFC although considered gold standard for CM allergy diagnosis has associated risks. CM specific IgE levels have been used mostly as screening test, but their use for determining the correct timing of the oral challenge test would avoid unnecessary time consuming and risks.
The aim of this study was to determine the best threshold value of CM specific IgE that could predict clinical tolerance, obviating the need for OFC.
Methods: All children submitted to cow's milk OFC from June 2009 to July 2011, for which specific IgE to CM was determined in the 6 months previous to the OFC were included. ROC curves were calculated to determine the sensitivity (SE) and specificity (SP) of CM specific IgE levels versus the OFC outcomes.
Results: A total of 84 children (44 males and 40 females) with clinical history of IgE-mediated CM allergy were enrolled. The median age of first symptoms was 4,0 months (P25-P75: 4,0-6,0 months). The median age at first visit was 9,5 months (P25-P75: 5,0-18,75 months). CM allergy diagnosis was based on clinical history of immediate hypersensitivity reaction (cutaneous 62.7%, digestive 14.5%, respiratory 3,6% and associated symptoms 19,3%) and confirmed by skin prick tests, CM specific IgE determination and open OFC (median age at the time of oral challenge 27 months P25-P75: 14-50 months). The determination of CM specific IgE levels was useful in discrimination cases at risk for CM allergy (AUC: 0.83). The best decision threshold for CM specific IgE was 2,15 KU/L (sensitivity: 77.8%; specificity: 83.9%).
Conclusions: CM specific IgE is a useful diagnostic test for symptomatic CM allergy in pediatric patients. The specific IgE threshold achieved could be indicative of CM allergy diagnosis in patients with a clinical history of immediate reaction. These results are consistent with those reported by other groups in particular by the Martorell et al. group from Spain.
Palavras-chave: cow's milk allergy, children, specific IgE.