1- Serviço de Imunoalergologia - Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
2- Serviço de Imunoalergologia, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, EPE, Lisboa;
3- CEDOC, Integrated Pathophysiological Mechanisms Research Group, Nova Medical School, Lisboa
- Reunião Internacional, apresentação sob a forma de comunicação oral, European Academy of Allergy and Clinical Immunology Annual Congress Lisboa, 1-5 de Julho de 2019
Background: Allergy to cow milk (CM) is one of the common food allergies in childhood. The ability to tolerate baked milk (BM) has been associated with an increased probability of developing tolerance to raw milk.
Method: Prospective historical cohort study that compared children (0-4 years old at first symptoms) with IgE-mediated CM allergy that strictly avoided CM proteins in the diet with patients who tolerated or introduced BM products. Patients were included in 3 groups: A, strictly avoided CM protein; B, always contacted with BM; C, initiated BM after negative food challenge or BM introduction at home. Immunologic parameters were measured and used for comparison between groups to evaluate the natural history of tolerance development.
Results: The study included 101 children (40 females, 61 males). Anaphylaxis occurred in 29 patients. The median age at first symptoms was 4 months, and the median sIgE to CM at diagnosis was 8.55 kU/L. Sensitization to casein occurred in 57 patients and sIgE to casein was 20.01 kU/L (SD 27.40). Sixty-nine patients maintained strict eviction of CM (group A), 5 patients tolerated BM at enrollment and maintained ingestion (group B) and 27 patients introduced BM after some period of strict eviction (group C). Spontaneous tolerance to raw CM (defined by negative oral food challenge or asymptomatic accidental ingestion without oral immunotherapy) occurred in 35 patients (26/69 eviction group vs 9/32 BM tolerant group, NS) and no significant differences were observed in the time to tolerance between the groups. Patients that achieved tolerance had, at the time of diagnosis, lower sIgE to CM (28.07 vs 8.77, p=0.015) and sIgE casein (23.24 vs 3.55, p<0.001)[S3] and smaller prick test wheals to CM (7.32 vs 4.41, p=0.014)[S4] . Age of allergy onset did not associate with development to tolerance.
Conclusion: In our study, ingestion of BM did not increase the probability or the speed of spontaneous tolerance acquisition to raw CM but it showed no deleterious effect and might allow a less strict diet. Lower sIgE and smaller prick test at the diagnosis are good predictors of spontaneous tolerance development.
Palavras Chave: Food allergy, Allergy diagnosis and systems medicine