1 Immunoallergy Department, Hospital de Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, EPE, Lisboa, Portugal
2 Immunoallergy Department, Centro Hospitalar e Universitário de Coimbra, EPE, Coimbra, Portugal
3 CEDOC, Integrated Pathophysiological Mechanisms Research Group, Nova Medical School, Lisboa, Portugal
- Reunião Internacional, apresentação sob a forma de Póster com discussão, na European Academy of Allergy and Clinical Immunology Annual Congress Lisboa, 1-5 de Julho de 2019
Background: The aim of the study was to characterize our patients with cow’s milk allergy (CMA) who underwent cow’s milk oral immunotherapy (CM OIT).
Methods: Retrospective analysis of the files of patients who performed CM OIT over a 10-year period (2008-2018). Before OIT, a positive oral provocation test or a consistent CM allergic reaction in the last year was needed.
Results: We included 44 patients (24 females) with CMA diagnosis, who started CM OIT at a median age of 8.9 years (1 - 20 years). We used a cluster protocol in 33 patients, with the need of slower doses’ increases in 13 of them. The other 11 patients went through personalized protocols, that included baked milk, yogurt and CM small dose increments at home. The target dose was 200ml/day. Symptoms occurred in 36 (82%) patients during OIT: 61% mucocutaneous, 61% gastrointestinal, 42% respiratory and 28% anaphylaxis. Most of the reactions were associated with doses’ increases. Most of the children (59%) are in the maintenance phase (n=26), 4 are in the up-dosing phase and 32% dropped off (n=14). Twenty-five patients (of the 26) reached the target dose (10.3 months on average) and one eats baked milk. We followed them for 2,7 years on average: 14 reached a CM diet without restrictions, 10 maintain tolerance to 200 ml of CM daily, at least, 1 reduced to 150ml/day and 1 eats baked milk with no restrictions. Eight of the patients who finished OIT had symptoms during the maintenance phase. Considering the patients who interrupted OIT, all of them had symptoms during OIT. This was referred as the main reason for stopping the procedure (n=8), followed by a difficult patient/family collaboration (n=5). In 1 patient, the interruption was due to the appearance of eosinophilic esophagitis. All patients had positive specific IgEs before the start of OIT, presenting an average of 49.8 KU/L CM proteins, 20.7 KU/L α-lactoalbumin, 10.7 KU/L β-lactoglobulin and 47.7 KU/L casein.
Conclusion: In our sample, OIT was successful in 2/3 of patients. It is a very demanding procedure with an elevated risk of associated reactions, so it must be performed in specialized centres. To increase the success rate of OIT we think that, before starting OIT, the candidates must be carefully chosen and the need to a psychological counselling during the process must be assessed. Also, we still lack evidence about the best age to start this approach to a CMA patient.