D1.63 - Descriptive Study on the Evolution of Patients Treated with Oral Immunotherapy (OIT) Using Pasteurized Egg White at the Fundación Alcorcón University Hospital

Oral immunotherapy (OIT) is an active treatment for food allergies. Long-term follow-up studies on maintained tolerance are scarce. Our objective was to analyze the evolution of patients treated with OIT using pasteurized egg white (PEW) at our hospital.

We included patients who underwent OIT with PEW between 2014 and 2018, with at least 1 year of follow-up in the maintenance phase. We collected demographic data, clinical manifestations, diagnostic tests before and after OIT, and egg tolerance during maintenance.

Partial tolerance (PT) was defined as the ability to consume cooked egg white, and complete tolerance (CT) as the ability to tolerate white egg in any form (raw or cooked). We also assessed whether sustained unresponsiveness (SU) was achieved after a period of egg exclusion.

We analyzed 30 patients, 29 of whom successfully completed OIT. The cohort included 19 males and the median age was 11 year (IQR 8–12) at initiation. In the maintenance phase, 22 patients achieved CT, 6 achieved PT, and 1 was lost to follow-up; another patient required a new OIT protocol with cooked egg after an anaphylactic reaction. SU was confirmed in 2 patients after a negative raw egg challenge following an exclusion period.

Skin prick tests (SPT) and specific IgE levels (sIgE) decreased significantly in all patients after OIT (Table 1). Patients with PT had higher sIgE levels at diagnosis (p<0.05), and similar trends were observed with pre-OIT sIgE levels, though statistical significance was only reached for egg yolk (Table 2).

OIT was successful in the majority of patients, with more than two-thirds maintaining CT. Patients with PT had higher sIgE levels at diagnosis. Significant reductions in SPT and sIgE were observed after OIT in all patients.