Long-Term Outcomes after Slow Low-Dose Oral Immunotherapy for Cow's Milk.

Introduction: We previously reported the result of slow low-dose oral immunotherapy (SLOIT), which is a 1-year severity-stratified low-dose OIT for severe cow's milk (CM) allergy (CMA) (threshold dose ≤287 mg of cumulative CM protein at the entry oral food challenge [OFC]). After completing the SLOIT protocol (exit OFC to cumulative 287 mg of CM protein), the participants were instructed to gradually increase the amount of CM, roughly doubling the increasing pace, if they could consume it symptom free for 2-3 months (SLOIT plus). This study evaluated the long-term outcomes of SLOIT and identified the factors associated with these outcomes.

Methods: The subjects were 23 children who completed the SLOIT protocol and proceeded with the SLOIT-plus instructions. The proportion of subjects who were desensitized to the full dose (FD; 200 mL of CM) was evaluated. Additionally, factors associated with FD 3 years after SLOIT (FD group) were analyzed. The allergic symptoms provoked in the OFC were quantified using the total score (TS) of the Anaphylaxis Scoring Aichi (ASCA), and the overall severity was expressed as TS/Pro (TS/cumulative protein dosage).

Results: The number of subjects who were desensitized to FD within 12, 24, and 36 months was 0 (0%), 3 (13%), and 8 (35%), respectively. The FD group exhibited a larger decrease in TS/Pro, IgE specific to CM, and casein after the SLOIT protocol.

Conclusion: A third of the children with severe CMA were desensitized to FD within 36 months after SLOIT. A better response to the 1-year SLOIT protocol was associated with better long-term outcomes.