Safety of 2-day rush induction protocol in sublingual immunotherapy with Pru p 3

Abstract

Aim: Allergy to lipid transfer proteins (LTPs) clinically manifests from oral allergy syndrome (OAS) to anaphylaxis. The risk of systemic symptoms and cross-reactivity make it an important target for allergen immunotherapy. Sublingual immunotherapy (SLIT) with Pru p 3 is effective and safe, but the induction phase (IP) of standard protocol (SP) is time consuming. Rush protocols (RPs) are described without serious adverse effects. The aim was to compare the safety of RP with SP and assess the existence of predictive factors for adverse reactions (ARs). Methods: Retrospective study of patients with LTP syndrome followed at the Food Allergy Unit undergoing SLIT with Pru p 3 between 2012 and 2021. SP has an IP of 4 days and an RP of 2 days. The safety of the IP was assessed by recording the AR. Results: Fifty-one patients: 41 (73.2% women) in SP group (SPG) and 10 (80% women) in RP group (RPG). Anaphylaxis as a presentation of LTP syndrome was overlapping in both groups (SPG 34.1%, RPG 33.3%). There were 5 (12.2%) ARs in SPG: 3 (60%) OAS, 1 (20%) oropharyngeal tightness, and 1 (20%) uvula edema; and 5 (50%) ARs in RPG: 4 (80%) OAS and 1 (20%) palmar pruritus and cough. All patients completed IP. Mean Pru p 3 specific immunoglobulin E (sIgE) value (kUA/L) of patients with ARs in IP: 6.7 kUA/L in SPG and 5.7 kUA/L in RPG. No group showed significant differences (P > 0.05) between Pru p 3 sIgE value, presence of atopy or greater severity in LTP syndrome presentation, and greater probability of AR/more severe ARs in IP. Conclusions: ARs in IP were similar in both groups. No association was found between Pru p 3 value, atopy and higher probability of ARs in IP. RP appears to be a safe and less expensive option.