The relevance of compounding factors and the risk of anaphylaxis in 63 patients allergic to alpha-gal

ABSTRACT

Background: Compounding factors have been frequently described as helpers in food allergic reactions, not only favouring but also intensifying them. However, in alpha-gal syndrome, cofactors haven been controversial or not clearly identified. Objective: Analyze the data in 63 alpha-gal allergic patients studied in the last 8 years in Araba University Hospital (HUA;Vitoria-Gasteiz;Basque Country, north of Spain), in order to clarify the envolvement of compounding factors, their relevance, and the risk of anaphylaxis. Method: We report 10 women and 53 men (range, 9-86 years) including 2 children and 1 teenager, diagnosed of alpha-gal allergy by skin tests to mammalian meat extracts and to cetuximab;specific IgE to mammalian meats, alpha-gal and Activation Basophil Test (BAT) in 26 cases. The number of patients which presented severe allergic reactions and the implication of possible cofactors involved in severe and non-severe allergic reactions are collected. Results: In 46 % of the patients (29/63), compounding factors were reported. Compounding factors were NSAIDs, exercise, alcohol, emotional stress, intense hot weather, infections, Angiotensin Converting Enzyme (ACE) Inhibitors and Proton Pump Inhibitors (PPIs). NSAIDs were the most reported (8/29), followed by exercise (7/29);alcohol (6/29);infections (3/29) 1 SARS-CoV- 2 virus infection, 1 Varicela virus and 1 bacterial infection. ACE Inhibitors (2/29);PPIs (1/29);intense hot weather (1/29) and emotional stress (1/29). Severe allergic reactions were presented in 44% (28/63) of total cases. Cofactors were involved in 12/28 severe patients (43%). Cofactors were presented in 3/5 anaphylactic shocks (2 alcohol, one of them associated with a bacterial infection, 1 emotional stress) and in 9/23 anaphylaxis (4 exercise, 3 NSAIDs, 1 PPIs, 1 alcohol). 35 cases were non-severe reactions. Cofactors were involved in 29% of non-severe reactions. In 3/35, various compounding factors were involved (9%). Case number (no) 1 exercise and NSAID (diclofenac);no 2 exercise and ACE inhibitor;no 3 exercise, NSAID and intense hot weather. Conclusion: We present 63 allergic alpha gal patients registered in the last 8 years in which, 1. Almost half of the patients, present severe allergic reactions. 2. Compounding factors are presented in 44% of the allergic reactions. 3. In severe cases, compounding factors are involved in 43% of the patients versus in 29% non-severe reactions.