Food Sublingual Immunotherapy: Safety and Simplicity of a Real Food Updosing Protocol

Abstract

BACKGROUNDSublingual immunotherapy (SLIT) using food extracts is safe and effective in desensitizing food allergy patients yet not often used in clinical practice. OBJECTIVESWe propose a cost-effective, expedited SLIT protocol using real food. METHODSFood allergy patients 5-50 years, median 11, initiated food SLIT in a single clinic setting. The daily maintenance dose was 4-11 mg protein in 0.1-0.5 ml volume, depending on the food. Some foods were available in liquid form at the local grocery (milk, egg white liquid, and cashew/walnut/sunflower/hazelnut milk), while others were prepared in the office using flour and 50% glycerin saline (peanut/sesame/wheat). The first cohort of 20 patients began dosing at a 1:1,000 dilution, the next 30 patients at 1:100 dilution. An exercise challenge was performed in a subset of patients on maintenance dosing to evaluate the need for a pre- or post-dose rest period. RESULTSThe 1:1,000 and 1:100 cohorts both completed day one without adverse reactions beyond itchy mouth. There were no systemic reactions requiring epinephrine throughout the study period and 88% reached their maintenance dose. Skin testing of 6-months-old peanut flour solution was not diminished from fresh solution and similar to food extract. Exercise challenge tests in 12 patients were negative. CONCLUSIONSAllergen extract food SLIT as used in published trials has limitations of cost and multiple office visits. Inexpensive real food, at the same or slightly higher protein dose, was well tolerated in 4 updose visits, a minimum of a week apart. Unlike food oral immunotherapy, a pre- or post-dose rest period may not be necessary.