Distribution of Sorbic Acid Tube Precipitation and Leukocyte Adherence Inhibition Results in Two Clinically Selected Patient Cohorts: A Retrospective Descriptive Study

Abstract

Background: Hypersensitivity has been reported in association with sorbic acid and sorbate salts in susceptible individuals. Objective: This retrospective descriptive analysis characterised the distribution of Tube Titration of Precipitins (TTP) and Leukocyte Adherence Inhibition Test (LAIT) responses to sorbic acid among patients with allergic multimorbidity and polysensitisation. Methods: Two clinically selected outpatient cohorts (100 patients each) were identified from electronic medical records. Humoral immunoreactivity was assessed by TTP with sorbic acid solution in one cohort, while the other underwent an ex vivo sorbic acid challenge monitored by LAIT to examine cellular immunoreactivity. The cohorts were independent and lacked healthy controls, disease controls, and an independent diagnostic reference standard. Results: All TTP observations were positive. The mean titre was 1:220, the median was 1:128, the mode was 1:128 and occurred 30 times, and the standard deviation was 1:167. LAI values extended from 0% to 98%; the mean was 29.4%, the median 25%, the standard deviation 28.6%, and the mode 0%, which occurred 29 times. Conclusion: These clinically selected cohorts showed wide distributions of humoral and cellular immunoreactivity to sorbic acid. The data do not determine sensitivity, specificity, diagnostic utility, or immune endotypes. Accordingly, the findings are descriptive and hypothesis-generating and require prospective confirmation using appropriate controls and an independent diagnostic reference standard.