A real-world data analysis of distribution and inconsistency between total serum IgE and allergen-specific IgE results in clinical practice.

Background: The inconsistency between serum total IgE (tIgE) and allergen-specific IgE (sIgE) results is often encountered in clinical practice, but the distribution and influencing factors of the inconsistent results have not been fully understood.

Objective: The aim of this study was to analyze the distribution and inconsistency between tIgE and sIgE test results.

Methods: A retrospective study, from the electronic medical records of 2139 patients who underwent both tIgE and sIgE tests, from January to December 2023 was reviewed. The tIgE and sIgE results and their distribution, as well as their inconsistency, were analyzed based on sex, age, and disease subgroups.

Results: 36.2% of the patients had a positive sIgE, and 43.7% had an elevated tIgE level. sIgE and tIgE results were discordant in nearly 30% of patients, with no difference between genders, while individuals aged over 60 exhibited a significantly higher inconsistency rate than the other age groups, and the inconsistency rate between tIgE and sIgE results was significantly different among different tIgE levels, sIgE grades, positive allergen count and positive allergen types. In addition, patients with chronic urticaria (CU) had a higher inconsistency rate than those with other allergic diseases, but the difference was not statistically significant.

Conclusion: The overall inconsistency rate between tIgE and sIgE results was about 30%. The elderly group older than 60 years old is more likely to have inconsistent results, and tIgE level, sIgE level, the number and type of positive allergens also affected the consistency of tIgE and sIgE results.