D3.378 - Long Covid in epithelial barrier type2 disease: an Italian experience

Long COVID, as defined by the World Health Organization, refers to the persistence ofsymptoms for three months or more after an acute COVID-19 infection. This condition presents as aheterogeneous syndrome, with a diverse range of symptoms that vary in severity and duration. Moreover,individuals with pre-existing allergic conditions, such as allergic rhinitis, appear to experience exacerbatedsymptoms, highlighting the need for further investigation in this subgroup. This study aims to determinewhether biomarkers associated with barrier dysfunction, which are commonly seen in allergic patients, areimplicated in the development of long COVID and could serve as predictors of disease progression.

In this single-center cohort study, we evaluated clinical (age, gender, pre-existing allergicconditions, and symptom duration) and laboratory (serum eosinophil count, total IgE, eosinophil cationicprotein (ECP), and free light chains (FLCs)) data from 17 allergic patients (10 males and 7 females)diagnosed with long COVID. The study was conducted at the Allergy and Clinical Immunology Unit ofPoliclinico Universitario A. Gemelli IRCCS of Rome, Italy, from July 2024 to December 2024. The primarygoal was to identify potential biomarkers associated with barrier dysfunction that could be used indiagnosing long COVID and predicting its course.

A total of 17 patients (mean age 43.17 years) were evaluated. Significant correlations wereobserved between elevated peripheral eosinophil count, total serum IgE, ECP, and FLCs levels, and theseverity of symptoms experienced by the patients. Specifically, patients with higher eosinophil counts andIgE levels exhibited more pronounced respiratory symptoms. Elevated serum ECP and FLCs were associatedwith greater symptom severity, particularly in patients with underlying allergic rhinitis, and increasedfrequency of respiratory infections. These findings suggest a potential role for these markers in assessingthe severity and progression of long COVID in allergic patients.

Our results indicate that markers of barrier dysfunction, such as eosinophil count, serum IgE,ECP, and FLCs, are significantly correlated with the severity of long COVID symptoms in allergic patients.While further research is needed to validate these findings, these biomarkers hold promise as potentialtools for predicting the course of long COVID, offering a foundation for more personalized treatmentstrategies. Future studies should focus on confirming these associations and exploring their broaderapplicability in non-allergic populations.