The prognostic role of IL-10 in non-severe COVID-19 with chemosensory dysfunction

Objectives: Olfactory and gustatory dysfunction (OD/GD) are now recognized as typical symptoms of COVID-19 infection. However, their pathogenesis remains unclear and no clear prognostic factors have been identified. We have analyzed a cohort of mild/moderate hospitalized patients to identify possible clinical or immunological predictors of recovery from OD/GD. Methods: Clinical and biological parameters were reviewed along with associated comorbidities. Chemosensory Complaint Score was administered on admission and 30 days after the first negative swab. Unpaired Wilcoxon and chi-squared tests were used to compare the variables in the patients who recovered versus those who did not. Results: From a cohort of 119 hospitalized patients, 43 (36%) reported OD/GD on admission. 60.6% had a full recovery from OD and 69.2% from GD. Only the concentration of IL-10 on admission emerged as significantly associated with recovery of taste (p = 0.041) while allergic respiratory disease was more prevalent in the group who did not recover from OD (p = 0.049) and GD (p = 0.007). Conclusion: These findings suggest that COVID-19 associated OD/GD is an inflammatory-mediated condition and that clinical and immunological parameters could predict the evolution of these symptoms.