Correlations between IL-6 serum level and olfactory dysfunction severity in COVID-19 patients: a preliminary study

Area of Science:

• Immunology
• Infectious Diseases
• Neurology

Background:

• Interleukin 6 (IL-6) is a proinflammatory cytokine linked to poor outcomes in SARS-CoV-2 infection.
• Olfactory dysfunction is a common symptom of COVID-19.

Purpose of the Study:

• To investigate the relationship between olfactory function and IL-6 serum levels in COVID-19 patients.
• To assess if olfactory scores correlate with a key inflammatory marker and indicator of disease severity.

Main Methods:

• 74 COVID-19 patients underwent psychophysical olfactory testing (Connecticut Chemosensory Clinical Research Center test).
• Plasma IL-6 levels were measured within 10 days of symptom onset.
• Patients were categorized by COVID-19 severity (mild, moderate, severe).

Main Results:

• No significant differences in olfactory scores were observed across COVID-19 severity groups.
• IL-6 plasma levels significantly correlated with COVID-19 severity.
• A weak, non-significant correlation was found between IL-6 levels and olfactory scores (r_s=0.182, p=0.12).

Conclusions:

• Olfactory psychophysical scores in COVID-19 patients do not significantly correlate with IL-6 plasma levels.
• The study suggests that olfactory dysfunction may not be a reliable indicator of disease prognosis based on IL-6 levels.