Circulatory Cytokine Levels Predicts Disease Severity in COVID-19

Inflammatory response in COVID-19 is responsible for acute respiratory distress syndrome (ARDS) and multiorgan failure and plays a major role in morbidity and mortality of patients. The present study in Journal of the Associations of Physcians of India, assessed serum level of cytokines and its association with other inflammatory markers and disease severity in COVID-19 and hence their prognostic significance.

This was a Retrospective observational study of 175 admitted COVID-19 patients. The patient's clinical data, laboratory investigations, inflammatory markers and serum level of cytokines were extracted. All patients were divided into three groups-

 Group A- Asymptomatic patients

 Group B -Mild to moderate ill patients

 Group C - Severe or critical ill patients.

It was found that  55% patients were asymptomatic 24% patients had mild to moderate illness remaining 21% patients had severe or critical illness. Fever, cough, dyspnoea and co-morbidities including hypertension and diabetes were more common in group C. Absolute lymphocyte count (ALC), lymphocyte monocyte ratio (LMR) showed decreasing trend whereas absolute neutrophil count (ANC), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and eosinophil-lymphocyte (ELR) showed increasing trend with increase in disease severity.

Serum IL-6 was found to be significantly higher in group C as compared to groups A and B. Researchers concluded that Elevated IL-6 levels lead to adverse clinical events so IL-6 level might serve as a potential prognostic marker for severity of disease in COVID-19. Inhibition of IL-6 might be helpful to prevent serious adverse events in COVID-19 infection.