Role of Inflammatory Markers, Immune Response, and Recovery Rate in COVID-19 Patients

Abstract

From mild symptoms to Severe Acute Respiratory Syndrome and multi-organ dysfunction induced by Coronavirus-2, COVID-19's clinical outcomes vary. An important aspect in illness severity and outcome is host immunological response, especially the ratio of protective immunity to excessive inflammation. In severe situations, abnormal immune activation can lead to hyperinflammation and elevated levels of biomarkers such as IL-6, CRP, TNF-α, ferritin, and D-dimer. These parameters are linked to illness severity, ICU admission, and death risk. Blood markers including lymphopenia and the neutrophil-lymphocyte ratio (NLR) also predict immunological failure. Balanced immune activation speeds virus clearance and recovery, but an excessive inflammatory response causes acute respiratory distress symptoms (ARDS) and prolonged hospitalisation. Inflammatory markers, immunological dysregulation, and their clinical relevance in COVID-19 disease development and recovery are highlighted in this study.