Assessment Of Inflammatory Variables As Diagnostic And Prognostic Biomarkers For Covid-19 Patients

Abstract

Background

Coronavirus Disease 2019 (COVID-19) presents with a wide clinical spectrum, ranging from asymptomatic infection to critical illness and death. Early identification of patients at risk of severe disease is essential for timely clinical intervention. Inflammatory biomarkers have emerged as potential tools for diagnosing disease severity and predicting outcomes, but evidence from local populations remains limited.

Objective

To assess the diagnostic and prognostic significance of inflammatory variables in COVID-19 patients and determine their ability to predict disease severity and 28-day mortality.

Methods

A prospective observational study was conducted at Bahria Town International Hospital, Lahore, including 200 RT-PCR–confirmed COVID-19 patients from December 2019 to December 2021. Patients were categorized into non-severe and severe groups based on WHO criteria. Blood samples collected at admission were analyzed for inflammatory biomarkers including total leukocyte count (TLC), lymphocyte percentage, lactate dehydrogenase (LDH), C-reactive protein (CRP), D-dimer, serum ferritin, IL-6, TNF-α, MMP-3, and MMP-9. Diagnostic accuracy was assessed using ROC curve analysis. Survivors and non-survivors were compared to determine prognostic significance.

Results

Severe COVID-19 cases demonstrated significantly higher levels of TLC, LDH, CRP, D-dimer, ferritin, IL-6, TNF-α, MMP-3, and MMP-9, while lymphocyte counts were markedly lower (all p<0.001). D-dimer showed the highest diagnostic accuracy (AUC=0.997), followed by MMP-9 (AUC=0.981) and MMP-3 (AUC=0.966). Among oxidative stress markers, SOD showed excellent diagnostic performance (AUC=0.974). Mortality was significantly higher in the severe group (14% vs. 6%, p=0.049). Non-survivors exhibited higher TLC, CRP, D-dimer, MMP-3, and MDA levels, and lower lymphocyte counts (p<0.05). Prognostic ROC analysis identified CRP (AUC=0.701), D-dimer (AUC=0.688), lymphocyte percentage (AUC=0.694), MMP-3 (AUC=0.650), and MDA (AUC=0.673) as significant predictors of 28-day mortality.

Conclusion

Inflammatory variables,including TLC, lymphocyte percentage, CRP, D-dimer, IL-6, TNF-α, MMP-3, and MMP-9, serve as reliable diagnostic indicators of COVID-19 severity. D-dimer and MMP-9 demonstrate exceptional diagnostic accuracy. Key inflammatory markers, particularly CRP, D-dimer, lymphocyte percentage, and MMP-3, also possess prognostic value for predicting short-term mortality. Early measurement of these biomarkers can enhance risk stratification and guide timely clinical decision-making for COVID-19 patients.