Journal of Research in Applied and Basic Medical Sciences (Jan 2025)
Assessment of immune response in ICU admitted SARS-CoV-2 patients from Kashmir, North India
Abstract
Background & Aims: The present study aimed to investigate the lymphocyte subpopulation counts (Th, Tc, B-cell, and NK cell) in SARS-CoV-2 patients (admitted to the ICU) to gain greater insight into the dysregulated immune response found in COVID-19. Materials & Methods: A total of 30 SARS-CoV-2 patients recruited in the intensive care unit (ICU) of Chest Disease (CD) and DRDO hospitals in Srinagar were investigated for lymphocyte subpopulation counts (T cell, B cell, and NK cell) by FACS analysis of blood samples (using the Beckman Coulter (Navios) and FACS Diva software). Results: Correlation analysis of lymphocyte subpopulation counts revealed, in comparison to normal healthy controls, an overall decreased mean T cell subset count, i.e., T-helper (CD3+, CD4+) (1422.5 cell/ul vs 662.4 cell/ul); T-cytotoxic (CD3+CD8+) (973.7 cell/ul Vs 629.2 cell/ul) and B cell count (CD45+CD19+) (442.1 cell/ul Vs. 144.4 cell/ul) with CD4+/CD8+ ratio (1.4 Vs. 1) in SARS-CoV-2 patients. On comparison, Stage 3 Vs Stage 2 patients, the mean T cytotoxic lymphocyte count i.e. CD3+CD8+, was lower (518.9 cells/ul Vs. 849.9 cell/ul) and the T-helper cell count, i.e. CD3+CD4+, was higher (764.9 cell/ul Vs. 457.3 cell/ul) with CD4+/CD8+ = 1.4 Vs. 0.5. Furthermore, the antibody immune response reflected by B-cell count was lower (i.e., CD19+131.9 cell/ul) in Stage 3 patients compared to Stage 2 patients (i.e., CD19+=162.9 cell/ul). ROC analysis with disease outcome revealed raised CD3+CD4+ count (T-helper cell response: AUC = 0.70) and decreased CD19+ count (humoral immune response: AUC = 0.80) and increased NLR (AUC = 0.65) as predictors of poor disease outcome. Conclusion: In conclusion, the study identified increased NLR, T-cell activation (increased T-helper cells), T-cytotoxic exhaustion (decreased T cytotoxic cells), and decreased humoral immune response (decreased CD19+ B cells) as predictive markers of severity and poor disease outcome in ICU-admitted patients with SARS-CoV-2.