CD4 and Sepsis: This study aims to explore the relationships between cell death biomarkers (serum-soluble levels of PD-1, PD-L1, and IL-7) and the percentages of various lymphocyte subsets (CD4+ T helper lymphocytes, CD8+ T cytotoxic lymphocytes, natural killer T CD3+ lymphocytes, and CD19+ B lymphocytes) in relation to the severity and progression of sepsis.