Higher circulating neutrophil apoptosis in non-survivors with sepsis

Unusual cell death in immune cells contributes to immunosuppression in sepsis. Neutrophils play a crucial role in fighting pathogens. However, the roles of apoptosis, pyroptosis, and neutrophil extracellular trap (NET) formation (NETosis) in neutrophils during sepsis remain unclear.

Patients admitted to the intensive care unit with sepsis were enrolled between August 2021 and July 2024. Apoptosis, pyroptosis, and NETosis in circulating neutrophils were measured on days 1 and 8. Finally, data from 43 patients were used for analysis.

On day 8, the count and percentage of neutrophils dying primarily through apoptosis were significantly higher in non-survivors compared to survivors (9.7 vs. 2.0/μL; 7.2 vs. 3.4%, respectively). General Linear Model revealed significant differences in both the percentage (p = 0.035) and count (p = 0.008) of apoptosis-predominant neutrophil death on days 1 and 8 between survivors and non-survivors. The percentage and count of apoptosis-predominant neutrophils on day 8 were positively correlated with the APACHE II score on day 8 with correlation coefficients of 0.560 (p < 0.001) and 0.513 (p = 0.002), respectively. SOFA score was weakly positively correlated with the count of apoptosis-predominant neutrophils on days 1 and 8 with correlation coefficients of 0.347 (p = 0.023) and 0.375 (p = 0.029), respectively.

This study suggests that increased neutrophil death via apoptosis is associated with higher mortality rates in sepsis patients. Neutrophil apoptosis levels correlated with disease severity scores. Larger-scale studies are needed to confirm these findings.