Comprehensive analysis of lymphocyte subsets and transcriptome profiles in sepsis-induced acute respiratory distress syndrome: a prospective, observational study.

Background: Inflammation caused by ongoing sepsis stimulation significantly contributes to immunosuppression. However, the alterations in lymphocyte subsets and transcriptome profiles in the development of sepsis-induced acute respiratory distress syndrome (ARDS) remain unclear.

Methods: Peripheral blood mononuclear cells were collected from patients with sepsis at various points after admission. RNA sequencing was utilized to investigate the transcriptional changes in sepsis patients with and without ARDS. The immune cell composition of patients was dynamically monitored using flow cytometry. The comparisons were made between the changes in T cell subsets in sepsis patients without ARDS and those who developed ARDS during their hospitalization. Furthermore, the authors continuously tracked CD8 T-cells in sepsis patients who progressed to ARDS. The role of CD8 T-cells in the worsening of sepsis into ARDS was evaluated.

Results: There were significant transcriptome gene differences between sepsis patients with and without ARDS. According to KEGG enrichment analysis, most of the differentially expressed genes between these patients were connected to infection, immunological response, cell proliferation, and death. Additional GO enrichment analysis revealed that many genes were linked to T-cell activation, proliferation, and growth. Compared with sepsis patients without ARDS, the number and percentage of lymphocytes, especially CD8 T-cells, were lower in patients with sepsis-induced ARDS. The recovery of CD8 T-cells in these patients was slow, too. The results of area analysis under the ROC curve suggested that by the seventh day of hospitalization, sepsis patients with ARDS typically have a CD8 T-cell count of less than 162.5.

Conclusion: Sepsis patients with and without ARDS exhibit markedly different genes and immune cells. Patients with ARDS typically exhibited reduced CD8 T-cell counts and experienced a more protracted recovery process. Monitoring the immune cell composition of sepsis patients regularly and identifying ARDS as soon as possible is critical.