Circulating T-lymphocyte subsets as promising biomarkers for the identification of sepsis-induced acute kidney injury.

Background: This retrospective study investigated whether disturbances in circulating T-lymphocyte subsets could predict the incidence of acute kidney injury (AKI) and in-hospital mortality in patients with sepsis.

Methods: Clinical data from patients with sepsis admitted to the intensive care unit were reviewed. Logistic regression analyses were used to identify independent predictors of in-hospital mortality and the development of AKI.

Results: Of 81 patients with sepsis, 50 developed AKI. Both nonsurvivors and patients with septic AKI exhibited higher Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores. Nonsurvivors exhibited more organ damage, with significantly lower levels of peripheral T-lymphocyte subsets, including total circulating lymphocytes, and CD3 + , CD3 + CD4 + , and CD3 + CD8 + T-lymphocytes. Patients with septic AKI exhibited fewer total peripheral lymphocytes and fewer CD3 + , CD3 + CD4 + , and CD3 + CD8 + T-lymphocytes, with higher serum lactate levels and lower nadir platelet counts. Independent predictors of 30-day hospital mortality included maximum SOFA and APACHE II scores, occurrence of encephalopathy, and peripheral CD3 + and CD3 + CD8 + T-lymphocyte counts. Moreover, the maximum SOFA score and CD3 + and CD3 + CD8 + T-lymphocyte counts demonstrated good predictive power for AKI in receiver operating characteristic (ROC) curve analyses, with an area under the ROC curve of 0.810 (95% confidence interval [CI], 0.712-0.908) for SOFA score, 0.849 (95% CI, 0.764-0.934) for CD3 + T-lymphocytes, and 0.856 (95% CI, 0.772-0.941) for CD3 + CD8 + T-lymphocytes.

Conclusion: Patients with sepsis-induced AKI experienced T lymphopenia and increased in-hospital mortality. Higher maximum SOFA scores and reduced peripheral CD3 + and CD3 + CD8 + T-lymphocyte levels were associated with in-hospital mortality and the development of AKI in patients with sepsis.