Inflammatory parameters in the prediction of sepsis-induced acute kidney injury: a case-control study

Although hypovolemia was long considered the main cause of sepsis-induced acute kidney injury (SI-AKI), current theories explore multifactorial causes of injury (inflammation, immune response, ischaemia-reperfusion system and hypovolemia). The aim of this study was to determine the significance of inflammatory parameters (leucocyte, neutrophil, lymphocyte, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), procalcitonin (PCT)) and mean-arterial pressure (MAP)) in prediction of SI-AKI development.

A total of 257 septic patients (Sepsis-3 criteria) were included. Patients were divided into two groups based on SI-AKI development (with SI-AKI, n = 133; without SI-AKI, n = 124). All patients had complete blood count with leukocyte formula, CRP, PCT, SOFA and qSOFA score available. Statistical analysis included non-parametric Mann-Whitney test, Spearman's correlations, ROC curve analysis, as well as binary logistic regression in order to identify independent predictors of SI-AKI.

CRP (p < 0.001), PCT (p < 0.001) and NLR (p = 0.002) were higher in the SI-AKI group, and showed a significant correlation with creatinine levels (p < 0.001). MAP was significantly lower in the SI-AKI group (p = 0.043). Binary logistic regression analysis showed that CRP and PCT were only independent predictors of SI-AKI, along with SOFA score. ROC curve analysis showed that CRP ≥ 199 mg/L, and PCT ≥ 13ng/L represent the cut-off values for SI-AKI prediction.

Obtained results highlight the potential role of the inflammatory response in SI-AKI development.