Macrophage Migration Inhibitory Factor Provides a Predictive Performance of Septic Acute Kidney Injury

Background: Septic acute kidney injury (AKI) is a common condition in ICU with poor outcomes. Septic AKI patients have a progressively decreased urine output and increased serum creatinine. However, urine volume and serum creatinine showed poor sensitivity to early diagnosis of septic AKI. Searching for potential biomarkers to early detect AKI is crucial in day-to-day clinical practice. Macrophage migration inhibitory factor (MIF), primarily released by renal tubular epithelial cells, vascular endothelial cells, and immune cells, was found to be closely associated with the inflammatory response in sepsis. MIF may be used as a biomarker of septic AKI indicating aggravation of systemic inflammatory response. Methods: Our study included sepsis patients admitted to the ICU. The KDIGO guideline was used to confirm the diagnosis and staging of septic AKI. Blood samples were collected and tested, as well as clinical data were recorded. Independent risk factors were selected via logistic regression analysis. By drawing the receiver operating characteristic (ROC) curves, the area under the ROC curves (AUC) was computed. The relationship between serum MIF level and mortality of septic AKI was analyzed using Cox regression analysis. Results: With high serum MIF level at ICU admission, the patients were more likely to develop AKI. The AUC of serum MIF (MIFAUC = 0.797) was found to be a good predictor of septic AKI. In addition, higher serum MIF levels corresponded to more severe AKI as well as a higher mortality rate. Conclusions: Serum MIF might be a biomarker for predicting the occurrence, development, and outcomes of septic AKI. This conclusion will need to be confirmed by more robust investigations in the future.