Risk stratification and prognostic value of serum neutrophil gelatinase-associated lipocalin (sNGAL) in sepsis patients

Abstract

Objective: Sepsis is a host response with life-threatening organ dysfunction caused by an infection. Although the overall mortality rate has increased from 30% to 37% by the surviving sepsis campaign, it is still not acceptable. Early identification, accurate stratification and appropriate intervention can improve the prognosis. In this study we assessed the risk stratification and prognostic value of serum neutrophil gelatinase-associated lipocalin (sNGAL) as a biomarker in sepsis patients. Methods: A total of 112 sepsis patients (38 patients with sepsis, 41 patients with severe sepsis, 33 patients with septic shock) and 25 healthy controls were enrolled in this study. Serum samples of all patients were collected and frozen before testing. Basic patient information was collected, including age, gender, primary infection, complications, and so on. Results of serum calcitonin, lactic acid, and SOFA score were followed up for 28 days. Results: Levels of serum procalcitonin (PCT), serum lactate, Sequential Organ Failure Assessment (SOFA) score and sNGAL of sepsis patients were significantly higher (p<0.05) than those of controls. The sNGAL level in sepsis patients who were alive on the 28th day of follow-up was significantly lower (p<0.05) than that of sepsis patients who had died before the 28th day of follow-up. Multiple logistic regression analysis showed that sNGAL-0h and lactates were independent risk factors of death due to sepsis within 28 days. At cut-off value of 250 ng/mL, the sensitivity and specificity sNGAL-0h predicting the 28-day mortality in septic patients were 0.838 and 0.827, respectively. The sNGAL level in sepsis patients with acute kidney injury (AKI) was significantly higher (p<0.05) than in sepsis patients without AKI. Conclusion: Serum NGAL may contribute to the assessment of the severity of sepsis. Serum NGAL and lactate can be independent risk factors for 28-day mortality in sepsis patients. Serum NGAL has potential of predicting septic-AKI.