Is Neutrophil Gelatinase-Associated Lipocalin a Culprit or a Bystander in Acute Kidney Injury in Septic Children?

Background: In this study we tried to answer the question whether neutrophil gelatinase-associated lipocalin (NGAL) is a culprit or only bystander in acute kidney injury (AKI) caused by sepsis in children.

Material and methods: Twenty-seven children (M-17, F-10) admitted to the Pediatric Intensive Care Unit diagnosed with sepsis were enrolled for this prospective study. Age- and sex-matched controls (n=21) were afebrile children without evidence of active infection or inflammatory condition. Activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen, C-reactive protein, creatinine, urea, protein C and S, antithrombin III, and NGAL levels were measured at admission and after an intensive 10-day and in healthy controls.

Results: On day 1 we found statistically decreased levels of protein C, protein S, and antithrombin III and increased concentration of serum NGAL, creatinine, and urea when compared to healthy controls. The serum NGAL correlated negatively with protein C (r=-0.48, p<0.01) and positively with serum creatinine (r=0.39, p<0.05) and urea (r=0.41, p<0.05). On day 10 statistically significant negative correlation between serum NGAL and protein C was still observed (r=-0.53, p<0.05). Multivariate regression revealed that serum NGAL levels were significantly predicted by creatinine (β=0.39, p<0.01) and protein C (β=-0.38; p<0.01), yielding a model R²=0.34 (p<0.01).

Conclusions: The results of this study suggest that not only acute kidney injury, but also other mechanisms probably caused by the infection, influenced serum NGAL levels in septic children.