Serum and urinary NGAL in septic newborns.

Neutrophil gelatinase-associated lipocalin (NGAL) is postulated to be a potentially new and highly specific/sensitive marker of acute kidney injury (AKI). The aim of this study was to assess the impact of inflammation on serum and urine NGAL in newborns that were treated due to infection. We determined serum and urine NGAL concentrations in 73 infants (51 with sepsis; 22 with severe sepsis) admitted to the Intensive Care Unit in the first month of life, for three consecutive days during the course of treatment for infection. 29 neonates without infection served as the control group. Septic patients, in particular, severe sepsis patients, had increased serum and urinary NGAL levels in the three subsequent days of observation. Five septic patients who developed AKI had elevated serum and urinary NGAL values to a similar extent as septic neonates without AKI. A strong correlation was found between the concentration of serum and urinary NGAL and inflammatory markers, such as CRP and procalcitonin. Serum and urinary NGAL levels were also significantly associated with NTISS (neonatal therapeutic intervention scoring system) values. We conclude that increased serum and urinary NGAL values are not solely a marker of AKI, and more accurately reflect the severity of inflammatory status.

Is serum cystatin C a better marker of kidney function than serum creatinine in septic newborns?

INTRODUCTION: Several studies have claimed that the estimation of serum cystatin C could be a better marker of kidney excretory function than serum creatinine. However, its role in the diagnosis of reduced kidney function was not unquestionably confirmed. The aim of this study was to analyze the concentrations of serum cystatin C in neonates with sepsis. MATERIAL/METHODS: Thirty-two neonates (gestational age from 34 to 40 weeks) admitted to the NICU during the first 14 days of life were enrolled. Serum cystatin C concentrations were estimated by ELISA during three successive days in neonates treated for infection. The study group consisted of 9 newborns with sepsis, 14 with severe sepsis and 9 with septic shock. RESULTS/DISCUSSION: At the beginning of the observational period the mean serum concentration of cystatin C in the study group was 1.35 mg/L (95% CI 1.20-1.49). Surprisingly, the lowest concentration of cystatin was observed in patients with septic shock (1.23 mg/L; 95%CI 0.92-1.54) within the observation period. Higher concentrations were found in neonates with sepsis (1.47 mg/L; 95%CI 1.04-1.90) and severe sepsis (1.50; 1.12-1.87). There was no correlation between serum cystatin C concentration and serum creatinine or gestational age. A significant correlation was discovered between chronological age and cystatin C (R=-0.439, p=0.01). There was a tendency for cystatin C to decline during the second observational day in patients with sepsis (to 1.53 mg/L; 95%CI: 1.19-1.86) and severe sepsis (to 1.32 mg/L; 95%CI: 1.07-1.57), while a slight insignificant increase in patient with septic shock (to 1.28 mg/L; 95%CI: 0.88-1.68) was revealed. The interrelation between age and cystatin C concentration disappeared in the following days of stay in the NICU. Even in patients who died in the course of septic shock the observed changes in cystatin C levels were small and did not exceed those of serum creatinine. CONCLUSIONS: Cystatin C is not a useful marker of kidney function in neonates with sepsis.