Performance of Serum Neutrophil-Gelatinase Associated Lipocalin (NGAL) in the Diagnosis of Pregnancy-Related Acute Kidney Injury (PRAKI) in Delta, State Nigeria: A Prospective Study.

Background: Pregnancy-related acute kidney injury (PRAKI) is associated with poor maternal and perinatal outcomes if not promptly recognized. Diagnosis of PRAKI is currently based on serum creatinine, which delays diagnosis and, inevitably, treatment.

Aims: To determine the performance of serum NGAL in the diagnosis of PRAKI among women in the peripartum period and determine the normal serum NGAL levels in nonpregnant women.

Methods: A prospective study involving 162 pregnant women who presented in labor in two hospitals in Delta State and 150 nonpregnant controls. Serum creatinine and NGAL were assayed using blood samples collected from study participant at 0, 6, 12, 24, and 48 hours and 7 days postdelivery. Diagnosis of PRAKI was based on both serum creatinine and NGAL. The diagnostic performance of NGAL was determined by performing a receiver operation curve and determining the area under the curve (AUC).

Results: The prevalence of AKI using creatinine-based KDIGO criteria was 22.2% and 50% using serum NGAL. The optimal diagnostic accuracy for serum NGAL was at the 12th hour, using a cut off of 142 ng/dl determined by Youden's index. The reference range for nonpregnant women was 12.77 - 135.67 ng/dl. The sensitivity and specificity of serum NGAL at a cut off 142 ng/ml were 77.2% and 75.4% (AUC = 0.79), respectively while using 135.67 ng/ml (upper limit determined from nonpregnant women) as cut-off, sensitivity was 77.78% and specificity was 70.63%.

Conclusion: Serum NGAL is a promising marker for early diagnosis of PRAKI with high sensitivity and specificity.