Evaluation of urinary neutrophil gelatinase-related lipocalin levels in the management of neonatal urinary system infections

Urinary tract infection (UTI) is a common infection in newborns. UTI without appropriate treatment in the newborn can lead to acute mortality and morbidity as well as chronic kidney disease in the long term. New markers for rapid diagnosis of UTI will help initiate treatment early. We investigated the use of urinary neutrophil gelatinase-associated lipocalin (uNGAL), which is specifically elevated in genitourinary epithelial damage, as an early marker of UTI. This study was conducted as a single-center prospective cohort study in Eskişehir Osmangazi University Faculty of Medicine, Department of Pediatrics, between March 1, 2022 and March 1, 2023, on 80 newborn babies who were thought to have UTI. Newborn who were below 37 weeks postmenstrual, over 44 weeks postmenstrual, and with a history of asphyxia at the time of urine culture were excluded from the study. UTI was identified in 50 of 80 patients and formed the patient group, 30 patients with normal urinary findings formed the control group and uNGAL levels were compared between the groups. A statistically higher uNGAL level was detected in the group with UTI (839.14 ng/ml) than in the group without UTI (718.14 ng/ml) (p=0.001). According to the ROC analysis results, the uNGAL cut-off value to diagnose UTI was determined as 973.43 ng/ml. All 5 patients who were above the uNGAL cut-off value for diagnosing UTI and had leukocyte esterase positivity in the complete urinalysis were in the group defined as UTI. The uNGAL level of 27 of 30 patients in whom UTI was not identified was below the uNGAL cut-off value diagnosing UTI. Although the uNGAL level was found to be high in cases with UTI, it was concluded that uNGAL level alone cannot replace urine culture, which is the gold standard in the diagnosis of UTI, due to the multitude of morbidities that may affect the neonatal period. Key Words: uNGAL, Urinary tract infection, Newborn Supporting Institution: Scientific Research Projects of Coordination Unit