Urine Neutrophil Gelatinase Associated-Lipocalin (NGAL) not a useful marker in the diagnosis of urinary tract infection in under-five children in a Tertiary Health Facility in South-south Nigeria

Abstract

Background: The diagnostic gold standard of urine culture in urinary tract infection often requires a long duration of 48-72 hours to obtain results, hence a setback for early intervention. The need for more sensitive rapid diagnostic clues has led to the use of renal biomarkers especially NGAL. NGAL, a novel renal biomarker produced by neutrophils, kidney cells and other body tissues is upregulated by inflammation, ischemia and infection; hence it could be used for early diagnosis as its assay time may be as short as 3.5-4 hours.

Subjects and Methods: This study set out to establish if urine NGAL could be useful in diagnosing UTI among children aged 1-60 months. It was a prospective cross- sectional study of 165 febrile under-five children presenting to the children's outpatient and children's emergency unit of the University of Uyo Teaching Hospital, Uyo, Nigeria. Urine specimen was obtained following strict asepsis by cleaning the genitalia with soap and clean water and genitalia was parted and suprapubic area tapped until child made urine. Urine was collected by clean catch / midstream method into 3 sterile specimen containers for urine culture using cysteine - lactose electrolyte deficient culture media; dip stick urinalysis using combi-11 and urine NGAL was assayed using ELISA method.

Results: Mean urine NGAL values in those with UTI was 26.78 ng/ml versus 47.56 ng/ml in the febrile non-UTI children. The AUC was 0.38 for urine NGAL with a sensitivity and specificity of 41% and 66% respectively at a diagnostic cut-off of 16.11 as obtained from the ROC.

Conclusion: This shows that urine NGAL, as an early renal marker, may be a poor diagnostic tool for early diagnosis of UTI in our locale.

Keywords:  Neutrophil gelatinase- associated lipocalin (NGAL), not useful, Diagnosis, UTI, Under-fives.