Urinary Lipocalin-2 Levels in Pregnant Women with Asymptomatic Fungal Urinary Tract Infection: A Cross-sectional Study from Enugu Metropolis, Nigeria

Abstract

Background: Fungal urinary tract infection (UTI) during pregnancy is an under-appreciated clinical challenge, with most cases presenting asymptomatically and therefore often undetected. Lipocalin-2 (neutrophil gelatinase-associated lipocalin; NGAL) is an acute-phase protein and an established urinary biomarker of renal tubular stress and urinary tract infection. Its utility in detecting asymptomatic fungal UTI in pregnancy remains unexplored. Aim: The purpose of this study was to assess urinary Lipocalin-2 concentrations in pregnant women with asymptomatic fungal UTI (funguria) and to examine associations between Lipocalin-2 levels and key obstetric variables. Materials and Methods: A hospital-based cross-sectional study was conducted among 72 pregnant women attending antenatal clinics in Enugu metropolis, Nigeria. Participants were allocated to a funguria group (n = 39) and a non-funguria control group (n = 33). Mid-stream urine specimens were analysed for Lipocalin-2 concentration by enzyme-linked immunosorbent assay (ELISA), urinary pH, and specific gravity. Results: Mean urinary Lipocalin-2 did not differ significantly between the funguria (4.19 ± 0.42 ng/mL) and non-funguria groups (4.38 ± 0.62 ng/mL; p = 0.799). Urinary pH and specific gravity were similarly comparable between groups (p = 0.524 and p = 0.452, respectively). Within the funguria group, gestational age was the only variable significantly associated with Lipocalin-2 level (p < 0.001), with the highest concentrations observed in the second trimester (6.85 ± 0.60 ng/mL). Age, parity, and history of UTI did not significantly influence Lipocalin-2 levels. Conclusion: Urinary Lipocalin-2 does not appear to be significantly elevated in asymptomatic fungal UTI during pregnancy compared to non-infected controls, suggesting limited utility as a standalone diagnostic biomarker for this condition. The observed gestational age-related variation in Lipocalin-2 warrants further investigation. Routine antenatal funguria screening using culture-based methods remains recommended in this population.