d‐mannosuria levels measured 1h afterd‐mannose intake can select out favorable responders: A pilot study

Backgroundd‐mannose is used as preventive measure against recurrent urinary tract infections (RUTIs). We studiedd‐mannosuria after a challenge test to identify favorable responders that could be targeted for long‐term preventive therapy.Material and MethodsFollowing institutional review board approval, women attending a specialized tertiary care center urology clinic with a history of RUTIs were invited to participate by providing a urine sample (baseline), followed by the intake of home‐dose d‐mannose, and a second urine sample 1 h later (post). Urine samples were processed according to ad‐mannosuria assay technique reported previously by our group.d‐mannose concentrations were normalized to urinary creatinine.ResultsFrom July 2020 to March 2021, 26 patients met study criteria. Thirteen had a lower or unchanged ratio of baseline to post d‐mannose, whereas 13 were responders. Among 19 taking 2 g, 12 had a lower or unchanged trend and 7 were responders with >20% increase in thed‐mannose/creatinine ratio. Comparison of urinary baselined‐mannose/creatinine ratios was significantly different between the responder (mean = 0.337 ± 0.158) and nonresponder (mean = 0.692 ± 0.444; p = 0.016) groups. Urinary postd‐mannose/creatinine ratios did not significantly differ between the two groups (p = 0.46).d‐mannose‐naïve patients had few responders, and age and urinary creatinine did not affect the findings.ConclusionThis preliminary study on d‐mannose challenge tests indicates a urine response if urinaryd‐mannose/creatinine ratio is low, which it was in some women with a history of RUTIs.