Soluble vascular endothelial growth factor receptor 1 (VEGFR1): A possible biomarker in BPS/IC?

Interstitial cystitis/bladder pain syndrome (IC/BPS) pathophysiology is not fully understood. Vascular endothelial growth factor (VEGF) has been implicated in bladder vasculature alterations and nociception, but the role of its soluble receptor, VEGFR1, remains poorly explored. This study aimed to determine whether urinary VEGF and VEGFR1 levels could be biomarkers for IC/BPS. As a post hoc analysis, we also examined VEGFR1 variation and its relationship with the clinical characteristics of IC/BPS patients and urinary serotonin levels. An observational cross-sectional pilot study was conducted after clearance from the ethics committee. Eighteen female IC/BPS patients and 19 healthy age-matched females without past urological conditions were included. ESSIC criteria were used to phenotype. The patient’s symptoms evaluated were bladder pain, urinary frequency, and life quality. Patients during flare episodes or taking antidepressant drugs were excluded. Urine samples from patients and healthy subjects were used to measure VEGF, VEGFR1, and serotonin urinary levels. The relation of VEGFR1 with serotonin and clinical parameters was assessed. Patients and healthy volunteers had a similar median age. No statistical differences in VEGF were detected. Urinary VEGFR1 was significantly lower in patients. Soluble VEGFR1 did not correlate to serotonin levels or clinical parameters. The urinary serotonin levels were similar between groups. Urinary VEGFR1, but not urinary VEGF, might be a useful IC/BPS biomarker. Further investigation is necessary to confirm the present observation and validate the relationship of VEGFR1 with clinical parameters and serotonin.