Urodynamics/Lower Urinary Tract Dysfunction/Female Pelvic Medicine: Female Incontinence: Therapy I (PD06): Podium 6: Friday, September 10, 2021
PD06-10 URINARY ATP LEVELS: A POTENTIAL BIOMARKER OF OVERACTIVE BLADDER TREATMENT RESPONSE FOLLOWING ONABOTULINUM TOXIN-A INJECTIONS
INTRODUCTION AND OBJECTIVE:
Overactive bladder (OAB) is diagnosed clinically based on symptoms. However, a biomarker may help provide objective measurement of disease severity and improvement after treatment. ATP is released from the urothelium and levels tend to be higher in animal models and patients with OAB. Bladder onabotulinum toxin-A (BTX-A) injections decrease stretch-induced ATP release in animal models, yet little is known about the effect of BTX-A on human urine ATP levels. The objective of this study is to quantify changes in voided urine ATP levels and correlate with OAB-V8 symptom improvement in women treated with BTX-A injection.
Urine samples were collected and frozen on dry ice from women prior to and after 100 units of BTX-A treatment. Urine ATP levels were quantified using the luciferin-luciferase luminescent assay. OAB-V8 questionnaires were administered at time of urine collection. Women with positive urine cultures or neurogenic bladder were excluded. Degree of OAB-V8 score improvement was used to categorize participants: non-responders (change<8), mild responders (change 8-16), moderate responders (change 17-24), and marked responders (change>24). Percent change in ATP level was compared based on OAB-V8 score improvement and statistical significance was determined using the Mann-Whitney test.
Urine was collected from 23 female patients (OAB-V8 scores 2 to 40); 7 were excluded. Median age was 53.5 years (49.5-61.5). 8 patients had chronic pain disorders, 2 patients had Type 2 diabetes, and 6 patients had prior pelvic surgery. After BTX-A injections, responders had significantly lower median ATP levels compared to non-responders at 2 weeks (p=0.0268). When patients were classified according to OAB-V8 score improvement (non-responder, mild, moderate, marked responders), the improvement directly correlated with a decrease in ATP levels (Figure 1).
Decreases in urine ATP levels after BTX-A injections were associated with clinical improvement in OAB symptoms. This may be the result of a direct or indirect effect of BTX-A on mechanisms of urothelial ATP release and signaling. Quantification of urine ATP may provide a valuable tool to assess treatment response and guide further management.
Source of Funding:
N/A© 2021 by American Urological Association Education and Research, Inc.