To explore inflammatory factors that influence symptom changes in interstitial cystitis/bladder pain syndrome (IC/BPS). This longitudinal, prospective study examined the association of inflammation elicited by Toll-Like Receptor (TLR) stimulation in peripheral blood mononuclear cells (PBMCs) and diurnal cortisol rhythms with changes in painful and urinary symptoms of IC/BPS and symptom flares over a 48 week period.
Participants were 24 women meeting criteria for IC/BPS who supplied blood for isolation of PBMCs and three days of salivary cortisol samples prior to a baseline visit. Participants completed the Genitourinary Pain Index (pain and urinary subscales) and reported symptom flares every 2 weeks for 48 weeks. Mixed effects longitudinal and regression models were used to determine if inflammatory variables were associated with the changes in IC/BPS symptoms (Time X variable interactions), and the probability of a symptom flare.
Elevated TLR-4 inflammation (p = . 031) and elevated TLR-2 inflammation (p = . 045) from PBMCs, and flattened diurnal cortisol slope (p = . 012) were each associated with less improvement in genitourinary pain over time. Additionally, elevated TLR-4 inflammation was associated with less improvement in urinary symptoms (p = . 018) while TLR-2 inflammation and cortisol slope were not (both p > . 16). In contrast, no inflammatory measure was associated with an increased likelihood of reporting a symptom flare (all p > . 25).
TLR-mediated inflammation and diurnal cortisol slope may be useful as markers of symptom changes in IC/BPS.
Urology. 2016 Jan 05 [Epub ahead of print]
Andrew Schrepf, Michael A O'Donnell, Yi Luo, Catherine S Bradley, Karl J Kreder, Susan K Lutgendorf
University of Michigan, Chronic Pain and Fatigue Research Center. , University of Iowa, Department of Obstetrics and Gynecology. , University of Iowa, Department of Urology. , University of Iowa, Department of Urology; University of Iowa, Department of Obstetrics and Gynecology. , University of Iowa, Department of Urology. , University of Iowa, Department of Urology; University of Iowa, Department of Obstetrics and Gynecology; University of Iowa, Department of Psychological and Brain Science.