Relationships between urinary neural and immune factors in the patients with interstitial cystitis/ bladder painful syndrome

The purpose of this work was to study the relationships between urinary cytokines, mast cells and nerve growth factor (NGF) in the patients with interstitial cystitis/bladder pain syndrome (IC/BPS). Sixty-eight women with clinically diagnosed IC/BPS were under study. Their mean age was 54.2±12.4 years. Urinary concentrations of interleukins (IL-1β, IL-6, IL-8), tumor necrosis factor-α (TNFα), and NGF were determined by ELISA technique. Mast cells were identified in biopsies of mucous membranes from urinary bladder harvested during cystoscopy. Statistical evaluation was performed by Statistica program in Microsoft Excel. Pearson correlation quotients were calculated. Depending on the type of IC/BPS, the patients were divided into 2 groups: group I included 36 patients with classic type of disease; group II comprised 32 patients with non-ulcer type of IC/BPS. No significant differences were revealed between the groups. In 13.9% of patients from group I, the onset of clinical manifestations of the disease was observed at the age of less than 40 years; in group II, 28.1% of the examined mentioned appearance of the disease symptoms at this age. The levels of IL-1β in the patients from group I was 2.4 times higher than in controls (p < 0.05). IL-6, IL-8 and TNFα concentrations exceeded control values by 2.0 (p < 0.05), 2.5 (p < 0.05) and 2.0 times (p < 0.05), respectively. In the patients from group II, the content of IL-1β, IL-6, IL-8 and TNFα was 2.4 (p < 0.05), 2.0 (p < 0.05), 2.0 (p < 0.05) and 1.9 (p < 0.05) times higher than in the control group, respectively. There were no significant differences between groups I and II, in IL-1β, IL-6, and TNFα levels, except of IL-8 in women of group I that was 20.3% higher than in group II. The urinary NGF level in the patients with IC/BPS exceeded the control level 1.6 times (p < 0.05) for group I, and 1.5 times (p < 0.05) for group II. The number of mast cells in the patients of group I was significantly higher than in controls and in group II, i.e., 1.6 (p < 0.05) and 1.4 times (p < 0.05), respectively. In most cases, a direct weak correlation was revealed between the indices. Only in group I, a moderate correlation (r = + 0.508) could be detected between IL-1β and mast cells. Determination of cytokine levels allows to detect activation of inflammatory cells in bladder tissue and provides an opportunity for developing diagnostic strategies. Increased numbers of mast cells may indicate the importance of these cells in the disease progression, whereas elevated levels of NGF in urine suggests that IC/BPS may be caused by chronic inflammation.