BLADDER MAST-CELL EXPRESSION OF HIGH-AFFINITY ESTROGEN-RECEPTORS IN PATIENTS WITH INTERSTITIAL CYSTITIS

Objective To investigate the role of oestrogens in the pathophysiology of interstitial cystitis (IC), specifically with respect to activated bladder mast cells (MC), as well as urine concentrations of MC-derive d histamine and methylhistamine, all of which are increased in patient s with IC. This goal appeared important because IC is a bladder disord er which occurs almost exclusively in women, and is characterized by p olyuria, nocturia and pelvic pain, which worsen perimenstrually. Patie nts and methods Biopsies from sir patients with SC and four control pa tients were analysed blindly for the presence of oestrogen receptors ( OR) using both custom-made and commercially available antibodies again st OR. Results Bladder MC alone were shown to express high-affinity OR and there was a higher number of such cells present in patients with IC compared with controls. The identity of MC in the bladder was docum ented with immunohistochemistry for tryptase. OR were also identified in human MC (HMC-1), a MC line kept in culture. These steps were neces sary because of the unique finding that only MC express OR, in spite o f the inflammatory infiltrate present. Conclusion These findings may h elp to explain why IC occurs primarily in women, why IC and other asso ciated symptoms tend to be worst at the midcycle, and may also suggest the prognostic usefulness of staining bladder biopsies for OR, These results are particularly interesting because oestradiol has been shown to augment MC histamine secretion in response to the neuropeptide, su bstance P, which may be released in certain neuroinflammatory disorder s which have a high prevalence in women, such as IC and irritable bowe l syndrome.