Relationship between nerve fiber density in bladder tissues and pain symptom in patients with interstitial cystitis

Abstract

Objective To investigate the relationship of nerve fiber density in bladder tissues and pain symptom in patients with interstitial cystitis (IC),in order to understand its role in the bladder pain of IC patients.Methods The experimental group included 51 cases of IC patients (9 male,42 female) and the control group included 25 cases with normal bladder tissue.All the cases underwent visual analogue scale (VAS) pain scores,immunohistochemistry of the PGP9.5 monoclonal antibody and nerve fiber counting.Results The nerve fiber density of the bladder tissue in the 2 groups was 4.78± 1.47/cm2,3.53± 1.19 /cm2,respectively (P=0.021).The nerve fiber density of IC with pain group and IC without pain group was 5.56±1.85/cm2,3.82±1.34/cm2,respectively (P=0.018).There was no significant difference in nerve fiber density between IC without pain group and the control group (P =0.164).The nerve fiber density of mild pain group,moderate pain group,severe pain group was 4.95± 1.52/cm2,5.37± 1.76/cm2,5.83± 1.91 /cm2,respectively,and the differences were significant (F=4.698,P=0.023; Pmoderate/mild =0.034,P /mod =0.029).Furthermore,the nerve fiber density of IC was positively correlated with VAS pain score (r=0.332,P=0.015).Conclusions The density of nerve fibers in bladder tissues of IC with pain group is higher than that of IC without pain group and normal controls,and it has a positive relationship with pain symptom scores,which suggestes that high expression of nerve fibers in bladder tissues may play an important role in the bladder pain of IC patients. Key words: Cystitis, interstitial; Nerve fiber density; Visual analogue scale