title: Increased urothelial cell apoptosis and chronic inflammation are associated with recurrent urinary tract infection in women.
abstract: OBJECTIVE
  This study was designed to investigate whether increased urothelial cell apoptosis and chronic inflammation might contribute to recurrent urinary tract infection (UTI) in women.
  
  
  METHODS
  The bladder biopsy specimens were collected from thirty women with recurrent UTI and ten controls. The bladder biopsies were performed at one to two months after UTI episode had been completely resolved and urine analysis and urine culture all showed negative. Immunofluorescence staining of the adhesive protein E-cadherin, mast cell and TUNEL were performed in all the bladder specimens. In addition, western blots were also performed to analyze the inflammatory proteins (phospho-p38, tryptase) and apoptotic protein (Bax) in the bladder mucosa specimens between patients with recurrent UTI and controls.
  
  
  RESULTS
  Immunofluorescence staining showed significantly lower E-cadherin in the recurrent UTI bladder tissue compared with the controls (25.4±8.9 v 42.4±16.7, p<0.0001). The mast cell expression was significantly stronger in the recurrent UTI bladder tissue compared with the controls (2.5±1.8 v 1.3±1.2, p = 0.046). TUNEL staining revealed a significantly higher numbers of apoptotic cells in the recurrent UTI bladder tissue compared with the control bladder tissue (1.5±1.8 v 0.08±0.3, p<0.0001). Western blot analysis also showed that the expressions of tryptase and Bax increased in five recurrent UTI specimens compared with two normal control specimens.
  
  
  CONCLUSIONS
  Chronic inflammation, urothelial cell apoptosis and impairment of barrier function of urothelial cells might contribute to recurrent UTI in women.
authors.affiliation: Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Kaohsiung, Taiwan. chuangfeichi@hotmail.com
authors.forename: Fei-Chi
authors.initials: FC
authors.lastname: Chuang
authors.forename: Hann-Chorng
authors.initials: HC
authors.lastname: Kuo
mesh_terms: D017209:Apoptosis; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D007249:Inflammation / Q000150:complications / Q000473:pathology*; D012008:Recurrence; D014552:Urinary Tract Infections / Q000150:complications / Q000473:pathology*; D019459:Urothelium / Q000473:pathology*