title: Chronic asymptomatic pyuria precedes overt urinary tract infection and deterioration of renal function in autosomal dominant polycystic kidney disease.
abstract: BACKGROUND
  Urinary tract infection (UTI) occurs in 30%-50% of individuals with autosomal dominant polycystic kidney disease (ADPKD). However, the clinical relevance of asymptomatic pyuria in ADPKD patients remains unknown.
  
  
  METHODS
  We retrospectively reviewed medical records of 256 ADPKD patients who registered to the ADPKD clinic at Seoul National University Hospital from Aug 1999 to Aug 2010. We defined the asymptomatic pyuria as more than 5-9 white blood cells in high-power field with no related symptoms or signs of overt UTI. Patients were categorized into 2 groups depending on its duration and frequency: Group A included non-pyuria and transient pyuria patients; Group B included recurrent and persistent pyuria patients. The association between asymptomatic pyuria and both the development of overt UTI and the deterioration of renal function were examined.
  
  
  RESULTS
  With a mean follow-up duration of 65.3 months, 176 (68.8%) out of 256 patients experienced 681 episodes of asymptomatic pyuria and 50 episodes of UTI. The annual incidence of asymptomatic pyuria was 0.492 episodes/patient/year. The patients in group B showed female predominance (58.5% vs. 42.0%, P=0.01) and experienced an upper UTI more frequently (hazard ratio: 4.612, 95% confidence interval: 1.735-12.258; P=0.002, adjusted for gender and hypertension). The annual change in estimated glomerular filtration rate (ΔeGFR) was significantly larger in magnitude in group B than in group A (-2.7±4.56 vs. -1.17±5.8, respectively; P=0.01). Age and Group B found to be the independent variables for ΔeGFR and developing end-stage renal disease (16.0% vs. 4.3%, respectively; P=0.001).
  
  
  CONCLUSIONS
  Chronic asymptomatic pyuria may increase the risk of developing overt UTI and may contribute to declining renal function in ADPKD.
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, 101 Daehak-no, Jongno-gu, Seoul, 110-744, South Korea.
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Hwang
authors.forename: Hayne Cho
authors.initials: HC
authors.lastname: Park
authors.forename: Jong Cheol
authors.initials: JC
authors.lastname: Jeong
authors.forename: Seon
authors.initials: S
authors.lastname: Ha Baek
authors.forename: Mi Yeun
authors.initials: MY
authors.lastname: Han
authors.forename: Kitae
authors.initials: K
authors.lastname: Bang
authors.forename: Jeong Yeon
authors.initials: JY
authors.lastname: Cho
authors.forename: Suk Hee
authors.initials: SH
authors.lastname: Yu
authors.forename: Jaeseok
authors.initials: J
authors.lastname: Yang
authors.forename: Kook-Hwan
authors.initials: KH
authors.lastname: Oh
authors.forename: Young-Hwan
authors.initials: YH
authors.lastname: Hwang
authors.forename: Curie
authors.initials: C
authors.lastname: Ahn
mesh_terms: D015984:Causality; D002908:Chronic Disease; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016891:Polycystic Kidney, Autosomal Dominant / Q000453:epidemiology*; D015995:Prevalence; D011776:Pyuria / Q000453:epidemiology*; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology*; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D017678:Sex Distribution; D014552:Urinary Tract Infections / Q000453:epidemiology*