title: Plasma Mitochondrial DNA Level is a Prognostic Marker in Peritoneal Dialysis Patients.
abstract: OBJECTIVE
  Circulating bacterial DNA fragment is related to systemic inflammatory state in peritoneal dialysis (PD) patients. We hypothesize that circulating mitochondrial DNA, which has a similar structure with bacterial DNA, correlates with systemic inflammatory state and predicts cardiovascular event in new PD patients.
  
  
  METHODS
  We measured plasma mitochondrial DNA level by quantitative polymerase chain reaction (PCR) in 197 new PD patients and 150 patients with chronic kidney disease. PD patients were followed for 24 months for the development of cardiovascular event, hospitalization, and patient survival.
  
  
  RESULTS
  There was a stepwise increase in plasma mitochondrial DNA level with worsening renal function. The average plasma mitochondrial DNA level was 18.0 ± 1.2 PCR cycles. Plasma mitochondrial DNA level correlated with serum CRP level (r = -0.538, p < 0.0001). At 24 months, the event-free survival was 67.4%, 66.4%, 63.4% and 44.2% for plasma mitochondrial DNA level quartiles I, II, III and IV, respectively (p = 0.049). After adjusting for confounders, plasma mitochondrial DNA level, malnutrition-inflammation score, and baseline arterial pulse wave velocity were independent predictors of composite cardiovascular end-point; each doubling in plasma mitochondrial DNA level confers 16.0% (95% confidence interval, 2.5 - 31.3%, p = 0.001) excess in risk. Plasma mitochondrial DNA also correlated with the number of hospital admission (r = -0.218, p = 0.002) and duration of hospitalization for cardiovascular reasons (r = -0.232, p = 0.001).
  
  
  CONCLUSIONS
  Plasma mitochondrial DNA level significantly correlates with systemic inflammatory state, and is a strong predictor of cardiovascular event as well as the need of hospitalization in new PD patients.
authors.affiliation: Carol &amp; Richard Yu Peritoneal Dialysis Research Centre, Department of Medicine &amp; Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Cheuk-Chun
authors.initials: CC
authors.lastname: Szeto
authors.forename: Ka-Bik
authors.initials: KB
authors.lastname: Lai
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chow
authors.forename: Bonnie Ching-Ha
authors.initials: BC
authors.lastname: Kwan
authors.forename: Phyllis Mei-Shan
authors.initials: PM
authors.lastname: Cheng
authors.forename: Vickie Wai-Ki
authors.initials: VW
authors.lastname: Kwong
authors.forename: Agnes Shin-Man
authors.initials: AS
authors.lastname: Choy
authors.forename: Chi-Bon
authors.initials: CB
authors.lastname: Leung
authors.forename: Philip Kam-Tao
authors.initials: PK
authors.lastname: Li
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000175:diagnosis; D004272:DNA, Mitochondrial / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D007249:Inflammation / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis; D011379:Prognosis; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000150:complications / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D004272:DNA, Mitochondrial