title: CCL18 in peritoneal dialysis patients and encapsulating peritoneal sclerosis.
abstract: BACKGROUND
  Peritoneal fibrosis manifests clinically as membrane failure or encapsulating peritoneal sclerosis (EPS). There are no clinical or biochemical tests to determine the rate of progression of peritoneal fibrosis. CCL18/pulmonary and activation-regulated chemokine (PARC) is profibrotic and stimulates collagen production independent of the effect of transforming growth factor beta. This has not been studied in peritoneal dialysis (PD) patients.
  
  
  METHODS
  We have prospectively studied 106 patients, free from infection/recent peritonitis. A high concentration of CCL18 was discovered by multiplex antibody arrays and quantified by ELISA. Serum and dialysate levels were examined for their prognostic values.
  
  
  RESULTS
  By multiple regression analysis, dialysate CCL18 (6·76 ± 0·66 μg 4 h⁻¹) correlated with increasing membrane transport status (TS) (P < 0·0001) and total glucose exposure/24 h (P = 0·033). Serum CCL18 correlated with high TS (P = 0·0001) and duration of PD (P = 0·001). After 12 months of follow-up, 57 patients remained on PD while 12 patients were transferred to haemodialysis (HD) and seven developed EPS. Patients who subsequently developed EPS had higher baseline dialysate CCL18 (11·5 ± 3·6 μg 4 h⁻¹ vs. 5·6 ± 0·82 μg 4 h⁻¹, P = 0·03) and serum CCL18 (156·9 ± 12·8 ng mL⁻¹ vs. 124·8 ± 12·2 ng mL⁻¹, P = 0·02) compared with the stable PD group.
  
  
  CONCLUSIONS
  This is the first report of high levels of CCL18 in the spent dialysate and serum from long-term PD patients. These levels correlated with dysfunction of peritoneal membrane transport status, therefore following CCL18 in a longitudinal study may be of interest.
authors.affiliation: Imperial College Kidney and Transplant Institute, Hammersmith Hospital, London, UK. sohailahmad@doctors.org.uk
authors.forename: Sohail
authors.initials: S
authors.lastname: Ahmad
authors.forename: Bernard V
authors.initials: BV
authors.lastname: North
authors.forename: Ashfaq
authors.initials: A
authors.lastname: Qureshi
authors.forename: Amir
authors.initials: A
authors.lastname: Malik
authors.forename: Gurjeet
authors.initials: G
authors.lastname: Bhangal
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Tarzi
authors.forename: Edwina A
authors.initials: EA
authors.lastname: Brown
authors.forename: Frederick W K
authors.initials: FW
authors.lastname: Tam
mesh_terms: D001692:Biological Transport; D019742:Chemokines, CC / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000009:adverse effects*; D056627:Peritoneal Fibrosis / Q000175:diagnosis*; D011446:Prospective Studies; D012044:Regression Analysis
chemical_list: C111792:CCL18 protein, human; D019742:Chemokines, CC