title: Plasma C-reactive protein in hemodialysis patients: a cross-sectional, longitudinal clinical survey.
abstract: In hemodialysis patients, C-reactive protein (CRP), an acute-phase reactant, is a sensitive and independent marker of malnutrition, anemia, and amyloidosis. The aim of the present studies was to evaluate CRP and interleukin 6 levels in plasma samples from long-term hemodialysis patients on different extracorporeal modalities associated with or without backfiltration. Two hundred and forty-seven patients were recruited in eight hospital-based centers. All patients had been on their dialytic modality for at least 6 months. At enrollment, 46 hemodialysis patients out of 247 (18.6%) had clinical evidence of pathologies known to be associated with high CRP values. The 201 remaining patients were defined as clinically stable and were on conventional hemodialysis (34%), hemodiafiltration with infusion volumes <10 liters/session (10%), hemodiafiltration with infusion volumes <20 liters/session (32%), and double-chamber hemodiafiltration with infusion volumes <10 liters/session (22%). Analysis of CRP values in the clinically stable patients showed that an unexpectedly high proportion (47%) of the patients had CRP values higher than 5 mg/l (taken as the upper limit in normal human subjects). The values of CRP and interleukin 6 were significantly higher in hemodiafiltration with infusion volumes <10 liters/session than in hemodiafiltration with infusion volumes >20 liters/session, in hemodialysis and in double-chamber hemodiafiltration. The same pattern occurred after 6 months of follow-up in 171 out of 201 clinically stable patients. Hemodialytic conditions that expose to the risk of backfiltration such as low exchange volume hemodiafiltration may induce a chronic inflammatory state as reflected by increased plasma values of both CRP and interleukin 6, thus suggesting the need for hemodialytic strategies that reduce (hemodialysis with low-permeability membranes or hemodiafiltration with infusion volumes >20 liters) or eliminate (double-chamber hemodiafiltration) backfiltration of bacteria-derived contaminants.
authors.affiliation: Department of Internal Medicine, University of Pisa, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Panichi
authors.forename: M
authors.initials: M
authors.lastname: Migliori
authors.forename: S
authors.initials: S
authors.lastname: De Pietro
authors.forename: M R
authors.initials: MR
authors.lastname: Metelli
authors.forename: D
authors.initials: D
authors.lastname: Taccola
authors.forename: R
authors.initials: R
authors.lastname: Perez
authors.forename: R
authors.initials: R
authors.lastname: Palla
authors.forename: P
authors.initials: P
authors.lastname: Rindi
authors.forename: R
authors.initials: R
authors.lastname: Cristofani
authors.forename: C
authors.initials: C
authors.lastname: Tetta
mesh_terms: D000209:Acute-Phase Proteins / Q000378:metabolism; D000328:Adult; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D017583:Hemodiafiltration; D006710:Homocysteine / Q000097:blood; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012709:Serum Albumin / Q000378:metabolism
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; D015850:Interleukin-6; D012709:Serum Albumin; D006710:Homocysteine; D005340:Fibrinogen; D002097:C-Reactive Protein