title: Serum polyclonal immunoglobulin free light chain levels predict mortality in people with chronic kidney disease.
abstract: OBJECTIVE
  To determine whether elevated serum polyclonal free light chain (FLC) levels predict mortality in a population of individuals with chronic kidney disease (CKD).
  
  
  METHODS
  From January 2, 2006, through July 31, 2007, we recruited a cohort of 848 people with CKD who were not receiving renal replacement therapy and did not have monoclonal gammopathy. We measured serum kappa FLC and lambda FLC isotype levels to determine combined FLC (cFLC) levels. The cohort was prospectively followed up for a median of 63 months (interquartile range, 0-93 months). Cox regression analysis was performed to determine variables predictive of mortality.
  
  
  RESULTS
  High cFLC levels were an independent risk factor for death (hazard ratio [HR], 2.71; 95% CI, 1.98-3.70; P<.001). Other independent risk factors were age (HR, 1.79; 95% CI, 1.52-2.10; P<.001), South Asian ethnicity (HR, 0.33; 95% CI, 0.14-0.64; P=.02), preexisting cardiovascular disease (HR, 1.59; 95% CI, 1.09-2.31; P=.02), and high-sensitivity C-reactive protein (HR, 1.13; 95% CI, 1.00-1.28; P=.04). Neither estimated glomerular filtration rate nor albuminuria was an independent risk factor for death.
  
  
  CONCLUSIONS
  High cFLC levels independently predict mortality in people with CKD.
authors.affiliation: Hawke's Bay District Health Board, Hawke's Bay, New Zealand.
authors.forename: Colin A
authors.initials: CA
authors.lastname: Hutchison
authors.affiliation: The Binding Site Group Ltd, Birmingham, United Kingdom; Department of Renal Medicine, Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Birmingham, United Kingdom.
authors.forename: Anne
authors.initials: A
authors.lastname: Burmeister
authors.affiliation: The Binding Site Group Ltd, Birmingham, United Kingdom; Division of Immunity and Infection, University of Birmingham, Medical School, Birmingham, United Kingdom.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Harding
authors.affiliation: Sussex Kidney Unit, Brighton and Sussex University Hospitals NHS Trust, Brighton, United Kingdom.
authors.forename: Kolitha
authors.initials: K
authors.lastname: Basnayake
authors.affiliation: Department of Renal Medicine, Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Birmingham, United Kingdom.
authors.forename: Hannah
authors.initials: H
authors.lastname: Church
authors.affiliation: Department of Renal Medicine, Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Birmingham, United Kingdom.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Jesky
authors.affiliation: Department of Renal Medicine, Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Birmingham, United Kingdom.
authors.forename: Katie
authors.initials: K
authors.lastname: White
authors.affiliation: Department of Renal Medicine, Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Birmingham, United Kingdom.
authors.forename: Clara E
authors.initials: CE
authors.lastname: Green
authors.affiliation: Department of Renal Medicine, Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Birmingham, United Kingdom; Division of Immunity and Infection, University of Birmingham, Medical School, Birmingham, United Kingdom.
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Stringer
authors.affiliation: Statsconsultancy, Ltd, Amersham, Bucks, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Bassett
authors.affiliation: Department of Renal Medicine, Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Birmingham, United Kingdom; Division of Immunity and Infection, University of Birmingham, Medical School, Birmingham, United Kingdom.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Ferro
authors.affiliation: Department of Renal Medicine, Queen Elizabeth Hospital Birmingham, Mindelsohn Way, Birmingham, United Kingdom; Division of Immunity and Infection, University of Birmingham, Medical School, Birmingham, United Kingdom. Electronic address: paul.cockwell@uhb.nhs.uk.
authors.forename: Paul
authors.initials: P
authors.lastname: Cockwell
mesh_terms: D015415:Biomarkers / Q000097:blood; D002423:Cause of Death; D015897:Comorbidity; D004739:England; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood*; D007145:Immunoglobulin kappa-Chains / Q000097:blood; D007146:Immunoglobulin lambda-Chains / Q000097:blood; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000175:diagnosis / Q000401:mortality*; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains