title: The impact of renal function on the clinical performance of FLC measurement in AL amyloidosis.
abstract: BACKGROUND
  The measurement of circulating free light chains (FLC) is of utmost importance in immunoglobulin light chain (AL) amyloidosis, being a fundamental part of the diagnostic workup, prognostic stratification and assessment of response to therapy. Renal failure is a common feature of AL amyloidosis and can considerably affect the concentration of FLC.
  
  
  METHODS
  We assessed the impact of renal failure on the clinical performance of the Freelite assay in 982 consecutive, newly diagnosed patients with AL amyloidosis, 822 with estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2, and 160 with eGFR <30 mL/min/1.73 m2.
  
  
  RESULTS
  The diagnostic sensitivity of the κ/λ FLC ratio was lower for λ amyloidogenic FLC in patients with renal failure (81% vs. 60%, p<0.001) and the FLC concentration had no independent prognostic significance in patients with severe renal dysfunction. However, FLC response to chemotherapy could still discriminate patients with better outcome.
  
  
  CONCLUSIONS
  Renal failure is a relevant interference factor when using the Freelite assay for the identification of the amyloidogenic light chain and for prognostic assessment in patients with AL amyloidosis and renal failure.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Palladini
authors.forename: Paolo
authors.initials: P
authors.lastname: Milani
authors.forename: Andrea
authors.initials: A
authors.lastname: Foli
authors.forename: Marco
authors.initials: M
authors.lastname: Basset
authors.forename: Francesca
authors.initials: F
authors.lastname: Russo
authors.forename: Tiziana
authors.initials: T
authors.lastname: Bosoni
authors.forename: Laura
authors.initials: L
authors.lastname: Pirolini
authors.forename: Veronica
authors.initials: V
authors.lastname: Valentini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ferraro
authors.forename: Francesca
authors.initials: F
authors.lastname: Lavatelli
authors.forename: Alessandra
authors.initials: A
authors.lastname: Barassi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Albertini
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Merlini
mesh_terms: D000368:Aged; D000686:Amyloidosis / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D005260:Female; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000097:blood*; D007146:Immunoglobulin lambda-Chains / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D051437:Renal Insufficiency / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy
chemical_list: D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains