title: Combined analysis using extended renal reference range of serum free light chain ratio and serum protein electrophoresis improves the diagnostic accuracy of multiple myeloma in renal insufficiency.
abstract: OBJECTIVE
  To determine the diagnostic accuracy of serum free light chain κ/λ ratio (rFLC) using extended renal reference (renal range rFLC) in multiple myeloma (MM) with renal insufficiency.
  
  
  METHODS
  Patients who visited a nephrologist due to renal insufficiency (n=471) were enrolled. Serum FLC quantification, protein electrophoresis (PEP), and pathologic diagnosis were performed.
  
  
  RESULTS
  Renal range rFLC showed the highest sensitivity to differentiate MM from non-MM among four tests (conventional rFLC, s-PEP, u-PEP). In intact immoglobulin MM (IIMM), the sensitivity and specificity were lower for both rFLCs than for s-PEP. On the other hand, both rFLC showed higher sensitivity compared than PEPs in light chain MM (LCMM). Combined analysis (renal rFLC+s-PEP) increased the sensitivity for both IIMM and LCMM.
  
  
  CONCLUSIONS
  Renal rFLC is a valuable screening tool in renal insufficiency patients suspected of having MM, especially for LCMM. Combined analysis (renal rFLC+s-PEP) improves the diagnostic accuracy for detecting MM in the setting of renal impairment.
authors.affiliation: Department of Nephrology, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Jeong Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Yeo-Kyeoung
authors.initials: YK
authors.lastname: Kim
authors.forename: Eun Hui
authors.initials: EH
authors.lastname: Bae
authors.forename: Seong Kwon
authors.initials: SK
authors.lastname: Ma
authors.forename: Soo Wan
authors.initials: SW
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D001797:Blood Protein Electrophoresis / Q000379:methods; D001798:Blood Proteins / Q000032:analysis; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000032:analysis / Q000097:blood*; D007145:Immunoglobulin kappa-Chains / Q000032:analysis / Q000097:blood*; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D012016:Reference Values; D051437:Renal Insufficiency / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001798:Blood Proteins; D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains