title: Diagnostic performances of M-protein tests according to the clinical presentations of kidney disease.
abstract: BACKGROUND
  Screening for monoclonal immunoglobulin (MIg) is critical in patients with kidney disease.
  
  
  METHODS
  We identified 943 subjects who underwent kidney biopsy and at least one of monoclonal (M)-protein tests (serum and urine electrophoresis [EP], serum and urine immunofixation [IF], and serum free light chain [FLC] ratio). The sensitivities of several combinations of the 5 tests were examined by clinical presentations of kidney disease.
  
  
  RESULTS
  The sensitivities of serum EP, urine EP, and the serum FLC ratio were 65%, 68%, and 71%, respectively, which were lower than those of serum IF (79%) and urine IF (87%) to detect MIg. In the nephrotic syndrome (NS) group, the panel including serum IF, urine IF, and the serum FLC ratio exhibited 100% sensitivity to identify MIg in patients with multiple myeloma (MM) or with monoclonal gammopathy of renal significance (MGRS). In subjects without NS, the panel of serum EP and serum FLC ratio detected MIg in all cases of MM, and the serum IF plus serum FLC ratio detected MIg in all cases of MGRS.
  
  
  CONCLUSIONS
  This study demonstrated that the sensitivity of screening panels differed by the presenting features of kidney disease. The M-protein tests had lower sensitivity for detection of MIg in subjects with NS compared to those with other clinical presentation.
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Eun Hee
authors.initials: EH
authors.lastname: Koo
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jung-Ho
authors.initials: JH
authors.lastname: Shin
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hye Ryoun
authors.initials: HR
authors.lastname: Jang
authors.affiliation: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hyung-Doo
authors.initials: HD
authors.lastname: Park
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Gee-Young
authors.initials: GY
authors.lastname: Kwon
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Wooseong
authors.initials: W
authors.lastname: Huh
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Dae Joong
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Yoon-Goo
authors.initials: YG
authors.lastname: Kim
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Ha Young
authors.initials: HY
authors.lastname: Oh
authors.affiliation: Nephrology Division, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: jungeun34.lee@samsung.com.
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007118:Immunoassay; D007147:Immunoglobulin Light Chains / Q000097:blood*; D007668:Kidney / Q000473:pathology; D007674:Kidney Diseases / Q000097:blood / Q000503:physiopathology* / Q000652:urine; D008297:Male; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000097:blood*; D009101:Multiple Myeloma / Q000097:blood*; D009194:Myeloma Proteins / Q000032:analysis*; D056910:Republic of Korea; D012189:Retrospective Studies
chemical_list: D007147:Immunoglobulin Light Chains; D009194:Myeloma Proteins; C085016:multiple myeloma M-proteins
keywords: Monoclonal gammopathy; Monoclonal gammopathy of renal significance (MGRS); Plasma cell disorder; Screening panels