title: [Evaluation of two beta 2-microglobulin reagents by turbidimetric immunoassay].
abstract: BACKGROUND
  An increased level of beta 2-microglobulin (beta 2M) is seen in diseases such as lymphoproliferative diseases, renal diseases, solid tumors, liver diseases, certain viral infection, or chronic inflammatory diseases, etc. In this study, we evaluated a quantitative beta 2M assay for precision and linearity using an automated turbidimetric immunoassay (TIA) by Hitachi 7600-110 (Hitachi High Technologies Co., Japan). The TIA of beta 2M was compared with a chemiluminescent immunoassay (CLIA) by Immulite 2000 (Diagnostic Products Corporation, USA).
  
  
  METHODS
  Two TIAs, the Hitachi 7600-110 with Roche reagent (Roche-TIA) and the Hitachi 7600- 110 with HBI reagent (HBI-TIA), were evaluated for within-run precision, within-day precision, betweendays precision, and linearity. With 68 serum samples, two TIAs were compared with Immulite 2000 using DPC reagent (DPC-CLIA). These data were analyzed by Passing-Bablok analysis and Bland- Altman analysis.
  
  
  RESULTS
  The coefficients of variation (CVs) of within-run precision, within-day precision, and between- days precision were less than 7% in all groups. The linearity tests of the two TIAs were maintained well (Roche-TIA: R2=0.9952; HBI-TIA: R2=0.9946). The comparison study indicated good correlations (Roche-TIA/DPC-CLIA: r=0.9738, y=0.9625x-0.0375; HBI-TIA/DPC-CLIA: r=0.9725, y= 1.1000x-0.3100). In Bland-Altman analysis, less than 2SD differences were observed between the two groups.
  
  
  CONCLUSIONS
  Both Roche-TIA and HBI-TIA showed a good precision and excellent correlations with DPC-CLIA; therefore, TIA could be used in the routine laboratory to determine a quantitative analysis of beta 2M.
authors.affiliation: Department of Laboratory Medicine, Kyung Hee University College of Medicine, Seoul, Korea.
authors.forename: Kyung Sun
authors.initials: KS
authors.lastname: Park
authors.forename: So Young
authors.initials: SY
authors.lastname: Kang
authors.forename: Woo In
authors.initials: WI
authors.lastname: Lee
mesh_terms: D000368:Aged; D017248:Enzyme Multiplied Immunoassay Technique; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry; D011933:Reagent Kits, Diagnostic; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D001613:beta 2-Microglobulin / Q000032:analysis*
chemical_list: D011933:Reagent Kits, Diagnostic; D001613:beta 2-Microglobulin