title: Analytical performance of a new one-step quantitative prostate-specific antigen assay, the FREND™ PSA Plus.
abstract: BACKGROUND
  We evaluated the analytical performance of a new one-step rapid quantitative sandwich immunoassay for total prostate-specific antigen (tPSA), the FREND™ PSA Plus (FREND PSA) (NanoEnTek Inc., Seoul, Korea).
  
  
  METHODS
  The imprecision, linearity, hook effect, detection limit (LoD), and interference were evaluated and trueness verification and matrix validation were performed. For method comparison, 79 patient specimens were analyzed with FREND PSA and two comparative tPSA assays (Architect® total PSA and cobas® total PSA assay).
  
  
  RESULTS
  Total CVs of the imprecision for low (0.208 ng/mL), medium (4.051 ng/mL), and high PSA levels (5.469 ng/mL) were 15.9%, 6.4%, and 9.1%, respectively. Linearity was observed from 1.01 to 19.15 ng/mL and the hook phenomenon was absent up to 171.48 ng/mL. The LoD was 0.094 ng/mL. The regression equations between FREND (y) and Architect or cobas were as follows: y=0.0133+1.054x (r=0.973), y=-0.2144+1.066x (r=0.977), respectively. Differences between FREND PSA and the comparative methods at a medical decision level of 4.0 ng/mL were less than the optimum specification bias (9.3%). The percentage biases from the trueness verification and interference test were less than the desirable specifications for bias (18.7%). The plasma tPSA level measured with lithium heparin or K2EDTA was comparable to that in the serum.
  
  
  CONCLUSIONS
  The FREND PSA provided reliable analytical performance and test results in comparison to two widely used tPSA assays. It is a simple and rapid test for tPSA and can be applied in point-of-care testing.
authors: Hae-Il
authors: HI
authors: Park
authors: Seungok
authors: S
authors: Lee
authors: Yonggoo
authors: Y
authors: Kim
authors: Dong-Yeok
authors: DY
authors: Shin
authors: Changseop
authors: C
authors: Lee
authors: Sunmi
authors: S
authors: Han
authors: Chanil
authors: C
authors: Chung
authors: Jun Keun
authors: JK
authors: Chang
authors: In Bum
authors: IB
authors: Seo
mesh_terms: D004492:Edetic Acid / Q000737:chemistry; D006493:Heparin / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D008094:Lithium / Q000737:chemistry; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis; D011933:Reagent Kits, Diagnostic
chemical_list: D011933:Reagent Kits, Diagnostic; D006493:Heparin; D008094:Lithium; D004492:Edetic Acid; D017430:Prostate-Specific Antigen