title: Evaluation of an immunoassay (Abbott-IMX Analyzer) allowing routine determination of sirolimus: comparison with LC-MS method.
abstract: BACKGROUND
  The use of the immunosuppressive agent sirolimus is increasing in renal transplantation but its monitoring often requires high-performance liquid chromatography (HPLC) with ultra-violet (UV) or tandem mass spectrometric (MS-MS) detection. The aim of this study was to compare a new microparticle enzyme immunoassay (MEIA, Microparticle Enzyme Immunoassay) on IMx Abbott Analyser with a liquid chromatography-mass spectometry (LC-MS) method.
  
  
  METHODS
  The accuracy of immunoassay analytical performance including within run and between run imprecision and linearity was tested. For comparison studies, sirolimus level was then determined with the two methods on 98 samples from 52 transplant patients.
  
  
  RESULTS
  Total intra-assay and inter-assay variation coefficients were below 10% at the three levels tested, and the coefficient of linearity was r = 0.99. The values obtained were highly correlated with the LC-MS method (MEIA = 1.02LC-MS + 0.91; r(2) = 0.87). As a result, the immunoassay showed good performance, and clinical sample measurements were not affected by the method. The MEIA may be a useful alternative for routine monitoring of sirolimus.
authors.affiliation: Department of Biochemistry, Transplantation and Peritoneal Dialysis, University Hôpital Lapeyronie, University of Montpellier Medical School, 191 avenue du doyen Gaston Giraud, 34295 Montpellier 05, France.
authors.forename: A S
authors.initials: AS
authors.lastname: Bargnoux
authors.forename: A
authors.initials: A
authors.lastname: Bonardet
authors.forename: G
authors.initials: G
authors.lastname: Chong
authors.forename: V
authors.initials: V
authors.lastname: Garrigue
authors.forename: S
authors.initials: S
authors.lastname: Deleuze
authors.forename: A M
authors.initials: AM
authors.lastname: Dupuy
authors.forename: G
authors.initials: G
authors.lastname: Mourad
authors.forename: J P
authors.initials: JP
authors.lastname: Cristol
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007118:Immunoassay; D007166:Immunosuppressive Agents / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020123:Sirolimus / Q000097:blood*; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D007166:Immunosuppressive Agents; D020123:Sirolimus