title: Switching from HPLC/UV to MEIA for whole blood sirolimus quantitation: comparison of methods.
abstract: Sirolimus is a immunosuppressive agent for renal transplant recipients. Monitoring of whole blood sirolimus concentration is necessary in order to improve clinical outcomes. An increasing number of clinical laboratories (4-14% during 2005) are using microparticle enzyme immunoassay (MEIA) for sirolimus quantitation but previous reports indicated a high variability, with a mean difference of 17% for MEIA method vs. high-performance liquid chromatography/ultraviolet (HPLC/UV). This study was aimed at comparing the reliability of MEIA with the HPLC/UV method. Blood samples from transplant patients were processed using both HPLC/UV and MEIA assays. Comparison and Bland-Altman plots, as well as regression analysis and paired t-test were used to compare results of the assays. Concentrations were stratified into three groups and used to investigate whether any observed difference between methods could be influenced by sirolimus concentration. Regression analysis yielded a coefficient of correlation R of 0.9756, the line of best fit being y=0.9832x+0.1976. The statistical analysis showed no difference between the two sets of experimental data. The average percentage difference between the two methods was found to be -0.2+/-19.2%. On the basis of our present results, the tested MEIA assay is able to quantify sirolimus concentration with a clinically acceptable imprecision, similar to that of HPLC/UV method.
authors.affiliation: Division of Toxicology and Clinical Pharmacology, University of Modena and Reggio Emilia, Policlinico of Modena, Modena, Italy. pinila@unimore.it
authors.forename: Luigi Alberto
authors.initials: LA
authors.lastname: Pini
authors.forename: Daniela
authors.initials: D
authors.lastname: Gallesi
authors.forename: Daria
authors.initials: D
authors.lastname: Brovia
authors.forename: Alfio
authors.initials: A
authors.lastname: Bertolini
authors.forename: Diego
authors.initials: D
authors.lastname: Pinetti
authors.forename: Valentina
authors.initials: V
authors.lastname: Ruggieri
authors.forename: Stefania
authors.initials: S
authors.lastname: Pisa
authors.forename: Brunella
authors.initials: B
authors.lastname: Poppi
authors.forename: Carmela
authors.initials: C
authors.lastname: Nives Castellana
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods / Q000706:statistics & numerical data; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000706:statistics & numerical data; D016903:Drug Monitoring; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods / Q000706:statistics & numerical data; D007166:Immunosuppressive Agents / Q000097:blood*; D015203:Reproducibility of Results; D020123:Sirolimus / Q000097:blood*; D014181:Transplantation Immunology; D014466:Ultraviolet Rays
chemical_list: D007166:Immunosuppressive Agents; D020123:Sirolimus