title: Falsely elevated whole blood tacrolimus concentrations due to interference in an affinity column-mediated immunoassay method on Xpand dimension.
abstract: The whole blood concentration of tacrolimus is required for therapeutic drug monitoring of this immunosuppressive drug. Abnormal tacrolimus levels affect its efficacy or toxicity, leading to changes in its dosage. Here, we report analytical interference in the affinity column-mediated immunoassay tacrolimus method on the Xpand autoanalyzer in a kidney transplant human immunodeficiency virus-infected patient. Tacrolimus concentrations obtained by affinity column-mediated immunoassay are 3- to 7-fold higher than measurements with the enzyme multiplied immunoassay technique assay. The cause of this interference remains unknown. However, it would be necessary to identify this type of interference to measure tacrolimus concentration with another method to avoid analytical error, which may lead to a poor clinical outcome.
authors.affiliation: Department of Clinical Pharmacy, Bicêtre Hospital, APHP, 78 rue du General Leclerc, Le Kremlin-Bicêtre, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Barau
authors.forename: Carlos
authors.initials: C
authors.lastname: Frangie
authors.forename: Cécile
authors.initials: C
authors.lastname: Goujard
authors.forename: Olivier
authors.initials: O
authors.lastname: Tribut
authors.forename: François
authors.initials: F
authors.lastname: Parant
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Taburet
authors.forename: Antoine
authors.initials: A
authors.lastname: Durrbach
authors.forename: Valérie
authors.initials: V
authors.lastname: Furlan
mesh_terms: D000328:Adult; D016903:Drug Monitoring; D005189:False Positive Reactions; D015658:HIV Infections / Q000503:physiopathology; D006526:Hepatitis C / Q000503:physiopathology; D006801:Humans; D007118:Immunoassay; D007166:Immunosuppressive Agents / Q000097:blood*; D016030:Kidney Transplantation; D008297:Male; D016559:Tacrolimus / Q000097:blood*
chemical_list: D007166:Immunosuppressive Agents; D016559:Tacrolimus