Evaluation of the Pro-Trac tacrolimus monoclonal whole-blood enzyme-linked immunosorbent assay for monitoring of tacrolimus levels in patients after kidney, heart, and liver transplantation.
In a prospective study, we evaluated a novel enzyme-linked immunosorbent assay (ELISA) (Pro-Trac) for determining tacrolimus (FK 506) concentrations in whole blood. Results obtained by the ELISA were compared with those obtained either by microparticle enzyme immunoassay (MEIA) or by high-performance liquid chromatography/mass spectrometry (HPLC-MS). The lower limit of quantitation of the ELISA was 0.5 microgram/L. The within-series coefficient of variation (CV) was < 11%. For spiked blood samples containing different concentrations of tacrolimus, interassay CV was 23.6% at 2.5 micrograms/L; however, at 15 and 60 micrograms/L, interassay CV was 44.9 and 50.8%, respectively. In crossover studies including blood samples from patients after liver, heart, or kidney transplantation, ELISA results correlated with those of the HPLC-MS (r = 0.73) as well as with those generated by MEIA (r = 0.82). The ELISA and MEIA showed 52.3 and 56.2% cross-reactivity with 15-O-demethyltacrolimus, respectively, but only 5.0 and 5.4% cross-reactivity with 13-O-demethyltacrolimus. We conclude that if assay precision in the upper range is improved, the Pro-Trac ELISA might be a valuable alternative to the MEIA for therapeutic drug monitoring of tacrolimus.
Winkler
M
M
Klinik für Abdominal- und Transplantationschirurgie, Medizinische Hochschule Hannover, Germany.
Christians
U
U
Baumann
J
J
Gonschior
A K
AK
Wonigeit
K
K
Pichlmayr
R
R
D002851:Chromatography, High Pressure Liquid; D016903:Drug Monitoring; D004797:Enzyme-Linked Immunosorbent Assay; D006084:Graft Rejection / Q000517:prevention & control; D016027:Heart Transplantation; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000097:blood*; D016030:Kidney Transplantation; D016031:Liver Transplantation; D011446:Prospective Studies; D016559:Tacrolimus / Q000008:administration & dosage / Q000097:blood*
D007166:Immunosuppressive Agents; D016559:Tacrolimus