Blood tacrolimus levels and calcineurin phosphatase activity early after renal transplantation.
Publication/Presentation Date
2-1-2002
Abstract
The toxicity of tacrolimus (FK) despite therapeutic levels (trough) has led us to investigate its relationship with the inhibition of calcineurin (CaN) in recently transplanted renal patients. Twenty-one patients taking FK had blood drawn on day 3 and 14 at 0,1,2,3,4 and 6h. CaN activity was measured by its ability to cleave 32P from a previously radiolabeled phosphorylated 19-amino acid peptide. Radioactivity was quantitated and results were converted to units CaN. FK concentration was measured simultaneously. Maximal suppression of CaN occurred after 2h on both days. Unlike FK levels, CaN activity returned to predose levels by 6h. Comparing mean CaN activity at time 0 with each subsequent time showed statistical significance at hours 1, 2 and 3 on each day. Comparing mean FK concentrations, similarly, revealed statistical significance at all hours. Area under CaN activity curve (AUCCaN) vs. mean FK levels failed to show significance. However, comparing AUCCaN with mean CaN activity was significant throughout. CaN capacity at time 0 and 6h (day 14) resulted in the best estimate of CaN inhibition. Prior to steady-state (day 3), the best estimate occurred at 2h. No single FK concentration seemed to be a reliable indicator of CaN inhibition.
Volume
2
Issue
2
First Page
173
Last Page
178
ISSN
1600-6135
Published In/Presented At
Koefoed-Nielsen, P. B., Gesualdo, M. B., Poulsen, J. H., & Jørgensen, K. A. (2002). Blood tacrolimus levels and calcineurin phosphatase activity early after renal transplantation. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons, 2(2), 173–178. https://doi.org/10.1034/j.1600-6143.2002.020209.x
Disciplines
Medicine and Health Sciences
PubMedID
12099520
Department(s)
Department of Medicine
Document Type
Article