Activity of the Calcineurin Pathway in Patients on the Liver Transplantation Waiting List: Factors of Variability and Response to Tacrolimus Inhibition

• Published in: Clinical chemistry (Baltimore, Md.) Vol. 63; no. 11; pp. 1734 - 1744
• Main Authors: Noceti, Ofelia, Pouché, Lucie, Esperón, Patricia, Lens, Daniela, Vital, Marcelo, Touriño, Cristina, Gerona, Solange, Woillard, Jean-Baptiste, Marquet, Pierre
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-11-2017
• Subjects: Biomarkers; Calcineurin; Calcineurin - blood; Calcineurin - drug effects; Calcineurin - genetics; Cardiovascular disease; CD25 antigen; CD8 antigen; Cell activation; Cytokines; Cytometry; Drugs; Flow cytometry; Gene expression; Humans; Immunosuppressive Agents - pharmacology; Interleukin 2; Interleukin 2 receptors; Leukocytes (mononuclear); Leukocytes, Mononuclear - metabolism; Liver; Liver diseases; Liver Transplantation; Liver transplants; Lymphocytes; Lymphocytes T; Multivariate statistical analysis; NF-AT1 protein; Nuclear transport; Nuclei (cytology); Patients; Peripheral blood mononuclear cells; Pharmacodynamics; Pharmacogenetics; Pharmacology; Statistical analysis; Studies; T cell receptors; Tacrolimus; Tacrolimus - pharmacology; Translocation; Transplantation; Transplants & implants; Waiting Lists
• DOI: 10.1373/clinchem.2017.272534
• EISSN: 1530-8561
• ISSN: 0009-9147

We sought to evaluate, in patients on a liver transplantation waiting list, potential biomarkers of the base calcineurin pathway activity with use of a new model of nonstimulated peripheral blood mononuclear cells (PBMC) and ex vivo response to tacrolimus (TAC).
The calcineurin pathway activity was explored ex vivo in stimulated and nonstimulated PBMC from 19 patients. The inhibition of NFAT1 translocation to PBMC nuclei, expression of intracellular IL-2, and membrane CD25 in different T-cell subsets were measured by multiparametric flow cytometry before and after exposure to TAC. We also studied the influence on the individual response of polymorphisms in 3 key genes of the calcineurin pathway:
,
, and
.
All pharmacodynamics profiles closely fitted an I/I
sigmoid model. Interindividual variability was higher in nonstimulated than in stimulated conditions, as well as in the presence of TAC. IL-2
CD8
cells at TAC I
showed the highest interindividual variability, suggesting its usefulness as a biomarker of individual TAC effects integrating many different sources of regulation and variability. Moreover, in the absence of TAC, patients with end-stage liver disease exhibited lower NFAT1 translocation and T-cell activation than healthy volunteers from a previous study under similar conditions. Multivariate statistical analysis showed strong and significant associations between TAC pharmacodynamic parameters and 2 polymorphisms in the gene-coding cyclophilin A (rs8177826 and rs6850).
We show the feasibility of using nonstimulated PBMCs to explore the calcineurin pathway under more physiologic conditions and point toward potential biomarkers for TAC pharmacodynamic monitoring. ClinicalTrials.gov Identifier: NCT01760356.