Rac1/pSTAT3 expression: A pharmacodynamic marker panel as a first step toward optimization of thiopurine therapy in inflammatory bowel disease patients.

Autor: Deben DS; Department of Clinical Pharmacy, Clinical pharmacology and Toxicology, Zuyderland Medical Centre Sittard-Geleen, Heerlen, The Netherlands., van Adrichem AJ; Department of Clinical Chemistry and Haematology, Zuyderland Medical Centre Sittard-Geleen, Heerlen, The Netherlands., Drent R; Department of Clinical Chemistry and Haematology, Zuyderland Medical Centre Sittard-Geleen, Heerlen, The Netherlands., Puts S; Department of Clinical Chemistry and Haematology, Zuyderland Medical Centre Sittard-Geleen, Heerlen, The Netherlands., Pelzer KEJM; Department of Clinical Chemistry and Haematology, Zuyderland Medical Centre Sittard-Geleen, Heerlen, The Netherlands., van Bodegraven AA; Department of Gastroenterology, Geriatrics, Internal and Intensive Care Medicine (Co-MIK), Zuyderland Medical Centre Sittard-Geleen, Heerlen, The Netherlands.; Department of Gastroenterology and Hepatology, Amsterdam University Medical Center, Amsterdam, The Netherlands., Wong DR; Department of Clinical Pharmacy, Clinical pharmacology and Toxicology, Zuyderland Medical Centre Sittard-Geleen, Heerlen, The Netherlands., Leers MPG; Department of Clinical Chemistry and Haematology, Zuyderland Medical Centre Sittard-Geleen, Heerlen, The Netherlands.
Jazyk: angličtina
Zdroj: Cytometry. Part A : the journal of the International Society for Analytical Cytology [Cytometry A] 2022 Feb; Vol. 101 (2), pp. 167-176. Date of Electronic Publication: 2021 Oct 08.
DOI: 10.1002/cyto.a.24506
Abstrakt: Thiopurine derivatives, such as azathioprine and mercaptopurine, are standard conventional treatment options in inflammatory bowel disease (IBD). Unfortunately, approximately half of patients discontinue thiopurine therapy within 2 years. To improve the prediction of clinical effectiveness, thiopurine therapy is currently optimized using therapeutic drug monitoring. Ras-related C3 botulinum toxin substrate 1 (Rac1) has been suggested as a potential pharmacodynamic marker of the thiopurine effect in lymphocytes. The active thiopurine metabolite 6-thioguanine triphosphate (6-Thio-GTP) causes T cell apoptosis via Rac1 and the downstream transcription factor signal transducer and activator of transcription 3 (STAT3). The aim of this study was to develop and validate a functional pharmacodynamic multiparameter flow cytometric assay to determine Rac1/pSTAT3 expression in the various leukocyte subpopulations in peripheral blood in order to predict therapeutic response in IBD patients in the future. Peripheral blood samples of healthy subjects (no fever or clinical complaints of active disease, C-reactive protein < 10 mg/L) were used for immunocytochemical labeling, applying an optimized fixation and permeabilization strategy. A gating procedure was performed to separate all leukocyte subpopulations. Quantitative data were obtained by measuring presence and median fluorescent intensity. In vitro, Rac1 presence and expression were detectable in all leukocyte subpopulations. After IL-6 stimulation, used as proxy for inflammation, a distinct pSTAT3 signal could be detected in T lymphocytes of healthy subjects. In vivo, an upregulated pSTAT3 signal was detected in nearly all IBD patients with active disease and differed substantially from the signal found in IBD patients in remission on thiopurines and healthy subjects. We developed and validated a functional flow cytometric assay to assess Rac1 and pSTAT3 presence and expression. This opens a venue for a pharmacodynamic assay to predict thiopurine effectiveness in IBD patients.
(© 2021 International Society for Advancement of Cytometry.)
Databáze: MEDLINE
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