Search

Your search keyword '"van Schaik, Ron H.N."' showing total 392 results
Start Over Author "van Schaik, Ron H.N."
392 results on '"van Schaik, Ron H.N."'

1. The Pharmacogenomics Global Research Network Implementation Working Group: global collaboration to advance pharmacogenetic implementation

Author

Cavallari, Larisa H., Hicks, J. Kevin, Patel, Jai N., Elchynski, Amanda L., Smith, D. Max, Bargal, Salma A., Fleck, Ashley, Aquilante, Christina L., Killam, Shayna R., Lemke, Lauren, Ochi, Taichi, Ramsey, Laura B., Haidar, Cyrine E., Ho, Teresa, El Rouby, Nihal, Monte, Andrew A., Allen, Josiah D., Beitelshees, Amber L., Bishop, Jeffrey R., Bousman, Chad, Campbell, Ronald, Cicali, Emily J., Cook, Kelsey J., Duong, Benjamin, Tsermpini, Evangelia Eirini, Girdwood, Sonya Tang, Gregornik, David B., Grimsrud, Kristin N., Lamb, Nathan, Lee, James C., Lopez, Rocio Ortiz, Mazhindu, Tinashe Adrian, Morris, Sarah A., Nagy, Mohamed, Nguyen, Jenny, Pasternak, Amy L., Petry, Natasha, van Schaik, Ron H.N., Schultz, April, Skaar, Todd C., Al Alshaykh, Hana, Stevenson, James M., Stone, Rachael M., Tran, Nam K., Tuteja, Sony, Woodahl, Erica L., Yuan, Li-Chi, and Lee, Craig R.

Published
2025
Full Text
View/download PDF

2. The Pharmacogenomics Global Research Network Implementation Working Group: global collaboration to advance pharmacogenetic implementation

Author

Cavallari, Larisa H., Hicks, J. Kevin, Patel, Jai N., Elchynski, Amanda L., Smith, D. Max, Bargal, Salma A., Fleck, Ashley, Aquilante, Christina L., Killam, Shayna R., Lemke, Lauren, Ochi, Taichi, Ramsey, Laura B., Haidar, Cyrine E., Ho, Teresa, El Rouby, Nihal, Monte, Andrew A., Allen, Josiah D., Beitelshees, Amber L., Bishop, Jeffrey R., Bousman, Chad, Campbell, Ronald, Cicali, Emily J., Cook, Kelsey J., Duong, Benjamin, Tsermpini, Evangelia Eirini, Girdwood, Sonya Tang, Gregornik, David B., Grimsrud, Kristin N., Lamb, Nathan, Lee, James C., Lopez, Rocio Ortiz, Mazhindu, Tinashe Adrian, Morris, Sarah A., Nagy, Mohamed, Nguyen, Jenny, Pasternak, Amy L., Petry, Natasha, van Schaik, Ron H.N., Schultz, April, Skaar, Todd C., Al Alshaykh, Hana, Stevenson, James M., Stone, Rachael M., Tran, Nam K., Tuteja, Sony, Woodahl, Erica L., Yuan, Li-Chi, and Lee, Craig R.

Published
2024
Full Text
View/download PDF

3. Implementation of model-informed precision dosing for tamoxifen therapy in patients with breast cancer: A prospective intervention study

Author

van Nijnatten, Ruben Y.M., Buijs, Sanne M., Agema, Bram C., Fischer, Raphaël M.J., Moghaddam-Helmantel, Inge Ghobadi, Contant, Caroline M.E., de Jongh, Felix E., Huijben, Auke M.T., Kop, Manon, van der Padt-Pruijsten, Annemieke, Zuetenhorst, Hanneke J.M., van Schaik, Ron H.N., Koch, Birgit C.P., Jager, A., Koolen, Stijn L.W., and Mathijssen, Ron H.J.

Published
2025
Full Text
View/download PDF

5. DPYD Genotyping Recommendations: A Joint Consensus Recommendation of the Association for Molecular Pathology, American College of Medical Genetics and Genomics, Clinical Pharmacogenetics Implementation Consortium, College of American Pathologists, Dutch Pharmacogenetics Working Group of the Royal Dutch Pharmacists Association, European Society for Pharmacogenomics and Personalized Therapy, Pharmacogenomics Knowledgebase, and Pharmacogene Variation Consortium

Author

Pratt, Victoria M., Cavallari, Larisa H., Fulmer, Makenzie L., Gaedigk, Andrea, Hachad, Houda, Ji, Yuan, Kalman, Lisa V., Ly, Reynold C., Moyer, Ann M., Scott, Stuart A., Turner, Amy J., van Schaik, Ron H.N., Whirl-Carrillo, Michelle, and Weck, Karen E.

Published
2024
Full Text
View/download PDF

6. Real-World Implementation of a Genotype-Guided P2Y12 Inhibitor De-Escalation Strategy in Acute Coronary Syndrome Patients

Author

Azzahhafi, Jaouad, van den Broek, Wout W.A., Chan Pin Yin, Dean R.P.P., van der Sangen, Niels M.R., Sivanesan, Shabiga, Bofarid, Salahodin, Peper, Joyce, Claassens, Daniel M.F., Janssen, Paul W.A., Harmsze, Ankie M., Walhout, Ronald J., Tjon Joe Gin, Melvyn, Nicastia, Deborah M., Langerveld, Jorina, Vlachojannis, Georgios J., van Bommel, Rutger J., Appelman, Yolande, van Schaik, Ron H.N., Henriques, José P.S., Kikkert, Wouter J., and ten Berg, Jurriën M.

Published
2024
Full Text
View/download PDF

8. Sex and Common Germline Variants Affect the Toxicity Profile and Pharmacokinetics of Alectinib: A Nationwide Cohort Study in Patients With ALK-Positive NSCLC

Author

Heersche, Niels, Lanser, Daan A.C., Muntinghe-Wagenaar, M. Benthe, Mohmaed Ali, Ma Ida, Ulas, Ezgi B., Trooster, Tessa M.A., de Jonge, Evert, Oomen-de Hoop, Esther, Paats, Marthe S., Bahce, Idris, Croes, Sander, Hendriks, Lizza E.L., van der Wekken, Anthonie J., Dingemans, Anne-Marie C., Huitema, Alwin D.R., van Schaik, Ron H.N., Mathijssen, Ron H.J., and Veerman, G.D. Marijn

Published
2024
Full Text
View/download PDF

11. CYP3A4 and CYP3A5 Genotyping Recommendations: A Joint Consensus Recommendation of the Association for Molecular Pathology, Clinical Pharmacogenetics Implementation Consortium, College of American Pathologists, Dutch Pharmacogenetics Working Group of the Royal Dutch Pharmacists Association, European Society for Pharmacogenomics and Personalized Therapy, and Pharmacogenomics Knowledgebase

Author

Pratt, Victoria M., Cavallari, Larisa H., Fulmer, Makenzie L., Gaedigk, Andrea, Hachad, Houda, Ji, Yuan, Kalman, Lisa V., Ly, Reynold C., Moyer, Ann M., Scott, Stuart A., van Schaik, Ron H.N., Whirl-Carrillo, Michelle, and Weck, Karen E.

Published
2023
Full Text
View/download PDF

13. Influence of germline variations in drug transporters ABCB1 and ABCG2 on intracerebral osimertinib efficacy in patients with non-small cell lung cancer

Author

Veerman, G.D. Marijn, Boosman, Rene J., Jebbink, Merel, Oomen-de Hoop, Esther, van der Wekken, Anthonie J., Bahce, Idris, Hendriks, Lizza E.L., Croes, Sander, Steendam, Christi M.J., de Jonge, Evert, Koolen, Stijn L.W., Steeghs, Neeltje, van Schaik, Ron H.N., Smit, Egbert F., Dingemans, Anne-Marie C., Huitema, Alwin D.R., and Mathijssen, Ron H.J.

Published
2023
Full Text
View/download PDF

20. Nonlinear Mixed‐Effects Model of Z‐Endoxifen Concentrations in Tamoxifen‐Treated Patients from the CEPAM Cohort.

Author

Mc Laughlin, Anna M., Helland, Thomas, Klima, Fenja, Koolen, Stijn L.W., van Schaik, Ron H.N., Mathijssen, Ron H.J., Neven, Patrick, Swen, Jesse J., Guchelaar, Henk‐Jan, Dalenc, Florence, White‐Koning, Melanie, Michelet, Robin, Mikus, Gerd, Schroth, Werner, Mürdter, Thomas, Brauch, Hiltrud, Schwab, Matthias, Søiland, Håvard, Mellgren, Gunnar, and Thomas, Fabienne

Subjects
CYTOCHROME P-450 CYP2D6, BIOTRANSFORMATION (Metabolism), TAMOXIFEN, BREAST cancer, BODY weight
Abstract

Tamoxifen is widely used in patients with hormone receptor‐positive breast cancer. The polymorphic enzyme CYP2D6 is primarily responsible for metabolic activation of tamoxifen, resulting in substantial interindividual variability of plasma concentrations of its most important metabolite, Z‐endoxifen. The Z‐endoxifen concentration thresholds below which tamoxifen treatment is less efficacious have been proposed but not validated, and prospective trials of individualized tamoxifen treatment to achieve Z‐endoxifen concentration thresholds are considered infeasible. Therefore, we aim to validate the association between Z‐endoxifen concentration and tamoxifen treatment outcomes, and identify a Z‐endoxifen concentration threshold of tamoxifen efficacy, using pharmacometric modeling and simulation. As a first step, the CYP2D6 Endoxifen Percentage Activity Model (CEPAM) cohort was created by pooling data from 28 clinical studies (> 7,000 patients) with measured endoxifen plasma concentrations. After cleaning, data from 6,083 patients were used to develop a nonlinear mixed‐effect (NLME) model for tamoxifen and Z‐endoxifen pharmacokinetics that includes a conversion factor to allow inclusion of studies that measured total endoxifen but not Z‐endoxifen. The final parent‐metabolite NLME model confirmed the primary role of CYP2D6, and contributions from body weight, CYP2C9 phenotype, and co‐medication with CYP2D6 inhibitors, on Z‐endoxifen pharmacokinetics. Future work will use the model to simulate Z‐endoxifen concentrations in patients receiving single agent tamoxifen treatment within large prospective clinical trials with long‐term survival to identify the Z‐endoxifen concentration threshold below which tamoxifen is less efficacious. Identification of this concentration threshold would allow personalized tamoxifen treatment to improve outcomes in patients with hormone receptor‐positive breast cancer. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

22. Clinical utility of circulating tumor DNA in patients with advanced KRASG12C-mutated non-small cell lung cancer treated with sotorasib.

Author

Ernst, Sophie M., primary, van Marion, Ronald, additional, Atmodimedjo, Peggy N., additional, de Jonge, Evert, additional, Mathijssen, Ron H.J., additional, Paats, Marthe S., additional, de Bruijn, Peter, additional, Koolen, Stijn L., additional, von der Thüsen, Jan H., additional, Aerts, Joachim G.J.V., additional, van Schaik, Ron H.N., additional, Dubbink, Hendrikus J., additional, and Dingemans, Anne-Marie C., additional

Published
2024
Full Text
View/download PDF

23. A low aldosterone/renin ratio and high soluble ACE2 associate with COVID-19 severity

Author

Akin, Sakir, Schriek, Paula, van Nieuwkoop, Cees, Neuman, Rugina I., Meynaar, Iwan, van Helden, Erik J., Bouazzaoui, Hassan El, Baak, Remon, Veuger, Marjan, Mairuhu, Ronne A.T.A., van den Berg, Lettie, van Driel, Vincent, Visser, Loes E., de Jonge, Evert, Garrelds, Ingrid M., Duynstee, Johannes F.A.B., van Rooden, Jan Kees, Ludikhuize, Jeroen, Verdonk, Koen, Caliskan, Kadir, Jansen, Tim, van Schaik, Ron H.N., and Danser, A.H. Jan

Published
2021
Full Text
View/download PDF

24. Dutch Pharmacogenetics Working Group (DPWG) guideline for the gene-drug interaction of CYP2C9, HLA-A and HLA-B with anti-epileptic drugs

Author

Manson, Lisanne E.N., Nijenhuis, Marga, Soree, Bianca, de Boer-Veger, Nienke J., Buunk, Anne Marie, Houwink, Elisa J.F., Risselada, Arne, Rongen, Gerard A.P.J.M., van Schaik, Ron H.N., Swen, Jesse J., Touw, Daan J., van Westrhenen, Roos, Deneer, Vera H.M., Guchelaar, Henk Jan, Manson, Lisanne E.N., Nijenhuis, Marga, Soree, Bianca, de Boer-Veger, Nienke J., Buunk, Anne Marie, Houwink, Elisa J.F., Risselada, Arne, Rongen, Gerard A.P.J.M., van Schaik, Ron H.N., Swen, Jesse J., Touw, Daan J., van Westrhenen, Roos, Deneer, Vera H.M., and Guchelaar, Henk Jan

Abstract

By developing evidence-based pharmacogenetics guidelines to optimize pharmacotherapy, the Dutch Pharmacogenetics Working Group (DPWG) aims to advance the implementation of pharmacogenetics (PGx). This guideline outlines the gene-drug interaction of CYP2C9 and HLA-B with phenytoin, HLA-A and HLA-B with carbamazepine and HLA-B with oxcarbazepine and lamotrigine. A systematic review was performed and pharmacotherapeutic recommendations were developed. For CYP2C9 intermediate and poor metabolisers, the DPWG recommends lowering the daily dose of phenytoin and adjust based on effect and serum concentration after 7–10 days. For HLA-B*15:02 carriers, the risk of severe cutaneous adverse events associated with phenytoin, carbamazepine, oxcarbazepine, and lamotrigine is strongly increased. For carbamazepine, this risk is also increased in HLA-B*15:11 and HLA-A*31:01 carriers. For HLA-B*15:02, HLA-B*15:11 and HLA-A*31:01 positive patients, the DPWG recommends choosing an alternative anti-epileptic drug. If not possible, it is recommended to advise the patient to report any rash while using carbamazepine, lamotrigine, oxcarbazepine or phenytoin immediately. Carbamazepine should not be used in an HLA-B*15:02 positive patient. DPWG considers CYP2C9 genotyping before the start of phenytoin “essential” for toxicity prevention. For patients with an ancestry in which the abovementioned HLA-alleles are prevalent, the DPWG considers HLA-B*15:02 genotyping before the start of carbamazepine, phenytoin, oxcarbazepine, and lamotrigine “beneficial”, as well as genotyping for HLA-B*15:11 and HLA-A*31:01 before initiating carbamazepine.

Published
2024

25. Real-World Implementation of a Genotype-Guided P2Y12 Inhibitor De-Escalation Strategy in Acute Coronary Syndrome Patients

Author

Team Medisch, Azzahhafi, Jaouad, van den Broek, Wout W.A., Chan Pin Yin, Dean R.P.P., van der Sangen, Niels M.R., Sivanesan, Shabiga, Bofarid, Salahodin, Peper, Joyce, Claassens, Daniel M.F., Janssen, Paul W.A., Harmsze, Ankie M., Walhout, Ronald J., Tjon Joe Gin, Melvyn, Nicastia, Deborah M., Langerveld, Jorina, Vlachojannis, Georgios J., van Bommel, Rutger J., Appelman, Yolande, van Schaik, Ron H.N., Henriques, José P.S., Kikkert, Wouter J., ten Berg, Jurriën M., Team Medisch, Azzahhafi, Jaouad, van den Broek, Wout W.A., Chan Pin Yin, Dean R.P.P., van der Sangen, Niels M.R., Sivanesan, Shabiga, Bofarid, Salahodin, Peper, Joyce, Claassens, Daniel M.F., Janssen, Paul W.A., Harmsze, Ankie M., Walhout, Ronald J., Tjon Joe Gin, Melvyn, Nicastia, Deborah M., Langerveld, Jorina, Vlachojannis, Georgios J., van Bommel, Rutger J., Appelman, Yolande, van Schaik, Ron H.N., Henriques, José P.S., Kikkert, Wouter J., and ten Berg, Jurriën M.

Published
2024

26. Is uracil enough for effective pre-emptive DPD testing?

Author

Heersche, Niels, Matic, Maja, Mathijssen, Ron H.J., Coenen, Marieke J.H., Van Schaik, Ron H.N., Heersche, Niels, Matic, Maja, Mathijssen, Ron H.J., Coenen, Marieke J.H., and Van Schaik, Ron H.N.

Published
2024

27. First-trimester maternal tryptophan metabolites, utero-placental (vascular)development and hypertensive disorders of pregnancy:The Rotterdam periconceptional cohort

Author

van Zundert, Sofie K.M., Broekhuizen, Michelle, Mirzaian, Mina, van Rossem, Lenie, Danser, A. H.Jan, Willemsen, Sten P., Griffioen, Pieter H., Koning, Anton H.J., Mulders, Annemarie G.M.G.J., van Schaik, Ron H.N., Steegers-Theunissen, Régine P.M., van Zundert, Sofie K.M., Broekhuizen, Michelle, Mirzaian, Mina, van Rossem, Lenie, Danser, A. H.Jan, Willemsen, Sten P., Griffioen, Pieter H., Koning, Anton H.J., Mulders, Annemarie G.M.G.J., van Schaik, Ron H.N., and Steegers-Theunissen, Régine P.M.

Published
2024

28. Dutch pharmacogenetics working group guideline for the gene-drug interaction of ABCG2, HLA-B and Allopurinol, and MTHFR, folic acid and methotrexate

Author

Apotheek Klinische Farmacie, van der Pol, Karel H., Nijenhuis, Marga, Soree, Bianca, de Boer-Veger, Nienke J., Buunk, Anne Marie, Guchelaar, Henk Jan, Risselada, Arne, van Schaik, Ron H.N., Swen, Jesse J., Touw, Daan, van der Weide, Jan, van Westrhenen, Roos, Deneer, Vera H.M., Houwink, Elisa J.F., Rongen, Gerard A., Apotheek Klinische Farmacie, van der Pol, Karel H., Nijenhuis, Marga, Soree, Bianca, de Boer-Veger, Nienke J., Buunk, Anne Marie, Guchelaar, Henk Jan, Risselada, Arne, van Schaik, Ron H.N., Swen, Jesse J., Touw, Daan, van der Weide, Jan, van Westrhenen, Roos, Deneer, Vera H.M., Houwink, Elisa J.F., and Rongen, Gerard A.

Published
2024

29. Discovering novel germline genetic variants linked to severe fluoropyrimidine-related toxicity in- and outside DPYD

Author

Knikman, Jonathan E., Zhai, Qinglian, Lunenburg, Carin A.T.C., Henricks, Linda M., Böhringer, Stefan, van der Lee, Maaike, de Man, Femke M., Offer, Steven M., Shrestha, Shikshya, Creemers, Geert Jan, Baars, Arnold, Dezentjé, Vincent O., Imholz, Alexander L.T., Jeurissen, Frank J.F., Portielje, Johanna E.A., Jansen, Rob L.H., Hamberg, Paul, Droogendijk, Helga J., Koopman, Miriam, Nieboer, Peter, van de Poel, Marlène H.W., Mandigers, Caroline M.P.W., van Schaik, Ron H.N., Gelderblom, Hans, Mathijssen, Ron H.J., Schellens, Jan H.M., Cats, Annemieke, Guchelaar, Henk Jan, Swen, Jesse J., Knikman, Jonathan E., Zhai, Qinglian, Lunenburg, Carin A.T.C., Henricks, Linda M., Böhringer, Stefan, van der Lee, Maaike, de Man, Femke M., Offer, Steven M., Shrestha, Shikshya, Creemers, Geert Jan, Baars, Arnold, Dezentjé, Vincent O., Imholz, Alexander L.T., Jeurissen, Frank J.F., Portielje, Johanna E.A., Jansen, Rob L.H., Hamberg, Paul, Droogendijk, Helga J., Koopman, Miriam, Nieboer, Peter, van de Poel, Marlène H.W., Mandigers, Caroline M.P.W., van Schaik, Ron H.N., Gelderblom, Hans, Mathijssen, Ron H.J., Schellens, Jan H.M., Cats, Annemieke, Guchelaar, Henk Jan, and Swen, Jesse J.

Abstract

Background: The Alpe-DPD study (NCT02324452) demonstrated that prospective genotyping and dose-individualization using four alleles in DPYD (DPYD*2A/rs3918290, c.1236G > A/rs75017182, c.2846A > T/rs67376798 and c.1679 T > G/rs56038477) can mitigate the risk of severe fluoropyrimidine toxicity. However, this could not prevent all toxicities. The goal of this study was to identify additional genetic variants, both inside and outside DPYD, that may contribute to fluoropyrimidine toxicity. Methods: Biospecimens and data from the Alpe-DPD study were used. Exon sequencing was performed to identify risk variants inside DPYD. In silico and in vitro analyses were used to classify DPYD variants. A genome-wide association study (GWAS) with severe fluoropyrimidine-related toxicity was performed to identify variants outside DPYD. Association with severe toxicity was assessed using matched-pair analyses for the exon sequencing and logistic, Cox, and ordinal regression analyses for GWAS. Results: Twenty-four non-synonymous, frameshift, and splice site DPYD variants were detected in ten of 986 patients. Seven of these variants (c.1670C > T, c.1913 T > C, c.1925 T > C, c.506delC, c.731A > C, c.1740 + 1G > T, c.763 − 2A > G) were predicted to be deleterious. The carriers of either of these variants showed a trend towards a 2.14-fold (95% CI, 0.41–11.3, P = 0.388) increased risk of severe toxicity compared to matched controls (N = 30). After GWAS of 942 patients, no individual single nucleotide polymorphisms achieved genome-wide significance (P ≤ 5 × 10−8), however, five variants were suggestive of association (P < 5 × 10−6) with severe toxicity. Conclusions: Results from DPYD exon sequencing and GWAS analysis did not identify additional genetic variants associated with severe toxicity, which suggests that testing for single markers at a population level currently has limited clinical value. Identifying additional variants on an i

Published
2024

30. Discovering novel germline genetic variants linked to severe fluoropyrimidine-related toxicity in- and outside DPYD

Author

MS Medische Oncologie, Cancer, Knikman, Jonathan E., Zhai, Qinglian, Lunenburg, Carin A.T.C., Henricks, Linda M., Böhringer, Stefan, van der Lee, Maaike, de Man, Femke M., Offer, Steven M., Shrestha, Shikshya, Creemers, Geert Jan, Baars, Arnold, Dezentjé, Vincent O., Imholz, Alexander L.T., Jeurissen, Frank J.F., Portielje, Johanna E.A., Jansen, Rob L.H., Hamberg, Paul, Droogendijk, Helga J., Koopman, Miriam, Nieboer, Peter, van de Poel, Marlène H.W., Mandigers, Caroline M.P.W., van Schaik, Ron H.N., Gelderblom, Hans, Mathijssen, Ron H.J., Schellens, Jan H.M., Cats, Annemieke, Guchelaar, Henk Jan, Swen, Jesse J., MS Medische Oncologie, Cancer, Knikman, Jonathan E., Zhai, Qinglian, Lunenburg, Carin A.T.C., Henricks, Linda M., Böhringer, Stefan, van der Lee, Maaike, de Man, Femke M., Offer, Steven M., Shrestha, Shikshya, Creemers, Geert Jan, Baars, Arnold, Dezentjé, Vincent O., Imholz, Alexander L.T., Jeurissen, Frank J.F., Portielje, Johanna E.A., Jansen, Rob L.H., Hamberg, Paul, Droogendijk, Helga J., Koopman, Miriam, Nieboer, Peter, van de Poel, Marlène H.W., Mandigers, Caroline M.P.W., van Schaik, Ron H.N., Gelderblom, Hans, Mathijssen, Ron H.J., Schellens, Jan H.M., Cats, Annemieke, Guchelaar, Henk Jan, and Swen, Jesse J.

Published
2024

31. Dutch Pharmacogenetics Working Group (DPWG) guideline for the gene-drug interaction of CYP2C9, HLA-A and HLA-B with anti-epileptic drugs

Author

Apotheek Klinische Farmacie, Manson, Lisanne E.N., Nijenhuis, Marga, Soree, Bianca, de Boer-Veger, Nienke J., Buunk, Anne Marie, Houwink, Elisa J.F., Risselada, Arne, Rongen, Gerard A.P.J.M., van Schaik, Ron H.N., Swen, Jesse J., Touw, Daan J., van Westrhenen, Roos, Deneer, Vera H.M., Guchelaar, Henk Jan, Apotheek Klinische Farmacie, Manson, Lisanne E.N., Nijenhuis, Marga, Soree, Bianca, de Boer-Veger, Nienke J., Buunk, Anne Marie, Houwink, Elisa J.F., Risselada, Arne, Rongen, Gerard A.P.J.M., van Schaik, Ron H.N., Swen, Jesse J., Touw, Daan J., van Westrhenen, Roos, Deneer, Vera H.M., and Guchelaar, Henk Jan

Published
2024

33. Determination of cortisone and cortisol in human scalp hair using an improved LC-MS/MS-based method

Author

Mirzaian, Mina, Van Zundert, Sofie K.M., Schilleman, Wim F., Mohseni, Mostafa, Kuckuck, Susanne, Van Rossum, Elisabeth F.C., Van Schaik, Ron H.N., Van Den Berg, Sjoerd A.A., Mirzaian, Mina, Van Zundert, Sofie K.M., Schilleman, Wim F., Mohseni, Mostafa, Kuckuck, Susanne, Van Rossum, Elisabeth F.C., Van Schaik, Ron H.N., and Van Den Berg, Sjoerd A.A.

Abstract

Objectives: Human scalp hair is an easily available but complex matrix for determination of cortisone and cortisol, and has been shown to reflect long-term glucocorticoid exposure. Hair glucocorticoid analysis has been used to detect hypo- and hypercortisolism. In this study, we describe the development and validation of a LC-MS/MS method for quantification of cortisone and cortisol in human scalp hair, and provide a novel approach for analysis and interpretation of the results.Methods:Improved sample preparation using pulverization and solid phase extraction allowed for low sample volumes (10 mg). Baseline chromatographic separation without matrix interference was achieved by reversed phase chromatography and MRM measurement in negative ion mode. Run-to-run time was 8 min. Mixed model analyses were performed to create individual patterns of cortisone and cortisol concentrations.Results:Matrix matched calibration curves showed excellent linearity up to 100 pg (analyte)/mg (hair) for both cortisone and cortisol (R2>0.995). LLOQ was 1.5 and 1.0 pg/mg for cortisone and cortisol, respectively. Matrix effect was negligible for hair color (recoveries 95-105 %). Cortisone and cortisol concentrations decreased from proximal to distal hair segments, following a predictable, but subject-specific pattern, with less individual variation for cortisone than for cortisol. Conclusions:This improved LC-MS/MS method is able to accurately quantify cortisone and cortisol in human hair with minimum matrix interference. This new way of data analysis and interpretation including individual patterns of cortisone and cortisol will be of help with detection of pathological concentrations in both the high - and the low ranges of glucocorticoids.

Published
2024

34. Modelling changes in the pharmacokinetics of tacrolimus during pregnancy after kidney transplantation:A retrospective cohort study

Author

Schagen, Maaike R., Ulu, Asiye Nur, Francke, Marith I., van de Wetering, Jacqueline, van Buren, Marleen C., Schoenmakers, Sam, Matic, Maja, van Schaik, Ron H.N., Hesselink, Dennis A., de Winter, Brenda C.M., Schagen, Maaike R., Ulu, Asiye Nur, Francke, Marith I., van de Wetering, Jacqueline, van Buren, Marleen C., Schoenmakers, Sam, Matic, Maja, van Schaik, Ron H.N., Hesselink, Dennis A., and de Winter, Brenda C.M.

Abstract

Aims: Pregnancy after kidney transplantation is realistic but immunosuppressants should be continued to prevent rejection. Tacrolimus is safe during pregnancy and is routinely dosed based on whole-blood predose concentrations. However, maintaining these concentrations is complicated as physiological changes during pregnancy affect tacrolimus pharmacokinetics. The aim of this study was to describe tacrolimus pharmacokinetics throughout pregnancy and explain the changes by investigating covariates in a population pharmacokinetic model. Methods: Data of pregnant women using a twice-daily tacrolimus formulation following kidney transplantation were retrospectively collected from 6 months before conception, throughout gestation and up to 6 months postpartum. Pharmacokinetic analysis was performed using nonlinear mixed effects modelling. Demographic, clinical and genetic parameters were evaluated as covariates. The final model was evaluated using goodness-of-fit plots, visual predictive checks and a bootstrap analysis. Results: A total of 260 whole-blood tacrolimus predose concentrations from 14 pregnant kidney transplant recipients were included. Clearance increased during pregnancy from 34.5 to 41.7 L/h, by 15, 19 and 21% in the first, second and third trimester, respectively, compared to prior to pregnancy. This indicates a required increase in the tacrolimus dose by the same percentage to maintain the prepregnancy concentration. Haematocrit and gestational age were negatively correlated with tacrolimus clearance (P ≤ 0.01), explaining 18% of interindividual and 85% of interoccasion variability in oral clearance.Conclusions: Tacrolimus clearance increases during pregnancy, resulting in decreased exposure to tacrolimus, which is explained by gestational age and haematocrit. To maintain prepregnancy target whole-blood tacrolimus predose concentrations during pregnancy, increasing the dose is

Published
2024

35. External Quality Assessment on Molecular Tumor Profiling with Circulating Tumor DNA-Based Methodologies Routinely Used in Clinical Pathology within the COIN Consortium

Author

van der Leest, Paul, Rozendal, Pim, Hinrichs, John, van Noesel, Carel J.M., Zwaenepoel, Karen, Deiman, Birgit, Huijsmans, Cornelis J.J., van Eijk, Ronald, Speel, Ernst Jan M., van Haastert, Rick J., Ligtenberg, Marjolijn J.L., van Schaik, Ron H.N., Jansen, Maurice P.H.M., Dubbink, Hendrikus J., de Leng, Wendy W., Leers, Mathie P.G., Tamminga, Menno, van den Broek, Daan, van Kempen, Leon C., Schuuring, Ed, van der Leest, Paul, Rozendal, Pim, Hinrichs, John, van Noesel, Carel J.M., Zwaenepoel, Karen, Deiman, Birgit, Huijsmans, Cornelis J.J., van Eijk, Ronald, Speel, Ernst Jan M., van Haastert, Rick J., Ligtenberg, Marjolijn J.L., van Schaik, Ron H.N., Jansen, Maurice P.H.M., Dubbink, Hendrikus J., de Leng, Wendy W., Leers, Mathie P.G., Tamminga, Menno, van den Broek, Daan, van Kempen, Leon C., and Schuuring, Ed

Abstract

Background: Identification of tumor-derived variants in circulating tumor DNA (ctDNA) has potential as a sensitive and reliable surrogate for tumor tissue-based routine diagnostic testing. However, variations in pre(analytical) procedures affect the efficiency of ctDNA recovery. Here, an external quality assessment (EQA) was performed to determine the performance of ctDNA mutation detection work flows that are used in current diagnostic settings across laboratories within the Dutch COIN consortium (ctDNA on the road to implementation in The Netherlands). Methods: Aliquots of 3 high-volume diagnostic leukapheresis (DLA) plasma samples and 3 artificial reference plasma samples with predetermined mutations were distributed among 16 Dutch laboratories. Participating laboratories were requested to perform ctDNA analysis for BRAF exon 15, EGFR exon 18-21, and KRAS exon 2-3 using their regular circulating cell-free DNA (ccfDNA) analysis work flow. Laboratories were assessed based on adherence to the study protocol, overall detection rate, and overall genotyping performance. Results: A broad range of preanalytical conditions (e.g., plasma volume, elution volume, and extraction methods) and analytical methodologies (e.g., droplet digital PCR [ddPCR], small-panel PCR assays, and next-generation sequencing [NGS]) were used. Six laboratories (38%) had a performance score of >0.90; all other laboratories scored between 0.26 and 0.80. Although 13 laboratories (81%) reached a 100% overall detection rate, the therapeutically relevant EGFR p.(S752_I759del) (69%), EGFR p.(N771_H773dup) (50%), and KRAS p.(G12C) (48%) mutations were frequently not genotyped accurately. Conclusions: Divergent (pre)analytical protocols could lead to discrepant clinical outcomes when using the same plasma samples. Standardization of (pre)analytical work flows can facilitate the implementation of reproducible liquid biopsy testing in the clinical routine.

Published
2024

37. DPYDGenotyping Recommendations

Author

Pratt, Victoria M., Cavallari, Larisa H., Fulmer, Makenzie L., Gaedigk, Andrea, Hachad, Houda, Ji, Yuan, Kalman, Lisa V., Ly, Reynold C., Moyer, Ann M., Scott, Stuart A., Turner, Amy J., van Schaik, Ron H.N., Whirl-Carrillo, Michelle, and Weck, Karen E.

Abstract

The goals of the Association for Molecular Pathology Clinical Practice Committee's Pharmacogenomics (PGx) Working Group are to define the key attributes of pharmacogenetic alleles recommended for clinical testing and a minimum set of variants that should be included in clinical PGx genotyping assays. This document series provides recommendations for a minimum set of variant alleles (tier 1) and an extended list of variant alleles (tier 2) that will aid clinical laboratories when designing assays for PGx testing. The Association for Molecular Pathology PGx Working Group considered the functional impact of the variant alleles, allele frequencies in multiethnic populations, the availability of reference materials, and other technical considerations for PGx testing when developing these recommendations. The goal of this Working Group is to promote standardization of PGx testing across clinical laboratories. This document will focus on clinical DPYDPGx testing that may be applied to all dihydropyrimidine dehydrogenase–related medications. These recommendations are not to be interpreted as prescriptive but to provide a reference guide.

Published
2024
Full Text
View/download PDF

38. A cost analysis of upfront DPYD genotype–guided dose individualisation in fluoropyrimidine-based anticancer therapy

Author

Henricks, Linda M., Lunenburg, Carin A.T.C., de Man, Femke M., Meulendijks, Didier, Frederix, Geert W.J., Kienhuis, Emma, Creemers, Geert-Jan, Baars, Arnold, Dezentjé, Vincent O., Imholz, Alexander L.T., Jeurissen, Frank J.F., Portielje, Johanna E.A., Jansen, Rob L.H., Hamberg, Paul, ten Tije, Albert J., Droogendijk, Helga J., Koopman, Miriam, Nieboer, Peter, van de Poel, Marlène H.W., Mandigers, Caroline M.P.W., Rosing, Hilde, Beijnen, Jos H., van Werkhoven, Erik, van Kuilenburg, André B.P., van Schaik, Ron H.N., Mathijssen, Ron H.J., Swen, Jesse J., Gelderblom, Hans, Cats, Annemieke, Guchelaar, Henk-Jan, and Schellens, Jan H.M.

Published
2019
Full Text
View/download PDF

42. Effects of CTLA-4 Single Nucleotide Polymorphisms on Toxicity of Ipilimumab-Containing Regimens in Patients With Advanced Stage Melanoma

Author

de Joode, Karlijn, Mora, Alfonso Rojas, van Schaik, Ron H.N., Zippelius, Alfred, van der Veldt, Astrid, Gerard, Camille Léa, Läubli, Heinz, Michielin, Olivier, von Moos, Roger, Joerger, Markus, Levesque, Mitchell P., Aeppli, Stefanie, Mangana, Johanna, Mangas, Cristina, Trost, Nadine, Meyer, Stefan, Parvex, Sandra Leoni, Mathijssen, Ron, and Metaxas, Yannis

Abstract

Single nucleotide polymorphisms (SNPs) in the cytotoxic T-lymphocyte–associated protein 4 (CTLA-4)gene, an inhibitor of T-cell priming, are associated with auto and alloimmunity. Studies implied a role for these SNPs as surrogate markers for immunotherapy-outcome in patients with melanoma. However, no predictive SNPs are defined to date. We analyzed different CTLA-4 SNPs in a large multicenter cohort of patients with ipilimumab-treated melanoma and investigated possible correlations with treatment-related outcomes. Archival blood and/or tumor tissue samples were collected from 361 patients with advanced-stage ipilimumab-treated (±nivolumab) in 6 Swiss and Dutch hospitals. Matrix-assisted laser desorption/ionization–time of flight mass spectrometry based DNA genotyping was performed for 10 different CTLA-4 SNPs: 49A>G, CT60G>A, Jo27T>C, Jo30G>A, Jo31G>T, −658C>T, −1722T>C, −1661A>G, 318C>T, and C>T rs1863800.Associations between different allele genotypes and occurrence of grade ≥3 adverse events (AEs) and survival were tested using univariable logistic regressions or Cox proportional hazard models. 262/361 (73%) patients could be analyzed; 65% of those were males, the median age was 58 years, 39% showed a partial or complete response, and 65% had ≥1 AEs. A TT-genotype of −1722T>C SNP was significantly associated with a lower incidence of grade ≥3 AEs (P= 0.049), whereas the GG-genotype of CT60G>A correlated with a higher incidence of grade ≥3 AEs (P= 0.026). The TT-genotype of Jo27T>C SNP (P= 0.056) and GG-genotype of Jo31G>T (P= 0.046) were associated with overall survival. CTLA-4 SNPs might predict treatment-related outcomes in patients with melanoma receiving ipilimumab. Confirmatory studies are needed to fully exploit those findings as predictive biomarkers for ipilimumab AEs.

Published
2024
Full Text
View/download PDF

49. Effects of Pharmacogenetic Screening for CYP2D6 Among Elderly Starting Therapy With Nortriptyline or Venlafaxine: A Pragmatic Randomized Controlled Trial (CYSCE Trial)

Author

van der Schans, Jurjen, Hak, Eelko, Postma, Maarten, Breuning, Laura, Brouwers, Jacobus R.B.J., Ditters, Kaspar, Jansen, Paul A.F., Kok, Rob M., Maring, Jan G., van Marum, Rob, Mulder, Hans, Nanninga, Jaap, Oude Voshaar, Richard C., Risselada, Arne J., Vleugel, Liesbeth, Stek, Max, van Schaik, Ron H.N., Berm, Elizabeth J.J., and Wilffert, Bob

Published
2019
Full Text
View/download PDF

50. Simultaneous quantification of tryptophan metabolites by liquid chromatography tandem mass spectrometry during early human pregnancy

Author

Van Zundert, Sofie K.M., Griffioen, Pieter H., Van Rossem, Lenie, Willemsen, Sten P., De Rijke, Yolanda B., Van Schaik, Ron H.N., Steegers-Theunissen, Régine P.M., Mirzaian, Mina, Van Zundert, Sofie K.M., Griffioen, Pieter H., Van Rossem, Lenie, Willemsen, Sten P., De Rijke, Yolanda B., Van Schaik, Ron H.N., Steegers-Theunissen, Régine P.M., and Mirzaian, Mina

Published
2023

Catalog

Books, media, physical & digital resources
See catalog results