{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T01:09:32Z","timestamp":1790730572831,"version":"4.1.0"},"reference-count":29,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2021,3,4]],"date-time":"2021-03-04T00:00:00Z","timestamp":1614816000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010115","name":"R\u00e9gion Auvergne-Rh\u00f4ne-Alpes","doi-asserted-by":"publisher","award":["Madmas project in Proof of concept"],"award-info":[{"award-number":["Madmas project in Proof of concept"]}],"id":[{"id":"10.13039\/501100010115","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Rituximab is a chimeric immunoglobulin G1-kappa (IgG1\u03ba) antibody targeting the CD20 antigen on B-lymphocytes. Its applications are various, such as for the treatment of chronic lymphoid leukemia or non-Hodgkin\u2019s lymphoma in oncology, and it can also be used in the treatment of certain autoimmune diseases. Several studies support the interest in therapeutic drug monitoring to optimize dosing regimens of rituximab. Thus, two different laboratories have developed accurate and reproductive methods to quantify rituximab in human plasma: one using liquid chromatography quadripolar tandem mass spectrometer (LC-MS\/MS) and the other, liquid chromatography orbitrap tandem mass spectrometer (LC-MS\/HRMS). For both assays, quantification was based on albumin depletion or IgG-immunocapture, surrogate peptide analysis, and full-length stable isotope-labeled rituximab. With LC-MS\/MS, the concentration range was from 5 to 500 \u00b5g\/mL, the within- and between-run precisions were &lt;8.5%, and the limit of quantitation was 5 \u00b5g\/mL. With LC-MS\/HRMS, the concentration range was from 10 to 200 \u00b5g\/mL, the within- and between-run accuracy were &lt;11.5%, and the limit of quantitation was 2 \u00b5g\/mL. Rituximab plasma concentrations from 63 patients treated for vasculitis were compared. Bland\u2013Altman analysis and Passing\u2013Bablok regression showed the interchangeability between these two methods. Overall, these methods were robust and reliable and could be applied to routine clinical samples.<\/jats:p>","DOI":"10.3390\/molecules26051383","type":"journal-article","created":{"date-parts":[[2021,3,5]],"date-time":"2021-03-05T00:39:07Z","timestamp":1614904747000},"page":"1383","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":20,"title":["Development, Validation, and Comparison of Two Mass Spectrometry Methods (LC-MS\/HRMS and LC-MS\/MS) for the Quantification of Rituximab in Human Plasma"],"prefix":"10.3390","volume":"26","author":[{"given":"Aur\u00e9lien","family":"Millet","sequence":"first","affiliation":[{"name":"Biochemistry and Pharmacology-Toxicology Laboratory, Lyon-Sud Hospital, Hospices Civils de Lyon, F-69495 Pierre B\u00e9nite, France"},{"name":"Inserm U1052, CNRS UMR5286 Cancer Research Center of Lyon, F-69000 Lyon, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8269-9817","authenticated-orcid":false,"given":"Nihel","family":"Khoudour","sequence":"additional","affiliation":[{"name":"Department of Pharmacokinetics and Pharmacochemistry, Cochin Hospital, AP-HP, CARPEM 75014 Paris, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Doroth\u00e9e","family":"Lebert","sequence":"additional","affiliation":[{"name":"Promise Proteomics, 7 Parvis Louis N\u00e9el, F-38040 Grenoble, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4494-8034","authenticated-orcid":false,"given":"Christelle","family":"Machon","sequence":"additional","affiliation":[{"name":"Biochemistry and Pharmacology-Toxicology Laboratory, Lyon-Sud Hospital, Hospices Civils de Lyon, F-69495 Pierre B\u00e9nite, France"},{"name":"Inserm U1052, CNRS UMR5286 Cancer Research Center of Lyon, F-69000 Lyon, France"},{"name":"Analytical Chemistry Laboratory, Faculty of Pharmacy ISPBL, University Lyon 1, F-69373 Lyon, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Benjamin","family":"Terrier","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, National Referral Center for Rare Systemic Autoimmune Diseases, Assistance Publique H\u00f4pitaux de Paris-Centre (APHP-CUP), University of Paris, F-75014 Paris, France"},{"name":"INSERM U970, PARCC, Universit\u00e9 de Paris, F-75006 Paris, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Benoit","family":"Blanchet","sequence":"additional","affiliation":[{"name":"Department of Pharmacokinetics and Pharmacochemistry, Cochin Hospital, AP-HP, CARPEM 75014 Paris, France"},{"name":"UMR8038 CNRS, U1268 INSERM, Faculty of Pharmacy, University of Paris, PRES Sorbonne Paris Cit\u00e9, CARPEM 75006 Paris, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6180-5708","authenticated-orcid":false,"given":"J\u00e9r\u00f4me","family":"Guitton","sequence":"additional","affiliation":[{"name":"Biochemistry and Pharmacology-Toxicology Laboratory, Lyon-Sud Hospital, Hospices Civils de Lyon, F-69495 Pierre B\u00e9nite, France"},{"name":"Inserm U1052, CNRS UMR5286 Cancer Research Center of Lyon, F-69000 Lyon, France"},{"name":"Toxicology Laboratory, Faculty of Pharmacy ISPBL, University of Lyon 1, F-69373 Lyon, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,3,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"398","DOI":"10.1016\/j.coph.2004.03.006","article-title":"Anti B Cell Therapy (Rituximab) in the Treatment of Autoimmune Diseases","volume":"4","author":"Kazkaz","year":"2004","journal-title":"Curr. 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