{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,3]],"date-time":"2026-11-03T23:30:57Z","timestamp":1793748657770,"version":"4.6.1"},"reference-count":53,"publisher":"BMJ","issue":"2","license":[{"start":{"date-parts":[[2026,8,11]],"date-time":"2026-08-11T00:00:00Z","timestamp":1786406400000},"content-version":"unspecified","delay-in-days":41,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"Chronic Disease Management Research Project of National Health Commission Capacity Building and Continuing Education Center","award":["GWJJMB202510025012"],"award-info":[{"award-number":["GWJJMB202510025012"]}]},{"name":"Research project on high quality development of Hospital pharmacy, National Institute of Hospital Administration, NHC, China","award":["NIHAYS2505"],"award-info":[{"award-number":["NIHAYS2505"]}],"id":[{"id":"https:\/\/ror.org\/00xdrzy17","id-type":"ROR","asserted-by":"crossref"}]},{"name":"Research Project Established by Chinese Pharmaceutical Association Hospital Phamacy Department","award":["CPA-Z05-ZC-2025002"],"award-info":[{"award-number":["CPA-Z05-ZC-2025002"]}],"id":[{"id":"https:\/\/ror.org\/023q20n38","id-type":"ROR","asserted-by":"crossref"}]},{"name":"China Higher Education Institution Industry-University-Research Innovation Fund","award":["2025XH101"],"award-info":[{"award-number":["2025XH101"]}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Lupus Sci Med"],"accepted":{"date-parts":[[2026,7,28]]},"published-print":{"date-parts":[[2026,7]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>This study aimed to evaluate the associations of free mycophenolic acid (f-MPA) concentration and total MPA (t-MPA) concentration with treatment response and haematologic toxicity and to determine whether f-MPA provides additional safety-related value for therapeutic drug monitoring (TDM) in patients with paediatric lupus nephritis (LN) treated with mycophenolate mofetil (MMF).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Sixty-five patients with paediatric LN receiving MMF were prospectively enrolled. The t-MPA and f-MPA were measured simultaneously using validated ultrafiltration and LC-MS\/MS. Full pharmacokinetic profiles were obtained over 12 hours, and area under the concentration-time curve (AUC) was calculated for t-MPA (t-MPA-AUC) and f-MPA (f-MPA-AUC). Univariate analysis identified factors influencing efficacy (relapse-free survival) and adverse drug reaction (ADR) over 12 months. Receiver operating characteristic (ROC) curves established predictive thresholds and Kaplan-Meier methods analysed time-to-event.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The 12-month relapse-free rate was 78.7% (95% CI 66.6% to 90.9%). Both t-MPA-AUC and f-MPA-AUC significantly correlated with relapse-free survival (ROC AUC 0.70 each; optimal thresholds: t-MPA-AUC=31.63\u2009\u00b5g\u00b7h\/mL, f-MPA-AUC=354.45\u2009ng\u00b7h\/mL). The average remission duration above these thresholds was 10.88 and 11.00\u2009months. The overall MMF-related ADR incidence was 25.2%, including 17 haematological events (26.2%). The t-MPA-AUC, f-MPA-AUC, glucose, \u03b22-microglobulin and C3 were haematological ADR risk factors. The f-MPA-AUC independently predicted haematological ADRs (optimal threshold: 492.96\u2009ng\u00b7h\/mL; specificity 86.2%).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Both t-MPA-AUC and f-MPA-AUC effectively predict MMF efficacy in paediatric LN. However, f-MPA-AUC demonstrates superior predictive value for safety outcomes, specifically haematological ADRs. This supports f-MPA as a potentially better TDM metric for optimising MMF therapy safety in this population.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/lupus-2026-002091","type":"journal-article","created":{"date-parts":[[2026,8,11]],"date-time":"2026-08-11T12:05:53Z","timestamp":1786449953000},"page":"e002091","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":2,"title":["Free mycophenolic acid exposure for therapeutic drug monitoring in paediatric lupus nephritis: associations with treatment response and haematologic toxicity"],"prefix":"10.1136","volume":"13","author":[{"given":"Xuerui","family":"Tong","sequence":"first","affiliation":[{"name":"Department of Pharmacy, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China"},{"name":"Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong, 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