Erythrocyte Methotrexate-polyglutamate Assay Using Fluorescence Polarization Immunoassay Technique: Application to the Monitoring of Patients with Rheumatoid Arthritis
| Autor: | Sachie Inoue, Shinichi Kawai, Mayumi Mochizuki, Masayuki Hashiguchi |
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| Rok vydání: | 2009 |
| Předmět: |
Male
musculoskeletal diseases Erythrocytes Pharmaceutical Science Fluorescence polarization immunoassay technique Sensitivity and Specificity Arthritis Rheumatoid Recovery rate immune system diseases Fluorescence Polarization Immunoassay medicine Humans heterocyclic compounds Methotrexate polyglutamate skin and connective tissue diseases Pharmacology Chromatography Chemistry Middle Aged medicine.disease Methotrexate Polyglutamic Acid Antirheumatic Agents Rheumatoid arthritis Fluorescence polarization immunoassay Female Drug Monitoring medicine.drug |
| Zdroj: | YAKUGAKU ZASSHI. 129:1001-1005 |
| ISSN: | 1347-5231 0031-6903 |
| DOI: | 10.1248/yakushi.129.1001 |
| Popis: | Methotrexate (MTX), i.e., MTX-polygluatmate 1 (MTX-PG(1)), exerts its antirheumatic effects mainly byor = 6 (MTX-PG(2-7)) via folypolyglutamyl synthase in cells. The authors developed a new method using fluorescence polarization immunoassay to determine MTX-PG(1-7) concentrations in erythrocytes (RBC). MTX-PG(2-7) in RBC of rheumatoid arthritis (RA) patients receiving MTX was converted to MTX in the presence of plasma gamma-glutamyl hydrolase and mercaptoethanol at 37 degrees C. The MTX in RBC was extracted in a perchloric acid deproteinization step then on a solid-phase extraction column. The concentration of MTX was measured by TDX analyzer. The mean MTX recovery rate was 76.1% (n=8). The intraday and interday coefficients of variation were11.3% (n=8) and12.4% (n=3), respectively, at low and high concentrations (30-300 nmol/l). The calibration curve was linear over the range 30-300 nmol/l. The total concentration of MTX-PGs (mean+/-S.D.) in RBC obtained from 95 Japanese RA patient blood samples was 97.3+/-8.1 nmol/l for the MTX dose of 0.13+/-0.05 mg/week/kg. This newly developed method for the quantification of MTX-PGs in RBC is sensitive and accurate and can be applied for routine monitoring of MTX therapy in RA patients. |
| Databáze: | OpenAIRE |
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