title: Measurements of red blood cell methotrexate concentrations and lymphocyte subsets during therapy of rheumatoid arthritis.
abstract: Nine patients with rheumatoid arthritis were treated with low dose oral weekly methotrexate for 6 months. Successful therapy was not associated with changes in concentrations of total circulating lymphocytes nor with alterations of T lymphocytes in the helper-inducer, OKT4, or cytotoxic-suppressor, OKT8, subpopulations. Concentrations of methotrexate in circulating erythrocytes stabilized by 1 month of therapy and this measurement did not correlate with clinical efficacy or methotrexate toxicity in the long-term patient assessments.
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D004341:Drug Evaluation; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000145:classification*; D008297:Male; D008727:Methotrexate / Q000009:adverse effects / Q000097:blood* / Q000627:therapeutic use; D008875:Middle Aged; D009994:Osmolar Concentration
chemical_list: D008727:Methotrexate