title: Erythrocyte-methotrexate and disease activity in children treated with oral methotrexate for juvenile chronic arthritis.
abstract: The concentration of methotrexate (MTX) in erythrocytes (E-MTX) was measured twice with three months interval in 21 children suffering from juvenile chronic arthritis (JCA). At the same time joint score, visual analogue scale (VAS), and laboratory parameters (CRP, WBC, PMNs, and ALAT) were obtained. There was only a weak insignificant correlation between the dose of MTX/m2 and E-MTX (r=0.24, p=0.11). No significant relations between the clinical or laboratory parameters and E-MTX was found. However, ALAT above normal range was associated with a lower dose of MTX (p=0.02) and lower VAS (p=0.02), indicating that toxicity may be associated with less articular discomfort. At present we consider routine determination of E-MTX in children with JCA of limited value.
authors.affiliation: Paediatric Clinic 2, the Juliane Marie Centre, the National University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Kristensen
authors.forename: S
authors.initials: S
authors.lastname: Nielsen
authors.forename: F
authors.initials: F
authors.lastname: Karup Pedersen
authors.forename: M
authors.initials: M
authors.lastname: Zak
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000410:Alanine Transaminase / Q000097:blood / Q000187:drug effects; D018501:Antirheumatic Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001171:Arthritis, Juvenile / Q000188:drug therapy / Q000378:metabolism*; D002097:C-Reactive Protein / Q000032:analysis / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007958:Leukocyte Count / Q000187:drug effects; D008727:Methotrexate / Q000493:pharmacokinetics* / Q000627:therapeutic use; D011446:Prospective Studies; D012720:Severity of Illness Index
chemical_list: D018501:Antirheumatic Agents; D002097:C-Reactive Protein; D000410:Alanine Transaminase; D008727:Methotrexate