Hyperhomocysteinemia in children with juvenile idiopathic arthritis is not influenced by methotrexate treatment and folic acid supplementation: a pilot study
Huemer, M.; Födinger, M.; Huemer, C.; Sailer-Höck, M.; Falger, J.; Rettenbacher, A.; Bernecker, M.; Artacker, G.; Kenzian, H.; Lang, T.; Stöckler-Ipsiroglu, S.
Clinical and Experimental Rheumatology 21(2): 249-255
2003
ISSN/ISBN: 0392-856X PMID: 12747286 Document Number: 561645
Objective: Our first objective was to compare plasma total homocysteine (tHcy) concentrations in juvenile idiopathic arthritis (JIA) patients requiring methotrexate (MTX) treatment and healthy children. Our second aim was to evaluate the influence of low-dose (10-15 mg/m2/week) MTX treatment combined with folic acid supplementation (1 mg/day) or placebo on tHcy concentrations in JIA patients. Methods: In 17 JIA patients and 17 age- and sex-matched healthy children, baseline tHcy concentrations were measured. When MTX treatment was initiated, JIA patients were randomly assigned to oral supplementation with folic acid (1 mg/day), followed by placebo (8 weeks each) or vice versa. Blood samples for measurement of tHcy, vitamin B6, B12 and folate were taken after 4 weeks, 12 weeks and 20 weeks of treatment. Results: (1) In the healthy children the mean tHcy concentration was 6.3+or-1.68 micro mol/litre as compared to 9.99+or-5.17 micro mol/litre in JIA patients (p<0.04). At baseline, 5 of 17 JIA patients had tHcy concentrations >10.5 micro mol/litre, the 99th percentile for teenagers. Three of 5 patients even exceeded the upper normal level for adults (tHcy>=15 micro mol/litre). MTX treatment did not result in a significant increase in tHcy and folic acid supplementation had no significant impact on tHcy levels. Conclusion: This pilot study showed that patients with JIA requiring MTX treatment have significantly elevated baseline plasma tHcy concentrations compared to age- and sex-matched healthy controls. No significant impact of MTX and folate supplementation on tHcy concentrations was found.