British Isles Survey of Methotrexate Monitoring Practice During Treatment of Juvenile Idiopathic Arthritis

Abstract

We surveyed current pediatric rheumatology monitoring practice in methotrexate treatment of juvenile idiopathic arthritis in the British Isles, and experiences of significant side effects during methotrexate monitoring. Single-center responses were sought from the current British Society for Pediatric and Adolescent Rheumatology membership, using a web-based survey tool. Thirty-three centers across the British Isles responded. Twenty-eight centers reported following British Society for Pediatric and Adolescent Rheumatology or local guidelines. Thirty-one centers were willing to modify their monitoring practice to individual circumstances. All centers used a full blood count and liver enzymes as monitoring tests. There was variation in frequency at which monitoring tests were performed, both at initiation of methotrexate therapy and once methotrexate therapy was established; 27 centers were willing to change the frequency of monitoring blood tests after a period of stability. Centers reported acting on alanine aminotransferase values ranging from 50 to 500 IU/L. Particular variation existed between smaller and larger centers. Few centers reported any experience of serious side effects, and only 1 cited a case of liver cirrhosis. Despite specific pediatric guidance for monitoring low-dose methotrexate use in juvenile idiopathic arthritis, variation in practice exists in the British Isles. It may be that blood test monitoring could safely be performed less frequently than currently recommended. To inform future changes to guidance, we suggest establishing a prospective registry for serious side effects.