Methotrexate safe in Dermatomyositis Patients, may not increase risk of interstitial lung disease: JAMA

A recent cohort study published in the Journal of American Medical Association provided reassuring findings for dermatomyositis (DM) patients regarding the safety of methotrexate (MTX) usage. DM is a condition characterized by muscle weakness and skin rash, often presents with interstitial lung disease (ILD) as a complication by affecting about 23% of DM patients in North America.

The study was conducted within the NIH-sponsored All of Us Research Program to investigate the link between MTX use and ILD development in DM patients. Despite MTX being a first-line treatment for DM, the concerns over its potential pulmonary toxicity have made clinicians to hesitate its use in this patient group.

This research analyzed data from a total of 315 DM patients, of whom 163 met the inclusion criteria. Among them, 58 patients received MTX, while the other 105 did not. The study found that 17% of MTX-exposed patients and 16% of MTX-unexposed patients developed ILD, showing no significant difference in ILD risk associated with MTX use.

The findings contrast with previous studies in populations with rheumatoid arthritis (RA) where MTX has been linked with pneumonitis and pulmonary fibrosis. In the DM group, MTX did not pose a significant risk of ILD development. Also, similar results were observed when analyzing the association between ILD and mycophenolate mofetil/mycophenolic acid (MMF/MPA) which is another commonly used medication for DM.