Rheumatology
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MTX, which is the anchor-drug for the treatment of RA, has been associated with lung injury and in particular with MTX-related pneumonitis (M-pneu). Although the frequency of M-pneu has been reported to range between 0.3 and 11.6%, more recent studies and meta-analyses have challenged that, suggesting that it is less common than previously thought. M-pneu is considered a hypersensitivity reaction usually occuring early after MTX commencement, and to be dose-independent. ⋯ However, treatment should not be delayed or limited in progressive RA that could lead to RA-ILD, and MTX remains one of the central players in the treat-to-target approach. In this review, we aimed to summarize the current evidence from observational studies and clinical trials on lung disease in MTX-treated RA patients. We focus the discussion on the lack of association between M-pneu and RA-ILD.