How do you approach management of new onset ILD in a patient with RA who is otherwise well controlled on methotrexate or leflunomide?

We do not have any randomized controlled trials for DMARDs in RA-ILD. Most of the data is case series or retrospective analysis. Nonetheless, we can use current data to at least make clinical decisions until we receive more direction from high-quality clinical trials. We now know that in general methotrexate is not as concerning for fibrotic lung disease in RA as once thought and may actually have some modest disease-modifying activity. In addition, there is data suggesting that abatacept has a disease-stabilizing effect on 90% of RA ILD patients independent of HRCT pattern and is best when used early. Given that methotrexate and abatacept can be used together, I would add abatacept to an RA patient with new onset ILD who is on methotrexate...

First and foremost. Is the ILD truly connected to the RA or therapy? I prefer to perform bronchoscopy with BAL stains and cultures, as well as cell differential, if it can be done safely. I want reassurance that this immunocompromised individual does not have an opportunistic infection causing diffuse pneumonitis. The nature of the alveolitis is also helpful. A lymphocytic alveolitis suggests that a change in the immune suppressive therapy might be beneficial. Perhaps a short course of steroid therapy with baseline and subsequent HRCT and PFT could be tried. Mycofenolate seems to be a reasonable choice for RA-ILD (Fischer et al., PMID 23457378). A neutrophilic alveolitis with an HRCT pattern suggestive of fibrosis leads me to consider addin...