More clinical guidance is needed for monitoring interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA), according to a new commentary.
Though ILD is a leading cause of death among patients with RA, these patients are not routinely screened for ILD, the authors say, and there are currently no guidelines on how to monitor ILD progression in patients with RA.
“ILD associated with rheumatoid arthritis is a disease for which there’s been very little research done, so it’s an area of rheumatology where there are many unknowns,” lead author Elizabeth R. Volkmann, MD, who co-directs the Connective Tissue Disease–Related Interstitial Lung Disease (CTD-ILD) Program at University of California, Los Angeles, told Medscape Medical News.
The commentary was published in The Lancet Rheumatology on February 6.
One of the major unknowns is how to define the disease, she said. RA patients sometimes undergo imaging for other medical reasons and interstitial lung abnormalities are incidentally detected. These patients can be classified as having “preclinical” or “subclinical” ILD, as they do not yet have symptoms; however, there is no consensus as to what these terms mean, the commentary authors write. “The other problem that we have with these terms is that it sometimes creates the perception that this is a non-worrisome feature of rheumatoid arthritis,” Volkmann said, although the condition should be followed closely.
“We know we can detect imaging features of ILD in people who may not yet have symptoms, and we need to know when to define a clinically important informality that requires follow-up or treatment,” added John M. Davis III, MD, a rheumatologist at the Mayo Clinic in Rochester, Minnesota. He was not involved with the work.
Volkmann proposed eliminating the prefixes “pre” and “sub” when referring to ILD. “In other connective tissue diseases, like systemic sclerosis, for example, we can use the term ‘limited’ or ‘extensive’ ILD, based on the extent of involvement of the ILD on high-resolution computed tomography (HRCT) imaging,” she said. “This could potentially be something that is applied to how we classify patients with RA-ILD.”
Tracking ILD Progression
Once ILD is identified, monitoring its progression poses challenges, as respiratory symptoms may be difficult to detect. RA patients may already be avoiding exercise because of joint pain, so they may not notice shortness of breath during physical activity, noted Jessica K. Gordon, MD, of the Hospital for Special Surgery in New York City, in an interview with Medscape. She was not involved with the commentary. Cough is a potential symptom of ILD, but cough can also be the result of allergies, postnasal drip, or reflux, she said. Making the distinction between “preclinical” and symptomatic disease can be “complicated,” she added; “you may have to really dig.”
Additionally, there has been little research on the outcomes of patients with preclinical or subclinical ILD and clinical ILD, the commentary authors write. “It is therefore conceivable that some patients with rheumatoid arthritis diagnosed with preclinical or subclinical ILD could potentially have worse outcomes if both the rheumatoid arthritis and ILD are not monitored closely,” they note.
To better track RA-associated ILD for patients with and those without symptoms, the authors advocate for monitoring patients using pulmonary testing and CT scanning as well as evaluating symptoms. How often these assessments should be conducted depends on the individual, they note. In her own practice, Volkmann sees patients every 3 months to evaluate their symptoms and conduct pulmonary function tests (PFTs). For patients early in the course of ILD, she orders HRCT imaging once per year.
For Davis, the frequency of follow-up depends on the severity of ILD. “For minimally symptomatic patients without compromised lung function, we would generally follow annually. For patients with symptomatic ILD on stable therapy, we may monitor every 6 months. For patients with active/progressive ILD, we would generally be following at least every 1–3 months,” he said.
Screening and Future Research
While there is no evidence to recommend screening patients for ILD using CT, there are certain risk factors for ILD in RA patients, including a history of smoking, male sex, and high RA disease activity despite antirheumatic treatment, Volkmann said. In both of their practices, Davis and Volkmann screen with RA via HRCT and PFTs for ILD for patients with known risk factors that predispose them to the lung condition and/or for patients who report respiratory symptoms.
“We still don’t have an algorithm [for screening patients], and that is a desperate need in this field,” added Joshua J. Solomon, MD, a pulmonologist at National Jewish Health in Denver, whose research focuses on RA-associated ILD. While recommendations state that all patients with scleroderma should be screened with CT, ILD incidence is lower among patients with RA, and thus these screening recommendations need to be narrowed, he said. But more research is needed to better fine tune recommendations, he said; “The only thing you can do is give some expert consensus until there are good data.”
Volkmann has received consulting and speaking fees from Boehringer Ingelheim and institutional support for performing studies on systemic sclerosis for Kadmon, Forbius, Boehringer Ingelheim, Horizon, and Prometheus. Gordon, Davis, and Solomon report no relevant financial relationships.
Lancet Rheumatol. Published online February 6, 2023. Abstract
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