Arundathi Jayatilleke, MD
Interstitial lung disease (ILD) is a serious and not infrequent complication of rheumatoid arthritis (RA). Despite the use of several immunosuppressive medications for ILD as well as others for RA, the most effective treatment for both is yet unclear. Prior cross-sectional, retrospective, and open-label registry studies have suggested that abatacept can be used in patients with RA-ILD, with stability or improvement in pulmonary parameters in a majority of patients. Mena-Vazquez and colleagues present the results of a prospective, observational cohort study with 57 patients from multiple centers in Spain. Similar to previously published results, this study found stability or improvement in pulmonary function tests in 70% of patients as well as improvement in RA disease activity. A relatively high proportion of patients (25 in 57) experienced infections. The study lends further weight to the proposal that abatacept is a reasonable choice in patients with RA-ILD for treatment of both joint and pulmonary inflammation, given the lack of randomized controlled trials.
Lauper and colleagues published the results of a large cohort study of more than 30,000 treatment courses in patients with RA, looking at the efficacy of different biologics and a Janus kinase (JAK) inhibitor. Discontinuation of therapy was used as the primary efficacy outcome, and one secondary outcome was low disease activity based on Clinical Disease Activity Index (CDAI) at 12 months. Over 17,000 courses were anti–tumor necrosis factor (TNF) therapy, with about 7000 JAK-inhibitor therapy courses and the remainder an interleukin 6 (IL-6) inhibitor or abatacept therapy; individual data was only available from 13 to 17 registries (depending on the parameter of interest). Overall, IL-6 inhibitors and JAK inhibitors were less frequently stopped for ineffectiveness compared with anti-TNF agents, but were more frequently stopped owing to adverse events. Drug retention rates also varied between different countries, suggesting that prescription pattern differences may affect the primary outcome. In terms of CDAI, response rates at 1 year were similar between anti-TNF agents, JAK inhibitors, and IL-6 inhibitors and was slightly lower for abatacept. This real-world study does support similar efficacy between these classes of medications, though further conclusions are somewhat hampered by the lack of individual data.
A study in Japan by Mori and colleagues looked at biologic disease-modifying antirheumatic drugs (bDMARD) (TNF inhibitors and an IL-6 inhibitor) and tofacitinib discontinuation in a cohort of 97 patients with RA . Patients were required to initially be in a high or moderate disease activity state prior to treatment, then in remission or a low disease activity state with treatment for more than 48 weeks. Mean follow-up was 2.1 years and disease flare occurred in about 75% of patients at about 1.6 years after medication discontinuation. Though bDMARD- or targeted synthetic DMARD (tsDMARD)–free remission was not "durable" for most patients, the majority of those patients who experienced flares improved with resumption of their previous medication. Though it is reassuring that most study patients were able to discontinue their bDMARD or tsDMARD medication for a period of time, the fact that most experienced flares within 2 years suggests that discontinuation of these medications in patients with high disease activity is not a viable long-term approach.
Krekeler and colleagues performed a retrospective analysis of about 500 patients seen in a single rheumatology clinic to evaluate possible misdiagnosis of RA. The diagnosis of calcium pyrophosphate deposition disease (CPPD), as well as the presence of radiographic chondrocalcinosis, were more frequently found among patients diagnosed with seronegative RA vs those diagnosed with seropositive RA, particularly RA in the wrists. The CPPD diagnosis was made by rheumatologists on the basis of the presence of radiographic chondrocalcinosis along with typical joint swelling and signs of inflammation. Because chondrocalcinosis was part of the CPPD diagnosis, it is unsurprising that both followed similar patterns. Whether patients with CPPD were actually misdiagnosed as having seronegative RA is unclear from this retrospective study; as the authors note, chondrocalcinosis itself has been found to be associated with older age and osteoarthritis in prior studies, particularly in the knee. However, the study confirms that alternative diagnoses in seronegative RA should be considered.