Remission, response, retention and persistence to treatment with disease-modifying agents in patients with rheumatoid arthritis: a study of harmonised Swedish, Danish and Norwegian cohorts

Evidence of membranolytic targeting and intracellular citrullination in neutrophils isolated from patients with rheumatoid arthritis

Anti-citrullinated protein autoantibodies (ACPA) are diagnostic for rheumatoid arthritis (RA). The antigens recognized by these autoantibodies are produced by protein arginine deiminases (PADs), particularly PAD4. However, it remains unknown why and how PAD4 causes this aberrant citrullination in RA. Here, we report that poly-perforin pores are present on freshly isolated neutrophils from RA patients, but not on healthy donor neutrophils. Neutrophils with perforin pores also contained intracellular citrullinated proteins in the region adjacent to the pores. This response was replicated in vitro by treating neutrophils with purified perforin, which generated intense dots of anti-perforin immunofluorescence, calcium influx, and intracellular citrullination. Extensive neutrophil killing in Felty's syndrome, an aggressive form of RA, correlated with particularly high ACPA, and PAD4 autoantibodies. In contrast, other forms of death, including NETosis, apoptosis, and pyroptosis, produced minimal citrullination. We conclude that neutrophil targeting by perforin leading to intracellular citrullination takes place in patients with RA.

Obesity is a risk factor for poor response to treatment in early rheumatoid arthritis: a NORD-STAR study

OBJECTIVE

This report from the NORD-STAR (Nordic Rheumatic Diseases Strategy Trials and Registries) trial aimed to determine if obesity is associated with response to conventional and biological antirheumatic treatment in early rheumatoid arthritis (RA).

METHODS

This report included 793 participants with untreated early RA from the randomised, longitudinal NORD-STAR trial, all of whom had their body mass index (BMI) assessed at baseline. Obesity was defined as BMI ≥30 kg/m2. All participants were randomised 1:1:1:1 to one of four treatment arms: active conventional treatment, certolizumab-pegol, abatacept and tocilizumab. Clinical and laboratory measurements were performed at baseline and at 8, 12, 24 and 48-week follow-up. The primary endpoint for this report was response to treatment based on Clinical Disease Activity Index (CDAI) and Simple Disease Activity Index (SDAI) remission and Disease Activity Score with 28 joints using C-reactive protein (DAS28-CRP) <2.6 stratified by BMI.

RESULTS

Out of 793 people included in the present report, 161 (20%) had obesity at baseline. During follow-up, participants with baseline obesity had higher disease activity compared with those with lower BMI, despite having similar disease activity at baseline. In survival analyses, obesity was associated with a lower likelihood of achieving response to treatment during follow-up for up to 48 weeks (CDAI remission, HR 0.84, 95% CI 0.67 to 1.05; SDAI, HR 0.77, 95% CI 0.62 to 0.97; DAS28-CRP <2.6, HR 0.78, 95% CI 0.64 to 0.95). The effect of obesity on response to treatment was not influenced by the treatment arms.

CONCLUSION

In people with untreated early RA followed up for up to 48 weeks, obesity was associated with a lower likelihood of good treatment response, irrespective of the type of randomised treatment received.

TRIAL REGISTRATION NUMBER

NCT01491815.

Comorbidities and chance of remission in patients with early rheumatoid arthritis receiving methotrexate as first-line therapy: a Swedish observational nationwide study

OBJECTIVES

This study aims to examine whether comorbidities affect the likelihood of reaching primary remission on methotrexate monotherapy as the first disease-modifying antirheumatic drug (DMARD) in early rheumatoid arthritis (RA).

METHODS

We used nationwide Swedish clinical and quality registers to collect RA disease activity measures and comorbidity data for patients diagnosed with RA 2007-2020 (n=11 001). The primary outcome was failure to reach 28-joint Disease Activity Score (DAS28) remission at 3 months. Secondary outcomes included Boolean, Simplified Disease Activity Index/Clinical Disease Activity Index remission, European Alliance of Associations for Rheumatology response and no swollen joint count at 3 and 6 months. For each comorbidity, and for combinations thereof, we calculated adjusted relative risks (RRs) of failure to reach remission, using modified Poisson regression.

RESULTS

In total, 53% (n=4019/7643) failed to reach DAS28 remission after 3 months of methotrexate monotherapy, ranging from 66% (n=25/38) among patients with chronic kidney disease to 48% (n=154/319) in patients with previous cancer. The risk of not reaching DAS28 remission at 3 months (RR adjusted for sex and age) was increased among patients with endocrine (RR 1.08, 95% CI 1.01 to 1.15), gastrointestinal (RR 1.16, 95% CI 1.03 to 1.30), infectious (RR 1.21, 95% CI 1.06 to 1.38), psychiatric (RR 1.24, 95% CI 1.15 to 1.35) and respiratory comorbidities (RR 1.16, 95% CI 1.01 to 1.32). Having three or more comorbidity categories was associated with a 27% higher risk of DAS28 remission failure at 3 months. A similar pattern was observed for the secondary outcomes.

CONCLUSIONS

Comorbidities decrease the chance of reaching remission on methotrexate as DMARD monotherapy in patients with early RA and are important to consider when assessing treatment outcomes.

Autoantibody-negative rheumatoid arthritis: still a challenge for the rheumatologist

Increased research over the past 30 years has greatly improved the understanding of the pathophysiological mechanisms and clinical aspects of autoantibody-positive rheumatoid arthritis, resulting in improved management and outcomes. In contrast, the subset of rheumatoid arthritis that does not have autoantibodies (such as rheumatoid factor and anti-citrullinated protein autoantibodies) remains less well defined in its pathogenic mechanisms. Autoantibody-negative rheumatoid arthritis continues to pose diagnostic challenges, might respond differently to therapies, and appears to be burdened with different comorbidities and outcomes. The clear separation of rheumatoid arthritis according to serotypes is still a subject of uncertainty and controversy, and studies specifically focused on comparing rheumatoid arthritis and rheumatoid arthritis-like arthritides that do not have autoantibodies remain scarce. The purpose of this Review is to summarise the peculiarities that make autoantibody-negative rheumatoid arthritis different from its autoantibody-positive counterpart, with the aim of generating debate and stimulating further research on this challenging condition.

Prevalence and predictors of sustained remission/low disease activity after discontinuation of induction or maintenance treatment with tumor necrosis factor inhibitors in rheumatoid arthritis: a systematic and scoping review

BACKGROUND

To determine the prevalence of sustained remission/low disease activity (LDA) in patients with rheumatoid arthritis (RA) after discontinuation of tumor necrosis factor inhibitors (TNFi), separately in induction treatment and maintenance treatment studies, and to identify predictors of successful discontinuation.

METHODS

We performed a systematic literature review of studies published from 2005 to May 2022 that reported outcomes after TNFi discontinuation among patients in remission/LDA. We computed prevalences of successful discontinuation by induction or maintenance treatment, remission criterion, and follow-up time. We performed a scoping review of predictors of successful discontinuation.

RESULTS

Twenty-two induction-withdrawal studies were identified. In pooled analyses, 58% (95% confidence interval (CI) 45, 70) had DAS28 < 3.2 (9 studies), 52% (95% CI 35, 69) had DAS28 < 2.6 (9 studies), and 40% (95% CI 18, 64) had SDAI ≤ 3.3 (4 studies) at 37-52 weeks after discontinuation. Among patients who continued TNFi, 62 to 85% maintained remission. Twenty-two studies of maintenance treatment discontinuation were also identified. At 37-52 weeks after TNFi discontinuation, 48% (95% CI 38, 59) had DAS28 < 3.2 (10 studies), and 47% (95% CI 33, 62) had DAS28 < 2.6 (6 studies). Heterogeneity among studies was high. Data on predictors in induction-withdrawal studies were limited. In both treatment scenarios, longer duration of RA was most consistently associated with less successful discontinuation.

CONCLUSIONS

Approximately one-half of patients with RA remain in remission/LDA for up to 1 year after TNFi discontinuation, with slightly higher proportions in induction-withdrawal settings than with maintenance treatment discontinuation.