Dutch gout patients' perspective on continuation or discontinuation of urate-lowering therapy during remission: a mixed methods study.

BACKGROUND: Long-term gout management is based on reducing serum urate by using urate-lowering therapy (ULT) 1, 2. A lifelong treat-to-target approach is advocated, though a ULT (taper to) stop attempt can be considered (treat-to-avoid symptoms approach) during remission. Exploring gout patients' beliefs on long-term ULT strategies during remission is important for optimising gout management. OBJECTIVE: To identify factors that influence the decision for continuation or discontinuation of ULT and to determine their relative importance according to gout patients in remission. METHODS: A mixed methods design was used. First, semi-structured interviews (substudy 1) were conducted to identify barriers and facilitators for (dis)continuation of ULT using inductive thematic analysis. Afterwards these barriers/facilitators were summarized into neutrally phrased items and used in a Maximum Difference Scaling study (MaxDiff, substudy 2) to determine their relative importance using the rescaled probability score (RPS). RESULTS: Substudies 1 and 2 included 18 and 156 patients, respectively. Substudy 1 yielded 22 items, within 10 overarching themes. Substudy 2 revealed that the perceived risk of joint damage and gout flares and that ULT use gives some assurance of ULT use were the most important items. The costs, ease of receiving ULT and its practical use were the least important items. CONCLUSION: These results can aid shared decision making and provide input for what's important to discuss with gout patients in remission, when they consider ULT discontinuation. Emphasis should be on the risk of having gout flares and joint damage, not so much on facilitating how easily medication is received.

Effect of using the Simple Erosion Narrowing Score or Sharp/van der Heijde score on power of rheumatoid arthritis clinical trials to detect differences in radiographic progression.

OBJECTIVES: The Simple Erosion Narrowing Score (SENS) is a simplification of the Sharp/van der Heijde score (SHS). Previous studies found SENS and SHS to have very similar measurement properties, but suggest that SENS has a lower discriminative ability that may result in reduced power. Therefore, we aimed to quantify the effect of using SENS rather than SHS on the power to show between-group differences in radiographic progression. METHODS: Using data from two clinical trials in rheumatoid arthritis (DRESS and BeSt), SENS was derived from the SHS. Criterion validity of the SENS in relation to the SHS was assessed by calculating the Spearman correlation. The power of both scores to show a difference between groups was compared using bootstrapping to generate 10.000 replications of each study. Then, the number of replications with a significant difference in progression (using ANCOVA adjusted for baseline scores) were compared. RESULTS: Correlations between SENS and SHS were all >0.9, indicating high criterion validity of SENS compared with SHS as a reference standard. There was one exception, the DRESS study showed a somewhat lower correlation for the change score at 18 months (0.787). The loss in power of SENS over SHS was limited to at most 19% (BeSt year 5). In addition, the difference in power between SENS and SHS is smaller at higher levels of power. CONCLUSION: SENS appears to be a reasonable alternative to SHS, with only a limited loss of power to show between-group differences in radiographic progression.

Rheumatoid arthritis patients' perspective on the use of prediction models in clinical decision-making.

OBJECTIVES: A rapidly expanding number of prediction models is being developed aiming to improve rheumatoid arthritis (RA) diagnosis and treatment. However, few are actually implemented in clinical practice. This study explores factors influencing the acceptance of prediction models in clinical decision-making by RA patients. METHODS: A qualitative study design was used with thematic analysis of semi-structured interviews. Purposive sampling was applied to capture a complete overview of influencing factors. The interview topic list was based on pilot data. RESULTS: Data saturation was reached after 12 interviews. Patients were generally positive about the use of prediction models in clinical decision-making. Six key themes were identified from the interviews. First, patients have the need for information on prediction models. Second, factors influencing trust in model-supported treatment are described. Third, patients envision the model to have a supportive role in clinical decision-making. Fourth, patients hope to personally benefit from model-supported treatment in various ways. Fifth, patients are willing to contribute time and effort to contribute to model input. And lastly, we discuss the theme on effects of the relationship with the caregiver in model-supported treatment. CONCLUSION: Within this study RA patients were generally positive about the use of prediction models in their treatment given some conditions were met and concerns addressed. The results of this study can be used during the development and implementation in RA care of prediction models in order to enhance patient acceptability.

Treat-to-target vs fixed interval retreatment strategy with rituximab in rheumatoid arthritis: a retrospective cohort study.

To compare the effectiveness of retreatment of rheumatoid arthritis (RA) patients with rituximab (RTX) following the treat-to-target retreatment (TTr) or fixed interval retreatment (FIr) strategy. RA patients starting RTX treatment between January 2008 and June 2016, and receiving at least three infusion cycles were grouped by strategy (TTr, FIr or both). Primary outcome (between strategy difference in DAS28-CRP (Disease Activity Score in 28 joints calculated with C-reactive protein)) and secondary outcomes (flares, use of co-medication and mean yearly dose of RTX) were analyzed by group using linear mixed models to account for different strategies within patients. A total of 213 patients, 59 TTr (of whom 32 switched from TTr to FIr) and 186 FIr were included. No between-group difference in mean DAS28-CRP was found (0.10 DAS28-CRP point (95% CI - 0.07 to 0.26)). The TTr strategy did not result in more flares (IRR 1.13, 95%CI 0.87 to 1.47), conventional synthetic disease-modifying antirheumatic drug use (difference - 11.7%, 95%CI - 26.3% to 2.9%), or lower mean yearly RTX dose (difference 172 mg/yr, 95%CI - 355 to 11.7 mg/yr). RTX retreatment with either a TTr or FIr strategy does not seem to lead to better disease control and/or less drug use when used in a DAS28-CRP treat-to-target context. Choice of either strategy can, therefore, be made based on patient and physician preferences and logistical context.

Prioritization of Adverse Consequences After Total Knee Arthroplasty Contributing to a Poor Response: A Best-Worst Scaling Exercise Among Total Knee Arthroplasty Patients and Knee Specialists.

BACKGROUND: Total knee arthroplasty (TKA) can have a number of adverse consequences for patients that might contribute to a poor outcome. This study aimed to prioritize these consequences, from the perspective of patients and knee specialists. METHODS: There were 95 TKA patients and 63 knee specialists who prioritized a set of 29 adverse consequences, based on a previous qualitative study, using a Maximum Difference Scaling method. A hierarchical Bayesian analysis was used to calculate relative importance scores. Differences and agreements between patients versus knee specialists and satisfied versus dissatisfied patients were analyzed using Mann-Whitney-U tests and Kendall's coefficients of concordance. RESULTS: There were 4 out of 5 items in the top-5 of both patients and knee specialists that were similar, however, the ranking was different. The highest-ranked consequence for patients was: "Inability to do normal activities such as walking, cycling, swimming and heavy household chores", while knee specialists ranked: "No improvement in pain during the day" as the highest. "No improvement in walking" was in the patients' top-5, but was not ranked in the top-5 of knee specialists. For satisfied and dissatisfied patients, the top-5 of consequences was similar. CONCLUSION: Comparable perspectives were found for patients versus knee specialists and satisfied versus dissatisfied patients on the importance of adverse consequences after TKA. However, when looking in more detail, differences in ranking of specific subitems suggest that patients place slightly more importance on the inability to perform valued activities, while knee specialists prioritize lack of pain relief to a higher degree.

The Use of Remote Consultations and Associated Factors in Rheumatology: A Large Retrospective Cohort Study of Follow-Up Consultations Before, During, and After COVID-19.

OBJECTIVE: To investigate the use of remote consultations (RCs) and the influence of consultation, health care provider (HCP), and patient characteristics on the choice for remote or face-to-face consultation. METHODS: A monocenter retrospective cohort study was conducted on follow-up consultations of patients with rheumatic diseases from January 1, 2019 to January 16, 2023, using data from electronic health records. Trends in the proportion of RCs before, during, and after COVID-19 were studied. Cross-classified multilevel logistic regression models were built to account for clustering of consultations (level 1) within both patients and HCPs (level 2). The influence of consultation, patient, and HCP characteristics on the type of consultation was assessed. RESULTS: 157,028 consultations of 30,215 unique patients seen by 64 HCPs were included in the data set. After an initial sharp increase in RC use at the beginning of the COVID-19 pandemic, the proportion of RCs decreased toward a seemingly steady state at around 30%. 90% of the variance in the use of RCs can be attributed to the consultation level, whereas 4% and 6% can be attributed to the patient and HCP level. Longer consultation durations and time since last consultation decreased the odds for a RC, as did higher patient age, shared care, and longer disease duration. Higher travel distance, consultation density, and patient digital access increased the odds for a RC. CONCLUSION: The COVID pandemic resulted in a structural increase in the use of RCs. Although several patient characteristics are associated with the type of consultation, most variance resulted from consultation characteristics compared with patients and HCPs.

Preferences of Patients With Musculoskeletal Disorders Regarding the Timing and Channel of eHealth and Factors Influencing Its Use: Mixed Methods Study.

BACKGROUND: Implementation of eHealth is progressing slowly. In-depth insight into patients' preferences and needs regarding eHealth might improve its use. OBJECTIVE: This study aimed to describe when patients want to use eHealth, how patients want to communicate and receive information digitally, and what factors influence the use of eHealth in clinical practice. METHODS: A multimethod study was conducted. Two meetings of ~5.5 hours with plenary information sessions and focus groups were held with 22 patients from the rheumatology, orthopedics, and rehabilitation departments of a Dutch hospital specialized in musculoskeletal disorders. Assignments were performed during the focus groups in which qualitative (eg, semistructured interview questions) and quantitative (ie, voting and ranking factors) data were collected. RESULTS: The way patients want to use eHealth varies between patients and moments of a patient's care pathway. Patients' digital channel preferences depended on the need for interaction with a health care provider (HCP). The interaction need is in turn influenced by the degree to which information or communication is specific to an individual patient and leads to consequences for the patient. The 5 most important factors influencing the use of eHealth were access to medical information (eg, electronic health records), perceived control over disease management, correctness and completeness of information, data security, and access to information or an HCP at any time. The 5 least important factors influencing eHealth use were help with using digital devices, having internet or equipment, digital skills, attitude or emotions toward eHealth, and societal benefits. CONCLUSIONS: Patients identified opportunities for using eHealth during all moments of their care pathway. However, preferences for eHealth varied between patients and phases in the care pathway. As a consequence, eHealth should be tailored to fit individual patients' preferences but also the need for interaction regarding different topics by offering a variety of digital channels with a gradient of interaction possibilities. Furthermore, digital skills and access to the internet might become less important to focus on in the future. Improving eHealth use by patients may be achieved by providing patients access to correct and safe (medical) information and more control over their care.

Non-Medical Switching from Tocilizumab to Sarilumab in Rheumatoid Arthritis Patients with Low Disease Activity, an Observational Study.

Tocilizumab and sarilumab are IL-6-receptor antagonists registered for rheumatoid arthritis (RA), with equal effectiveness and safety. Switching from tocilizumab to sarilumab could be a strategy to reduce injection burden, in case of drug shortages, and to reduce costs. This study therefore aims to investigate the effectiveness and safety of switching patients with RA with well-controlled disease under tocilizumab treatment to sarilumab. Patients with RA with low Disease Activity Score 28 (DAS28;-CRP < 2.9 or < 3.5 with clinical judgment), on stable dose tocilizumab (> 6 months) were offered to switch to sarilumab. Patients who switched and consented were followed for 6 months. Sarilumab was started at 200 mg and double the last tocilizumab interval. Co-primary outcomes at 6 months were (i) the 90% confidence interval (CI) of DAS28-CRP change from baseline compared with the non-inferiority margin of 0.6 and (ii) the 90% CI of the proportion of patients persisting with sarilumab, compared with a prespecified minimum of 70%. Of 50 invited patients, 25 agreed to switch to sarilumab, and 23 patients switched and were included. One patient was lost to follow-up immediately after inclusion, therefore 22 patients are included in the analyses. At 6 months, mean change in DAS28-CRP was 0.48 (90% CI: 0.11-0.87), compared with the non-inferiority margin of 0.6. Sarilumab persistence was 68% (90% CI: 51-82%, 15 out of 22 patients), compared with the prespecified minimum of 70%. Non-medical switching from tocilizumab to sarilumab in patients doing well on tocilizumab failed to show non-inferiority regarding disease activity and drug persistence.

Infection incidence, timing, and dose dependency in rheumatoid arthritis patients treated with rituximab: a retrospective cohort study.

OBJECTIVES: Rituximab (RTX) is a safe and effective treatment for rheumatoid arthritis (RA). However, there are some concerns about infection risk and preliminary data suggest dose and time dependency. This study aims to determine the infection incidence in a large real-life population of RA patients using RTX, with special focus on (ultra-)low dosing and time since last infusion. METHODS: RA patients treated with 1000, 500 or 200 mg RTX per cycle between 2012 and 2021 at the Sint Maartenskliniek were included in a retrospective cohort study. Patient-, disease-, treatment- and infection characteristics were retrieved from electronic health records. Infection incidence rates, dose and time relations with RTX infusion were analysed using mixed-effects Poisson regression. RESULTS: Among 490 patients, we identified 819 infections in 1254 patient years. Most infections were mild and respiratory tract infections were most common. Infection incidence rates were 41, 54 and 71 per 100 patient years for doses of 200, 500 and 1000 mg. Incidence rate ratio (IRR) was significantly lower for 200 mg compared to 1000 mg (adjusted IRR 0.35, 95% CI 0.17-0.72, p = 0.004). In patients receiving 1000 or 500 mg RTX, infections seemed to occur more frequently within the first two months after infusion compared to later on in the treatment cycle, suggesting an association with peak concentration. CONCLUSION: Ultra-low dosing (200 mg) of RTX is associated with a lower risk of infections in RA. Future interventions focusing on ultra-low dosing and slow release of RTX (e.g. by subcutaneous administration) may lower infection risk.

Exploring the perspective of patients with immune-mediated inflammatory diseases and care providers on the use of immunomodulatory drugs in infections: an interview study.

Objectives: Immunomodulatory agents are safe and effective as treatment for various immune-mediated inflammatory diseases (IMIDs), but are associated with a slightly increased infection risk. It is uncertain whether, in the event of an infection, continuation or temporary interruption of immunomodulatory agents leads to better outcomes. Owing to this uncertainty, it is of importance to explore the perspectives of health-care providers (HCPs) and patients on this topic. In this study, we set out to identify and provide an overview of reasons for both treatment strategies. Methods: Semi-structured interviews were conducted with HCPs involved in the pharmacological treatment of IMIDs and with IMID patients using one or more immunomodulatory agent. Purposive sampling was used to enrich data variation. Interviews were conducted until data saturation was reached and subsequently analysed using qualitative content analysis. Results: In total, 13 HCPs and 19 IMID patients were interviewed. A wide range of reasons for both treatment strategies were identified, categorized into 10 overarching themes, including IMID characteristics, infection characteristics and the patient-HCP relationship. Conclusion: In this interview study, we identified various reasons for continuation or temporary interruption of immunomodulatory agents during infections for both IMID patients and HCPs. We found overlapping themes, such as IMID characteristics; however, the content and interpretation of these themes might differ between HCPs and patients. Both HCPs and patients mentioned that the decision for a treatment strategy is often about weighing benefits against risks (e.g. infection severity vs disease flare).

The added value of predictive biomarkers in treat-to-target strategies for rheumatoid arthritis patients: a conceptual modelling study.

OBJECTIVES: To quantify the additional value of a hypothetical biomarker predicting response to treatment for RA regarding efficacy and costs by using a modelling design. METHODS: A Markov model was built comparing a usual care T2T strategy with a biomarker-steered strategy for RA patients starting biologic therapy. Outcome measures include time spent in remission or low disease activity (LDA) and costs. Four additional scenario analyses were performed by varying biomarker or clinical care characteristics: (i) costs of the biomarker; (ii) sensitivity and specificity of the biomarker; (iii) proportion of eligible patients tapering; and (iv) medication costs. RESULTS: In the base model, patients spent 2.9 months extra in LDA or remission in the biomarker strategy compared with usual care T2T over 48 months. Total costs were €43 301 and €42 568 for, respectively, the usual care and biomarker strategy, and treatment costs accounted for 91% of total costs in both scenarios. Cost savings were driven due to patients in the biomarker strategy experiencing remission or LDA earlier, and starting tapering sooner. Cost-effectiveness was not so much driven by costs or test characteristics of the biomarker (scenario 1/2), but rather by the level of early and proactive tapering and drug costs (scenarios 3/4). CONCLUSIONS: The use of a biomarker for prediction of response to b/tsDMARD treatment in RA can be of added value to current treat-to-target clinical care. However, gains in efficacy are modest and cost gains are depending on a combination of early proactive tapering and high medication costs.

Pharmacokinetic boosting to enable a once-daily reduced dose of tofacitinib in patients with rheumatoid arthritis and psoriatic arthritis (the PRACTICAL study).

Background: Tofacitinib is a Janus Kinase (JAK) inhibitor used for the treatment of rheumatoid arthritis (RA) and psoriatic arthritis (PsA), dosed as 5 mg twice daily (BID). It is primarily metabolized by the cytochrome P-3A (CYP3A) enzyme, and therefore, the manufacturer recommends to halve the dose when using CYP3A-inhibiting co-medication. Combining half-dose tofacitinib with a registered CYP3A inhibitor (cobicistat) could reduce costs and improve patient experience. Objectives: Primary: bioequivalence of tofacitinib 5 mg combined with cobicistat once daily (QD; intervention) to tofacitinib 5 mg BID (control). Secondary: safety, patient preference (7-point Likert scale at study end) and predicted differences in disease activity (DAS28-CRP and probability of ACR20 response) using a validated exposure-response model. Design: Open-label, cross-over pharmacokinetic study. Methods: We included patients with RA or PsA, treated with tofacitinib 5 mg BID for ⩾14 days without co-medication affected by CYP3A inhibition. Pharmacokinetic sampling was performed at baseline and after 2-6 weeks of intervention treatment. Bioequivalence was defined as 90% CI of the average tofacitinib concentration (Cavg,ss; intervention to control) falling between 80% and 125%, assessed by non-linear mixed-effects modelling. Results: Between 16 September 2019 and 15 January 2021, 30 patients were included, of whom 25 completed both PK measurements. The tofacitinib Cavg,ss was 85% (90% CI: 75-96%). No serious adverse events occurred. Patient preference was 56% for intervention versus 18% for control. No relevant differences in median predicted disease activity were found (DAS28-CRP: 0.03, 95% CI: -0.16 to 0.22; ACR20: -0.01, -0.07 to 0.05). Conclusion: Due to slightly lower tofacitinib concentrations during intervention treatment, pharmacokinetic bioequivalence could not formally be established. However, pharmacokinetic boosting may be an attractive strategy for cost reduction of tofacitinib because of its safety, similar predicted pharmacodynamics and patient preference. Registration: This study was registered on 29 May 2019 in the Netherlands Trial Register (register number: NL7766).

Rituximab dose-dependent infection risk in rheumatoid arthritis is not mediated through circulating immunoglobulins, neutrophils or B cells.

OBJECTIVES: Rituximab (RTX) is a safe and effective treatment for RA. A dose-dependent infection risk was found in the REDO trial. Some studies associate RTX use with higher infection risks, possibly explained by low immunoglobulin levels and/or neutropenia. Additionally, a higher infection risk shortly after RTX infusion is reported. The objectives of this study were (i) to compare incidence rates of infections between doses and over time, and (ii) to assess B-cell counts, immunoglobulin levels, neutrophil counts and corticosteroid/disease modifying rheumatic drug use as mediating factors between RTX study dose and infection risk. METHODS: Post hoc analyses of the REDO trial were performed. Infection incidence rates between RTX dosing groups and between time periods were compared using Poisson regression. A step-wise mediation analysis was performed to investigate if any of the factors mentioned above act as a mediator in the observed dose-dependent difference in infection risk. RESULTS: The potential mediators that were investigated (circulating B-cell counts, immunoglobulin levels, neutrophil counts and drug use) did not explain the dose-dependent infection risk observed in the REDO trial. Additionally, a trend towards a time-dependent infection risk was found, with higher infection rates shortly after RTX infusion. CONCLUSIONS: These secondary analyses of the REDO trial confirmed the observed dose-dependent infection risk. Additionally, we found that infection risks were higher shortly after RTX infusion. However, a mediating pathway was not found.

Treat-to-target dose reduction and withdrawal strategy of TNF inhibitors in psoriatic arthritis and axial spondyloarthritis: a randomised controlled non-inferiority trial.

OBJECTIVES: Tumour necrosis factor inhibitors (TNFi) are effective in psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA), but are associated with a small (0.6%) increase in serious infection risk, patient burden due to need for self-injection and high costs. Treat-to-target (T2T) tapering might ameliorate these drawbacks, but high-quality evidence on T2T tapering strategies is lacking in PsA and axSpA. METHODS: We performed a pragmatic open-label, monocentre, randomised controlled non-inferiority (NI) trial on T2T tapering of TNFi. Patients with PsA and axSpA using a TNFi with ≥6 months stable low disease activity (LDA) were included. Patients were randomised 2:1 to disease activity-guided T2T with or without tapering until withdrawal and followed-up to 12 months. Primary endpoint was the difference in proportion of patients having LDA at 12 months between groups, compared with a prespecified NI margin of 20%, estimated using a Bayesian prior. RESULTS: 122 patients (64 PsA and 58 axSpA) were randomised to a T2T strategy with (N=81) or without tapering (N=41). The proportion of patients in LDA at 12 months was 69% for the tapering and 73% for the no-tapering group: adjusted difference 5% (Bayesian 95% credible interval: -10% to 19%) which confirms NI considering the NI margin of 20%. The mean percentage of daily defined dose was 53% for the tapering and 91% for the no-tapering group at month 12. CONCLUSIONS: A T2T TNFi strategy with tapering attempt is non-inferior to a T2T strategy without tapering with regard to the proportion of patients still in LDA at 12 months, and results in a substantial reduction of TNFi use. TRIAL REGISTRATION NUMBER: NL 6771.

Effect of metformin use on clinical outcomes and serum urate in gout patients with diabetes mellitus: a retrospective cohort study.

OBJECTIVE: Gout and diabetes mellitus type 2 (DM) frequently co-exist. The pharmacological effects of metformin may include anti-inflammatory and urate lowering effects. The objective of this study was to test these effects in patients with gout starting uric acid lowering treatment (ULT) in secondary care. METHODS: Retrospective cohort study including patients with gout and DM starting ULT. Differences in the incidence density of gout flares, proportion of patients reaching target sUA in the first six months after starting ULT, and difference in mean allopurinol dose at sUA target were compared between users of metformin and users of other or no anti-diabetic drugs (control group). Correction for confounding was applied. RESULTS: A total of 307 patients were included, of whom 160 (52.1%) used metformin. The incidence of flares was 1.61 and 1.70 in the first six months for respectively the metformin group and control group. The incidence rate ratio for gout flares was not significant (0.95, 95% CI 0.78 to 1.14). At six months, 62.8% and 54.9% reached target sUA in the metformin and control group respectively, corrected odds ratio of 1.09 (95% CI 0.66 to 1.80). There was no difference in mean allopurinol dose at sUA target 266 mg for metformin users and 236 mg for the control group, difference 30 mg (95% CI - 4.7 to 65.5). CONCLUSIONS: In conclusion we could not confirm a clinically relevant anti-inflammatory or urate lowering effect of metformin in patients starting ULT treatment and receiving usual care flare prophylaxis.

Identification of Risk Factors for COVID-19 Hospitalization in Patients With Anti-Rheumatic Drugs: Results From a Multicenter Nested Case Control Study.

Patients with inflammatory rheumatic diseases (IRDs) do not have an increased risk for coronavirus disease 2019 (COVID-19) compared with the general population. However, it remains uncertain whether subgroups of patients with IRD using different immunosuppressive antirheumatic drugs carry a higher risk for severe COVID-19 compared with other patients with IRD. The aim of this study is to identify risk factors for severe COVID-19, requiring hospitalization in patients with IRD. This is a multicenter nested case control study conducted in the Netherlands. Cases are hospital known patients with IRD requiring hospitalization for COVID-19 between March 1, 2020, and May 31, 2020. Controls are hospital known patients with IRD not requiring hospitalization for COVID-19 in this period, included at a 4:1 ratio. Patient, disease, and treatment characteristics were extracted from electronic medical records and a questionnaire. Potential risk factors were analyzed using unconditional logistic regression, corrected for confounders and multiple testing. Eighty-one cases and 396 controls were included. General risk factors of older age and obesity apply to patients with IRD as well (odds ratio (OR) for age ≥ 75 3.5, 95% confidence interval (CI) 1.9-6.3, OR for body mass index ≥ 40 4.5, 95% CI 1.5-14). No significantly increased ORs for COVID-19 hospitalization were found for any antirheumatic agent or IRD. A protective effect was found for use of methotrexate (OR 0.53, 95% CI 0.31-0.92). In conclusion, similar to the general population, elderly and obese patients with IRD have a higher risk for hospitalization for COVID-19. We did not identify a specific antirheumatic agent or IRD to increase the risk of COVID-19 hospitalization in patients with IRD, except for a possible protective effect of methotrexate.

Drug levels, anti-drug antibodies and B-cell counts were not predictive of response in rheumatoid arthritis patients on (ultra-)low-dose rituximab.

OBJECTIVES: The REDO trial (REtreatment with Rituximab in RhEumatoid arthritis: Disease Outcome after Dose Optimisation) showed that ultra-low-dose rituximab (500 mg or 200 mg) was similarly effective to a 1000 mg dosage in the majority of RA patients. This pre-planned secondary analysis investigated (1) associations between rituximab dosage, drug levels, anti-drug antibodies (ADAs) and B-cell counts and (2) the predictive value of pharmacokinetic and pharmacodynamic parameters, and of patient, disease and treatment characteristics in relation to response to ultra-low-dose rituximab. METHODS: For 140 RA patients from the REDO trial, differences in drug levels, ADAs and B-cell counts were examined at baseline, and at 3 and 6 months after dosing. Treatment response was defined as absence of flare and no extra rituximab or >1 glucocorticoid injection received during follow-up. The association between potential predictors and response was investigated using logistic regression analyses. RESULTS: Lower doses of rituximab resulted in lower drug levels but did not significantly affect ADA levels or B-cell counts, and 3 (10.7%), 12 (20.7%) and 7 (13.0%) patients failed to meet the response criteria in, respectively, the 1000 mg, 500 mg and 200 mg dosage groups. Drug levels, ADAs, B-cell counts, and patient, disease and treatment characteristics were not predictive for response to ultra-low-dose rituximab. CONCLUSION: The results of this study further support the hypothesis that continued treatment with 500 or 200 mg rituximab is similarly effective to a 1000 mg dosage in RA patients doing well on rituximab. These results, combined with lack of finding a clinical dose-response relationship in the original REDO study, suggest that 200 mg rituximab is not yet the lowest effective rituximab retreatment dose in RA.

Tumour necrosis factor inhibitor dose adaptation in psoriatic arthritis and axial spondyloarthritis (TAPAS): a retrospective cohort study.

OBJECTIVES: We investigated the effect of disease activity-guided dose optimization (DAGDO) of TNF inhibitor (TNFi) on disease activity and TNFi dose in PsA and axial spondyloarthritis (axSpA) patients with low disease activity (LDA). METHODS: A retrospective cohort study was conducted in PsA and axSpA patients doing well on TNFi and eligible for TNFi DAGDO. Three different treatment periods were defined: (i) full dose continuation period, (ii) TNFi DAGDO period, and (iii) period with stable TNFi dose after DAGDO. A mixed-model analysis was used to estimate mean Disease Activity Score 28-joint count CRP (DAS28-CRP) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) during these periods, and a mean percentage of the daily defined dose (%DDD) was calculated as secondary outcome. RESULTS: Three hundred and twenty-four patients (153 PsA and 171 axSpA) were included, with a mean of 6.5 DAS28-CRP and 6.4 BASDAI measurements and a median follow-up duration of 46 and 44 months, respectively. A corrected difference of 0.06 (95% CI: -0.09, 0.21) in mean DAS28-CRP was found for the TNFi DAGDO period and 0.03 (95% CI: -0.14, 0.20) for the period with stable TNFi dose, compared with full dose continuation period. Differences for BASDAI were 0.03 (95% CI: -0.21, 0.27) and 0.05 (95% CI: -0.24, 0.34), respectively. The mean %DDD for the three treatment periods was for PsA 108%, 62% and 78%, and for axSpA 108%, 62% and 72%, respectively. CONCLUSION: DAGDO of TNFi reduces drug exposure and has no negative effects on disease activity in PsA and axSpA patients compared with full dose continuation.

Prediction of response to anti-TNF treatment using laboratory biomarkers in patients with rheumatoid arthritis: a systematic review.

OBJECTIVES: In this systematic review, we aim to identify laboratory biomarkers that predict response to tumour necrosis factor inhibitors (TNFi) in patients with rheumatoid arthritis (RA). METHODS: EMBASE, PubMed and Cochrane Library (CENTRAL) were searched for studies that presented predictive accuracy measures of laboratory biomarkers, or in which these were calculable. Likelihood ratios were calculated in order to determine whether a test result relevantly changed the probability of response. Likelihood ratios between 2-10 and 0.5-0.1 were considered weak predictors, respectively, and ratios above 10 or below 0.1 were considered strong predictors of response. Primary focus was on biomarkers studied ≥3 times. RESULTS: From 41 included studies, data on 99 different biomarkers were extracted. Five biomarkers were studied ≥3 times, being (1) anti-cyclic citrullinated peptide (CCP), (2) rheumatoid factor, (3) -308 polymorphism in the TNF-α gene, (4) SE copies in the HLA-DRB1 gene and (5) FcGR2A polymorphism. No studies showed a strong predictive association and only one study on anti-CCP showed a weak positive association. CONCLUSIONS: No biomarkers were found that consistently showed a (strong) predictive effect for response to TNFi in patients with RA. Given the disappointing yield of previous predictive biomarker research, future studies should focus on exploring, combining and validating the most promising laboratory biomarkers identified in this review, and searching for new predictors. Besides this, they should focus on contexts where prediction-aided decision-making can have a large impact (even with limited predictive value of markers/models). PROSPERO REGISTRATION NUMBER: CRD42021278987.