Truncating NFKB1 variants cause combined NLRP3 inflammasome activation and type I interferon signaling and predispose to necrotizing fasciitis.

In monogenic autoinflammatory diseases, mutations in genes regulating innate immune responses often lead to uncontrolled activation of inflammasome pathways or the type I interferon (IFN-I) response. We describe a mechanism of autoinflammation potentially predisposing patients to life-threatening necrotizing soft tissue inflammation. Six unrelated families are identified in which affected members present with necrotizing fasciitis or severe soft tissue inflammations. Exome sequencing reveals truncating monoallelic loss-of-function variants of nuclear factor κ light-chain enhancer of activated B cells (NFKB1) in affected patients. In patients' macrophages and in NFKB1-variant-bearing THP-1 cells, activation increases both interleukin (IL)-1ß secretion and IFN-I signaling. Truncation of NF-κB1 impairs autophagy, accompanied by the accumulation of reactive oxygen species and reduced degradation of inflammasome receptor nucleotide-binding oligomerization domain, leucine-rich repeat-containing protein 3 (NLRP3), and Toll/IL-1 receptor domain-containing adaptor protein inducing IFN-ß (TRIF), thus leading to combined excessive inflammasome and IFN-I activity. Many of the patients respond to anti-inflammatory treatment, and targeting IL-1ß and/or IFN-I signaling could represent a therapeutic approach for these patients.

Evaluation of discontinuation for adverse events of JAK inhibitors and bDMARDs in an international collaboration of rheumatoid arthritis registers (the 'JAK-pot' study).

BACKGROUND: In a clinical trial setting, patients with rheumatoid arthritis (RA) taking the Janus kinase inhibitor (JAKi) tofacitinib demonstrated higher adverse events rates compared with those taking the tumour necrosis factor inhibitors (TNFi) adalimumab or etanercept. OBJECTIVE: Compare treatment discontinuations for adverse events (AEs) among second-line therapies in an international real-world RA population. METHODS: Patients initiating JAKi, TNFi or a biological with another mode of action (OMA) from 17 registers participating in the 'JAK-pot' collaboration were included. The primary outcome was the rate of treatment discontinuation due to AEs. We used unadjusted and adjusted cause-specific Cox proportional hazard models to compare treatment discontinuations for AEs among treatment groups by class, but also evaluating separately the specific type of JAKi. RESULTS: Of the 46 913 treatment courses included, 12 523 were JAKi (43% baricitinib, 40% tofacitinib, 15% upadacitinib, 2% filgotinib), 23 391 TNFi and 10 999 OMA. The adjusted cause-specific hazard rate of treatment discontinuation for AEs was similar for TNFi versus JAKi (1.00, 95% CI 0.92 to 1.10) and higher for OMA versus JAKi (1.11, 95% CI 1.01 to 1.23), lower with TNFi compared with tofacitinib (0.81, 95% CI 0.71 to 0.90), but higher for TNFi versus baricitinib (1.15, 95% CI 1.01 to 1.30) and lower for TNFi versus JAKi in patients 65 or older with at least one cardiovascular risk factor (0.79, 95% CI 0.65 to 0.97). CONCLUSION: While JAKi overall were not associated with more treatment discontinuations for AEs, subgroup analyses suggest varying patterns with specific JAKi, such as tofacitinib, compared with TNFi. However, these observations should be interpreted cautiously, given the observational study design.

Predictors of DAPSA28 remission in patients with psoriatic arthritis initiating a first TNF inhibitor: results from 13 European registries.

OBJECTIVES: In bio-naïve patients with PsA initiating a TNF inhibitor (TNFi), we aimed to identify baseline predictors of Disease Activity index for PsA in 28 joints (DAPSA28) remission (primary objective) and DAPSA28 moderate response at 6 months, as well as drug retention at 12 months across 13 European registries. METHODS: Baseline demographic and clinical characteristics were retrieved and the three outcomes investigated per registry and in pooled data, using logistic regression analyses on multiply imputed data. In the pooled cohort, selected predictors that were either consistently positive or negative across all three outcomes were defined as common predictors. RESULTS: In the pooled cohort (n = 13 369), 6-month proportions of remission, moderate response and 12-month drug retention were 25%, 34% and 63% in patients with available data (n = 6954, n = 5275 and n = 13 369, respectively). Five common baseline predictors of remission, moderate response and 12-month drug retention were identified across all three outcomes. The odds ratios (95% CIs) for DAPSA28 remission were: age, per year: 0.97 (0.96-0.98); disease duration, years (<2 years as reference): 2-3 years: 1.20 (0.89-1.60), 4-9 years: 1.42 (1.09-1.84), ≥10 years: 1.66 (1.26-2.20); men vs women: 1.85 (1.54-2.23); CRP of >10 vs ≤10 mg/l: 1.52 (1.22-1.89) and 1 mm increase in patient fatigue score: 0.99 (0.98-0.99). CONCLUSION: Baseline predictors of remission, response and adherence to TNFi therapy were identified, of which five were common for all three outcomes, indicating that the predictors emerging from our pooled cohort may be considered generalizable from country level to disease level.

Oral glucocorticoid use in patients with rheumatoid arthritis initiating TNF-inhibitors, tocilizumab or abatacept: Results from the international TOCERRA and PANABA observational collaborative studies.

OBJECTIVE: To evaluate and compare the use of oral glucocorticoids with three classes of bDMARDs in patients with rheumatoid arthritis (RA). METHODS: We included patients from 13 observational registries treated with a TNF-inhibitor, abatacept or tocilizumab and with available information on the use of oral glucocorticoids. The main outcome was oral glucocorticoid withdrawal. A McNemar test was used to analyse the change in the use of glucocorticoids after 1 year. Kaplan-Meier estimates and Cox regressions, adjusted for patient, treatment, and disease characteristics, were used to evaluate glucocorticoid discontinuation in patients with glucocorticoids at baseline. Because of heterogeneity, analyses were done by registers and pooled using random-effects meta-analysis. RESULTS: A total of 12,334 participants treated with TNF-inhibitors, 2100 with tocilizumab and 3229 with abatacept were included. At one-year, oral glucocorticoid use decreased in all treatment groups (odds ratio for stopping vs. starting of 2.19 [95% CI 1.58; 3.04] for TNF-inhibitors, 2.46 [1.39; 4.35] for tocilizumab; 1.73 [1.25; 2.21] for abatacept). Median time to glucocorticoid withdrawal was ≈2 years or more in most countries, with a gradual decrease over time. Compared to TNF-inhibitors, crude hazard ratios of glucocorticoid discontinuation were 0.65[0.48-0.87] for abatacept, and 1.04 [0.76-1.43] for tocilizumab, and adjusted hazard ratios were 1.1 [0.83-1.47] for abatacept, and 1.30 [0.96-1.78] for tocilizumab. CONCLUSION: After initiation of a bDMARD, glucocorticoid use decreased similarly in all treatment groups. However, glucocorticoid withdrawal was much slower than advocated by current international guidelines. More effort should be devoted to glucocorticoid tapering when low disease activity is achieved.

Certolizumab pegol, abatacept, tocilizumab or active conventional treatment in early rheumatoid arthritis: 48-week clinical and radiographic results of the investigator-initiated randomised controlled NORD-STAR trial.

BACKGROUND: The optimal first-line treatment in early rheumatoid arthritis (RA) is debated. We compared clinical and radiographic outcomes of active conventional therapy with each of three biological treatments with different modes of action. METHODS: Investigator-initiated, randomised, blinded-assessor study. Patients with treatment-naïve early RA with moderate-severe disease activity were randomised 1:1:1:1 to methotrexate combined with (1) active conventional therapy: oral prednisolone (tapered quickly, discontinued at week 36) or sulfasalazine, hydroxychloroquine and intra-articular glucocorticoid injections in swollen joints; (2) certolizumab pegol; (3) abatacept or (4) tocilizumab. Coprimary endpoints were week 48 Clinical Disease Activity Index (CDAI) remission (CDAI ≤2.8) and change in radiographic van der Heijde-modified Sharp Score, estimated using logistic regression and analysis of covariance, adjusted for sex, anticitrullinated protein antibody status and country. Bonferroni's and Dunnet's procedures adjusted for multiple testing (significance level: 0.025). RESULTS: Eight hundred and twelve patients were randomised. Adjusted CDAI remission rates at week 48 were: 59.3% (abatacept), 52.3% (certolizumab), 51.9% (tocilizumab) and 39.2% (active conventional therapy). Compared with active conventional therapy, CDAI remission rates were significantly higher for abatacept (adjusted difference +20.1%, p<0.001) and certolizumab (+13.1%, p=0.021), but not for tocilizumab (+12.7%, p=0.030). Key secondary clinical outcomes were consistently better in biological groups. Radiographic progression was low, without group differences.The proportions of patients with serious adverse events were abatacept, 8.3%; certolizumab, 12.4%; tocilizumab, 9.2%; and active conventional therapy, 10.7%. CONCLUSIONS: Compared with active conventional therapy, clinical remission rates were superior for abatacept and certolizumab pegol, but not for tocilizumab. Radiographic progression was low and similar between treatments. TRIAL REGISTRATION NUMBER: NCT01491815.

Uptake and effectiveness of newer biologic and targeted synthetic disease-modifying antirheumatic drugs in psoriatic arthritis: results from five Nordic biologics registries.

BACKGROUND: We aimed to describe the uptake of newer biologic or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in psoriatic arthritis (PsA) in the Nordic countries and to compare their retention and effectiveness. METHODS: Patients with PsA starting a b/tsDMARD in 2012-2020 in five Nordic rheumatology registers were included. Uptake and patient characteristics were described, with comorbidities identified from linkages to national patient registries. One-year retention and 6-month effectiveness (proportions achieving low disease activity (LDA) on the Disease Activity Index for PSoriatic Arthritis based on 28-joint evaluation) for the newer b/tsDMARDs (abatacept/apremilast/ixekizumab/secukinumab/tofacitinib/ustekinumab) were compared with adalimumab through adjusted regression models stratified by treatment course (first, second/third, and fourth or more). RESULTS: In total, 5659 treatment courses with adalimumab (56% biologic-naïve) and 4767 courses with a newer b/tsDMARD (21% biologic-naïve) were included. The uptake of newer b/tsDMARDs increased from 2014 and plateaued in 2018. Patient characteristics appeared similar across treatments at treatment start. Adalimumab was more often used as the first course and newer b/tsDMARDs more often in biologic-experienced patients. Used as a second/third b/tsDMARD, the retention rate and the proportion achieving LDA were significantly better for adalimumab (rate 65%, proportion 59%) compared with abatacept (45%, 37%), apremilast (43%, 35%), ixekizumab (LDA only, 40%) and ustekinumab (LDA only, 40%), but not significantly different from other b/tsDMARDs. CONCLUSION: Uptake of newer b/tsDMARDs occurred mainly in biologic-experienced patients. Regardless of mode of action, only a minority of patients starting a second or later b/tsDMARD course remained on drug and achieved LDA. Superior outcomes for adalimumab indicate that the positioning of newer b/tsDMARDs in the PsA treatment algorithm remains to be established.

IL-17A and TNF synergistically drive expression of proinflammatory mediators in synovial fibroblasts via IκBζ-dependent induction of ELF3.

OBJECTIVE: IL-17A and TNF act in synergy to induce proinflammatory mediators in synovial fibroblasts thus contributing to diseases associated with chronic arthritis. Many of these factors are regulated by transcription factor E74-like factor-3 (ELF3). Therefore, we sought to investigate ELF3 as a downstream target of IL-17A and TNF signalling and to characterize its role in the molecular mechanism of synergy between IL-17A and TNF. METHODS: Regulation of ELF3 expression by IL-17A and TNF was studied in synovial fibroblasts of RA and OA patients and RA synovial explants. Signalling leading to ELF3 mRNA induction and the impact of ELF3 on the response to IL-17A and TNF were studied using siRNA, transient overexpression and signalling inhibitors in synovial fibroblasts and HEK293 cells. RESULTS: ELF3 was marginally affected by IL-17A or TNF alone, but their combination resulted in high and sustained expression. ELF3 expression was regulated by the nuclear factor-κB (NF-κB) pathway and CCAAT/enhancer-binding protein ß (C/EBPß), but its induction required synthesis of the NF-κB co-factor IκB (inhibitor of NF-κB) ζ. siRNA-mediated depletion of ELF3 attenuated the induction of cytokines and matrix metalloproteinases by the combination of IL-17A and TNF. Overexpression of ELF3 or IκBζ showed synergistic effect with TNF in upregulating expression of chemokine (C-C motif) ligand 8 (CCL8), and depletion of ELF3 abrogated CCL8 mRNA induction by the combination of IκBζ overexpression and TNF. CONCLUSION: Altogether, our results establish ELF3 as an important mediator of the synergistic effect of IL-17A and TNF in synovial fibroblasts. The findings provide novel information of the pathogenic mechanisms of IL-17A in chronic arthritis and implicate ELF3 as a potential therapeutic target.

After JAK inhibitor failure: to cycle or to switch, that is the question - data from the JAK-pot collaboration of registries.

OBJECTIVES: The expanded therapeutic arsenal in rheumatoid arthritis (RA) raises new clinical questions. The objective of this study is to compare the effectiveness of cycling Janus kinase inhibitors (JAKi) with switching to biologic disease-modifying antirheumatic drug (bDMARD) in patients with RA after failure to the first JAKi. METHODS: This is a nested cohort study within data pooled from an international collaboration of 17 national registries (JAK-pot collaboration). Data from patients with RA with JAKi treatment failure and who were subsequently treated with either a second JAKi or with a bDMARD were prospectively collected. Differences in drug retention rates after second treatment initiation were assessed by log-rank test and Cox regression analysis adjusting for potential confounders. Change in Clinical Disease Activity Index (CDAI) over time was estimated using a linear regression model, adjusting for confounders. RESULTS: 365 cycling and 1635 switching patients were studied. Cyclers were older and received a higher number of previous bDMARDs. Both strategies showed similar observed retention rates after 2 years of follow-up. However, adjusted analysis revealed that cycling was associated with higher retention (p=0.04). Among cyclers, when the first JAKi was discontinued due to an adverse event (AE), it was more likely that the second JAKi would also be stopped due to an AE. Improvement in CDAI over time was similar in both strategies. CONCLUSIONS: After failing the first JAKi, cycling JAKi and switching to a bDMARD appear to have similar effectiveness. Caution is advised if an AE was the reason to stop the first JAKi.

Effectiveness of TNF-inhibitors, abatacept, IL6-inhibitors and JAK-inhibitors in 31 846 patients with rheumatoid arthritis in 19 registers from the 'JAK-pot' collaboration.

BACKGROUND: JAK-inhibitors (JAKi), recently approved in rheumatoid arthritis (RA), have changed the landscape of treatment choices. We aimed to compare the effectiveness of four current second-line therapies of RA with different modes of action, since JAKi approval, in an international collaboration of 19 registers. METHODS: In this observational cohort study, patients initiating tumour necrosis factor inhibitors (TNFi), interleukin-6 inhibitors (IL-6i), abatacept (ABA) or JAKi were included. We compared the effectiveness of these treatments in terms of drug discontinuation and Clinical Disease Activity Index (CDAI) response rates at 1 year. Analyses were adjusted for patient, disease and treatment characteristics, including lines of therapy and accounted for competing risk. RESULTS: We included 31 846 treatment courses: 17 522 TNFi, 2775 ABA, 3863 IL-6i and 7686 JAKi. Adjusted analyses of overall discontinuation were similar across all treatments. The main single reason of stopping treatment was ineffectiveness. Compared with TNFi, JAKi were less often discontinued for ineffectiveness (adjusted HR (aHR) 0.75, 95% CI 0.67 to 0.83), as was IL-6i (aHR 0.76, 95% CI 0.67 to 0.85) and more often for adverse events (aHR 1.16, 95% CI 1.03 to 1.33). Adjusted CDAI response rates at 1 year were similar between TNFi, JAKi and IL-6i and slightly lower for ABA. CONCLUSION: The adjusted overall drug discontinuation and 1 year response rates of JAKi and IL-6i were similar to those observed with TNFi. Compared with TNFi, JAKi were more often discontinued for adverse events and less for ineffectiveness, as were IL-6i.

The impact of seropositivity on the effectiveness of biologic anti-rheumatic agents: results from a collaboration of 16 registries.

OBJECTIVES: RF and ACPA are used as diagnostic tools and their presence has been associated with clinical response to some biologic DMARDs (bDMARDs) in RA. This study compared the impact of seropositivity on drug discontinuation and effectiveness of bDMARDs in patients with RA, using head-to-head comparisons in a real-world setting. METHODS: We conducted a pooled analysis of 16 observational RA registries. Inclusion criteria were a diagnosis of RA, initiation of treatment with rituximab (RTX), abatacept (ABA), tocilizumab (TCZ) or TNF inhibitors (TNFis) and available information on RF and/or ACPA status. Drug discontinuation was analysed using Cox regression, including drug, seropositivity, their interaction, adjusting for concomitant and past treatments and patient and disease characteristics and accounting for country and calendar year of bDMARD initiation. Effectiveness was analysed using the Clinical Disease Activity Index evolution over time. RESULTS: Among the 27 583 eligible patients, the association of seropositivity with drug discontinuation differed across bDMARDs (P for interaction <0.001). The adjusted hazard ratios for seropositive compared with seronegative patients were 1.01 (95% CI 0.95, 1.07) for TNFis, 0.89 (0.78, 1.02)] for TCZ, 0.80 (0.72, 0.88) for ABA and 0.70 (0.59, 0.84) for RTX. Adjusted differences in remission and low disease activity rates between seropositive and seronegative patients followed the same pattern, with no difference in TNFis, a small difference in TCZ, a larger difference in ABA and the largest difference in RTX (Lundex remission difference +5.9%, low disease activity difference +11.6%). CONCLUSION: Seropositivity was associated with increased effectiveness of non-TNFi bDMARDs, especially RTX and ABA, but not TNFis.

Tumor necrosis factor primes and metal particles activate the NLRP3 inflammasome in human primary macrophages.

Aseptic loosening of total joint replacements is driven by a macrophage-mediated inflammatory reaction to implant-derived wear particles. Phagocytosis of implant debris has been suggested to activate the NLRP3 inflammasome leading to secretion of interleukin (IL)-1ß. However, factors and molecular mechanisms driving the particle-induced inflammasome activation are yet to be fully elucidated. In this study, we investigated the inflammasome response of human primary macrophages to titanium, chromium, and molybdenum particles in vitro. We observed that particles alone were not sufficient to induce IL-1ß secretion, but an additional priming signal-such as bacterial lipopolysaccharide (LPS)-was required to license the inflammasome activation. By using specific inhibitors against the inflammasome signaling pathway, we demonstrate that the particle-induced IL-1ß secretion depended upon activation of the NLRP3 inflammasome. We further hypothesized that tumor necrosis factor (TNF) could substitute for LPS as a priming signal, and found that particle stimulation together with preceding TNF treatment resulted in inflammasome-dependent IL-1ß production as well. Our results show that the NLRP3 inflammasome mediates wear particle responses in human primary macrophages, and its activation does not necessarily require the presence of bacterial components, but can be induced under aseptic conditions by TNF priming. STATEMENT OF SIGNIFICANCE: This study was conducted to elucidate the molecular mechanisms of metal particle-induced IL-1ß secretion in human primary macrophages. Production of this pro-inflammatory mediator from wear particle-activated macrophages has been associated with increased bone loss around total joint replacements-a condition eventually requiring revision surgery. Our results confirm that together with a co-stimulatory priming signal, particles of common implant metals elicit macrophage-mediated IL-1ß secretion through activation of the NLRP3 inflammasome pathway. We also present a concept of TNF priming in this context, demonstrating that the particle-related IL-1ß secretion can take place in a truly sterile environment. Thus, inhibition of inflammasome signaling appears a means to prevent wear particle-induced inflammation and development of peri­prosthetic osteolysis.

Comparative effectiveness of TNF inhibitors and tocilizumab with and without conventional synthetic disease-modifying antirheumatic drugs in a pan-European observational cohort of bio-naïve patients with rheumatoid arthritis.

OBJECTIVES: To compare treatment effectiveness in rheumatoid arthritis (RA) patients naïve to biological disease-modifying antirheumatic drugs (bDMARDs) treated with tocilizumab (TCZ) or TNF-inhibitor (TNFi) with (-combo) or without (-mono) conventional synthetic DMARDs (csDMARDs). METHODS: Patients with RA across 7 European registries, naïve to bDMARDs who initiated treatment with TCZ or TNFi from 2009 to 2016 were included. Drug retention rate was analyzed using Kaplan-Meier and Cox models, and CDAI over time by mixed models. The proportions of patients reaching CDAI low disease activity (LDA) and remission after one year were corrected for attrition. RESULTS: 6713 TNFi-combo, 3762 TNFi-mono, 646 TCZ-combo and 384 TCZ-mono were eligible. Crude median retention was 3.67 years (95%CI 3.41-3.83) for TNFi-combo, 4.14 (3.77-4.62) for TNFi-mono, 2.98 (2.76-3.34) for TCZ-combo and 3.63 years (3.34-5.03) for TCZ-mono. After adjustment for covariates, country and year of treatment initiation stratification, hazards of discontinuation were lower for TCZ-mono (0.60, 95% CI 0.52-0.69) and TCZ-combo (0.66, 95% CI 0.54-0.81) compared to TNFi-combo. Adjusted CDAI evolution was not significantly different between groups. CDAI LDA and remission corrected for attrition were similar between TCZ with or without csDMARDs and TNFi-combo. CONCLUSION: In routine care across 7 European countries, the adjusted drug retention, adjusted CDAI over time and attrition-corrected response proportion for RA patients were similar for bio-naïve patients if treated with TNFi-combo, TCZ-combo or TCZ-mono.

Haploinsufficiency of A20 impairs protein-protein interactome and leads into caspase-8-dependent enhancement of NLRP3 inflammasome activation.

OBJECTIVES: TNFAIP3 encodes A20 that negatively regulates nuclear factor kappa light chain enhancer of activated B cells (NF-κB), the major transcription factor coordinating inflammatory gene expression. TNFAIP3 polymorphisms have been linked with a spectrum of inflammatory and autoimmune diseases and, recently, loss-of-function mutations in A20 were found to cause a novel inflammatory disease 'haploinsufficiency of A20' (HA20). Here we describe a family with HA20 caused by a novel TNFAIP3 loss-of-function mutation and elucidate the upstream molecular mechanisms linking HA20 to dysregulation of NF-κB and the related inflammasome pathway. METHODS: NF-κB activation was studied in a mutation-expressing cell line using luciferase reporter assay. Physical and close-proximity protein-protein interactions of wild-type and TNFAIP3 p.(Lys91*) mutant A20 were analysed using mass spectrometry. NF-κB -dependent transcription, cytokine secretion and inflammasome activation were compared in immune cells of the HA20 patients and control subjects. RESULTS: The protein-protein interactome of p.(Lys91*) mutant A20 was severely impaired, including interactions with proteins regulating NF-κB activation, DNA repair responses and the NLR family pyrin domain containing 3 (NLRP3) inflammasome. The p.(Lys91*) mutant A20 failed to suppress NF-κB signalling, which led to increased NF-κB -dependent proinflammatory cytokine transcription. Functional experiments in the HA20 patients' immune cells uncovered a novel caspase-8-dependent mechanism of NLRP3 inflammasome hyperresponsiveness that mediated the excessive secretion of interleukin-1ß and interleukin-18. CONCLUSIONS: The current findings significantly deepen our understanding of the molecular mechanisms underlying HA20 and other diseases associated with reduced A20 expression or function, paving the way for future therapeutic targeting of the pathway.

Comparative effectiveness of tocilizumab versus TNF inhibitors as monotherapy or in combination with conventional synthetic disease-modifying antirheumatic drugs in patients with rheumatoid arthritis after the use of at least one biologic disease-modifying antirheumatic drug: analyses from the pan-European TOCERRA register collaboration.

OBJECTIVE: To compare the effectiveness of tocilizumab (TCZ) and tumour necrosis factor (TNF) inhibitors (TNFi) as monotherapy or in combination with conventional synthetic disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA) after the use of at least one biologic DMARD (bDMARD). METHODS: We included patients with RA having used at least one bDMARD from 10 European registries. We compared drug retention using Kaplan-Meier and Cox models and Clinical Disease Activity Index (CDAI) change over time with mixed-effects models for longitudinal data. The proportions of CDAI remission and low disease activity (LDA) at 1 year were compared using LUNDEX correction. RESULTS: 771 patients on TCZ as monotherapy (TCZ mono), 1773 in combination therapy (TCZ combo), 1404 on TNFi as monotherapy (TNFi mono) and 4660 in combination therapy (TNFi combo) were retrieved. Crude median retention was higher for TCZ mono (2.31 years, 95% CI 2.07 to 2.61) and TCZ combo (1.98 years, 95% CI 1.83 to 2.11) than TNFi combo (1.37 years, 95% CI 1.30 to 1.45) and TNFi mono (1.31 years, 95% CI 1.18 to 1.47). In a country and year of treatment initiation-stratified, covariate-adjusted analysis, hazards of discontinuation were significantly lower among patients on TCZ mono or combo compared with patients on TNFi mono or combo, and TNFi combo compared with TNFi mono, but similar between TCZ mono and combo. Average adjusted CDAI change was similar between groups. CDAI remission and LDA rates were comparable between groups. CONCLUSION: With significantly longer drug retention and similar efficacy to TNFi combo, TCZ mono or combo are reasonable therapeutic options in patients with inadequate response to at least one bDMARD.

Toll-like receptors and their soluble forms differ in the knee and thumb basal osteoarthritic joints.

Background and purpose - Although the pathogenesis of osteoarthritis (OA) is not well understood, chondrocyte-mediated inflammatory responses (triggered by the activation of innate immune receptors by damage-associated molecules) are thought to be involved. We examined the relationship between Toll-like receptors (TLRs) and OA in cartilage from 2 joints differing in size and mechanical loading: the first carpometacarpal (CMC-I) and the knee. Patients and methods - Samples of human cartilage obtained from OA CMC-I and knee joints were immunostained for TLRs (1-9) and analyzed using histomorphometry and principal component analysis (PCA). mRNA expression levels were analyzed with RT-PCR. Collected synovial fluid (SF) samples were screened for the presence of soluble forms of TLR2 and TLR4 by enzyme-linked immunosorbent assay (ELISA). Results - In contrast to knee OA, TLR expression in CMC-I OA did not show grade-dependent overall profile changes, but PCA revealed that TLR expression profiles clustered according to their cellular compartment organization. Protein levels of TLR4 were substantially higher in knee OA than in CMC-I OA, while the opposite was the case at the mRNA level. ELISA assays confirmed the presence of soluble forms of TLR2 and TLR4 in SF, with sTLR4 being considerably higher in CMC-I OA than in knee OA. Interpretation - We observed that TLRs are differentially expressed in OA cartilage, depending on the joint. Soluble forms of TLR2 and TLR4 were detected for the first time in SF of osteoarthritic joints, with soluble TLR4 being differentially expressed. Together, our results suggest that negative regulatory mechanisms of innate immunity may be involved in the pathomolecular mechanisms of osteoarthritis.

Correlations between macrophage polarizing cytokines, inflammatory mediators, osteoclast activity, and toll-like receptors in tissues around aseptically loosened hip implants.

Aseptic loosening and osteolysis of joint replacements are driven by macrophage-mediated inflammatory reactions to implant-derived wear debris, but many aspects of these events remain poorly characterized. To better understand the relationships among inflammatory and chemotactic mediators, macrophage phenotype and polarizing cytokines, osteoclast activity, and Toll-like receptors (TLRs) in the pathogenesis of aseptic loosening, we determined how the relative expressions of these factors in the peri-implant tissues correlate to each other and to the life span of the implants using Pearson correlation. The expression of pro-inflammatory mediators and chemokines showed positive correlations among themselves, and with TLR4. Furthermore, M1-polarizing IFN-γ showed positive correlations with a number of pro-inflammatory and chemotactic mediators, whereas M2-polarizing IL-4 showed no such association. IL-8 expression significantly correlated with early time to revision. Similar trends were observed for TNF-α, IFN-γ, and CCL3, while the opposite was detected for IL-4. However, none of the inflammatory mediators correlated with the markers of osteoclast activity or the RANKL/OPG ratio. The results highlight the importance of the inflammatory mediators, IFN-γ and TLR4, in the pathogenesis of aseptic loosening; increased pro-inflammatory status was associated with early time to revision, whereas IL-4 correlated with longer implant survival. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 454-463, 2017.

Effectiveness of two different doses of rituximab for the treatment of rheumatoid arthritis in an international cohort: data from the CERERRA collaboration.

BACKGROUND: The approved dose of rituximab (RTX) in rheumatoid arthritis is 1000 mg × 2, but some data have suggested similar clinical efficacy with 500 mg × 2. The purpose of this study was to compare the effectiveness of the regular and low doses given as first treatment course. METHODS: Twelve European registries participating in the CERERRA collaboration (The European Collaborative Registries for the Evaluation of Rituximab in Rheumatoid Arthritis) submitted anonymized datasets with demographic, efficacy and treatment data for patients who had started RTX. Treatment effectiveness was assessed by DAS28 reductions and EULAR responses after 6 months. RESULTS: Data on RTX dose were available for 2,873 patients, of whom 2,625 (91.4 %) and 248 (8.6 %) received 1000 mg × 2 and 500 mg × 2, respectively. Patients treated with 500 mg × 2 were significantly older, had longer disease duration, higher number of prior DMARDs, but lower number of prior biologics and lower baseline DAS28 than those treated with 1000 mg × 2. Fewer patients in the low-dose group received concomitant DMARDs but more frequently received concomitant corticosteroids. Both doses led to significant clinical improvements at 6 months. DAS28 reductions at 6 months were comparable in the 2 dose regimens [mean DeltaDAS28 ± SD -2.0 ± 1.3 (high dose) vs. -1.7 ± 1.4 (low dose), p = 0.23 adjusted for baseline differences]. Similar percentages of patients achieved EULAR good response in the two dose groups, 18.4 % vs. 17.3 %, respectively (p = 0.36). CONCLUSIONS: In this large observational cohort initial treatment with RTX at 500 mg × 2 and 1000 mg × 2 led to comparable clinical outcomes at 6 months.

Rituximab done: what's next in rheumatoid arthritis? A European observational longitudinal study assessing the effectiveness of biologics after rituximab treatment in rheumatoid arthritis.

OBJECTIVE: To compare the effectiveness of biologics after rituximab (RTX) treatment in RA. METHODS: The effectiveness of TNF-α inhibitors (TNFi), abatacept (ABA) or tocilizumab (TCZ) was examined in patients previously treated with RTX using clinical data collected in the Collaborative Registries for the Evaluation of Rituximab in RA Collaborative registry. Patients had stopped RTX 6 months or less prior to the new biologic and had a baseline visit within 21 days of starting the new biologic. RESULTS: Two hundred and sixty-five patients were analysed after 6 months of treatment. Patients on TCZ (n = 86) had a greater decline of DAS28-ESR and clinical disease activity index than patients on TNFi (n = 89) or ABA (n = 90). This effect was also seen after adjusting for baseline prednisone use and the number of previous biologics. The mean DAS28-ESR scores in patients on TCZ were 1.0 (95% CI: 0.2, 1.7) and 1.8 (95% CI: 1.0, 2.5) points lower than in patients on TNFi or ABA, respectively. In patients on TCZ, the clinical disease activity index was 9.4 (95% CI: 1.7, 16.1) and 8.1 (95% CI: 0.9, 15.3) points lower than on TNFi and ABA, respectively. Patients on TCZ more frequently had good EULAR responses than patients on TNFi or ABA (66 vs 31 vs 14%, P < 0.001). The HAQ disability index improved in all treatment groups (P < 0.001), but did not differ between biologics, as did drug retention rates. The reasons for discontinuation of RTX and the number of previous biologics had no influence on outcomes. CONCLUSION: In this observational cohort of patients who discontinued RTX, TCZ provided a better control of RA than ABA or TNFi.

Effectiveness of tocilizumab with and without synthetic disease-modifying antirheumatic drugs in rheumatoid arthritis: results from a European collaborative study.

OBJECTIVES: To examine the effectiveness of tocilizumab (TCZ) with and without synthetic disease-modifying antirheumatic drugs (sDMARDs) in a large observational study. METHODS: Patients with rheumatoid arthritis treated with TCZ who had a baseline visit and information on concomitant sDMARDs were included. According to baseline data, patients were considered as taking TCZ as monotherapy or combination with sDMARDs. Main study outcomes were the change of Clinical Disease Activity Index (CDAI) and TCZ retention. The prescription of TCZ as monotherapy was analysed using logistic regression. CDAI change was analysed with a mixed-effects model for longitudinal data. TCZ retention was analysed with a stratified extended Cox model. RESULTS: Multiple-adjusted analysis suggests that prescription of TCZ as monotherapy varied according to age, corticosteroid use, country of the registry and year of treatment initiation. The change of disease activity assessed by CDAI as well as the likelihood to be in remission were not significantly different whether TCZ was used as monotherapy or in combination with sDMARDs in a covariate-adjusted analysis. Estimates for unadjusted median TCZ retention were 2.3 years (95% CI 1.8 to 2.7) for monotherapy and 3.7 years (lower 95% CI limit 3.1, upper limit not estimable) for combination therapies. In a covariate-adjusted analysis, TCZ retention was also reduced when used as monotherapy, with an increasing difference between mono and combination therapy over time after 1.5 years (p=0.002). CONCLUSIONS: TCZ with or without concomitant sDMARDs resulted in comparable clinical response as assessed by CDAI change, but TCZ retention was shorter under monotherapy of TCZ.