Efficacy of tocilizumab and evaluation of clinical remission as determined by CDAI and MMP-3 level

Periodontitis and periodontopathic bacteria as risk factors for rheumatoid arthritis: A review of the last 10 years

Rheumatoid arthritis (RA) is characterized by chronic inflammatory destruction of joint tissue and is caused by an abnormal autoimmune response triggered by interactions between genetics, environmental factors, and epigenetic and posttranslational modifications. RA has been suggested to be interrelated with periodontitis, a serious form or stage of chronic inflammatory periodontal disease associated with periodontopathic bacterial infections, genetic predisposition, environmental factors, and epigenetic influences. Over the last decade, a number of animal and clinical studies have been conducted to assess whether or not periodontitis and associated periodontopathic bacteria constitute risk factors for RA. The present review introduces recent accumulating evidence to support the associations of periodontitis and periodontopathic bacteria with the risk of RA or the outcome of RA pharmacological treatment with disease-modifying antirheumatic drugs. In addition, the results from intervention studies have suggested an improvement in RA clinical parameters after nonsurgical periodontal treatment. Furthermore, the potential causal mechanisms underlying the link between periodontitis and periodontopathic bacteria and RA are summarized.

Differential long-term retention of biological disease-modifying antirheumatic drugs in patients with rheumatoid arthritis by age group from the FIRST registry

BACKGROUND

The effectiveness and safety of biological disease-modifying antirheumatic drugs (bDMARDs) by age group (< 65, 65-74, and ≥ 75 years) are uncertain. We examined retention rates reflecting the effectiveness and safety of bDMARDs in actual clinical practice for clarifying optimal therapeutic strategies for rheumatoid arthritis (RA) by age groups.

METHODS

Data of patients who were treated with tumor necrosis factor inhibitors (TNFi), abatacept (ABA), and tocilizumab (TCZ) between February 2011 and April 2017 were collected from a prospective observational registry of RA patients. A total of 1362 patients were enrolled, of which 695 were aged < 65 years, 402 were aged 65-74 years, and 265 were aged ≥ 75 years. Primary outcome was the drug retention rate in adjusted data using inverse probability of treatment weighting based on generalized propensity scores.

RESULTS

In patients aged < 65 years, 3-year retention rates of TNFi, ABA, and TCZ were 43%, 47%, and 69%, respectively (ABA versus TCZ, p = 0.017; TNFi versus TCZ, p = 0.002). In patients aged 65-74 years, 3-year retention rates of TNFi, ABA, and TCZ were 44%, 53%, and 60%, respectively (TCZ versus TNFi, p = 0.034). In patients aged ≥ 75 years, 3-year retention rates for TNFi, ABA, and TCZ were 38%, 63%, and 58%, respectively (ABA versus TNFi, p = 0.017).

CONCLUSIONS

We found that the effectiveness and safety of TCZ were maximal in patients aged < 75 years and that patients aged ≥ 75 years might be suitable candidates for TCZ and ABA therapy. The use of therapeutic strategies appropriate to each age group might improve the outcomes of bDMARD therapy for RA.

Use and effectiveness of tocilizumab among patients with rheumatoid arthritis: an observational study from the British Society for Rheumatology Biologics Register for rheumatoid arthritis

The aims of the present study are to describe the characteristics of rheumatoid arthritis (RA) patients selected for tocilizumab (TCZ), compare the “real-world” effectiveness of TCZ and tumour necrosis factor inhibitors (TNFi) when used as a first biologic and assess the influence of past biologic exposure/concurrent methotrexate (MTX) therapy on post-TCZ treatment outcomes. The British Society for Rheumatology Biologics Register (BSRBR-RA) is a prospective cohort study following RA patients starting biologics in the UK. This includes patients starting TCZ as first or subsequent biologic, alongside biologic-naïve patients starting TNFi. Six-month disease activity and 1-year drug survival were compared between biologic-naïve patients starting TCZ versus TNFi and first-line versus subsequent TCZ users and TCZ users with MTX versus without using regression models adjusted by propensity score. Two hundred seventeen patients started TCZ, and 2419 started TNFi as first biologic. Seven hundred seventy-seven started TCZ after other biologics. First-line TCZ users had a higher prevalence of pulmonary fibrosis and cancer history than TNFi users. The first-line TCZ users were more likely to achieve DAS28 remission at 6 months than first-line TNFi, but other improvement markers were similar. The treatment response at 6 months was similar between subsequent-line TCZ users and first-line users after adjusting for baseline patient differences. Concurrent MTX use was not associated with treatment response in either first- or subsequent-line TCZ users. TCZ has been primarily used as subsequent-line biologic in the UK. When used as first line, the response appears similar to that observed in patients starting TNFi, suggesting that clinical response alone should not decide between initial biologic therapies.

Continuously elevated serum matrix metalloproteinase-3 for 3 ~ 6 months predict one-year radiographic progression in rheumatoid arthritis: a prospective cohort study

INTRODUCTION

Core disease activity indicators of rheumatoid arthritis (RA) have been found to be limited in predicting joint destruction progression. Matrix metalloproteinase (MMP) 3 plays an essential role in joint destruction and was found elevated in some remission patients. We aimed to monitor dynamic core disease activity indicators and serum MMP-3 for one year and evaluate their value for predicting radiographic progression.

METHODS

Patients with active RA (Simplified disease activity index > 3.3) were treated according to the treat-to-target strategy. Serum MMP-3 was detected by enzyme-linked immunosorbent assay and clinical data were collected simultaneously at 0, 1st, 3rd, 6th and 12th month. X-ray assessment of hand/wrist was repeated at baseline and the 12th month and a change of total Sharp score > 0.5 units was defined as radiographic progression.

RESULTS

Fifty-six patients completed one year follow-up and 29 % showed radiographic progression. Although not significantly different at baseline, serum MMP-3 and all core disease activity indicators, except for erythrocyte sedimentation rate, at the 12th month were significantly higher in the progressive group than in the non-progressive group. Among sixteen progressive patients, 69 % achieved the therapeutic target and 56 % had continuous elevated serum MMP-3, 38 % had continuous elevated serum MMP-3 and normal C-reactive protein (CRP) at the 6th month. Log-rank tests and repeated measures analysis revealed a significant difference in dynamic serum MMP-3 between progressive and non-progressive patients. Receiver operating characteristic curve and univariate logistic regression analysis showed that elevated serum MMP-3 at 0, 1st, 3rd and 6th months, compared with CRP at the 1st month, were significant predictors for one-year radiographic progression (MMP-3 odds ratio (OR):10.500 ~ 27.000, all P < 0.05; CRP: OR = 7.400, P = 0.011).

CONCLUSIONS

Our data showed that continuously elevated serum MMP-3 for 3 ~ 6 months predicted one-year radiographic progression which implied that monitoring of dynamic serum MMP-3 combined with core disease activity indicators may be more helpful for predicting radiographic progression and treatment decision in RA.

Evaluation of tocilizumab therapy in patients with rheumatoid arthritis based on FDG-PET/CT

Background

Positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) can detect the presence of synovitis in rheumatoid arthritis (RA) patients. The aim of this study was to investigate whether the findings of FDG-PET matched the conventional assessments of the disease activity score (DAS) 28, DAS28-CRP, simplified disease activity index (SDAI) and clinical disease activity index (CDAI) in RA patients receiving tocilizumab (TCZ) therapy.

Methods

Seventeen RA patients treated with TCZ were assessed. FDG-PET was performed at baseline and three and six months after the initiation of TCZ therapy. The maximum SUV (SUVmax) of the bilateral shoulder, elbow, wrist, hip, knee and ankle joints were added together (total SUV) and were used to assess the degree of FDG uptake as a representative parameter. The correlations between the ΔSUV and the difference in the clinical parameters at baseline and at each observation period, and the differences in each clinical parameters, were assessed.

Results

The ΔSUV, the differences in the total SUV at baseline and at three/six months after starting treatment positively correlated with the ΔDAS28 (r = 0.615 p = 0.009/ r = 0.775 p < 0.001), ΔDAS28-CRP (r = 0.696, p = 0.002/ r = 0.828, p < 0.001), ΔSDAI (r = 0.652, p = 0.005/ r = 0.686, p = 0.002) and ΔCDAI (r = 0.662, p = 0.004/ r = 0.711, p = 0.001) for each period. The total SUV was significantly decreased at three and six months after the initiation of TCZ (p < 0.05).

Conclusions

A reduction in the FDG uptake was observed at three and six months after the initiation of TCZ therapy. The disease activity estimated on FDG-PET/CT matched the conventional parameters following the TCZ therapy in RA patients.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-393) contains supplementary material, which is available to authorized users.

Could biomarkers of bone, cartilage or synovium turnover be used for relapse prediction in rheumatoid arthritis patients?

OBJECTIVE

The aim of this review is to clarify the usefulness of bone, cartilage, and synovial biomarker in the management of rheumatoid arthritis (RA) therapy in remission. SYNOVIAL BIOMARKERS: High MMP-3 levels are associated with joint progression in RA patients, but there is no data about their utility in clinical remission. IIINys and Glc-Gal-PYD seem to be more specific to synovium, but more studies are required. CARTILAGE BIOMARKERS: Unbalance between cartilage break-down biomarkers (urinary CTX II and COMP) and cartilage formation biomarker (PIIANP) was described. This unbalance is also associated with joint destruction and prognosis of destruction. No data are available on patients in remission. BONE BIOMARKERS: RA activity is correlated with an increase of bone resorption markers such as CTX I, PYD, and TRACP 5b and a decrease of bone formation markers such as OC and BALP. RA therapies seem to improve bone turnover in limiting bone resorption. There is no study about bone marker utility in remission.

CONCLUSION

Biomarkers seem to correlate with RA activity and progression. They also could be used to manage RA therapies, but we need more data on RA remission to predict relapse.

Monitoring C-reactive protein levels to predict favourable clinical outcomes from tocilizumab treatment in patients with rheumatoid arthritis

OBJECTIVES

The inflammatory cytokine interleukin-6 (IL-6) directly stimulates C-reactive protein (CRP) expression. The present study aimed to examine how clinical treatment outcomes of rheumatoid arthritis (RA) with tocilizumab (TCZ), a humanised monoclonal anti-IL-6 receptor antibody, are related to CRP levels monitored for 52 weeks.

METHODS

One hundred and twenty-two RA patients who underwent TCZ treatment between May 2008 and September 2009 were registered in the Tsurumai Biologics Communication Registry. Data were collected at initiation of treatment (baseline) and over 52 weeks for Disease Activity Score 28-ESR (DAS28-ESR), Boolean core measurements, serum CRP levels and matrix metalloproteinase-3 levels. To compare clinical results, patients were divided into three groups based on treatment time required to achieve normal CRP levels.

RESULTS

Multivariate analysis using the Cox proportional-hazards regression model found that higher CRP levels at baseline was a significant and independent factor in predicting normal CRP levels over 52 weeks (hazard ratio 0.86 per 1 mg/dL). In contrast, disease duration, concomitant methotrexate use and previous tumour necrosis factor inhibitor failure were not significant factors. Patients with normal CRP levels at 12 weeks of TCZ treatment achieved better clinical outcomes, including remission based on DAS28-ESR criteria, compared to patients with elevated CRP levels at 12 weeks.

CONCLUSIONS

Adequate suppression of pathological IL-6 signalling during TCZ treatment improves clinical outcomes and can be monitored with serum CRP levels, a readily available biomarker in clinical practice.

Reexamination of the assessment criteria for rheumatoid arthritis disease activity based on comparison of the Disease Activity Score 28 with other simpler assessment methods

OBJECTIVE

To explore simpler and possibly more appropriate tools than the conventional Disease Activity Score 28 (DAS28) for assessing rheumatoid arthritis (RA) and to derive more reliable DAS28-based criteria.

METHODS

The capabilities of assessing disease activities in 250 RA patients were compared between DAS28 and other methods, including the Simplified DA Index (SDAI), Clinical DA Index (CDAI), and Routine Assessment of Patient Index Data-3 (RAPID-3).

RESULTS

SDAI and CDAI showed a good correlation and consistency with DAS28, whereas RAPID-3 yielded inferior results. In terms of remission criteria, DAS28 was less stringent than SDAI or CDAI; when RA remission was reexamined based on more stringent SDAI or CDAI criteria, cut-off values for DAS28-C-reactive protein of <1.72 were considered to be appropriate. The conventional DAS28 was considered to be appropriate for assessing low, middle and high disease activities because it provides criteria similar to or more stringent than those of other methods, while SDAI and CDAI were considered to be simpler and more appropriate criteria for assessing remission.

CONCLUSION

For assessing remission, DAS28-CRP provides the most appropriate criterion of the methods compared when the currently used cut-off value of 2.3 is lowered to a new value of 1.72.

The roles of interleukin-6 in the pathogenesis of rheumatoid arthritis

Several clinical studies have demonstrated that the humanized anti-interleukin-6 (IL-6) receptor antibody tocilizumab (TCZ) improves clinical symptoms and prevents progression of joint destruction in rheumatoid arthritis (RA). However, the precise mechanism by which IL-6 blockade leads to the improvement of RA is not well understood. IL-6 promotes synovitis by inducing neovascularization, infiltration of inflammatory cells, and synovial hyperplasia. IL-6 causes bone resorption by inducing osteoclast formation via the induction of RANKL in synovial cells, and cartilage degeneration by producing matrix metalloproteinases (MMPs) in synovial cells and chondrocytes. Moreover, IL-6 is involved in autoimmunity by altering the balance between T_h17 cells and T_reg. IL-6 also acts on changing lipid concentrations in blood and on inducing the production of hepcidin which causes iron-deficient anemia. In conclusion, IL-6 is a major player in the pathogenesis of RA, and current evidence indicates that the blockade of IL-6 is a beneficial therapy for RA patients.

Tocilizumab, a humanized anti-interleukin-6 receptor antibody, for treatment of rheumatoid arthritis

Interleukin (IL)-6 has a variety of biological functions. For example, it stimulates the production of acute-phase reactants (C-reactive protein and serum amyloid A) and hepcidin which interferes with iron recycling and absorption, causing iron-deficient anemia, and augments expression of vascular endothelial growth factor and receptor activator of nuclear factor-κB ligand in synovial cells, leading to neovascularization and osteoclast formation. IL-6 also acts on lymphocytes, not only on B cells to stimulate autoantibody production, but also on naïve T helper cells to promote T_h17 cell differentiation. Thus, an imbalance between T cell subsets possibly contributes to development of rheumatoid arthritis. Several clinical studies have demonstrated that a humanized anti-IL-6 receptor antibody, tocilizumab, improves clinical symptoms in rheumatoid arthritis. Tocilizumab prevented radiographic progression of joint destruction by inhibiting cartilage/bone resorption. Tocilizumab also improved hematological abnormalities, including hypergammaglobulinemia, high levels of autoantibodies, and elevation of erythrocyte sedimentation rate and acute-phase proteins. Importantly, tocilizumab improved quality of life by reducing systemic symptoms, including fatigue, anemia, anorexia, and fever. These findings have confirmed that hyperproduction of IL-6 is responsible for the above clinical symptoms, including joint destruction. Many patients treated with tocilizumab achieved clinical remission associated with decreased serum IL-6, suggesting that IL-6 enhances autoimmunity. Tocilizumab is a new therapeutic option for rheumatoid arthritis.

Expression of K2P5.1 potassium channels on CD4+ T lymphocytes correlates with disease activity in rheumatoid arthritis patients

INTRODUCTION

CD4+ T cells express K(2P)5.1 (TWIK-related acid-sensitive potassium channel 2 (TASK2); KCNK5), a member of the two-pore domain potassium channel family, which has been shown to influence T cell effector functions. Recently, it was shown that K(2P)5.1 is upregulated upon (autoimmune) T cell stimulation. The aim of this study was to correlate expression levels of K(2P)5.1 on T cells from patients with rheumatoid arthritis (RA) to disease activity in these patients.

METHODS

Expression levels of K(2P)5.1 were measured by RT-PCR in the peripheral blood of 58 patients with RA and correlated with disease activity parameters (C-reactive protein levels, erythrocyte sedimentation rates, disease activity score (DAS28) scores). Twenty patients undergoing therapy change were followed-up for six months. Additionally, synovial fluid and synovial biopsies were investigated for T lymphocytes expressing K(2P)5.1.

RESULTS

K(2P)5.1 expression levels in CD4+ T cells show a strong correlation to DAS28 scores in RA patients. Similar correlations were found for serological inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein). In addition, K(2P)5.1 expression levels of synovial fluid-derived T cells are higher compared to peripheral blood T cells. Prospective data in individual patients show a parallel behaviour of K(2P)5.1 expression to disease activity parameters during a longitudinal follow-up for six months.

CONCLUSIONS

Disease activity in RA patients correlates strongly with K(2P)5.1 expression levels in CD4+ T lymphocytes in the peripheral blood in cross-sectional as well as in longitudinal observations. Further studies are needed to investigate the exact pathophysiological mechanisms and to evaluate the possible use of K(2P)5.1 as a potential biomarker for disease activity and differential diagnosis.

In rheumatoid arthritis patients treated with tocilizumab, the rate of clinical disease activity index (CDAI) remission at 24 weeks is superior in those with higher titers of IgM-rheumatoid factor at baseline

We aimed to evaluate the efficacy of tocilizumab in patients with rheumatoid arthritis (RA), using the clinical disease activity index (CDAI), and to determine the baseline variables associated with CDAI remission. Fifty-eight patients with active RA were enrolled. We tried to evaluate whether baseline variables were associated with CDAI remission at 24 weeks. Twenty-two of the 58 patients (37.9%) had received tumor necrosis factor (TNF) inhibitors. The continuation rate of tocilizumab at 24 weeks was 87.9%. The seropositivity rates of IgM-rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibodies at baseline were both 91.4%. The rate of CDAI remission at 24 weeks was 20.7%. We selected baseline variables including age, gender, duration of disease, concomitant use of glucocorticoids, concomitant use of methotrexate (MTX), previous anti-TNF therapy, titer of anti-CCP antibodies (high or low toward median), titer of IgM-RF (high or low toward median), and CDAI, and found that a high titer of IgM-RF was the only variable to be associated with CDAI remission, according to univariate and logistic regression analyses. This is a new finding, and may be specific to tocilizumab as compared with previous observations in anti-TNF therapy.

Disease activity score 28 may overestimate the remission induction of rheumatoid arthritis patients treated with tocilizumab: comparison with the remission by the clinical disease activity index

We evaluated the efficacy of tocilizumab (TCZ) in patients with rheumatoid arthritis (RA) by the clinical disease activity index (CDAI) and disease activity score (DAS) 28-erythrocyte sedimentation rate (ESR). Thirty-two RA patients received 8 mg/kg of TCZ intravenously every 4 weeks for 48 weeks. The therapeutic response was also evaluated in 30 RA patients treated with 3 mg/kg of infliximab (IFX) for 46 weeks. We compared the therapeutic course of TCZ with IFX in order to evaluate the efficacy of TCZ therapy. A strong positive correlation between CDAI and DAS28-ESR was observed at baseline, whereas their associations dropped significantly within the first 2 months. The association recovered to the baseline by IFX, but still remained low in TCZ. Although a decrement of DAS28-ESR was prominent in TCZ as compared with IFX, that of CDAI was significant in the early phase and even in the latter in patients treated by IFX. The present study revealed that DAS28-ESR may not be sufficient to estimate RA disease activity treated by TCZ, probably due to the significant effect toward inhibition of acute phase reactants by TCZ. CDAI is suggested to be an important alternate of composite measure in these cases.

Recent advances in neutralizing the IL-6 pathway in arthritis

Recent advances in understanding the mechanism(s) of how IL-6 trans-signaling regulates immune cell function and promotes inflammation in autoimmune arthritis are critically reviewed. Serum and/or synovial fluid (SF) IL-6 is markedly elevated in adult and juvenile rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS) and osteoarthritis (OA). IL-6, in concert with IL-17, determines the fate of CD4⁺ lymphocytes and therefore TH₁₇ cell differentiation. IL-6 also plays a critical role in modulating B-lymphocyte activity. The recognition that IL-6 trans-signaling regulates inflammation resulted in the development of tocilizumab, a fully humanized monoclonal antibody that neutralizes the biological activity of the IL-6-receptor (IL-6R). Significant clinical benefit was demonstrated as well as reduced serum IL-6 levels with suppression of X-ray progression of disease in several clinical trials in which juvenile or adult RA patients were treated with tocilizumab monotherapy or tocilizumab plus methotrexate. However, levels of serum and/or SF IL-6 cytokine protein superfamily members, adiponectin, oncostatin M, pre-B-cell colony enhancing factor/visfatin and leukemia inhibitory factor are also elevated in RA. Additional studies will be required to determine if anti-IL-6 trans-signaling inhibition strategies with tocilizumab or recombinant soluble IL-6R reduce the level of these cytokines.