Search

INTRODUCTION: This study describes the results of the Belgian 'MabThera In Rheumatoid Arthritis (MIRA)' registry: effectiveness, safety and evaluation of the current retreatment practice on the background of the Belgian reimbursement criteria for rituximab. METHODS: All Belgian rheumatologists had the possibility to participate in the study. Patients entered the registry in November 2006 and the entry is still open. RESULTS: By mid-September 2009, 401 patients had entered the registry with a mean follow-up time of 70 weeks. Overall, DAS28-ESR decreased from 6.0 at baseline to 4.2 at week 16. Further decrease of disease activity was observed at the end of year 1 and year 2 with mean DAS28-ESR of 4.0 and 3.7 at these respective time points. More than 80% of patients showed a EULAR response at week 16. Patients could be retreated if they had DAS scores of > 3.2 at least 6 months after the previous course. Second and third courses were given in 224 and 104 patients, respectively. At month 6 after the second course, significantly lower DAS28-ESR values were observed compared to the first course. This was especially the case for patients who were retreated before they showed an obvious flare (DAS increase > 1.2). CONCLUSIONS: This study describes the follow-up of a daily clinical practice cohort of 401 RA patients with long-standing refractory disease treated with rituximab. Relatively high DAS28 values at the start of each retreatment, compared to values 6 months after each treatment course, were noted. Moreover, further decrease of DAS28 scores after the second course was significantly more pronounced in those patients who didn't show an obvious flare. These two elements suggest that treatment of RA patients with rituximab could be optimized by earlier retreatment.

Introduction: Rheumatoid arthritis (RA) is an inflammatory disease, which results in destruction of the joint. The presence of immune complexes (IC) in serum and synovial fluid of RA patients might contribute to this articular damage through different mechanisms, such as complement activation. Therefore, identification of the antigens from these IC is important to gain more insight into the pathogenesis of RA. Since RA patients have antibodies against citrullinated proteins (ACPA) in their serum and synovial fluid (SF) and since elevated levels of citrullinated proteins are detected in the joints of RA patients, citrullinated antigens are possibly present in IC from RA patients. Methods: IC from serum of healthy persons, serum of RA patients and IC from synovial fluid of RA patients and Spondyloarthropathy (SpA) patients were isolated by immunoprecipitation. Identification of the antigens was performed by SDS-PAGE, mass spectrometry and immunodetection. The presence of citrullinated proteins was evaluated by anti-modified citrulline (AMC) staining. Results: Circulating IC in the serum of RA patients and healthy controls contain fibrinogen beta and fibronectin, both in a non-citrullinated form. Additionally, in IC isolated from RA SF, fibrinogen. and vimentin were identified as well. More importantly, vimentin and a minor portion of fibrinogen beta were found to be citrullinated in the isolated complexes. Moreover these citrullinated antigens were only found in ACPA+ patients. No citrullinated antigens were found in IC from SF of SpA patients. Conclusions: Citrullinated fibrinogen beta and citrullinated vimentin were found in IC from SF of ACPA+ RA patients, while no citrullinated antigens were found in IC from SF of ACPA-RA patients or SpA patients or in IC from serum of RA patients or healthy volunteers. The identification of citrullinated vimentin as a prominent citrullinated antigen in IC from SF of ACPA+ RA patients strengthens the hypothesis that citrullinated vimentin plays an important role in the pathogenesis of RA.

Although there is strong evidence supporting the short-term efficacy and safety of anti-tumour necrosis factor-α agents, few studies have examined the long-term effects. We evaluated 511 patients with long-standing refractory rheumatoid arthritis treated with intravenous infusions of infliximab 3 mg/kg at weeks 0, 2, 6, and 14 and every 8 weeks thereafter for 4 years. Among the initial 511 patients included in the study, 479 could be evaluated; of these, 295 (61.6%) were still receiving infliximab treatment at year 4 of follow-up. The most common reasons for treatment discontinuation were lack of efficacy (65 patients, 13.6%), safety (81 patients, 16.9%), and elective change (38 patients, 7.9%). Analysis of disease activity scores (DAS28 [disease activity score based on the 28-joint count]) over time showed that, after the initial rapid improvement during the first 6 to 22 weeks of therapy, a further decrease in disease activity of 0.2 units in the DAS28 score per year was observed. DAS28 scores, measured at week 14 or 22, were found to predict subsequent discontinuation due to lack of efficacy. In conclusion, long-term maintenance therapy with infliximab 3 mg/kg is effective in producing further reductions in disease activity. Disease activity measured by the DAS28 at week 14 or 22 of infliximab therapy was the best predictor of long-term attrition.

The February issue of Arthritis Research & Therapy included a commentary by Aletaha [1] on a recent report from our group [2]. First, Aletaha states that evaluation of the 'physician's mind' is best performed in a study setting in which the physician is unaware that their clinical decision is part of the investigation. It should be noted that the analysis we reported [2] was a post hoc analysis on a cohort of patients with rheumatoid arthritis (RA) who began infliximab therapy within the context of an expanded access programme, and in which infliximab therapy was provided for free until reimbursement in 2002. In the initial protocol it was pre-specified that, from week 30 onward, patients with insufficient response to the therapy could receive an extra vial at each infusion. This decision had to be taken at week 22 and was based on the treating rheumatologist's appreciation of the patient's condition and disease activity. Because the analysis presented in our report was not planned for in the initial protocol, a post hoc amendment to the initial protocol for our analysis was approved by the ethical committee in 2004. Thus, at the time of the study, the physicians were unaware that their behaviour would be evaluated in a separate analysis. Second, we should like to clarify that the components of the American College of Rheumatology (ACR) core set response score and the Disease Activity Score (DAS28) were known to the treating physician, but not the calculated values of the ACR core set response score and DAS28. A third issue highlighted by Aletaha [1] and by Van Riel and Fransen [3] is that in our study more than 50% of patients did not receive a dose increase, even though those patients had a DAS28 score greater than 3.2, indicating moderate or high disease activity. It can therefore be questioned why physicians 'neglected' to treat their patients more aggressively. It should be noted that the patients included in the study had long-standing destructive disease (median disease duration 10 years) and had previously failed to respond to aggressive therapy, as reflected by a failure to respond to a median of four disease-modifying antirheumatic drugs. Infliximab therapy was for most patients the final therapeutic option at the time of the study, and for such individuals and their physicians moderate disease activity was acceptable, representing an improvement over their previous state. Sokka and Makinen [4] recently suggested that when more treatment options become available, lower levels of RA disease activity will be required. Also, it should be mentioned that the study was a reflection of real life practice for an important number of rheumatologists, because about half of all Belgian rheumatologists were involved in this large multicentre study. Aletaha [1] also suggests that the DAS28 score places undue emphasis on erythrocyte sedimentation rate (ESR), and thus it may misrepresent disease activity in the lower ranges [2,5,6]. We evaluated coefficients and weighting of the DAS28 score by means of a discriminant analysis. The coefficients obtained by discriminant analysis were similar to the coefficients of the DAS28. A 20% difference was observed for the coefficient of ESR (Table ​(Table1),1), suggesting that ESR might be slightly over-weighted in the DAS28. In our study, this difference in weight of the ESR did not induce a significant difference between the discriminant score and the DAS28. The absolute difference between the discriminant score and the DAS28 was similar in the higher and the lower ranges of disease activity. Table 1 Coefficients of the DAS28-ESR versus the coefficients of the discriminant score obtained in the study Finally, we agree that the different DAS variants may have strengths in specific situations. In our analysis, we found that the DAS28-ESR correlated slightly better with the decision to give a dose increase than the other 28 joint count disease activity scores, including Simplified Disease Activity Index (SDAI) and Clinical Disease Activity Index (CDAI). This appears to contradict the findings of Soubrier and coworkers [7], who found that the SDAI performed better than the DAS28-ESR. An important difference between that study and ours is that our study was multicentre and that reported by Soubrier and coworkers was a monocentre study. In a monocentre study, it is intuitive that the SDAI will correlate better with the physician's decision than the DAS28 because the SDAI includes the physician's global visual-analogue scale (VAS). In contrast, in a multicentre study the physician's global VAS may be subject to interobserver and intercentre variability. These sources of variability may explain why the SDAI performed slightly worse than the DAS28 in our multicentre study; the DAS28 does not include the physician's global VAS and weights the swollen joint count lower than the SDAI. To conclude, the analysis that we performed supports the validity of the DAS28 score for measuring disease activity in the follow up of RA patients undergoing anti-tumour necrosis factor treament. Variants of the DAS28 have been described, and each variant may have pros and cons in certain situations.

We studied the diagnostic performance of the anti-human citrullinated fibrinogen antibody (AhFibA) ELISA for rheumatoid arthritis (RA) in a consecutive cohort (population 1) and evaluated the agreement between the AhFibA ELISA and four other assays for anti-citrullinated protein/peptide antibodies (ACPAs) as well as rheumatoid factor in patients with longstanding RA (population 2). Population 1 consisted of 1024 patients with rheumatic symptoms; serum samples from these patients were sent to our laboratory for ACPA testing within the context of a diagnostic investigation for RA. Ninety-two of these patients were classified as having RA according to the American College of Rheumatology criteria and 463 were classified as non-RA patients. Population 2 consisted of 180 patients with longstanding RA and was used to assess agreement and correlations between five ACPA assays: anti-cyclic citrullinated peptide (CCP)1 and anti-CCP2 antibodies were detected using a commercially available ELISA, AhFibA using ELISA, and anti-PepA and anti-PepB antibodies using line immunoassay. Applying previously proposed cut-offs for AhFibA, we obtained a sensitivity of 60.9% and a specificity of 98.7% in population 1. Receiver operating characteristic curve analysis could not detect a significant difference in diagnostic performance between the AhFibA ELISA and anti-CCP2 assay. Performing a hierarchical nearest neighborhood cluster analysis of the five different ACPA assays in population 2, we identified two clusters: a cluster of anti-pepA, anti-pepB and anti-CCP1, and a cluster of AhFibA and anti-CCP2. In conclusion, we found that AhFibA and anti-CCP2 antibodies had similar diagnostic performance. However, disagreement between ACPA tests may occur.

At present only few biological data are available to indicate whether psoriatic arthritis (PsA) is part of the spondyloarthropathy (SpA) concept, whether it is a separate disease entity or a heterogeneous disease group with oligoarticular/axial forms belonging to SpA and polyarticular forms resembling rheumatoid arthritis (RA). To address this issue with regard to peripheral synovitis, we compared the synovial characteristics of PsA with those of ankylosing spondylitis (AS)/undifferentiated SpA (USpA) and RA, and compared the synovium of oligoarticular versus polyarticular PsA. Synovial biopsies were obtained from patients with RA, nonpsoriatic SpA (AS + USpA), and oligoarticular and polyarticular PsA. The histological analysis included examination(s) of the lining layer thickness, vascularity, cellular infiltration, lymphoid aggregates, plasma cells and neutrophils. Also, we performed immunohistochemical assessments of CD3, CD4, CD8, CD20, CD38, CD138, CD68, CD163, CD83, CD1a, CD146, αVβ3, E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, S100A12, intracellular citrullinated proteins and major histocompatibility complex (MHC)–human cartilage (HC) gp39 peptide complexes. Comparing SpA (PsA + AS + USpA) with RA, vascularity, and neutrophil and CD163+ macrophage counts were greater in SpA (P < 0.05), whereas lining layer thickness and the number of CD83+ dendritic cells were greater in RA (P < 0.05). In RA, 44% of samples exhibited positive staining for intracellular citrullinated proteins and 46% for MHC–HC gp39 peptide complexes, whereas no staining for these markers was observed in SpA samples. We excluded influences of disease-modifying antirheumatic drug and/or corticosteroid treatment by conducting systematic analyses of treated and untreated subgroups. Focusing on PsA, no significant differences were observed between PsA and nonpsoriatic SpA. In contrast, vascularity (P < 0.001) and neutrophils were increased in PsA as compared with RA (P = 0.010), whereas staining for intracellular citrullinated proteins and MHC–HC gp39 peptide complexes was exclusively observed in RA (both P = 0.001), indicating that the same discriminating features are found in PsA and other SpA subtypes compared with RA. Exploring synovial histopathology between oligoarticular and polyarticular PsA, no significant differences were noted. Moreover, intracellular citrullinated proteins and MHC–HC gp39 peptide complexes, which are specific markers for RA, were observed in neither oligoarticular nor polyarticular PsA. Taken together, these data indicate that the synovial histopathology of PsA, either oligoarticular or polyarticular, resembles that of other SpA subtypes, whereas both groups can be differentiated from RA on the basis of these same synovial features, suggesting that peripheral synovitis in PsA belongs to the SpA concept.

Considering the relation between synovial inflammation and global disease activity in rheumatoid arthritis (RA) and the distinct but heterogeneous histology of spondyloarthropathy (SpA) synovitis, the present study analyzed whether histopathological features of synovium reflect specific phenotypes and/or global disease activity in SpA. Synovial biopsies obtained from 99 SpA and 86 RA patients with active knee synovitis were analyzed for 15 histological and immunohistochemical markers. Correlations with swollen joint count, serum C-reactive protein concentrations, and erythrocyte sedimentation rate were analyzed using classical and multiparameter statistics. SpA synovitis was characterized by higher vascularity and infiltration with CD163+ macrophages and polymorphonuclear leukocytes (PMNs) and by lower values for lining-layer hyperplasia, lymphoid aggregates, CD1a+ cells, intracellular citrullinated proteins, and MHC–HC gp39 complexes than RA synovitis. Unsupervised clustering of the SpA samples based on synovial features identified two separate clusters that both contained different SpA subtypes but were significantly differentiated by concentration of C-reactive protein and erythrocyte sedimentation rate. Global disease activity in SpA correlated significantly with lining-layer hyperplasia as well as with inflammatory infiltration with macrophages, especially the CD163+ subset, and with PMNs. Accordingly, supervised clustering using these synovial parameters identified a cluster of 20 SpA patients with significantly higher disease activity, and this finding was confirmed in an independent SpA cohort. However, multiparameter models based on synovial histopathology were relatively poor predictors of disease activity in individual patients. In conclusion, these data indicate that inflammatory infiltration of the synovium with CD163+ macrophages and PMNs as well as lining-layer hyperplasia reflect global disease activity in SpA, independently of the SpA subtype. These data support a prominent role for innate immune cells in SpA synovitis and warrant further evaluation of synovial histopathology as a surrogate marker in early-phase therapeutic trials in SpA.

Blocking tumor necrosis factor-α either with monoclonal antibodies or with soluble receptor constructs has been proven to be effective with an acceptable safety profile in patients with rheumatoid arthritis, and more recently also in the diseases belonging to the spondyloarthropathy concept. Nevertheless multiple questions still remain unresolved especially concerning longer-term treatment. Data from a recent manuscript by Baraliakos and colleagues seem to indicate that at least for the vast majority of ankylosing spondylitis patients treatment with infliximab can not be withdrawn, if one wants to control disease activity in a continuous way. Although still unproven, this might be of crucial importance with regard to structure modification and prevention of ankylosis in this chronic inflammatory disorder.

This study is based on an expanded access program in which 511 patients suffering from active refractory rheumatoid arthritis (RA) were treated with intravenous infusions of infliximab (3 mg/kg+methotrexate (MTX)) at weeks 0, 2, 6 and every 8 weeks thereafter. At week 22, 474 patients were still in follow-up, of whom 102 (21.5%), who were not optimally responding to treatment, received a dose increase from week 30 onward. We aimed to build a model to discriminate the decision to give a dose increase. This decision was based on the treating rheumatologist's clinical judgment and therefore can be considered as a clinical measure of insufficient response. Different single and composite measures at weeks 0, 6, 14 and 22, and their differences over time were taken into account for the model building. Ranking of the continuous variables based on areas under the curve of receiver-operating characteristic (ROC) curve analysis, displayed the momentary DAS28 (Disease Activity Score including a 28-joint count) as the most important discriminating variable. Subsequently, we proved that the response scores and the changes over time were less important than the momentary evaluations to discriminate the physician's decision. The final model we thus obtained was a model with only slightly better discriminative characteristics than the DAS28. Finally, we fitted a discriminant function using the single variables of the DAS28. This displayed similar scores and coefficients as the DAS28. In conclusion, we evaluated different variables and models to discriminate the treating rheumatologist's decision to increase the dose of infliximab (+MTX), which indicates an insufficient response to infliximab at 3 mg/kg in patients with RA. We proved that the momentary DAS28 score correlates best with this decision and demonstrated the robustness of the score and the coefficients of the DAS28 in a cohort of RA patients under infliximab therapy.