Rheumatoid Arthritis: De Keyser F

De Rycke L, Baeten D, Kruithof E, Van den Bosch F, Veys EM, De Keyser F. · Department of Rheumatology, Ghent University Hospital, Ghent, Belgium. · Lupus. · Pubmed #16425572 No free full text.

Abstract: Since the first proof of efficacy of TNFalpha blockade, both the number of patients treated worldwide and the number of indications for treatment with TNFalpha blockers have grown steadily. Surprisingly, the profound immunomodulation induced by anti-TNFalpha therapy is associated with a relatively low incidence of immune-related complications such as lupus-like syndromes and demyelinating disease. This contrasts sharply with the prominent induction of autoantibodies such as antinuclear antibodies (ANA) and anti-dsDNA antibodies during TNFalpha blockade. Although this phenomenon has been recognized for several years, the clinical and biological implications are not yet fully understood. In this review, recent studies analysing the effect of TNFalpha blockade (infliximab and etanercept) on the ANA profile in autoimmune arthritis will be discussed. Taken together, these reports indicate that the prominent ANA and anti-dsDNA autoantibody response is 1) not a pure class effect of TNFalpha blockers, 2) independent of the disease background, 3) largely restricted to the induction of short-term IgM anti-dsDNA antibodies, and 4) not associated with other serological or clinically relevant signs of lupus. Nevertheless, a careful follow-up of patients treated with TNFalpha blockers remains mandatory, including monitoring for lupus-like characteristics.

Vander Cruyssen B, Peene I, Cantaert T, Hoffman IE, De Rycke L, Veys EM, De Keyser F. · Department of Rheumatology, Ghent University Hospital, B-9000 Gent, Belgium. · Autoimmun Rev. · Pubmed #16137613 No free full text.

Abstract: Anti-citrullinated protein/peptide antibodies (ACPA) are highly specific and sensitive markers for rheumatoid arthritis (RA). For instance, for the anti-CCP2 assay, sensitivities ranging from 55% to 80% and specificities ranging from 90% to 98% have been reported. Despite their high specificity, recent reports have suggested that ACPA may be found in some patients with other rheumatic autoimmune diseases, including psoriatic arthritis, systemic lupus erythematosus and Sjögren's syndrome. Also, the differences between the classical rheumatoid factor (RF) and ACPA, as well as the complementarity between both tests have recently been demonstrated more clearly. Indeed, both antibody systems have a different association with specific RA features like extra-articular manifestations, a different association with the HLA shared epitope and, behave differently following anti-TNF therapy.

Van den Bosch F, De Keyser F, Mielants H, Veys EM. · University Hospital, Department of Rheumatology, Gent, Belgium. · Arthritis Res Ther. · Pubmed #15899063 links to  free full text

Abstract: Blocking tumor necrosis factor-alpha 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.

Peene I, De Rycke L, Baeten D, Hoffman I, Veys EM, De Keyser F. · Department of Rheumatology, University Hospital of Gent, Belgium. · Int J Immunopathol Pharmacol. · Pubmed #15171811 No free full text.

Abstract: Rheumatoid arthritis is a chronic inflammatory joint disease characterized by the presence of autoantibodies. The best known autoantibody is the rheumatoid factor. Another group of antibodies directed against citrullinated epitopes is proven to be more specific for rheumatoid arthritis. This review gives an overview of the history of the different anti-citrullinated protein antibody detection methods and their diagnostic and prognostic properties in RA.

Wittkowski H, Foell D, af Klint E, De Rycke L, De Keyser F, Frosch M, Ulfgren AK, Roth J. · Interdisciplinary Centre of Clinical Research, University of Münster, Röntgenstr. 21, D-48149 Münster, Germany. · Ann Rheum Dis. · Pubmed #17223658 No free full text.

Abstract: OBJECTIVE: The pro-inflammatory calcium-binding protein S100A12 has been recently ascribed to the novel group of damage associated molecular pattern (DAMP) molecules. Serum levels of S100A12 reflect neutrophil activation during synovial inflammation. The aim of this project was to analyse the effect of intra-articular corticosteroids or systemic anti-TNF treatment on synovial expression and serum levels of S100A12 in rheumatoid arthritis (RA). METHODS: Serum and synovial tissue was obtained from 19 RA patients prior to and 2 weeks after intra-articular corticosteroid therapy. Serum was collected for 34 other patients, and in 14 of these patients synovial tissue was additionally obtained prior to and after 8 weeks of infliximab treatment. The expression of S100A12 was analysed by immunohistochemistry on frozen sections. Levels of S100A12 in serum were determined by ELISA. RESULTS: S100A12 serum levels were elevated in patients with active RA prior to therapy and decreased significantly in patients who responded to treatment in both patient groups, but not in non-responders. The synovial expression of S100A12 was reduced 2 weeks after successful intra-articular corticosteroid treatment. A similar decrease in local expression was found after 8 weeks of successful infliximab treatment. CONCLUSIONS: Successful treatment of RA leads to downregulation of the DAMP protein S100A12. Expression and secretion of S100A12 is rapidly diminished after therapy with intra-articular corticosteroids or infliximab. Taking these findings together, decreasing serum concentrations of S100A12 could reflect alleviated synovial neutrophil activation during successful anti-inflammatory therapy in RA.

Dendooven A, De Rycke L, Verhelst X, Mielants H, Veys EM, De Keyser F. · No affiliation provided · Ann Rheum Dis. · Pubmed #16699056 links to  free full text

This publication has no abstract.

De Rycke L, Vandooren B, Kruithof E, De Keyser F, Veys EM, Baeten D. · Ghent University Hospital, Ghent, Belgium. · Arthritis Rheum. · Pubmed #15986373 links to  free full text

Abstract: OBJECTIVE: Abnormal host defense against pathogens has been implicated in the pathogenesis of spondylarthropathy (SpA), a disease characterized by abundant synovial infiltration with innate immune cells. Given the role of Toll-like receptors (TLRs) in activation of innate inflammation and the occurrence of TLR-dependent infections after tumor necrosis factor alpha (TNFalpha) blockade treatment, the present study was undertaken to analyze TLRs and their modulation by TNFalpha blockade in SpA. METHODS: Peripheral blood mononuclear cells (PBMCs) were obtained from SpA and rheumatoid arthritis (RA) patients during infliximab therapy, and from healthy controls. TLR-2 and TLR-4 expression and TNFalpha production upon lipopolysaccharide (LPS) stimulation were analyzed by flow cytometry on different monocyte subsets. Synovial biopsy specimens from 23 SpA patients before and after infliximab or etanercept treatment, from 15 RA patients, and from 18 osteoarthritis (OA) patients were analyzed by immunohistochemistry. RESULTS: Expression of TLR-4, but not TLR-2, was increased on PBMCs from patients with SpA, whereas both TLRs were increased in RA patients. TLR expression was particularly increased on the CD163+ macrophage subset. Infliximab reduced TLR-2 and TLR-4 expression on monocytes of SpA and RA patients, leading to lower levels than in controls and to impaired TNFalpha production upon LPS stimulation. In inflamed synovium, the expression of both TLRs and of CD163 was significantly higher in patients with SpA than in those with RA or OA. Paralleling the systemic effect, TLRs in synovium were down-regulated following treatment with infliximab as well as etanercept, indicating a class effect of TNFalpha blockers. CONCLUSION: Inflammation in SpA is characterized by increased TLR-2 and TLR-4 expression, which is sharply reduced by TNFalpha blockade. These findings suggest a potential role of innate immunity-mediated inflammation in SpA and provide an additional clue regarding the mechanism of action as well as the potential side effects of TNFalpha blockade.

De Rycke L, Baeten D, Kruithof E, Van den Bosch F, Veys EM, De Keyser F. · Department of Rheumatology, Ghent University Hospital, Ghent, Belgium. · Arthritis Rheum. · Pubmed #15986349 links to  free full text

Abstract: OBJECTIVE: To analyze the clinical and biologic correlates of autoantibody induction during longer-term tumor necrosis factor alpha (TNFalpha) blockade with either the monoclonal antibody infliximab or the soluble receptor etanercept. METHODS: Thirty-four patients with spondylarthropathy (SpA) and 59 patients with rheumatoid arthritis (RA) were treated with infliximab for 2 years. Additionally, 20 patients with SpA were treated with etanercept for 1 year. Sera were blindly analyzed for antinuclear antibodies (ANAs), anti-double-stranded DNA (anti-dsDNA) antibodies, anti-extractable nuclear antigen (anti-ENA) antibodies, and antihistone, anti-nucleosome, and anticardiolipin antibodies (aCL). The anti-dsDNA antibodies were isotyped. RESULTS: High numbers of infliximab-treated patients with SpA or RA had newly induced ANAs (61.8% and 40.7%, respectively) and anti-dsDNA antibodies (70.6% and 49.2%, respectively) after 1 year, but no further increase between year 1 and year 2 was observed. In contrast, induction of ANAs and anti-dsDNA antibodies was observed only occasionally in the etanercept-treated patients with SpA (10% of patients each). Isotyping revealed almost exclusively IgM or IgM/IgA anti-dsDNA antibodies, which disappeared upon interruption of treatment. Neither infliximab nor etanercept induced other lupus-related reactivities such as anti-ENA antibodies, antihistone antibodies, or anti-nucleosome antibodies, and no clinically relevant lupus-like symptoms were observed. Similarly, infliximab but not etanercept selectively increased IgM but not IgG aCL titers. CONCLUSION: The prominent ANA and anti-dsDNA autoantibody response is not a pure class effect of TNFalpha blockers, is largely restricted to short-term IgM responses, and is not associated with other serologic or clinical signs of lupus. Similar findings with aCL suggest that modulation of humoral immunity may be a more general feature of infliximab treatment.

De Rycke L, Kruithof E, Van Damme N, Hoffman IE, Van den Bossche N, Van den Bosch F, Veys EM, De Keyser F. · Ghent University Hospital, Belgium. · Arthritis Rheum. · Pubmed #12687543 links to  free full text

Abstract: OBJECTIVE: To investigate the effect of infliximab treatment on antinuclear antibodies (ANAs), anti-double-stranded DNA (anti-dsDNA), antinucleosome, antihistone, and anti-extractable nuclear antigen (anti-ENA) antibodies in rheumatoid arthritis (RA) and spondylarthropathy (SpA) patients. METHODS: Sera from 62 RA and 35 SpA patients treated with infliximab were tested at baseline and week 30 (RA group) or week 34 (SpA group). ANAs were tested by indirect immunofluorescence (IIF) on HEp-2 cells. Anti-dsDNA antibodies were detected by IIF on Crithidia luciliae and by enzyme-linked immunosorbent assay (ELISA) and were further isotyped with gamma, mu, and alpha chain-specific conjugates at various time points. Antinucleosome antibodies were tested by ELISA. Antihistone and anti-ENA antibodies were detected by line immunoassay. RESULTS: Initially, 32 of 62 RA patients and 6 of 35 SpA patients tested positive for ANAs. After infliximab treatment, these numbers shifted to 51 of 62 (P < 0.001) and 31 of 35 (P < 0.001), respectively. At baseline, none of the RA or SpA patients had anti-dsDNA antibodies. After infliximab treatment, 7 RA patients (P = 0.016) and 6 SpA patients (P = 0.031) became positive for anti-dsDNA antibodies. All 7 anti-dsDNA-positive RA patients had IgM and IgA anti-dsDNA antibodies. Three of the 6 anti-dsDNA-positive SpA patients had IgM and IgA anti-dsDNA antibodies, and 2 had IgM anti-dsDNA antibodies alone. In both diseases, the IgM anti-dsDNA antibodies appeared before the IgA anti-dsDNA antibodies. During the observation period, no IgG anti-dsDNA antibodies or lupus symptoms were observed. The development of antinucleosome, antihistone, or anti-ENA antibodies following infliximab treatment was observed in some patients, but the numbers were not statistically significant. CONCLUSION: Infliximab treatment may induce ANAs, and especially IgM and IgA anti-dsDNA antibodies, in RA and SpA patients. However, no anti-dsDNA IgG antibodies or lupus symptoms were observed during the period of observation in this study, and the development of antinucleosome, antihistone, or anti-ENA antibodies was not statistically significant. These observations do not exclude potential induction of clinically significant lupus in the long term, and further followup is therefore mandatory.

VanderBorght A, De Keyser F, Geusens P, De Backer M, Malaise M, Baeten D, Van den Bosch F, Veys EM, Raus J, Stinissen P. · Biomedisch Onderzoeksinstituut DWI, Limburgs Universitair Centrum, Diepenbeek, Belgium. · J Rheumatol. · Pubmed #11908552 No free full text.

Abstract: OBJECTIVE: To study T cell receptor (TCR) repertoire changes in synovial membrane over a 16 week period in patients with early rheumatoid arthritis (RA); and to study the influence of cyclosporin A (CSA) on TCR repertoire in a subgroup of these patients. METHODS: Synovial tissue biopsies and paired blood samples were obtained from 12 patients with early RA at 2 time points. Seven patients were treated with CSA (Neoral-Sandimmun, 3 mg/kg/day) and 5 patients with placebo for 16 weeks. TCR V gene repertoires were analyzed by semiquantitative PCR-ELISA. CDR3 spectratyping and sequence analysis was used to compare TCR clonotype distributions. RESULTS: TCR-specific mRNA was detected in all synovial tissue biopsies at the first sampling, but in only 8/12 biopsies 16 weeks later (4/7 CSA group, 4/5 placebo group). Overrepresented TCR BV genes were found in biopsies of 10/12 patients at the first time point, and in 7/12 patients after 16 weeks (3/7 CSA, 4/5 placebo). CDR3 sequence analysis revealed dynamic repertoire changes with only a few persisting clonotypes in the synovial tissue of placebo controls. Persisting T cell clonotypes were more frequently found in the synovial tissue of CSA treated patients compared to the placebo group. CONCLUSION: These data suggest a dynamic process of T cell recruitment in the joints of RA patients. This process, possibly due to activation and subsequent infiltration of new T cell clones, apparently is influenced by CSA treatment. Synovial tissue T cells were no longer detected after 16 weeks' CSA treatment in 3 patients. In the other CSA treated patients, new T cell clones infiltrated, while other clones were persistently represented in the joints. These data may have important consequences for the design of T cell targeted therapies for RA.

Baeten D, Van den Bosch F, Elewaut D, Stuer A, Veys EM, De Keyser F. · Department of Rheumatology, University of Ghent, University Hospital of Ghent, Belgium. · Clin Rheumatol. · Pubmed #10638766 No free full text.

Abstract: Needle arthroscopy is an office-based technique allowing direct visualisation of the knee cavity and selective sampling of the synovial membrane. We performed needle arthroscopy in 150 patients with synovitis of the knee (1) to evaluate the diagnostic potential in early arthritis, (2) to perform therapeutic lavage in persistent inflammatory synovitis and (3) to assess the balance between technical feasibility, safety and patient comfort on the one hand, and the relevance of the obtained macro- and microscopic information for diagnosis and research purposes on the other. After disinfection of the leg and local anaesthesia of the skin and joint, a 1.8-2.7 mm needle arthroscope was introduced into the knee. Synovial fluid was aspirated and lavage of the joint cavity was performed to allow macroscopic evaluation of hyperaemia and hypertrophy of the synovial membrane. Biopsies were taken at inflamed sites, followed by another lavage to remove blood and debris. Needle arthroscopy of the knee is a simple and easy to perform technique made particularly attractive by the local anaesthesia and the ambulatory setting. It allows good macroscopic evaluation of synovial inflammation and selective sampling of the synovial membrane. Biopsies are suitable for RNA and DNA extraction, bacterial or lymphocyte culture, and cell isolation. Because samples were sometimes too small for representative histology, we switched from a 1.8 mm to a 2.7 mm biopsy forceps with good results. In nearly all cases the arthroscopy was well tolerated. Moreover, some patients reported relief of symptoms and even improvement of mobility after lavage of the inflamed joint. No major complications were noted. It was concluded that needle arthroscopy of the knee is a simple, safe and well-tolerated technique, with promising perspectives as a diagnostic, scientific and possibly therapeutic tool in rheumatic diseases.

Van Beneden K, Coppieters K, Laroy W, De Keyser F, Hoffman IE, Van den Bosch F, Vander Cruyssen B, Drennan M, Jacques P, Rottiers P, Verbruggen G, Contreras R, Callewaert N, Elewaut D. · Department of Rheumatology, Laboratory of Molecular Immunology and Inflammation, Ghent University Hospital, 0K12 IB, De Pintelaan 185, B-9000 Ghent, Belgium. · Ann Rheum Dis. · Pubmed #18772190 No free full text.

Abstract: OBJECTIVES: Improved DNA sequencer-aided fluorophore-assisted carbohydrate electrophoresis (DSA-FACE) technology was used to monitor the changes in the galactosylation status of serum immunoglobulins during the immune response and therapy of autoimmune arthritis. METHODS: Collagen-induced arthritis (CIA) was induced in susceptible DBA/1 mice and the undergalactosylation status (UGS) of serum immunoglobulins was determined using the improved DSA-FACE technology. Prophylactic intravenous tolerisation with type II collagen as well as semitherapeutic treatment with dexamethasone (DEX) were performed and UGS was analysed. Next, the serum immunoglobulin glycosylation profiles of patients with rheumatoid arthritis (RA) and spondyloarthropathy (SpA) were studied and changes in the UGS scores during anti-tumour necrosis factor (TNF)alpha therapy followed. RESULTS: In the longitudinal CIA study, the undergalactosylation state of immunoglobulins was found to be significantly correlated with the clinical arthritis scores. Upon collagen-specific tolerisation as well as glucocorticoid semitherapeutic treatment, improvement of the clinical arthritis scores correlated with decreased levels of UGS. It was also demonstrated that withdrawal of DEX was associated with an increased UGS score. Interestingly, reversibility in the UGS was also shown during treatment of patients with RA and SpA with anti-TNFalpha. CONCLUSIONS: These findings demonstrate that the UGS of serum immunoglobulins changes during the disease course of CIA and that this UGS is inhibited by antigen-specific and antigen-independent treatment procedures. The observation that Ig galactosylation is a reversible process is also documented during treatment of patients with RA and SpA with anti-TNFalpha.

Vandooren B, Cantaert T, van Lierop MJ, Bos E, De Rycke L, Veys EM, De Keyser F, Bresnihan B, Luyten FP, Verdonk PC, Tak PP, Boots AH, Baeten D. · Academic Medical Center/University of Amsterdam, The Netherlands. · Ann Rheum Dis. · Pubmed #18633128 No free full text.

Abstract: OBJECTIVE: In mice, melanoma inhibitory activity (MIA) is a chondrocyte-specific molecule with similar regulation to collagen type II. As MIA is a small secreted protein, its value as cartilage biomarker in human inflammatory arthritis was assessed. METHODS: MIA tissue distribution was studied by quantitative PCR and immunohistochemistry. The regulation of MIA production was studied in vivo in rheumatoid arthritis (RA) (n = 37) and spondyloarthritis (SpA) (n = 30) synovial fluid (SF), and in vitro in alginate embedded human chondrocytes. Therapeutic modulation of serum MIA was evaluated during tumour necrosis factor (TNF)alpha and interleukin (IL)1 blockade in RA. RESULTS: MIA was primarily expressed by chondrocytes in the human joint. SF MIA levels were lower in RA than in SpA despite similar levels of overall synovial inflammation. Further analysis indicated that these levels were inversely correlated with the degree of joint inflammation in RA, but not in SpA, and that the levels of TNFalpha and IL1beta were significantly increased in RA versus SpA. Accordingly, these proinflammatory cytokines suppressed MIA mRNA and protein in cultured chondrocytes. This suppression was paralleled by suppression of cartilage anabolism as assessed by collagen type 2 and aggrecan mRNA. Treatment of patients with RA with TNF blockade or IL1 blockade induced an increase of serum MIA levels. CONCLUSION: The decreased levels of MIA in the inflamed RA joint and the coregulation of MIA and cartilage matrix molecules by proinflammatory cytokines indicate that joint inflammation in RA not only drives accelerated cartilage degradation but also suppresses cartilage anabolism. This inflammation-driven suppression is reversible in vivo.

Tilleman K, Van Steendam K, Cantaert T, De Keyser F, Elewaut D, Deforce D. · Laboratory for Pharmaceutical Biotechnology, Ghent University, Harelbekestraat 72, B- 9000 Ghent, Belgium. · Rheumatology (Oxford). · Pubmed #18326534 links to  free full text

Abstract: OBJECTIVES: To investigate the presence and characteristics of citrullinated vimentin in protein extracts of inflamed synovial tissue. METHODS: Cytosolic protein extracts obtained from RA (n = 14) and SpA patients (n = 14) were analysed by gel electrophoresis and western blotting. Citrullinated vimentin isoforms were visualized by a combination of anti-modified citrulline (AMC) staining and anti-vimentin detections (V9, H-84). This was subsequently confirmed by immunoprecipitation. Autoantibody detection was verified using sera obtained form RA (n = 6) and SpA (n = 6) patients. RESULTS: A specific cluster of spots displayed on the 2D gel images of cytosolic synovial tissue extracts, was identified by mass spectrometry as vimentin. Interestingly, our results suggested that these isoforms could be the result of caspase cleavage. In addition, these cleaved forms of vimentin were found to be citrullinated in synovial cytosolic protein extracts of inflammatory arthritides, mainly in RA patients. Caspase-3 is able to cleave vimentin at amino acid 85. Western blot analysis with a specific antibody against amino acids 1-84 of vimentin (H-84) confirmed that the citrullinated isoforms of vimentin were lacking this part of the protein. These results were also confirmed by immunoprecipitation of vimentin derived from cytosolic protein extracts of RA and SpA patients. Furthermore, the presence of autoantibodies against these citrullinated processed forms of vimentin was found to be predominantly associated with RA patients. CONCLUSIONS: These findings show the presence of processed citrullinated vimentin in inflammatory arthritides, mainly in RA and suggest a possible origin of the ACPA immune response in RA.

Vander Cruyssen B, Nuytinck L, Boullart L, Elewaut D, Waegeman W, Van Thielen M, De Meester E, Lebeer K, Rossau R, De Keyser F. · Department of Rheumatology, Ghent University Hospital, B-9000 Ghent, Belgium. · Rheumatology (Oxford). · Pubmed #18032536 No free full text.

Abstract: OBJECTIVES: We investigated the possible association of rheumatoid arthritis (RA) with single nucleotide polymorphisms (SNP) within the ficolin (FCN) genes. Two SNPs in the FCN1 gene, four SNPs in the FCN2 gene and one SNP in the FCN3 gene were studied. METHODS: The SNPs within the FCN genes were detected by an experimental INNO-LiPA methodology (Innogenetics, Belgium) in a population consisting of 338 RA patients and 595 controls. The significant SNPs were further evaluated in two subpopulations and related to carriage of the human leukocyte antigen-shared epitope (HLA-SE), rheumatoid factor (RF) and the presence of anti-citrullinated protein/peptide antibodies (ACPA). RESULTS: Two SNPs in the FCN1 gene were significantly associated with RA: the A allele rs2989727 was significantly increased in RA patients (67%) compared with controls (60%) (P = 0.002). Also, the frequency of the G allele of rs1071583 was increased in RA patients (68%) compared with controls (61%) (P = 0.003). Analysis of agreement between SNPs suggested strong linkage between rs2989727 and rs1071583. Carriage of a FCN1 SNP was independent of carriage of the HLA-SE, RF status and ACPA positivity. CONCLUSIONS: We describe two linked SNPs in the FCN1 gene that are associated with the development of RA.

Vander Cruyssen B, Miltenburg AM, Van den Bosch F, Houbiers JG, Wittoek R, Boots AM, De Keyser F. · Ghent University, Gent, Belgium. · J Rheumatol. · Pubmed #17924607 No free full text.

Abstract: OBJECTIVE: To evaluate whether the baseline presence of rheumatoid arthritis (RA)-associated biomarkers could define subgroups of patients that are more prone to show a spontaneous decrease of RA disease activity. In a previous placebo-controlled phase II trial that failed to show any superiority of the experimental compound versus placebo, a remarkable decrease of such disease activity was observed despite the lack of effective treatment. METHODS: A subgroup of 83 disease modifying antirheumatic drug-naive RA patients with disease duration < 3 years was analyzed. Rheumatoid factor (RF), anti-citrullinated protein/peptide antibodies (ACPA), and HLA shared epitope (SE) were determined at baseline. RESULTS: RF-positive patients tended to have higher levels of disease activity at baseline compared to RF-negative patients [Disease Activity Score (DAS) 6.12 vs 5.65, p = 0.02 at screening], but the decrease in disease activity was similar in both subgroups (DAS -1.23 vs -1.07). In contrast, ACPA-positive patients showed similar baseline disease activity scores compared to ACPA-negative patients, but tended to show a smaller decrease of disease activity than patients without ACPA (Delta DAS -1.53 vs -0.79, p = 0.013). Presence of the HLA-SE seemed not to have any effect on the baseline DAS or on the spontaneous decrease of DAS. CONCLUSION: The predictive value of baseline RA-associated biomarkers for spontaneous decrease of disease activity under placebo or ineffective treatment is limited. Yet the data analyzed here might be useful for the design of future placebo-controlled trials in RA.

Vander Cruyssen B, Nogueira L, Van Praet J, Deforce D, Elewaut D, Serre G, De Keyser F. · Department of Rheumatology, Ghent University Hospital, B-9000 Gent, Belgium. · Ann Rheum Dis. · Pubmed #17644546 No free full text.

Abstract: BACKGROUND: Different methods exist to demonstrate anti-citrullinated protein/peptide antibodies (ACPA). AIMS: To evaluate discrepancy between four ACPA tests. PATIENTS AND METHODS: Population 1 consisted of patients with a new diagnostic problem, including 86 patients with rheumatoid arthritis (RA) and 450 patients without RA. Population 2 consisted of 155 patients with RA who had long-standing disease. Population 3 consisted of 188 patients with psoriatic arthritis and in population 4 there were 192 patients with systemic lupus erythematosus. Populations 1 and 2 were tested with the anti-human fibrinogen antibody (AhfibA) test, anti-CCP2 from Eurodiagnostica (CCP2-euro), anti-CCP2 from Pharmacia (CCP2-phar) and anti-CCP3 test by Inova (CCP3). Samples were annotated as discrepant if positive in one and negative in at least one other test. Each discrepant sample was re-analysed in a different run. Populations 3 and 4 were analysed in the CCP2-euro and AhFibA test. RESULTS: In population 1, ACPA positivity was found in 17 of 450 (3.8%) patients without RA; 14 (82%) of these 17 samples were discrepant. In contrast, 61 of 86 (70.9%) patients with RA were ACPA positive of whom 18 of 61 (29.5%) were discrepant (70.9% vs. 29.5%, p<0.001). The discrepancies between tests could be partly attributed to borderline results, inter-assay discrepancy and inter-test variability. They were more prevalent in patients with systemic lupus erythematosus who were ACPA positive than in those with psoriatic arthritis who were ACPA positive. CONCLUSIONS: Discrepancy between different ACPA tests was observed attributable to the occurrence of borderline results, inter-assay variability and mainly to inter-test variability. The lowest inter-test discrepancy is observed between tests that use the same substrate.

van Lierop MJ, den Hoed L, Houbiers J, Vencovsky J, Ruzickova S, Krystufkova O, van Schaardenburg M, van den Hoogen F, Vandooren B, Baeten D, De Keyser F, Sønderstrup G, Bos E, Boots AM. · Organon NV, Oss, The Netherlands. · Arthritis Rheum. · Pubmed #17599744 links to  free full text

Abstract: OBJECTIVE: The cartilage proteins melanoma inhibitory activity (MIA) and human cartilage gp-39 (HC gp-39) are candidate autoantigens in rheumatoid arthritis (RA). The present study was undertaken to investigate the endogenous HLA-DR4-restricted presentation of these self proteins, in order to seek in vivo evidence in support of their potential immunologic role. METHODS: MIA and HC gp-39 were assessed in synovial fluid (SF) by enzyme-linked immunosorbent assay and in synovial tissue (ST) by immunohistochemistry. Presentation by SF cells was investigated using specific, HLA-DR-restricted T cell hybridomas. RESULTS: MIA and HC gp-39 were detected in RA SF and ST, as well as in specimens from patients with other forms of arthritis. When HC gp-39-specific and MIA-specific HLA-DR4-restricted T cell hybridomas raised in HLA-DR4-transgenic mice were incubated with RA SF cells as antigen-presenting cells in the presence of HC gp-39 or MIA peptides, the corresponding T cell hybridomas showed strong responses, which were blocked by anti-HLA-DR antibodies. Weaker but qualitatively similar responses were observed with exogenous protein, indicating uptake and processing of these antigens by SF cells. More importantly, without addition of peptide or protein, endogenous presentation of MIA and HC gp-39 was detected in SF cells from 53% and 80% of HLA-DRB1*0401-positive RA patients, respectively. In addition, SF cells from 3 of 10 patients with spondylarthritis exhibited endogenous HC gp-39 presentation. CONCLUSION: These data indicate that immunodominant epitopes of MIA and HC gp-39 are actively presented in an HLA-DR-restricted manner in the inflamed RA joint. The question remains as to whether this leads to activation of autoreactive T cells, which could play a role in either the immunopathology or the immunomodulation of arthritis.

Vander Cruyssen B, Van Looy S, Wyns B, Westhovens R, Durez P, Van den Bosch F, Mielants H, De Clerck L, Peretz A, Malaise M, Verbruggen L, Vastesaeger N, Geldhof A, Boullart L, De Keyser F. · Department of Rheumatology, Ghent University Hospital, B-9000 Gent, Belgium. · Arthritis Res Ther. · Pubmed #16978395 links to  free full text

Abstract: Although there is strong evidence supporting the short-term efficacy and safety of anti-tumour necrosis factor-alpha 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.

Vander Cruyssen B, Cantaert T, Nogueira L, Clavel C, De Rycke L, Dendoven A, Sebag M, Deforce D, Vincent C, Elewaut D, Serre G, De Keyser F. · Department of Rheumatology, Ghent University Hospital, Ghent, Belgium. · Arthritis Res Ther. · Pubmed #16859515 links to  free full text

Abstract: 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.

Vander Cruyssen B, Hoffman IE, Peene I, Union A, Mielants H, Meheus L, De Keyser F. · Department of Rheumatology, Ghent University Hospital, B-9000 Ghent, Belgium. · Ann Rheum Dis. · Pubmed #16840502 No free full text.

Abstract: OBJECTIVES: To calculate the probabilities for rheumatoid arthritis in a consecutive cohort of patients during diagnostic investigation. Different logistic regression models evaluating the value of human leucocyte antigen (HLA)-shared epitope determination and testing for rheumatoid factor and anti-citrullinated protein/peptide antibodies (ACPA) were fitted. METHODS: 1003 consecutive patients were included in the study, presenting a new diagnostic problem for which rheumatoid arthritis was included in the differential diagnosis. All patients were tested for ACPA, rheumatoid factor and HLA-shared epitope. RESULTS: After 1 year, diagnoses were established: 153 patients had definite rheumatoid arthritis and 629 patients had rheumatoid arthritis excluded. Rheumatoid factor, used as a continuous marker, is useful in evaluating the probability for rheumatoid arthritis. Combined rheumatoid factor and shared epitope testing may provide additional predictive information, but combined ACPA and rheumatoid factor testing is superior. The redundancy of shared epitope testing in a model that includes ACPA testing can be explained by the high association between ACPA and shared epitope both in patients with rheumatoid arthritis and in those with non-rheumatoid arthritis. The value of rheumatoid factor testing increased if patients presented with at least one swollen joint at baseline. CONCLUSION: Valid probabilities for rheumatoid arthritis during routine diagnostic investigation were calculated, and showed that the potential additional value of shared epitope testing disappears when ACPA testing is available. Combined rheumatoid factor and ACPA testing is useful, especially when rheumatoid factor is considered as a continuous parameter reflecting an increasing probability for rheumatoid arthritis at higher rheumatoid factor titres. The value of (continuous) rheumatoid factor testing increases when the a priori chance is higher.

Baeten D, Houbiers J, Kruithof E, Vandooren B, Van den Bosch F, Boots AM, Veys EM, Miltenburg AM, De Keyser F. · Clinical Immunology and Rheumatology, Academic Medical Centre University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. · Ann Rheum Dis. · Pubmed #16414969 links to  free full text

Abstract: OBJECTIVES: To determine the impact on synovial histopathology of changes in clinical disease activity in the absence of effective treatment. METHODS: Twelve patients with active RA not receiving effective treatment were studied over a 14 week period. Synovial biopsy specimens obtained at baseline and week 14 were analysed by histology and immunohistochemistry. RESULTS: Over the course of 14 weeks, there was a trend towards a decrease of the DAS28, with 7/12 patients being good or moderate DAS28 responders despite the absence of effective treatment. Patients' assessment of global disease activity and swollen joint count both decreased significantly. Histologically, there was a decrease of lining layer hyperplasia and lymphoid aggregates, a similar trend for vascularity, but there was no effect on global synovial infiltration. Accordingly, there was no decrease of the cellular infiltration with T lymphocytes (CD3, CD4, CD8), B lymphocytes (CD20), plasma cells (CD38), dendritic cells (CD1a, CD83), and even an increase of CD163+ sublining macrophages, with a similar trend for CD68+ sublining macrophages. The changes in DAS28 scores in these patients did not correlate with changes in histological variables, with the exception of an inverse correlation with plasma cells. Remarkably, even in the DAS28 responders, no significant changes in synovial inflammatory infiltration were noted. CONCLUSIONS: Despite variations in global disease activity, synovial inflammatory infiltration did not change significantly in the absence of effective treatment. The lack of a placebo effect on synovial markers of treatment response such as sublining macrophages can facilitate conclusive early phase trials with small numbers of patients with RA.

Vander Cruyssen B, Van Looy S, Wyns B, Westhovens R, Durez P, Van den Bosch F, Veys EM, Mielants H, De Clerck L, Peretz A, Malaise M, Verbruggen L, Vastesaeger N, Geldhof A, Boullart L, De Keyser F. · Department of Rheumatology, Ghent University Hospital, Belgium. · Arthritis Res Ther. · Pubmed #16207323 links to  free full text

Abstract: 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.

Dewint P, Hoffman IE, Rogge S, Joos R, Union A, Dehoorne J, Delanghe J, Veys EM, De Keyser F, Elewaut D. · Department of Rheumatology, Ghent University Hospital, De Pintelaan 185, 9000 Gent, Belgium. · Rheumatology (Oxford). · Pubmed #16188943 links to  free full text

Abstract: OBJECTIVES: Anticitrullinated protein/peptide antibodies (ACPA) have an excellent diagnostic performance for rheumatoid arthritis (RA). Despite similarities between RA and polyarticular juvenile idiopathic arthritis (JIA), the prevalence of ACPA in polyarticular JIA is low. We wanted to evaluate the influence of age, disease duration and total immunoglobulin G (IgG) concentration on ACPA positivity in this cohort. METHODS: Patients with JIA were classified according to age and International League of Associations for Rheumatology classification. Sixty-one JIA patients aged less than 16 yr were included and classified as polyarticular JIA (poly JIA <16; n=23) or non-polyarticular JIA (n=38). In addition, a group of 21 polyarticular JIA patients, aged more than 16 yr (poly JIA >16) and a group of 51 RA patients were included. Antibodies to the synthetic citrullinated peptides pepA and pepB were detected by line immunoassay and antibodies to cyclic citrullinated peptides (CCP2) by enzyme-linked immunosorbent assay. Serum IgG was measured by fixed-time immunonephelometry. RESULTS: No ACPA reactivity was observed in the non-polyarticular group. In poly JIA <16, only 1/23 had anti-CCP2 antibody, whereas in poly JIA >16 patients a significantly higher fraction was detected (6/21). All but one of the anti-CCP2 reactive patients were rheumatoid factor (RF) positive. Assessing anti-CCP2 antibody concentration as a continuous variable, significantly higher titres were found in poly JIA >16 compared with poly JIA <16. No correlation between anti-CCP2 concentration and total IgG was detected. Four patients demonstrated immunoreactivity against pepA and pepB; all of them were anti-CCP2 reactive, poly JIA >16 patients. CONCLUSIONS: ACPA are present in low prevalence in polyarticular JIA and are particularly found in the RF-positive subset. With age, a significant increase in anti-CCP2 positivity is observed in polyarticular JIA patients.

De Rycke L, Nicholas AP, Cantaert T, Kruithof E, Echols JD, Vandekerckhove B, Veys EM, De Keyser F, Baeten D. · Ghent University Hospital, Belgium. · Arthritis Rheum. · Pubmed #16052592 links to  free full text

Abstract: OBJECTIVE: To address the ongoing debate concerning the specificity of synovial citrullinated proteins for rheumatoid arthritis (RA) and to analyze their pathophysiologic relevance to the induction or perpetuation of the RA-specific anti-citrullinated protein antibodies (ACPAs). METHODS: Synovium of 19 RA patients and 19 non-RA controls was immunostained for the presence of citrullinated proteins with a mouse monoclonal antibody (F95), for the citrullinating enzyme peptidyl arginine deiminase type 2 (PAD-2), and for the free citrulline-producing enzyme inducible nitric oxide synthase (iNOS). Extending the RA cohort to 61 patients, the findings of anticitrulline staining in synovium were related to serum and synovial fluid ACPA levels, as measured by enzyme-linked immunosorbent assay. RESULTS: F95 staining indicated the presence of synovial intracellular citrullinated proteins in 53% of RA samples versus 5% of control samples, whereas extracellular staining was not RA specific. Immunoblotting and inhibition experiments confirmed that the antibody recognized citrullinated proteins but not free citrulline. Accordingly, iNOS was equally found in RA and control synovium and in intracellular citrullinated protein-positive and intracellular citrullinated protein-negative samples. In contrast, intracellular citrullinated proteins colocalized with PAD-2, which was found in 59% of RA samples versus 17% of control samples. Independent of local disease activity, the presence of the RA-specific synovial intracellular citrullinated proteins was associated with significantly higher systemic and local ACPA levels and with local ACPA production in the joint. CONCLUSION: These data confirm the presence of RA-specific intracellular citrullinated proteins in synovium. The link with PAD-2 and local and systemic ACPA levels emphasizes their pathophysiologic relevance for RA-specific humoral autoimmunity.