Arthritis Research & Therapy

Zwerina, Jochen;Tuerk, Birgit;Redlich, Kurt;Smolen, Josef S;Schett, Georg

doi: 10.1186/ar1872pmid: 16507121

Abstract Chronic arthritis typically leads to loss of periarticular bone, which results from an imbalance between bone formation and bone resorption. Recent research has focused on the role of osteoclastogenesis and bone resorption in arthritis. Bone resorption cannot be observed isolated, however, since it is closely linked to bone formation and altered bone formation may also affect inflammatory bone loss. To simultaneously assess bone resorption and bone formation in inflammatory arthritis, we developed a histological technique that allows visualization of osteoblast function by in-situ hybridization for osteocalcin and osteoclast function by histochemistry for tartrate-resistant acid phosphatase. Paw sections from human tumor necrosis factor transgenic mice, which develop an erosive arthritis, were analyzed at three different skeletal sites: subchondral bone erosions, adjacent cortical bone channels, and endosteal regions distant from bone erosions. In subchondral bone erosions, osteoclasts were far more common than osteoblasts. In contrast, cortical bone channels underneath subchondral bone erosions showed an accumulation of osteoclasts but also of functional osteoblasts resembling a status of high bone turnover. In contrast, more distant skeletal sites showed only very low bone turnover with few scattered osteoclasts and osteoblasts. Within subchondral bone erosions, osteoclasts populated the subchondral as well as the inner wall, whereas osteoblasts were almost exclusively found along the cortical surface. Blockade of tumor necrosis factor reversed the negative balance of bone turnover, leading to a reduction of osteoclast numbers and enhanced osteoblast numbers, whereas the blockade of osteoclastogenesis by osteoprotegerin also abrogated the osteoblastic response. These data indicate that bone resorption dominates at skeletal sites close to synovial inflammatory tissue, whereas bone formation is induced at more distant sites attempting to counter-regulate bone resorption.

Chinoy, Hector;Salway, Fiona;Fertig, Noreen;Shephard, Neil;Tait, Brian D;Thomson, Wendy;Isenberg, David A;Oddis, Chester V;Silman, Alan J;Ollier, William ER;Cooper, Robert G

doi: 10.1186/ar1862pmid: 16507114

Abstract The aim of this study was to investigate HLA class II associations in polymyositis (PM) and dermatomyositis (DM), and to determine how these associations influence clinical and serological differences. DNA samples were obtained from 225 UK Caucasian idiopathic inflammatory myopathy patients (PM = 117, DM = 108) and compared with 537 randomly selected UK Caucasian controls. All cases had also been assessed for the presence of related malignancy and interstitial lung disease (ILD), and a number of myositis-specific/myositis-associated antibodies (MSAs/MAAs). Subjects were genotyped for HLA-DRB1, DQA1 and DQB1. HLA-DRB1*03, DQA1*05 and DQB1*02 were associated with an increased risk for both PM and DM. The HLA-DRB1*03-DQA1*05-DQB1*02 haplotype demonstrated strong association with ILD, irrespective of myositis subtype or presence of anti-aminoacyl-transfer RNA synthetase antibodies. The HLA-DRB1*07-DQA1*02-DQB1*02 haplotype was associated with risk for anti-Mi-2 antibodies, and discriminated PM from DM (odds ratio 0.3, 95% confidence interval 0.1–0.6), even in anti-Mi-2 negative patients. Other MSA/MAAs showed specific associations with other HLA class II haplotypes, irrespective of myositis subtype. There were no genotype, haplotype or serological associations with malignancy. The HLA-DRB1*03-DQA1*05-DQB1*02 haplotype associations appear to not only govern disease susceptibility in Caucasian PM/DM patients, but also phenotypic features common to PM/DM. Though strongly associated with anti-Mi-2 antibodies, the HLA-DRB1*07-DQA1*02-DQB1*02 haplotype shows differential associations with PM/DM disease susceptibility. In conclusion, these findings support the notion that myositis patients with differing myositis serology have different immunogenetic profiles, and that these profiles may define specific myositis subtypes.

Hückel, Marion;Schurigt, Uta;Wagner, Andreas H;Stöckigt, Renate;Petrow, Peter K;Thoss, Klaus;Gajda, Mieczyslaw;Henzgen, Steffen;Hecker, Markus;Bräuer, Rolf

doi: 10.1186/ar1869pmid: 16507120

Abstract The transcription factor STAT-1 (signal transducer and activator of transcription-1) plays a pivotal role in the expression of inflammatory gene products involved in the pathogenesis of arthritis such as various cytokines and the CD40/CD40 ligand (CD40/CD40L) receptor-ligand dyad. The therapeutic efficacy of a synthetic decoy oligodeoxynucleotide (ODN) binding and neutralizing STAT-1 was tested in murine antigen-induced arthritis (AIA) as a model for human rheumatoid arthritis (RA). The STAT-1 decoy ODN was injected intra-articularly in methylated bovine serum albumin (mBSA)-immunized mice 4 h before arthritis induction. Arthritis was evaluated by joint swelling measurement and histological evaluation and compared to treatment with mutant control ODN. Serum levels of pro-inflammatory cytokines, mBSA-specific antibodies and auto-antibodies against matrix constituents were assessed by enzyme-linked immunosorbent assay (ELISA). The transcription factor neutralizing efficacy of the STAT-1 decoy ODN was verified in vitro in cultured synoviocytes and macrophages. Single administration of STAT-1 decoy ODN dose-dependently suppressed joint swelling and histological signs of acute and chronic arthritis. Delayed-type hypersensitivity (DTH) reaction, serum levels of interleukin-6 (IL-6) and anti-proteoglycan IgG titres were significantly reduced in STAT-1 decoy ODN-treated mice, whereas mBSA, collagen type I and type II specific immunoglobulins were not significantly affected. Intra-articular administration of an anti-CD40L (anti-CD154) antibody was similarly effective. Electrophoretic mobility shift analysis (EMSA) of nuclear extracts from synoviocytes incubated with the STAT-1 decoy ODN in vitro revealed an inhibitory effect on STAT-1. Furthermore, the STAT-1 decoy ODN inhibited the expression of CD40 mRNA in stimulated macrophages. The beneficial effects of the STAT-1 decoy ODN in experimental arthritis presumably mediated in part by affecting CD40 signalling in macrophages may provide the basis for a novel treatment of human RA.

Atzeni, Fabiola;Sarzi-Puttini, Piercarlo;Acqua, Donata Dell';de Portu, Simona;Cecchini, Germana;Cruini, Carola;Carrabba, Mario;Meroni, Pier Luigi

doi: 10.1186/ar1851pmid: 16356192

Abstract Studies on autoantibody production in patients treated with tumor necrosis factor-α (TNF-α) inhibitors reported contradictory results. We investigated in a prospective study the efficacy of a treatment with human monoclonal anti-TNF-α antibody (adalimumab) in patients with rheumatoid arthritis (RA) and we evaluated the relationship between treatment efficacy and the incidence and titers of disease-associated and non-organ-specific autoantibodies. Fifty-seven patients with RA not responsive to methotrexate and treated with adalimumab were enrolled. Antinuclear, anti-double-stranded(ds)DNA, anti-extractable nuclear antigens, anti-cardiolipin (aCL), anti-β2 glycoprotein I (anti-β2GPI) autoantibodies, rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) autoantibodies were investigated at baseline and after 6 and 12 months of follow-up. Comparable parameters were evaluated in a further 55 patients treated with methotrexate only. Treatment with adalimumab induced a significant decrease in RF and anti-CCP serum levels, and the decrease in antibody titers correlated with the clinical response to the therapy. A significant induction of antinuclear autoantibodies (ANA) and IgG/IgM anti-dsDNA autoantibodies were also found in 28% and 14.6% patients, respectively, whereas aCL and anti-β2GPI autoantibodies were not detected in significant quantities. No association between ANA, anti-dsDNA, aCL and anti-β2GPI autoantibodies and clinical manifestations was found. Clinical efficacy of adalimumab is associated with the decrease in RF and anti-CCP serum levels that was detected after 24 weeks and remained stable until the 48th week of treatment. Antinuclear and anti-dsDNA autoantibodies, but not anti-phospholipid autoantibodies, can be induced by adalimumab but to a lower extent than in studies with other anti-TNF blocking agents.

Aletaha, Daniel

doi: 10.1186/ar1870pmid: 16542465

Abstract Several pooled indices for the assessment of rheumatoid arthritis disease activity are available to rheumatologists. Face and criterion validity of these instruments can be assessed by determining the association of their measurements with opinions of physicians. Several confounding aspects must be considered in such analyses, especially blinding of the person(s) making the decisions to the instruments being studied and to the objective of the study in general. From several studies in the literature, there is currently no evidence that any one of the available composite indices is better or worse than any other. The choice of index in clinical practice should ideally be based on practical considerations related to the needs of the rheumatologist in the respective health care setting.

Fritsch, Christine;Hoebeke, Johan;Dali, Hayet;Ricchiuti, Vincent;Isenberg, David A;Meyer, Olivier;Muller, Sylviane

doi: 10.1186/ar1848pmid: 16356190

Abstract Neonatal lupus erythematosus is a rare disorder caused by the transplacental passage of maternal autoantibodies. The 52-kDa Ro/SSA antigen (Ro52) ribonucleoprotein represents an antigenic target strongly associated with the autoimmune response in mothers whose children have neonatal lupus and cardiac conduction disturbances, mainly congenital heart block. The objective of this study was to identify putative Ro52/60-kDa Ro/SSA antigen (Ro60) epitopes associated with neonatal lupus and congenital heart block. The reactivity of IgG antibodies present in the sera from mothers with systemic lupus erythematosus and Sjögren's syndrome and in the sera from asymptomatic mothers (a longitudinal study of 192 samples from 66 subjects) was investigated by ELISA using Ro52, Ro60 and 48-kDa La/SSB antigen proteins, as well as 45 synthetic peptides, 13–24 residues long, of Ro52/Ro60 proteins. One to 19 samples collected before, during and after pregnancy were available for each mother. Forty-three disease controls selected randomly and normal sera were tested in parallel. Although no differences were found between Sjögren's syndrome and asymptomatic mothers of group I, who had at least one infant with neonatal lupus, and of group II, who had healthy babies only, significant differences were observed between lupus mothers from both groups. In the former group of lupus mothers, a significantly higher frequency of antibodies to Ro52 peptides 107–122 and 277–292 was observed. Between 18 and 30 weeks of gestation, the period of risk, there was clearly an elevated level of antibodies reacting with Ro52 peptides 1–13, 277–292 and 365–382. Antibodies to Ro52 peptide 365–382 have been shown previously to cross-react with residues 165–185 of the heart 5-HT4 serotoninergic receptor, and might be pathologically important. The level of these Ro52 antibody subsets decreased at the end of pregnancy and after delivery. IgG antibodies to Ro52 peptides 1–13, 107–122, 277–292 and 365–382 may therefore represent important biomarkers to predict a complication in pregnant lupus women with Ro52 antibodies.

Jongbloed, Sarah L;Lebre, M Cristina;Fraser, Alasdair R;Gracie, J Alastair;Sturrock, Roger D;Tak, Paul P;McInnes, Iain B

doi: 10.1186/ar1864pmid: 16507115

Abstract Dendritic cells (DCs) comprise heterogeneous subsets of professional antigen-presenting cells, linking innate and adaptive immunity. Analysis of DC subsets has been hampered by a lack of specific DC markers and reliable quantitation assays. We characterised the immunophenotype and functional characteristics of psoriatic arthritis (PsA)-derived and rheumatoid arthritis (RA)-derived myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) to evaluate their potential role in arthritis. Circulating peripheral blood (PB) pDC numbers were significantly reduced in PsA patients (P = 0.0098) and RA patients (P = 0.0194), and mDCs were significantly reduced in RA patients (P = 0.0086) compared with healthy controls. The number of circulating mDCs in RA PB was significantly inversely correlated to C-reactive protein (P = 0.021). The phenotype of both DC subsets in PsA PB and RA PB was immature as compared with healthy controls. Moreover, CD62L expression was significantly decreased on both mDCs (PsA, P = 0.0122; RA, P = 0.0371) and pDCs (PsA, P = 0.0373; RA, P = 0.0367) in PB. Both mDCs and pDCs were present in PsA synovial fluid (SF) and RA SF, with the mDC:pDC ratio significantly exceeding that in matched PB (PsA SF, P = 0.0453; RA SF, P = 0.0082). pDCs isolated from RA SF and PsA SF displayed an immature phenotype comparable with PB pDCs. RA and PsA SF mDCs, however, displayed a more mature phenotype (increased expression of CD80, CD83 and CD86) compared with PB mDCs. Functional analysis revealed that both SF DC subsets matured following toll-like receptor stimulation. pDCs from PB and SF produced interferon alpha and tumour necrosis factor alpha on TLR9 stimulation, but only SF pDCs produced IL-10. Similarly, mDCs from PB and SF produced similar tumour necrosis factor alpha levels to TLR2 agonism, whereas SF mDCs produced more IL-10 than PB controls. Circulating DC subset numbers are reduced in RA PB and PsA PB with reduced CD62L expression. Maturation is incomplete in the inflamed synovial compartment. Immature DCs in SF may contribute to the perpetuation of inflammation via sampling of the inflamed synovial environment, and in situ presentation of arthritogenic antigen.

Moore, R Andrew;Derry, Sheena;Makinson, Geoffrey T;McQuay, Henry J

doi: 10.1186/ar1866pmid: N/A

Thieme, Kati;Turk, Dennis C

doi: 10.1186/ar1863pmid: 16356200

Abstract Dysregulated psychophysiological responses have been observed in patients with fibromyalgia syndrome (FMS), although the results are inconsistent. Surface electromyographic (EMG), systolic and diastolic blood pressure, heart rate (HR), and skin conductance levels (SCLs) were continuously recorded at baseline, and during a series of stress and relaxation tasks in 90 FMS patients and 30 age and sex matched healthy controls (HCs). The patient sample demonstrated lower baseline EMG levels compared to the HCs on all tasks. In contrast, the patients displayed elevated HR and SCL (sympathetic vasomotor and sudomotor indices, respectively) during both stress tasks. A cluster analysis identified four psychophysiological response patterns: 63.3% of HCs showed increased muscle tension and stable cardiovascular responses; 34.8% of FMS patients showed a pattern of increased sympathetic vasomotor reactivity with stable sudomotor and reduced muscular response; 12.2% of FMS patients showed a pattern of increased sympathetic sudomotor reactivity connected with increased sympathetic vasomotor response and reduced muscular response; and, in contrast, 46.7% of FMS patients showed a pattern of parasympathetic vasomotor reactivity and reduced sudomotor as well as muscular response. The identification of low baseline muscle tension in FMS is discrepant with other chronic pain syndromes and suggests that unique psychophysiological features may be associated with FMS. The different psychophysiological response patterns within the patient sample support the heterogeneity of FMS.

Reddi, A Hari

doi: 10.1186/ar1858pmid: 16356196

Abstract Osteoarthritis is a common malady of the musculoskeletal system affecting the articular cartilage. The increased frequency of osteoarthritis with aging indicates the complex etiology of this disease, which includes pathophysiology and joint stability including biomechanics. The balance between anabolic morphogens and growth factors and catabolic cytokines is at the crux of the problem of osteoarthritis. One such signal is transforming growth factor-β (TGF-β). The impaired TGF-β signaling has been identified as a culprit in old mice in a recent article in this journal. This commentary places this discovery in the context of anabolic and catabolic signals and articular cartilage homeostasis in the joint.