Arthritis Research最新文献

Osteoporosis (OP) and osteoarthritis (OA), the two most common age-related chronic disorders of articular joints and skeleton, represent a major public health problem in most developed countries. They are influenced by environmental factors and exhibit a strong genetic component. Large population studies clearly show their inverse relationship; therefore, an accurate analysis of the genetic bases of one of these two diseases may provide data of interest for the other disorder. The discovery of risk and protective genes for OP and OA promises to revolutionize strategies for diagnosing and treating these disorders. The primary goal of this symposium was to bring together scientists and clinicians working on OP and OA in order to identify the most promising and collaborative approaches for the coming decade. This meeting put into focus the importance of an adequate genetic approach to several areas of research: the search for the genetic determinants underlying new susceptibilities, the optimization of previously acquired data; the establishment of correlations between genetic polymorphism and functional variants, and gene-gene and gene-environment interactions (particularly those between genes and nutrients). An adequate genetic approach is also essential with regard to determining more selective criteria for phenotypic definition of familial OP, in order to obtain more homogeneous and statistically powerful family-based studies. The symposium concluded with an interesting overview of the future perspectives offered by DNA microarray technologies for identifying novel candidate genes, for developing proteomics and bioinformatics analyses and for designing low-cost clinical trials.

The 3rd Annual EULAR Congress, held in Stockholm on 12-15 June 2002, had a turnout of 8300 delegates, almost identical to last year's record attendance level in Prague. The venue was close to ideal, allowing ample space for poster sessions in the exhibition hall. The manned poster sessions were well attended, even on the last day of the Congress. The numerous invited speakers represented the world's elite, allowing the staging of excellent state-of-the-art podium sessions. The aim of attracting the young scientific community was partly achieved, but individual delegates' dependence on industry sponsorship poses potential problems. The organization was a big improvement compared to that of the two previous congresses. Approximately 1800 abstracts were submitted, an increase of 50%, resulting in a higher quality of accepted abstracts. The satellite symposia held every morning and late afternoon were well attended; thus, industry exposure of new products, both in podium sessions and at the exhibitions, was well accommodated. The Annual EULAR Congress consolidates its position as one of the two most important annual congresses of rheumatology, but EULAR economy and commercial aspects are still too dominant in relation to science.

To confirm an association between cytomegalovirus (CMV) infection and the presence of antibodies to Smith (Sm), to ribonucleoprotein (RNP), and to a component of the U1 ribonucleoproteins (U1-70 kD), we measured antibodies to these protein antigens using an enzyme immunoassay and an immunoblot. The antibodies were measured in the sera of 80 healthy subjects, one-half of whom were naturally CMV seropositive and one-half were CMV seronegative, and in eight subjects immunized with a live attenuated strain of CMV. None of the vaccinees developed antibodies to Sm, to RNP, or to U1-70 kD at either 4 or 12 months after immunization. Additionally, there was no statistically significant association between levels of antibodies to Sm or to RNP and between sera obtained from vaccinees, natural CMV seropositive individuals, and CMV seronegative individuals. One CMV seropositive serum and one CMV seronegative serum tested positive for antibodies to U1-70 kD. These data indicate that neither wild-type infection nor the live-attenuated Towne vaccine frequently induce autoantibody production.

Anti-tumor-necrosis-factor-alpha (TNF-alpha) monoclonal antibody was used to treat Tg197 transgenic mice, which constitutively produce human TNF-alpha (hTNF-alpha) and develop a progressive polyarthritic disease. Treatment of both young (7- or 8-week-old) and aged (27- or 28-week-old) mice commenced when at least two limbs showed signs of moderate to severe arthritis. The therapeutic efficacy of anti-TNF-alpha antibody was assessed using various pathological indicators of disease progression. The clinical severity of arthritis in Tg197 mice was significantly reduced after anti-TNF-alpha treatment in comparison with saline-treated mice and in comparison with baseline assessments in both young and aged mice. The treatment with anti-TNF-alpha prevented loss of body weight. Inflammatory pathways as reflected by elevated circulating hTNF-alpha and local expression of various proinflammatory mediators were all diminished by anti-TNF-alpha treatment, confirming a critical role of hTNF-alpha in this model of progressive polyarthritis. More importantly, the amelioration of the disease was associated with reversal of existing structural damage, including synovitis and periosteal bone erosions evident on histology. Repair of cartilage was age dependent: reversal of cartilage degradation after anti-TNF-alpha treatment was observed in young mice but not in aged mice.

Osteoarthritis (OA), one of the most common age-related chronic disorders of articular cartilage, joints, and bone tissue, represents a major public health problem. Genetic studies have identified multiple gene variations associated with an increased risk of OA. These findings suggest that there is a large genetic component to OA and that the disorder belongs in the multigenetic, multifactorial class of genetic diseases. Studies of chondrodysplasias and associated hereditary OA have provided a better understanding of the role of structural genes in the maintenance and repair of articular cartilage, in the regulation of chondrocyte proliferation and gene expression, and in the pathogenesis of OA.

T-cell responses to antigens are classified on the basis of the cytokines they produce as either Th1 (IFN-gamma, IL-2) or Th2 (IL-4, IL-10), with these Th types being indicative of either cell-mediated or antibody-mediated responses, respectively. Using this classification, T-cell responses in MHC-class-II-restricted autoimmune diseases appear to be predominantly of the Th1 type, based on the presence of high levels of IFN-gamma. This simplistic classification has recently been challenged, however, as disease incidence and severity are frequently elevated in animals that have a deficient IFN-gamma response. The recent data discussed here indicate that the cytokine circuits involved in the regulation of cell-mediated and humoral immune responses during the development of autoimmune arthritis are more complex than originally proposed; perhaps our characterization of autoimmune responses as strictly Th1 or Th2 is overly simplistic, especially as it pertains to the role of IFN-gamma.

Interleukin (IL)-12, being a major cytokine that induces T helper (Th) 1 differentiation and inflammatory response, has been postulated to be an important mediator of synovial inflammation in rheumatoid arthritis (RA). However, the regulation of IL-12 production in RA has not been elucidated. Our knowledge is mainly based on studies of the production of IL-12p40 and not the functional IL-12p70 heterodimer. We have studied the CD154-induced IL-12p40 and IL-12p70 production by synovial fluid (SF) macrophages from patients with RA. CD40 ligation induced the secretion of IL-12p40 but not IL-12p70. The observed increase in IL-10 and tumor necrosis factor (TNF)-alpha production indicated that SF macrophages responded to CD40 ligation. The expression of p40 mRNA was increased significantly and remained upregulated after CD40 ligation, whereas the increase of p35 transcript expression was observed only transiently and at a lower level. We further observed that dendritic cells (DCs) derived in vitro from SF macrophages produced IL-12p70. Most importantly, IL-4 and IL-13 primed SF macrophages to produce IL-12p70, whereas IFN-gamma was not observed to activate IL-12p70 production in these cells, in contrast with normal peripheral blood monocytes. These results provide novel information about the regulation of IL-12p70 production and the function of the cytokine network in RA.

Studies have established the magnitude of the genetic basis of juvenile idiopathic arthritis (JIA). JIA is a complex genetic condition and the genes that influence susceptibility are actively being sought. A candidate gene approach is being used by several groups. MHC-, cytokine- and T-cell-related genes have all been positively associated with JIA. Here we review some of the latest genetic data, and discuss ways in which JIA genetic research might proceed.

Nurse-like stromal cell lines from the synovial tissue of patients with rheumatoid arthritis (RA-SNC) produce, on coculture with lymphocytes, large amounts of proinflammatory cytokines. In the present paper, we analyze the molecular events necessary for the induction of cytokine release from RA-SNC cells, and particularly the roles played by cell adhesion and the transmigration (also known as pseudoemperipolesis) of lymphocytes. For this purpose, the effects of various mAbs on the binding and transmigration of a human B-cell line, MC/car, were examined using a cloned RA-SNC line, RA-SNC77. To analyze the role of lymphocyte binding and transmigration on upregulated cytokine production by the RA-SNC77 cells, we used C3 exoenzyme-treated MC/car cells, which could bind to RA-SNC77 cells but could not transmigrate. Treatment with anti-CD29 or anti-CD49d mAb significantly reduced binding and transmigration of the MC/car cells. In contrast, the neutralizing anti-CD106/vascular cell adhesion molecule 1 mAb did not show any inhibitory effect. Likewise, none of the neutralizing mAbs against CD11a, CD18, CD44, CD49e, or CD54 showed significant effects. Binding of C3-treated or untreated MC/car cells to RA-SNC77 cells induced comparable levels of IL-6 and IL-8 production. In addition, the enhanced cytokine production by RA-SNC77 cells required direct lymphocyte contact via a very late antigen-4 (VLA-4)-independent adhesion pathway. These results indicate that, although both the VLA-4-dependent/vascular cell adhesion molecule 1-independent and the VLA4-independent adhesion pathways are involved in MC/car binding and subsequent transmigration, only the VLA4-independent adhesion pathway is necessary and sufficient for the enhanced proinflammatory cytokine production by RA-SNC77 cells. The transmigration process, which is dependent on Rho-GTPase, is not a prerequisite for this phenomenon.

Rheumatoid arthritis (RA) patients experience a markedly increased frequency of cardiovascular disease. We evaluated cardiovascular risk profiles in 79 RA patients and in 39 age-matched and sex-matched osteoarthritis (OA) patients. Laboratory tests comprised ultrasensitive C-reactive protein (CRP) and fasting lipids. Insulin sensitivity (IS) was determined by the Quantitative Insulin Sensitivity Check Index (QUICKI) in all OA patients and in 39 of the RA patients. Ten RA patients were on glucocorticoids. RA patients exercised more frequently than OA patients (chi2 = 3.9, P < 0.05). Nine RA patients and one OA patient had diabetes (chi2 = 4.5, P < 0.05). The median CRP, the mean QUICKI and the mean high-density lipoprotein (HDL) cholesterol were 9 mg/l (range, 0.5-395 mg/l), 0.344 (95% confidence interval [CI], 0.332-0.355) and 1.40 mmol/l (95% CI, 1.30-1.49 mmol/l) in RA patients, respectively, as compared with 2.7 mg/l (range, 0.3-15.9 mg/l), 0.369 (95% CI, 0.356-0.383) and 1.68 mmol/l (95% CI, 1.50-1.85 mmol/l) in OA patients. Each of these differences was significant (P < 0.05). After controlling for the CRP, the QUICKI was similar in RA and OA patients (P = 0.07), while the differences in HDL cholesterol were attenuated but still significant (P = 0.03). The CRP correlated with IS, while IS was associated with high HDL cholesterol and low triglycerides in RA patients and not in OA patients. A high CRP (>/= 8 mg/l) was associated with hypertension (chi2 = 7.4, P < 0.05) in RA patients. RA glucocorticoid and nonglucocorticoid users did not differ in IS and lipids (P > 0.05). Excess cardiovascular risk in RA patients as compared with OA patients includes the presence of decreased IS and HDL cholesterol in RA patients. The latter is only partially attributable to the acute phase response. The CRP, IS, HDL cholesterol, triglycerides and hypertension are inter-related in RA patients, whereas none of these relationships were found in OA patients.