Properties of the International Classification for Functioning, Disability and Health in assessing hand outcomes in patients with rheumatoid arthritis

OBJECTIVES

Variables from a study of patients with rheumatoid arthritis were linked to the International Classification of Functioning, Disability and Health (ICF) Core Set for rheumatoid arthritis. The purpose of this analysis was to evaluate the ICF Core Sets for rheumatoid arthritis for assessing the functional outcomes of the rheumatoid hand.

DESIGN

Prospective cohort.

SUBJECTS

A total of 142 subjects with rheumatoid arthritis.

METHODS

Patients who elected to have or not have arthroplasty were linked with the ICF Core Sets. Study variables were assigned into one of the Core Set blocks that compose the ICF model. The blocks were then entered into multiple regression models to determine the contribution of each block in explaining the variation in hand outcome at enrollment, as well as the change in hand outcome after one year.

RESULTS

Seventy percent of the reported hand outcome at enrollment was explained by the ICF Core Set blocks. For change in hand outcome at one year, the ICF Core Set blocks measured at enrollment explained 18% of the variance.

CONCLUSION

The components of the ICF Core Set for rheumatoid arthritis explained much of the variation in hand functioning for patients with rheumatoid arthritis, but were not predictive of the change in hand functioning after one year.

Are Th17 cells an appropriate new target in the treatment of rheumatoid arthritis?

Th17 cells play crucial roles not only in host defense but also in many human autoimmune diseases and corresponding animal models. Although many of the fundamental principles regarding Th17 biology have been rapidly elucidated in mice, there remain numerous controversies regarding the differentiation, plasticity, and pathogenicity of human Th17 cells. In this review, we consider these open questions in comparison to what has already been clarified in mice, and discuss the potential impact of discoveries related to the Th17 pathway on the development of new therapeutic strategies in Th17 driven autoimmune diseases, specifically rheumatoid arthritis.

Historical perspective on the etiology of rheumatoid arthritis

Contributions of historical analyses to the development of a cogent etiologic theory of rheumatoid arthritis (RA) have been limited to date. In this article, the authors analyze this literature with respect to the types and conclusions of the research that has been conducted, present the major points of evidence and conclusions that have been drawn, and trace the evolution of 3 historical theories of RA. The authors combine a comprehensive overview of paintings and paleopathological investigations with consideration of contemporary immunologic and genetic studies.

Pharmacotherapy: concepts of pathogenesis and emerging treatments. Co-stimulation and T cells as therapeutic targets

Full activation and differentiation of resting T cells into effector T cells requires at least two signals, the first through engagement of the T cell antigen receptor (TCR) by the antigen-major histocompatibility complex (MHC) on antigen-presenting cells (APCs), and the second by engagement of co-stimulatory molecules such as CD28, on T cells by ligands such as CD80/86 on APCs. Effector T cell differentiation is associated with proliferation, secretion of cytokines and expression of additional surface molecules. These inducible structures may have stimulatory (ICOS, OX40 and 4-1BB) or inhibitory (cytotoxic T-lymphocyte antigen (CTLA)-4) potential. To the extent that T cells have a role in particular immune-mediated diseases, interruption of T cell co-stimulation is a potentially worthwhile approach to the treatment of those conditions. This article summarises the experience in treating rheumatological disease by perturbation of T cell co-stimulation, and also describes structures that could be future targets for this type of therapeutic approach.

Validity and responsiveness of the Michigan Hand Questionnaire in patients with rheumatoid arthritis: a multicenter, international study

OBJECTIVE

Millions of patients experience the disabling hand manifestations of rheumatoid arthritis (RA), yet few hand-specific instruments are validated in this population. Our objective was to assess the reliability, validity, and responsiveness of the Michigan Hand Questionnaire (MHQ) in patients with RA.

METHODS

At enrollment and at 6 months, 128 RA patients with severe subluxation of the metacarpophalangeal joints completed the MHQ, a 37-item questionnaire with 6 domains: function, activities of daily living (ADL), pain, work, aesthetics, and satisfaction. Reliability was measured using Spearman's correlation coefficients between time periods. Internal consistency was measured using Cronbach's alpha. Construct validity was measured by correlating MHQ responses with the Arthritis Impact Measurement Scales 2 (AIMS2). Responsiveness was measured by calculating standardized response means (SRMs) between time periods.

RESULTS

The MHQ demonstrated good test-retest reliability (r = 0.66, P < 0.001). Cronbach's alpha scores were high for ADL (α = 0.90), function (α = 0.87), aesthetics (α = 0.79), and satisfaction (α = 0.89), indicating redundancy. The MHQ correlated well with AIMS2 responses. Function (r = -0.63), ADL (r = -0.77), work (r = -0.64), pain (r = 0.59), and summary score (r = -0.74) were correlated with the physical domain. Affect was correlated with ADL (r = -0.47), work (r = -0.47), pain (r = 0.48), and summary score (r = -0.53). Responsiveness was excellent among arthroplasty patients in function (SRM 1.42), ADL (SRM 0.89), aesthetics (SRM 1.23), satisfaction (SRM 1.76), and summary score (SRM 1.61).

CONCLUSION

The MHQ is easily administered, reliable, and valid to measure rheumatoid hand function, and can be used to measure outcomes in rheumatic hand disease.

Outcomes of silicone arthroplasty for rheumatoid metacarpophalangeal joints stratified by fingers

PURPOSE

Previous studies have demonstrated that outcomes for the ulnar digits appear to be worse than those of the radial digits after silicone metacarpophalangeal joint arthroplasty (SMPA) for the rheumatoid hand. This study examines various components of hand deformities in an effort to understand SMPA outcomes in terms of metacarpophalangeal (MCP) joint range of motion and alignment. We hypothesize that the ulnar fingers will have less improvement, marked by greater ulnar drift, extension lag, and less MCP joint arc of motion than the radial fingers.

METHODS

Sixty-eight surgical patients were recruited from 3 sites in this multicenter, international prospective cohort study. All patients had a diagnosis of rheumatoid arthritis, were between the ages of 18 and 80, and were eligible to have SMPA based on measured hand deformities (extensor lag and ulnar drift). Ulnar drift, extension lag, and arc of motion for the MCP joint of each finger were measured at baseline (before surgery) and 1 year after SMPA.

RESULTS

All fingers showed an improvement in ulnar drift from baseline to 1 year after surgery. The smallest improvement was in the index finger, and the largest improvement was in the little finger. Similarly, the largest improvement in extension lag was seen in the little finger, and the smallest improvement was seen in the index finger. In terms of MCP joint arc of motion, all fingers moved to a more extended posture and gained an improved arc of motion, but the biggest improvement was observed in the 2 ulnar fingers and less in the 2 radial fingers.

CONCLUSIONS

Our hypothesis that the ulnar fingers would have worse outcomes than the radial fingers was not proven by this study. Although experiences have indicated that it is more difficult to maintain posture for the ring and little fingers after SMPA owing to the deforming forces, sufficient correction of the deformities in the ulnar fingers is possible, if adequate bone resection and realigning of the extensor mechanism are carefully performed during the procedure.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.

Regulation of pathogenic IL-17 responses in collagen-induced arthritis: roles of endogenous interferon-gamma and IL-4

INTRODUCTION

Interleukin (IL)-17 plays an important role in the pathogenesis of rheumatoid arthritis and the mouse model collagen-induced arthritis (CIA). Interferon(IFN)-gamma and IL-4 have been shown to suppress Th17 development in vitro, but their potential immunoregulatory roles in vivo are uncertain. The goals of this study were to determine the relationship between Th17 responses and disease severity in CIA and to assess regulation of IL-17 by endogenous IFN-gamma and IL-4.

METHODS

DBA1/LacJ mice were immunized with type II collagen in complete Freund's adjuvant (CFA) to induce arthritis, and treated with neutralizing antibody to IFN-gamma and/or IL-4. Systemic IL-17, IFN-gamma, and IL-4 were measured in serum. At the peak of disease, cytokine production was measured by ELISA of supernatants from spleen, lymph node and paw cultures. Paws were also scored for histologic severity of arthritis.

RESULTS

Joint inflammation was associated with a higher ratio of systemic IL-17/IFN-gamma. Neutralization of IFN-gamma accelerated the course of CIA and was associated with increased IL-17 levels in the serum and joints. The IFN-gamma/IL-4/IL-17 responses in the lymphoid organ were distinct from such responses in the joints. Neutralization of IL-4 led to increased arthritis only in the absence of IFN-gamma and was associated with increased bone and cartilage damage without an increase in the levels of IL-17.

CONCLUSIONS

IL-4 and IFN-gamma both play protective roles in CIA, but through different mechanisms. Our data suggests that the absolute level of IL-17 is not the only determinant of joint inflammation. Instead, the balance of Th1, Th2 and Th17 cytokines control the immune events leading to joint inflammation.

The role of T helper type 17 cells in inflammatory arthritis

While T cells have been implicated in the pathogenesis of inflammatory arthritis for more than three decades, the focus on the T helper type 17 (Th17) subset of CD4 T cells and their secreted cytokines, such as interleukin (IL)-17, is much more recent. Proinflammatory actions of IL-17 were first identified in the 1990s, but the delineation of a distinct Th17 subset in late 2005 has sparked great interest in the role of these cells in a broad range of immune-mediated diseases. This review summarizes current understanding of the role of Th17 cells and their products in both animal models of inflammatory arthritis and human immune-driven arthritides.

Reduced Fas ligand-expressing splenic CD5+ B lymphocytes in severe collagen-induced arthritis

Introduction

The objective was to study immune regulation in a mouse model of rheumatoid arthritis that exhibits considerable heterogeneity of disease activity.

Methods

T-cell receptor transgenic mice, in which nearly all CD4⁺ T cells recognize a single peptide of type II collagen, were immunized with collagen and observed for development of arthritis for 4 weeks. At 28 days post-immunization, splenocytes were analyzed by flow cytometry and in vitro assays for markers of immune activation and regulation.

Results

Disease severities ranging from 0 to 12 (on a 12-point scale) were observed. Among splenic lymphocyte populations, only the CD5⁺ B-cell subset displayed a decrease in relative numbers as arthritis severity increased. Splenic CD5⁺ B cells expressed higher levels of Fas ligand (FasL) than did CD4⁺ T cells or CD5^- B cells in all mice, and antigen-dependent T-cell death correlated with higher levels of CD5⁺ B cells in cocultures. Ratios of interleukin (IL)-17 to interferon-gamma production were higher in antigen-driven cultures of splenocytes from severely arthritic mice compared to mildly or nonarthritic mice. A correlation was established between the reduced production of IL-17 in antigen-driven T-cell/B-cell cocultures and FasL, but not IL-10. Confirmation of the direct killing effect of B cells on T cells was demonstrated using an antigen-specific T hybridoma cell line.

Conclusions

Reduced numbers of splenic FasL⁺ CD5⁺ B cells correlated with increasing arthritis severity and decreased T-cell death in a T-cell receptor transgenic mouse model of collagen-induced arthritis. These 'killer' B cells may provide a novel mechanism for inducing T-cell death as a treatment for arthritis.

Th17 cells in human disease

SUMMARY

Our understanding of the role of T cells in human disease is undergoing revision as a result of the discovery of T-helper 17 (Th17) cells, a unique CD4(+) T-cell subset characterized by production of interleukin-17 (IL-17). IL-17 is a highly inflammatory cytokine with robust effects on stromal cells in many tissues. Recent data in humans and mice suggest that Th17 cells play an important role in the pathogenesis of a diverse group of immune-mediated diseases, including psoriasis, rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, and asthma. Initial reports also propose a role for Th17 cells in tumorigenesis and transplant rejection. Important differences, as well as many similarities, are emerging when the biology of Th17 cells in the mouse is compared with corresponding phenomena in humans. As our understanding of human Th17 biology grows, the mechanisms underlying many diseases are becoming more apparent, resulting in a new appreciation for both previously known and more recently discovered cytokines, chemokines, and feedback mechanisms. Given the strong association between excessive Th17 activity and human disease, new therapeutic approaches targeting Th17 cells are highly promising, but the potential safety of such treatments may be limited by the role of these cells in normal host defenses against infection.

Th17 cells in human disease

SUMMARY

Our understanding of the role of T cells in human disease is undergoing revision as a result of the discovery of T-helper 17 (Th17) cells, a unique CD4(+) T-cell subset characterized by production of interleukin-17 (IL-17). IL-17 is a highly inflammatory cytokine with robust effects on stromal cells in many tissues. Recent data in humans and mice suggest that Th17 cells play an important role in the pathogenesis of a diverse group of immune-mediated diseases, including psoriasis, rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, and asthma. Initial reports also propose a role for Th17 cells in tumorigenesis and transplant rejection. Important differences, as well as many similarities, are emerging when the biology of Th17 cells in the mouse is compared with corresponding phenomena in humans. As our understanding of human Th17 biology grows, the mechanisms underlying many diseases are becoming more apparent, resulting in a new appreciation for both previously known and more recently discovered cytokines, chemokines, and feedback mechanisms. Given the strong association between excessive Th17 activity and human disease, new therapeutic approaches targeting Th17 cells are highly promising, but the potential safety of such treatments may be limited by the role of these cells in normal host defenses against infection.

Interactions of T cells with fibroblast-like synoviocytes: role of the B7 family costimulatory ligand B7-H3

Fibroblast-like synoviocytes (FLS) and T cells can activate each other in vitro, and in vivo interactions between these cells may be important in rheumatoid arthritis (RA), yet FLS lack significant expression of CD28 ligands. We sought to identify molecules homologous to CD28 ligands that are strongly expressed by FLS, and documented strong B7-H3 expression on FLS and by fibroblasts of other tissues, which was unaffected by a variety of cytokines. Western blot analysis of FLS lysates showed predominant expression of the larger, four Ig-like domain isoform of B7-H3. Immunohistological sections of RA synovial tissue showed strong staining for B7-H3 on FLS. Cells expressing B7-H3 were distinct from but in close proximity to cells that expressed CD45, CD20, and CD3. Confocal microscopy of FLS and T cell cocultures showed localization of B7-H3 in the region of the T cell-FLS contact point, but distinct from the localization of T cell CD11a/CD18 (LFA-1) and FLS CD54 (ICAM-1). Reduction of B7-H3 expression on FLS by RNA interference affected interactions of FLS with resting T cells or cytokine-activated T cells. Resting T cells showed increased production of TNF-alpha, IFN-gamma, and IL-2, whereas cytokine-activated T cells showed reduced cytokine production relative to control. However, cytokine production by T cells activated through their TCR was not notably altered by knock down of B7-H3. These observations suggest that B7-H3 may be important for the interactions between FLS and T cells in RA, as well as other diseases, and the outcome of such interactions depends on the activation state of the T cell.

CD19+CD5+ B cells in primary IgA nephropathy

The source of IgA and the mechanism for deposition of IgA in the mesangium remain unknown for primary IgA nephropathy. Because CD19(+)CD5(+) B cells are important producers of IgA and contribute to several autoimmune diseases, they may play an important role in IgA nephropathy. In this study, flow cytometry, quantitative PCR, and confocal microscopy were used to assess the frequency, distribution, Ig production, CD phenotypes, cytokine production, and sensitivity to apoptosis of CD19(+)CD5(+) B cells in the peripheral blood, peritoneal fluid, and kidney biopsies of 36 patients with primary IgA nephropathy. All patients with IgA nephropathy were significantly more likely to have CD19(+)CD5(+) B cells in the peripheral blood, peritoneal fluid, and kidney biopsies than were five control subjects and 10 patients with active systemic lupus erythematosus. The 33 patients who had IgA nephropathy and responded to treatment demonstrated a significant decrease in CD19(+)CD5(+) B cells in the peripheral blood, peritoneal fluid, and kidney (all P < 0.01). In the three patients who had IgA nephropathy and did not respond to treatment, the frequency of CD19(+)CD5(+) B cells did not change. CD19(+)CD5(+) B cells isolated from patients with untreated IgA nephropathy expressed higher levels of IgA, produced more IFN-gamma, and were more resistant to CD95L-induced apoptosis than cells isolated from control subjects and patients with lupus; these properties reversed with effective treatment of IgA nephropathy. In conclusion, these results strongly suggest that CD19(+)CD5(+) B cells play a prominent role in the pathogenesis of primary IgA nephropathy.

High-throughput profiling of ion channel activity in primary human lymphocytes

We present a high-throughput method to quantify the functional activity of potassium (K (+)) ion channels in primary human lymphocytes. This method is rapid, automated, specific (here for the voltage-gated Kv1.3 ion channel), and capable of measuring, in parallel, the electrical currents of over 200 individual lymphocytes isolated from freshly drawn blood. The statistics afforded by high-throughput measurements allowed direct comparison of Kv1.3 activity in different subsets of lymphocytes, including CD4 (+) and CD8 (+) T cells, gammadelta T cells, and B cells. High-throughput measurements made it possible to quantify the heterogeneous, functional response of Kv1.3 ion channel activity upon stimulation of CD4 (+) and CD8 (+) T cells with mitogen. These experiments enabled elucidation of time-courses of functional Kv1.3 activity upon stimulation as well as studies of the effects of the concentration of mitogenic antibodies on Kv1.3 levels. The results presented here suggest that Kv1.3 ion channel activity can be used as a functional activation marker in T cells and that it correlates to cell size and levels of a surface antigen, CD25. Moreover, this work presents an enabling methodology that can be applied widely, allowing high-throughput screening of specific voltage-gated ion channels in a variety of primary cells.

Molecular interactions between T cells and fibroblast-like synoviocytes: role of membrane tumor necrosis factor-alpha on cytokine-activated T cells

The mechanism of fibroblast-like synoviocyte (FLS) transformation into an inflammatory phenotype in rheumatoid arthritis (RA) is not fully understood. FLS interactions with invading leukocytes, particularly T cells, are thought to be a critical component of this pathological process. Resting T cells and T cells activated through the T-cell receptor have previously been shown to induce inflammatory cytokine production by FLS. More recently, a distinct population of T cells has been identified in RA synovium that phenotypically resembles cytokine-activated T (Tck) cells. Using time lapse microscopy, the interactions of resting, superantigen-activated, and cytokine-activated T cells with FLS were visualized. Rapid and robust adhesion of Tck and superantigen-activated T cells to FLS was observed that resulted in flattening of the T cells and a crawling movement on the FLS surface. Tck also readily activated FLS to produce interleukin IL-6 and IL-8 in a cell contact-dependent manner that was enhanced by exogenous IL-17. Although LFA-1 and ICAM-1 co-localized at the Tck-FLS synapse, blocking the LFA-1/ICAM-1 interaction did not substantially inhibit Tck effector function. However, antibody blocking of membrane tumor necrosis factor (TNF)-alpha on the Tck surface did inhibit FLS cytokine production, thus illustrating a novel mechanism for involvement of TNF-alpha in cell-cell interactions in RA synovium and for the effectiveness of TNF-alpha blockade in the treatment of RA.

Presentation of arthritogenic peptide to antigen-specific T cells by fibroblast-like synoviocytes

OBJECTIVE

To assess the ability of rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) to function as antigen-presenting cells (APCs) for arthritogenic autoantigens found within inflamed joint tissues.

METHODS

Human class II major histocompatibility complex (MHC)-typed FLS were used as APCs for murine class II MHC-restricted CD4 T cell hybridomas. Interferon-gamma (IFNgamma)-treated, antigen-loaded FLS were cocultured with T cell hybridomas specific for immunodominant portions of human cartilage gp-39 (HC gp-39) or human type II collagen (CII). T cell hybridoma activation was measured by enzyme-linked immunosorbent assay of culture supernatants for interleukin-2. Both synthetic peptide and synovial fluid (SF) were used as sources of antigen. APC function in cocultures was inhibited by using blocking antibodies to human class II MHC, CD54, or CD58, or to murine CD4, CD11a, or CD2.

RESULTS

Human FLS could present peptides from the autoantigens HC gp-39 and human CII to antigen-specific MHC-restricted T cell hybridomas. This response required pretreatment of FLS with IFNgamma, showed MHC restriction, and was dependent on human class II MHC and murine CD4 for effective antigen presentation. Furthermore, FLS were able to extract and present antigens found within human SF to both the HC gp-39 and human CII T cell hybridomas in an IFNgamma-dependent and MHC-restricted manner.

CONCLUSION

RA FLS can function as APCs and are able to present peptides derived from autoantigens found within joint tissues to activated T cells in vitro. In the context of inflamed synovial tissues, FLS may be an important and hitherto overlooked subset of APCs that could contribute to autoreactive immune responses.

Fluvastatin reverses endothelial dysfunction and increased vascular oxidative stress in rat adjuvant-induced arthritis

OBJECTIVE

To investigate the effect of statins on vascular dysfunction in rat adjuvant-induced arthritis (AIA).

METHODS

Fluvastatin (5 mg/kg/day) was administered orally to rats with AIA, for 21 days after the onset of arthritis. The vasodilatory response to acetylcholine of aortic rings isolated from rats with AIA that were not treated or were treated with fluvastatin and from normal rats was determined. The amounts of 4-hydroxy-2-nonenal (HNE) and nitrotyrosine in aortas were measured by Western blotting. In vitro and in situ superoxide production in aortas was evaluated based on fluorogenic oxidation of dihydroethidium to ethidium. Expression of NAD(P)H components and endothelial nitric oxide synthase (eNOS) in aortas was examined by real-time reverse transcriptase-polymerase chain reaction and Western blotting. Serum levels of tetrahydrobiopterin, a critical eNOS cofactor, were determined by high-performance liquid chromatography.

RESULTS

Fluvastatin reversed endothelial dysfunction in AIA without affecting the clinical severity of arthritis or serum cholesterol concentration. Fluvastatin reduced the amounts of HNE and nitrotyrosine in the aorta, and the levels of superoxide expressed in endothelial cells and smooth muscle cells in the tissue, in rats with AIA. NADH- or L-arginine-induced superoxide production was not observed in the aortic samples from fluvastatin-treated rats with AIA. Fluvastatin decreased the levels of expression of messenger RNA for p22phox, a NAD(P)H oxidase component, in the aortas of rats with AIA, but did not affect the expression of eNOS. Serum levels of tetrahydrobiopterin were significantly reduced in rats with AIA, and were increased by administration of fluvastatin.

CONCLUSION

Our findings demonstrate that fluvastatin has potent vascular protective effects in AIA and provide additional scientific rationale for the use of statins to reduce cardiovascular mortality in patients with rheumatoid arthritis.

Cells of the synovium in rheumatoid arthritis. T lymphocytes

Recent findings have substantiated the importance of T lymphocytes to the pathogenesis of rheumatoid arthritis (RA). Here, we review emerging data regarding genetic predisposition, spontaneous animal models of arthritis, and cell-cell interactions that implicate T cells as driving synovial inflammation and joint destruction. Information regarding the proinflammatory role of interleukin-17-producing T cells and the functional state of regulatory T cells both in animal models and in patients with RA is also discussed. In light of the overwhelming evidence that disrupted T-cell homeostasis greatly contributes to joint pathology in RA, the therapeutic potential of targeting activators of pro-inflammatory T cells or their products is compelling.