The relationship between synovitis and bone changes in early untreated rheumatoid arthritis: a controlled magnetic resonance imaging study

How should we manage early rheumatoid arthritis? From imaging to intervention

PURPOSE OF REVIEW

Rheumatoid arthritis is a chronic systemic and progressive inflammatory disorder of the synovium characterised by destruction of bone and cartilage. It is associated with significant morbidity and economic costs. Recent advances have shown that early diagnosis and timely, intensive therapy of rheumatoid arthritis can modify disease outcomes.

RECENT FINDINGS

Current investigations into the role of ultrasonography and magnetic resonance imaging in early rheumatoid arthritis suggest these modalities will provide information to assist in the early diagnosis of rheumatoid arthritis, identify poor prognostic factors, and aid in the monitoring of response to therapy. New developments in pharmacologic therapy, particularly the development of biologic agents, allow better disease control than was previously achievable, and the early application of these drugs in combination with conventional disease-modifying antirheumatic drugs seems to produce the best outcomes.

SUMMARY

The application of novel imaging techniques will aid the target application of biologic therapy within the window of opportunity and aid in the monitoring of response to therapy. This is likely to significantly decrease the rate of structural damage and offers hope of a future when the normal outcome for rheumatoid arthritis will be remission.

Structural evaluation in the management of patients with rheumatoid arthritis: development of recommendations for clinical practice based on published evidence and expert opinion

OBJECTIVES

To develop French evidence-based recommendations for the structural evaluation of rheumatoid arthritis (RA) in everyday practice.

METHODS

A scientific committee selected 10 questions using the Delphi consensus procedure. Evidence-based responses to each question were sought by searching the PubMed and Ovid databases and the abstract databases for the 2002, 2003, and 2004 annual meetings of the French Society for Rheumatology, the EULAR, and the American College of Rheumatology. The following indexing terms were used: rheumatoid arthritis, arthritis, patient, diagnostic imaging, radiography, joint, erosion, and joint space width. All articles published in French or English prior to May 2004 were identified. The evidence from these articles was reported to a panel of 77 rheumatologists working in hospital or office practice. The panel developed detailed recommendations, filling gaps in evidence with their expert opinion. The strength of each recommendation was determined.

RESULTS

The 10 questions probed the structural evaluation of RA by plain radiography, magnetic resonance imaging (MRI), and ultrasonography, both for diagnostic and monitoring purposes. The literature search retrieved 673 publications, of which 166 were selected and reviewed. The panel developed 10 recommendations, one for each question, which were accepted by consensus.

CONCLUSION

Recommendations relative to the diagnosis or monitoring of structural involvement in patients with RA in everyday practice were developed. They should help to improve practice uniformity and, ultimately, to improve the management of RA.

New developments in imaging for diagnosis and therapy monitoring in rheumatic diseases

The availability of therapeutic modalities that are able to stop inflammatory joint damage has also markedly influenced recent developments in muskuloskeletal imaging. One focus of interest is the detection of joint pathology as early as possible in order to prevent erosive bony changes. Ultrasonography and magnetic resonance imaging are the most valuable technologies in this respect. Another focus is on the exact assessment and documentation of joint damage using scoring systems not only in therapeutic trials, but also in clinical practice. In addition to these recent advances in peripheral and axial joint imaging, this chapter also discusses advances in vascular imaging and scintigraphy in rheumatoid diseases as well as interventional procedures guided by imaging technologies.

Magnetic resonance imaging of peripheral joints in rheumatic diseases

The need for better methods than the conventional clinical, biochemical and radiographical examinations in the management of inflammatory joint diseases is evident, since these methods are not sensitive or specific to early pathologies and subtle changes. Magnetic resonance imaging (MRI) offers improved sensitivity to early inflammatory and destructive changes in peripheral joints in rheumatoid arthritis (RA) and, even though less well documented, in other inflammatory joint diseases. Good evidence is available that MRI bone erosions represent true bone abnormalities and are predictors of radiographical outcome in RA. Similarly, there is solid evidence for MRI synovitis representing true synovial inflammation and being of considerable practical, clinical and radiological significance in RA. Describing the encouraging current knowledge regarding MRI for diagnosis, monitoring and prognosis, this chapter discusses the potential for the use of MRI in the clinical management of patients with suspected and diagnosed inflammatory joint diseases, as well as research priorities and clinical situations where the use of MRI could be suggested.

Imaging in early arthritis

Imaging can play a vital role in the evaluation of patients with early arthritis. Various imaging methods can be utilized to aid with diagnosis, predict prognosis and follow disease progression and treatment response. Previously, conventional radiography was the principal method used to evaluate and follow bone damage in patients with inflammatory arthritis. More recently the use of magnetic resonance imaging and ultrasonography has gained wider acceptance and popularity due to the ability of these multiplanar techniques to image both bone changes and soft tissue abnormalities, including synovitis. This chapter discusses the current imaging modalities used in the evaluation of patients with early arthritis, as well as the use of imaging in establishing the extent of disease, in prognosis and in monitoring disease course. Current data on imaging of patients with early arthritis due to rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis is reviewed.

HLA-B27-restricted CD8+ T cell response to cartilage-derived self peptides in ankylosing spondylitis

OBJECTIVE

Several hypotheses have been proposed to explain the strong association between HLA-B27 and ankylosing spondylitis (AS). Among these, the arthritogenic peptide theory proposes that certain B27 subtype alleles bind specific arthritogenic peptide(s) due to their unique amino acid anchor residues. Cartilage antigens have been discussed as candidate targets for the immune response in AS. The recognition of HLA-B27-peptide complexes by self-reactive CD8+ T cells might contribute to joint-specific tissue damage. Therefore, we investigated the presence of autoreactive CD8+ T cells specific for cartilage-derived peptides in patients with AS.

METHODS

An HLA-B27-binding prediction program and a proteasome-cutting prediction program for the human 20S proteasome were used to screen 18 human cartilage proteins for potentially immunogenic nonamer peptides. The peptides identified were used to stimulate peripheral blood mononuclear cells from 20 HLA-B27-positive patients with AS and synovial fluid (SF) mononuclear cells from 7 HLA-B27-positive patients with AS. Activation of T cells was measured by antigen-specific intracellular cytokine staining and quantified by flow cytometry.

RESULTS

From the screening analysis, we identified 121 nonamer peptides. Of these, 1 peptide derived from type II collagen and 1 from type VI collagen were stimulatory for peripheral blood CD8+ T cells in only 1 of 20 patients. However, in 4 of 7 SF samples the same type VI collagen-derived nonamer peptide stimulated SF CD8+ T cells, but none of the other peptides was stimulatory. This CD8+ T cell response could be blocked by an anti-HLA-B27 antibody, confirming an HLA-B27-restricted immune response.

CONCLUSION

Our findings suggest that cartilage-directed cellular autoimmunity might play an important role in joint-specific tissue damage in patients with AS. Future research is necessary to determine whether the identified peptide is of pathogenetic relevance.

Magnetic resonance imaging of the wrist in rheumatoid arthritis: demonstration of progression between 1 and 6 years

OBJECTIVE

To describe the changes seen in the wrist in rheumatoid arthritis (RA) on magnetic resonance (MR) imaging obtained at 1 year and 6 years.

DESIGN

A cohort of patients with RA has been studied prospectively from symptom onset.

PATIENTS

MR scans of the dominant wrist in 31 patients obtained at 1 year and 6 years were compared for bone erosions, marrow signal change (oedema), synovial thickness and tenosynovitis.

RESULTS

Twenty-two patients had an increase in erosion score in the interval and three patients showed a decrease in erosion score suggesting erosion healing. Fourteen patients had an increase in oedema score in the interval and eight patients had a decrease in oedema score. Synovial thickness increased in 13 patients and decreased in eight. Tenosynovitis increased in 15 patients and decreased in five. Bone erosions developed immediately adjacent to the tenosynovitis in two patients.

CONCLUSIONS

MR imaging is useful in following the progress of bone erosions, marrow oedema, synovitis and tenosynovitis in RA.

Analysis of the CD8+ T cell response to the G1 domain of aggrecan in ankylosing spondylitis

BACKGROUND

CD4+ T cell responses to the G1 domain of aggrecan in patients with ankylosing spondylitis (AS) were recently reported. Whether such an immune response can be seen in the CD8+ subpopulation has not yet been determined.

OBJECTIVE

To determine if HLA-B27 restricted G1-specific CD8+ T cells are present in AS and to analyse immunodominant CD8+ T cell epitopes.

METHODS

Peripheral blood mononuclear cells of 45 patients with AS were stimulated with overlapping 18-mer peptides covering the whole G1 protein. Results were compared with those for patients with rheumatoid arthritis (RA) and healthy controls. For epitope analysis, G1-specific interferon gamma positive (IFNgamma+) T cells were isolated by magnetic activated cell sorting. After in vitro expansion, CD8+ T cells were restimulated with 14 subpools of G1 peptides. T cells responding to G1 peptide subpools were quantified by flow cytometry according to IFNgamma secretion. Predicted peptides were subsequently confirmed by stimulation with single peptides.

RESULTS

G1-specific CD8+ T cell responses were found in 29/45 (64%) patients with AS, 18/35 (51%) patients with RA, but not in healthy controls. Five CD8+ T cell epitopes were identified as immunodominant in five patients. However, the T cell response was not HLA-B27 restricted. Nonamer peptides with an HLA-B27 binding motif did not induce a T cell response.

CONCLUSION

A G1 peptide-specific CD8+ T cell response is present in AS but also in patients with RA. It does not seem to be HLA-B27 restricted. Whether such a response has a role in the pathogenesis of AS needs clarification.

Metacarpophalangeal Joints at US in Asymptomatic Volunteers and Cadaveric Specimens

PURPOSE

To determine normal anatomy of metacarpophalangeal (MCP) joints at ultrasonography (US) and to compare findings with anatomic and histopathologic findings.

MATERIALS AND METHODS

Right hands of five cadavers (two women, three men; age range at death, 46-96 years; mean age at death, 62 years) and dominant hands of 30 volunteers (15 men, 15 women; age range, 27-74 years; mean age, 43 years) were evaluated. Nonthumb MCP joints were scanned longitudinally and transversely by two musculoskeletal radiologists working independently at US with a high-frequency linear-array transducer (frequency, 12 MHz). US appearances of intraarticular and periarticular structures were analyzed independently by these radiologists. Specimen sectioning provided anatomic and histopathologic comparisons. Interobserver precision was assessed with determination of coefficient of variation (CV).

RESULTS

Sagittal US images enabled good visualization of the dorsal metacarpal synovial recess and the metacarpal head cartilage. In 37% of cases, a small depression (mean depth, 0.3 mm) was identified on the dorsal aspect of the metacarpal head, especially at the second MCP joint (19% of cases). Direct visualization of sagittal bands of the extensor hood was possible on dorsal transverse US scans, especially at the second and third MCP joints. In all cases, the first annular pulley was well seen on palmar transverse US scans. The radial collateral ligament of the second MCP joint was better recognized by the two observers than was the ulnar collateral ligament of the fifth MCP joint. Interobserver precision was high (CV range, 1.5%-6.5%) for intraarticular and periarticular structures.

CONCLUSION

US provides detailed information about normal anatomy of nonthumb MCP joints.

Diagnostic value of magnetic resonance imaging of the forefeet in early rheumatoid arthritis when findings on imaging of the metacarpophalangeal joints of the hands remain normal

OBJECTIVE

To investigate the diagnostic role of magnetic resonance imaging (MRI) of the forefeet in patients with early rheumatoid arthritis (RA) in whom findings on MR images of the hands are normal and conventional radiographs of the hands and feet do not show erosions.

METHODS

The study group comprised 25 patients with early RA (disease duration of <12 months) in whom erosions were not demonstrated on conventional radiographs of the hands and feet. These patients underwent MRI of the clinically dominant hand to detect signs of arthritis. If results of MRI of the hand were normal according to the Outcome Measures in Rheumatology Clinical Trials (OMERACT) RA-MRI scoring system (RAMRIS), MRI of the dominant forefoot was performed. The MRI protocol comprised coronal and sagittal T1-weighted spin-echo (before and after administration of contrast medium), coronal fat-suppressed short tau inversion recovery sequences, coronal and sagittal T2-weighted turbo spin-echo sequences, and axial fat-suppressed T1-weighted spin-echo sequences after administration of contrast medium. MRI of the forefeet was analyzed on the basis of a modified RAMRIS.

RESULTS

MRI revealed pathologic findings in the hands of 15 of 25 patients (edema in 9 patients, synovitis in 12, erosions in 6, defects in 3). In 10 patients with a mean disease duration of 9.4 weeks, hand MRI scans were normal according to RAMRIS. Four of these 10 patients had tenosynovitis of the finger flexor tendons (there was no OMERACT criterion for tenosynovitis). RAMRIS analysis of the corresponding MRI scans of the forefeet of these patients revealed signs of edema in 7 patients, synovitis in all 10 patients (at the third metatarsophalangeal [MTP] joint in 7, at the fourth MTP joint in 6, at the first MTP joint in 4, and at the fifth MTP joint in 2 patients), tenosynovitis of the foot flexor tendons in 2 patients, erosions at the second and third MTP joints in 1 patient, and a single defect at the first MTP joint in 1 patient.

CONCLUSION

RAMRIS analysis of MRI scans of the forefeet detected synovitis and bone edema in patients with early RA in whom MRI of the finger joints was normal. MRI of the forefeet contributes an additional tool aimed at earlier and more accurate diagnosis and thus might allow an earlier decision to start appropriate medication in patients with early RA.

Noninvasive techniques for assessing skeletal changes in inflammatory arthritis: imaging technique

New imaging techniques such as ultrasound and MRI are likely to play increasing roles in the future management of patients with inflammatory arthritis, particularly those with rheumatoid arthritis and spondyloarthropathies. Ultrasound has a number of distinct advantages including its ability to scan multiple joints, safety, and immediately availability in clinic. MRI, however, is more sensitive and has a greater field of view because of its tomographic nature. Both modalities have the added advantage over radiography in that they can image soft tissue as well as bone. Dual X-ray absorptiometry already has an established role to play in the assessment of osteoporosis, but new techniques such as digital radiogrametry, quantitative CT, and ultrasound potentially will have a more important role to play in the future.

MR imaging: arthropathies and infectious conditions of the elbow, wrist, and hand

The superior soft tissue contrast and multiplanar capability of MR imaging has contributed to earlier diagnosis and implementation of effective treatment for a variety of arthropathies and infectious conditions of the elbow, wrist, and hand. Because of overlapping clinical signs and symptoms, MR imaging plays an important role in delineating the features and staging of each of these conditions. This article discusses the seropositive and seronegative inflammatory arthropathies, with emphasis on early detection and surveillance, as well as gout, synovial osteochondromatosis, pigmented villonodular synovitis, tenosynovitis, and de Quervain's tenosynovitis. Certain noninflammatory arthritides and infectious conditions are also reviewed.

Multispectral analysis of bone lesions in the hands of patients with rheumatoid arthritis

Quantitative measures of rheumatoid arthritis (RA) disease progression can provide valuable tools for evaluation of new treatments during clinical trials. In this study, a novel multispectral (MS) MRI analysis method is presented to quantify changes in bone lesion volume (DeltaBLV) in the hands of RA patients. Image registration and MS analysis were employed to identify MS tissue class transitions between two serial MRI exams. DeltaBLV was determined from MS class transitions between two time points. The following three classifiers were investigated: (a) multivariate Gaussian (MVG), (b) k-nearest neighbor (k-NN), and (c) K-means (KM). Unlike supervised classifiers (MVG, k-NN), KM, an unsupervised classifier, does not require labeled training data, resulting in potentially greater clinical utility. All MS estimates of DeltaBLV were linearly correlated (r(p)) with manual estimates. KM and k-NN estimates also exhibited a significant rank-order correlation (r(s)) with manual estimates. For KM, r(p) = 0.94 p < 0.0001, r(s) = 0.76 p = 0.002; for k-NN, r(p) = 0.86 p = 0.0001, r(s) = 0.69 p = 0.009; and for MVG, r(p) = 0.84 p = 0.0003, r(s) = 0.49 p = 0.09. Temporal classification rates were as follows: for KM, 90.1%; for MVG, 89.5%; and for k-NN, 86.7%. KM matched the performance of k-NN, offering strong potential for use in multicenter clinical trials. This study demonstrates that MS tissue class transitions provide a quantitative measure of DeltaBLV.

Magnetic resonance imaging of wrist and finger joints in healthy subjects occasionally shows changes resembling erosions and synovitis as seen in rheumatoid arthritis

OBJECTIVE

To explore the presence of changes resembling rheumatoid arthritis erosions and synovitis in metacarpophalangeal (MCP) and wrist joints of healthy individuals on magnetic resonance imaging (MRI) and to compare the MRI findings with conventional radiographic, clinical, and biochemical findings.

METHODS

Twenty-eight healthy individuals were studied. Contrast-enhanced MRI and conventional radiography of the dominant wrist and second through fifth MCP joints were performed, coupled with standard clinical assessments and biochemical analyses. MR images were evaluated according to the latest OMERACT (Outcome Measures in Rheumatology Clinical Trials) recommendations with respect to synovitis, erosions, and bone marrow edema.

RESULTS

Conventional radiography revealed erosion-like changes in 1 of 224 MCP joint bones (0.4%) and in 1 of 420 wrist joint bones (0.2%). MRI depicted low-grade erosion-like changes in 5 of 224 MCP joint bones (2.2%) and in 7 of 420 wrist joint bones (1.7%), but postcontrast enhancement within the lesion was detected in only 8.3% of these. MRI depicted low-grade synovitis-like changes in 10 of 112 MCP joints (8.9%) and in 8 of 84 assessed wrist areas (9.5%), while only minimal early synovial enhancement was detected by dynamic MRI. Three subjects had elevated serum levels of C-reactive protein, and these subjects displayed 44.5% of the synovitis-like changes and 41.7% of the erosion-like changes. Bone marrow edema-like changes were not found in any joints.

CONCLUSION

Changes resembling mild synovitis or small bone erosions are occasionally found in the MCP and wrist joints of healthy controls. Signs of synovitis on dynamic MRI, enhancement within bone erosion-like changes, and signs of bone marrow edema appear rarely or are absent in healthy controls. These signs may thus prove to be very specific in the distinction between arthritic and normal joints.

Rheumatoid Arthritis of the Hand and Wrist:Comparison of Three Imaging Techniques

OBJECTIVE

The purpose of this study was to compare the relative results from conventional high-field-strength 1.5-T MRI, 0.2-T low-field-strength dedicated extremity MRI, and radiography to detect and grade bone erosions, joint-space narrowing, and synovitis in the hands and wrists of patients with rheumatoid arthritis.

SUBJECTS AND METHODS

Eighteen patients with rheumatoid arthritis underwent conventional high-field-strength MRI, low-field-strength dedicated extremity MRI, and conventional radiography of both hands and wrists. Two independent reviewers searched for the presence and extent of bone erosions, joint-space narrowing, and synovitis. Bone erosions (E scores) and joint-space narrowing (J scores) were evaluated at 14 and 13 sites, respectively, on conventional high-field-strength MRI, low-field-strength dedicated extremity MRI, and radiography, using the Sharp-Genant scoring system. Synovitis (S scores) were evaluated at 13 sites on conventional high-field-strength MRI and low-field-strength dedicated extremity MRI.

RESULTS

For the detection of bone erosions, we found no significant difference (p = 0.71) between conventional high-field-strength MRI (mean +/- SD E score, 27.5 +/- 9.8) and low-field-strength dedicated extremity MRI (28.8 +/- 10.0), but a significant difference (p < 0.001) appeared between MRI and radiography (13.1 +/- 8.3). J scores derived from MRI (conventional high-field-strength MRI, 15.2 +/- 8.3; low-field-strength dedicated extremity MRI, 14.5 +/- 10.4) were higher than those derived from radiography (12.7 +/- 9.6), although the difference was not significant (p = 0.70). Conventional high-field-strength MRI (S score, 35.1 +/- 8.6) and low-field-strength dedicated extremity MRI (30.8 +/- 10.2) were equivalent (p = 0.14) for the evaluation of synovitis. The interobserver agreement for MRI scores was good to excellent (intraclass correlation coefficients, 0.83-0.94).

CONCLUSION

Conventional high-field-strength MRI and low-field-strength dedicated extremity MRI showed similar results in terms of cross-sectional grading of bone erosions, joint-space narrowing, and synovitis in the hands and wrists of patients with rheumatoid arthritis.

Durability and Rapidity of Response to Anakinra in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic and progressive inflammatory disease that ultimately leads to disability and functional decline. Because patients usually develop RA in mid-life, they may experience its consequences for 20-30 years or longer. Proinflammatory cytokines, notably interleukin (IL)-1 and tumour necrosis factor-alpha, are believed to play significant pathophysiological roles. Clinical trials of biologicals that block these cytokines confirm their importance.Anakinra, a recombinant human IL-1 receptor antagonist, improves clinical signs and symptoms, and slows radiographic progression in patients with active RA. In clinical trials, patients receiving anakinra doses >1 mg/kg, whether administered alone or in combination with methotrexate, were two to three times more likely than patients receiving placebo to achieve a sustained ACR20 (American College of Rheumatology criteria) response. Notably, bone erosion slows to a greater extent and shows accelerated benefit when anakinra treatment is continued for periods beyond 24 weeks. Anakinra has a rapid onset of action, with substantial improvements in biochemical indices (C-reactive protein) seen within 1 week and clinical responses (ACR20 or joint counts) seen within 4 weeks of starting treatment. Anakinra is generally well tolerated, with injection site reactions being the most common adverse event. These reactions are generally mild and typically resolve within 2-3 weeks of treatment. The anakinra product labelling does include a warning regarding an increased risk of infections of 2% in anakinra-treated patients versus <1% in patients receiving placebo.

Pursuit of optimal outcomes in rheumatoid arthritis

The aim of this review is to describe methods of quantifying disease activity and symptomatology and discuss treatment goals for rheumatoid arthritis (RA). The benefits and limitations of existing therapeutic approaches, the importance of early therapy in preventing disease progression and the place of biologicals in early therapy will be discussed. Disease activity and symptomatology in RA are often measured using a set of core endpoints that incorporate pain, patient global assessment, physical disability, swollen joints, tender joints, acute phase reactants, physician global assessment and radiographic imaging of joints. Imaging of joints is the only means by which to measure the effects of disease-modifying antirheumatic drugs (DMARDs) on the irreversible joint damage that occurs during RA. There is increasing evidence that this damage and its functional consequences occur early in the onset of disease. The consensus is that patients with RA should be treated with DMARDs earlier rather than later in the disease process. Remission, or a state of sustained response or low disease activity that is not damaging or disabling, is the ideal goal of therapy for RA, but formal criteria defining a state of remission need to be revised and, ideally, updated to include a radiographic component. Currently available DMARDs are limited in their ability to achieve early, sustained response or remission, by delayed onset of action, cumulative toxicity and lack of long-term therapeutic response. It is hoped that the emergence of novel DMARDs--targeted biological agents, such as anti-tumour necrosis factor-alpha (anti-TNF-alpha)--will help to counteract such limitations and will allow early DMARD use to be adopted as standard practice in place of their use as a last resort therapy after failure of other treatment. One such biological agent, etanercept, has been shown to reduce radiographic disease progression and induce overall clinical response during the early stages of RA. It is significantly more effective and fast-acting than methotrexate, one of the most effective, commonly used DMARDs.

Advanced imaging of early rheumatoid arthritis

Advances in MR imaging of arthritis include contrast-enhanced, dynamic, and quantitative imaging techniques. These advances may result in MR imaging becoming the gold standard in diagnosing early RA. MR imaging is a useful technique in diagnosis, follow-up, and evaluation of remission in rheumatic diseases of the joints. Early diagnosis of RA, in the first 6 months after the onset of symptoms, may lead to earlier control and prevent future erosions and deformities.

Prognostic factors in a large cohort of patients with early undifferentiated inflammatory arthritis after application of a structured management protocol

OBJECTIVE

Inflammatory arthritis of the hands is a frequent clinical presentation with a variable outcome. Patients not satisfying the classification criteria for recognized arthritides are described as having undifferentiated inflammatory arthritis, for which there are no accepted therapeutic algorithms. This study assessed the clinical outcome of patients with undifferentiated arthritis of the hands after use of a treatment algorithm, and evaluated the prognostic features in these patients.

METHODS

One hundred consecutive patients with undifferentiated arthritis of the hands were assessed following use of a pragmatic treatment algorithm that was based on clinical presentation and response to treatment. The following standard step-up treatment protocol was used: 1) nonsteroidal antiinflammatory drugs (NSAIDs), 2) a single dose of corticosteroid administered by either intramuscular or intraarticular injection, and 3) disease-modifying antirheumatic drugs (DMARDs). Patients with specific rheumatologic diagnoses were excluded. The primary outcome was persistence of synovitis at 12 months.

RESULTS

Seventy-eight percent of patients received NSAIDs, 72% received corticosteroids, and 30% received DMARD therapy. Among patients who had synovitis at 12 months, the prevalence of rheumatoid factor (RF) seropositivity, swollen joints, and synovitis at baseline was greater than in those without persistent synovitis. Logistic regression analysis showed baseline investigations to be poor predictors of subsequent DMARD use, with the best predictor being persistence of synovitis at 12 weeks. Rheumatoid arthritis (RA) developed in 14 patients. Logistic regression analysis showed that significant predictors of RA were RF seropositivity and the painful joint count at baseline. No patient who experienced resolution of synovitis by 12 weeks had persistent synovitis that subsequently required DMARD therapy. Only 13% of patients entered remission. Early resolution of synovitis was associated with an excellent prognosis.

CONCLUSION

Undifferentiated arthritis of the hands is not a benign condition, with 30% of patients receiving DMARD therapy by 12 months and low remission rates. Results of the clinical assessment at 12 weeks is the single best predictor of future therapy. This study provides background data for use in determining future therapeutic interventions.

Turnover of type II collagen and aggrecan in cartilage matrix at the onset of inflammatory arthritis in humans: Relationship to mediators of systemic and local inflammation

OBJECTIVE

To determine in vivo the extent of damage to, and changes in turnover of, articular cartilage type II collagen (CII) and the proteoglycan aggrecan following the onset of inflammatory arthritis in humans, and to examine the hypothesis that there are direct relationships between cartilage biomarkers of damage/turnover and clinical, histologic, and molecular markers of inflammation.

METHODS

Synovial fluid (SF) and synovial membrane (SM) were obtained by arthroscopy, and a synovitis score was determined, in 32 patients with rheumatoid arthritis (RA) (13 with early untreated disease, 19 with established disease), 18 with psoriatic arthritis (PsA), and 10 with osteoarthritis (OA). Systemic disease activity markers were recorded, and SM CD3+ T cells, CD4+ T cells, CD68+ macrophages, and lining layer hyperplasia were quantified. SF levels of tumor necrosis factor alpha (TNFalpha), interleukin-10 (IL-10), matrix metalloproteinase 1 (MMP-1), MMP-3, Col2-3/4C(Long mono) neoepitope (C2C) (reflecting collagenase cleavage of cartilage CII), C-propeptide of type II procollagen (PIICP) (a biosynthesis marker), keratan sulfate (KS), and the 846 epitope of aggrecan (turnover) were measured by enzyme-linked immunosorbent assay or radioimmunoassay.

RESULTS

Levels of cartilage degradation products in early RA or early PsA were not elevated above levels in OA, although in early inflammatory arthritis, TNFalpha and MMP-1 levels were similar to those observed in late inflammatory disease and higher than those in OA. PIICP was reduced in early RA. Correlations were observed between the SF C2C neoepitope level and the Health Assessment Questionnaire score, C-reactive protein level, plasma viscosity, synovitis score, and SF TNFalpha and MMP-1 levels. KS epitope content was reduced in direct relation to SM macrophage infiltration in the sublining and lining layers and in the presence of elevated SF MMP-3. Both SF MMP-1 and SF MMP-3 levels correlated with CD4+ T cell infiltration and lining layer hyperplasia in the SM, and MMP-1 levels correlated with lining layer CD68 levels, but TNFalpha and IL-10 levels did not.

CONCLUSION

Except for CII synthesis, there were no significant changes in extracellular matrix turnover of aggrecan or CII in the early stages of human inflammatory arthritis. However, the direct correlation between the increases in TNFalpha and MMP-1 production and collagen degradation suggests that collagenase cleavage of cartilage collagen is related to the activities of TNFalpha and MMP-1. The reduction in CII synthesis in early RA may contribute to the developing pathology, since a lack of synthesis of this molecule would inhibit maintenance of cartilage matrix.

Bone edema scored on magnetic resonance imaging scans of the dominant carpus at presentation predicts radiographic joint damage of the hands and feet six years later in patients with rheumatoid arthritis

OBJECTIVE

Magnetic resonance imaging (MRI) is capable of revealing synovitis and tendinitis in early rheumatoid arthritis (RA), as well as bone edema and erosion. These features are visible before radiographic joint damage occurs. We sought to examine whether MRI of one body region (the wrist) can be used to predict whole-body radiography scores reflecting joint damage at 6 years.

METHODS

We conducted a 6-year prospective study of a cohort of patients who fulfilled the criteria for RA at presentation, using clinical parameters, radiographs, and MRI scans of the dominant wrist. Of the 42 patients enrolled at baseline, full MRI, radiographic, and clinical data were available for 31 at 6-year followup. MRI scans were scored by 2 radiologists, using a validated scoring system. Radiographs of the hands and feet were graded using the modified Sharp scoring method. MRI and radiography scores obtained at baseline and 6 years were compared, and baseline MRI scores were examined for their ability to predict radiographic outcome at 6 years.

RESULTS

At 6 years, the total Sharp score correlated significantly with the total MRI score and the MRI erosion score (r = 0.81, P < 0.0001 and r = 0.79, P < 0.0001, respectively). The 6-year Sharp score also correlated with the baseline total MRI and MRI erosion scores (r = 0.56, P < 0.0001 and r = 0.33, P = 0.03, respectively). MRI synovitis and bone edema scores remained constant for the group as a whole over 6 years, but bone erosion scores progressed (P = 0.0001), consistent with radiographic deterioration. Erosions on 6-year MRI scans were frequently preceded by MRI bone edema at baseline (odds ratio 6.5, 95% confidence interval 2.78-18.1). Regression models indicated that the baseline MRI bone edema score was predictive of the 6-year total Sharp score (P = 0.01), as was the C-reactive protein (CRP) level (P = 0.0002). Neither shared epitope status nor swollen or tender joint counts predicted radiographic outcome in this cohort. A model incorporating baseline MRI scores for erosion, bone edema, synovitis, and tendinitis plus the CRP level and the erythrocyte sedimentation rate explained 59% of the variance in the 6-year total Sharp score (R(2) = 0.59, adjusted R(2) = 0.44).

CONCLUSION

MRI scans performed at the first presentation of RA can be used to help predict future radiographic damage, allowing disease-modifying therapy to be targeted to patients with aggressive disease.

New developments in imaging in rheumatoid arthritis

Despite the advances made in medical imaging over the past 3 decades and the central role that magnetic resonance imaging and other sophisticated technologies now play in routine clinical practice, patients with rheumatoid arthritis have benefited relatively little from these advances thus far. Over the past few years, however, evidence has accumulated to show that magnetic resonance imaging and ultrasonography can identify joint damage in patients with rheumatoid arthritis earlier and more sensitively than other techniques can, and that these techniques can directly visualize and monitor changes in synovium and bone that precede actual bone erosion. Much of this development is being driven by the pharmaceutical and biotechnology industries as they search for novel therapies to combat this disease. Accordingly, the imaging tools that ultimately will be used to direct patients to specific therapies and then to monitor treatment effectiveness and safety are currently being refined and validated in rigorous multicenter and multinational clinical trials aimed at gaining regulatory approval of these new therapies. As these therapies become available for clinical use, we can anticipate increased demand for expertise and experience in evaluating disease progression and treatment response, and to the emergence of magnetic resonance imaging systems specifically adapted for this application. The following discussion reviews the current status of this development, and notable advances that have been reported in the literature in the past year.

Role of metacarpophalangeal joint anatomic factors in the distribution of synovitis and bone erosion in early rheumatoid arthritis

OBJECTIVE

To investigate the role of metacarpophalangeal (MCP) joint anatomic and biomechanical factors in the distribution of synovitis and bone erosion in early rheumatoid arthritis (RA).

METHODS

Thirty-three patients with early RA with clinically diagnosed MCP joint disease and 28 healthy controls were examined by magnetic resonance imaging of the second to fifth MCP joints of the dominant hand. T1 and T2 fat-suppressed coronal sequences were obtained to assess erosion, and dynamic contrast-enhanced images were acquired to assess synovitis in all of the RA patients and in 8 of the controls. Erosions were defined as bone defects with sharp margins observed using T1-weighted imaging in 2 planes, with a cortical break seen in at least 1 plane. The location of erosions was recorded. The volume of synovitis surrounding each MCP joint (divided into 8 regions) was calculated by summation of voxels derived from the maximal enhancement parameters. The synovial volumes adjacent to MCP joint collateral ligaments were determined by correcting synovial volumes for the positions of asymmetrically placed flexor tendons.

RESULTS

In patients with early RA in whom bone erosions were present, there was a propensity for involvement of the radial side of the second (P < 0.0001), third (P = 0.002), and fourth (P = 0.056) MCP joints, but not the fifth. Fifty-two of the 110 erosions (47.3%) occurred adjacent to the radial collateral ligaments of the second, third, and fourth MCP joints. The volume of synovitis was also greater on the radial side of the second (P < 0.0001) and third (P < 0.001) MCP joints. A predilection for synovitis in all of the MCP joints adjacent to the radial collateral ligaments was evident when the positional effects of the flexor tendon were considered. The position of radial collateral ligaments had an effect on erosion formation that was independent of synovitis. A predilection for radial bone damage was also evident in the controls, although lesions were 5-fold less frequent, were generally smaller, and had well-defined margins.

CONCLUSION

This study shows that there is a predilection for both synovitis and bone erosion formation on the radial side of the MCP joints in early RA, and that joint inflammation appears to drive the inherent tendency for bone damage on the radial side of joints. These findings have implications regarding the pathogenesis of joint damage in RA.

Computerized measurement of magnetic resonance imaging erosion volumes in patients with rheumatoid arthritis: a comparison with existing magnetic resonance imaging scoring systems and standard clinical outcome measures

OBJECTIVE

One of the major aims of therapy in rheumatoid arthritis (RA) is to prevent erosive disease and subsequent disability. One of the important goals of therapy assessment must therefore be the accurate measurement of damage progression. We undertook this study to assess the feasibility, reliability, and validity of measuring magnetic resonance imaging (MRI) erosion volumes and synovial volumes in the wrists of RA patients with the use of a semiautomated computerized method.

METHODS

Twelve subjects with seropositive RA were chosen to reflect a spectrum of RA severity as determined by the clinical Joint Alignment and Motion (JAM) Scale. MRI of the dominant wrist was performed at the same time of day at baseline and at 48 hours. Images were transferred to a workstation. Erosion volumes and synovial volumes were measured on the coronal images using OSIRIS imaging software. All images were reread in random order at 72 hours by 1 observer. The results were compared with erosion scores and global synovitis scores obtained by the same observer using the Outcome Measures in Rheumatology Clinical Trials MRI RA scoring system. Radiographs were performed at baseline and were read on 2 occasions by 1 observer using the Scott modification of the Larsen method.

RESULTS

Total erosion volume per subject ranged from 0 cm(3) to 4.7 cm(3). The total synovial membrane volume per subject ranged from 0.1 mm(3) to 12.1 cm(3). Intraclass correlation coefficients for erosion volumes and synovial volumes demonstrated excellent intraobserver reliability and interoccasion reliability. There was a strong positive correlation between the total erosion volume and the total erosion score. The correlation between the synovial volumes and synovitis score was less favorable (r = 0.53-0.86). Positive correlations were demonstrated between the erosion volumes, the JAM score, and the modified Larsen scores. No significant correlation was demonstrated between the erythrocyte sedimentation rate, C-reactive protein level, swollen joint count, tender joint count, or the Disease Activity Score in 28 swollen and 28 tender joints and the synovial volumes or synovitis scores.

CONCLUSION

This study is the first to demonstrate the feasibility, reliability, and validity of computerized MRI erosion volume measurements in the wrists of RA patients. The method will require further evaluation in terms of interobserver reliability, with examination of responsiveness in longitudinal studies, but the method demonstrates excellent interoccasion and intraobserver reliability and compares favorably with existing RA clinical outcome measures. Synovial volume measurements demonstrated good intraobserver reliability and appeared to be more responsive to synovial change over a 48-hour period in this group of patients.

The value of sensitive imaging modalities in rheumatoid arthritis

X-ray evaluation of rheumatoid joints is relatively inexpensive, is widely available and has standardised methods for interpretation. It also has limitations, including the inability to reliably determine structural change in less than 6-12 months, the need for experienced readers to interpret images and the limited acceptance of this technique in routine clinical practice. High-frequency ultrasound, with or without power Doppler, and magnetic resonance imaging of rheumatoid joints permit an increasingly refined analysis of anatomic detail. However, further research using these sensitive imaging technologies is required to delineate pathophysiological correlates of imaging abnormalities and to standardise methods for assessment.

Prospective two year follow up study comparing novel and conventional imaging procedures in patients with arthritic finger joints

OBJECTIVE

To carry out a prospective two year follow up study comparing conventional radiography, three-phase bone scintigraphy, ultrasonography (US), and three dimensional (3D) magnetic resonance imaging (MRI) with precontrast and dynamic postcontrast examination in detecting early arthritis. The aim of the follow up study was to monitor the course of erosions during treatment with disease modifying antirheumatic drugs by different modalities and to determine whether the radiographically occult changes like erosive bone lesions of the finger joints detected by MRI and US in the initial study would show up on conventional radiographs two years later. Additionally, to study the course of soft tissue lesions depicted in the initial study in comparison with the clinical findings.

METHODS

The metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints (14 joints) of the clinically more severely affected hand (soft tissue swelling and joint tenderness) as determined in the initial study of 49 patients with various forms of arthritis were examined twice. The patients had initially been divided into two groups. The follow up group I included 28 subjects (392 joints) without radiographic signs of destructive arthritis (Larsen grades 0-1) of the investigated hand and wrist, and group II (control group) included 21 patients (294 joints) with radiographs showing erosions (Larsen grade 2) of the investigated hand or wrist, or both, at the initial examination.

RESULTS

(1) Radiography at the two year follow up detected only two erosions (two patients) in group I and 10 (nine patients) additional erosions in group II. Initial MRI had already detected both erosions in group I and seven (seven patients) of the 10 erosions in group II. Initial US had depicted one erosion in group I and four of the 10 erosions in group II. (2) In contrast with conventional radiography, 3D MRI and US demonstrated an increase in erosions in comparison with the initial investigation. (3) The abnormal findings detected by scintigraphy were decreased at the two year follow up. (4) Both groups showed a marked clinical improvement of synovitis and tenosynovitis, as also shown by MRI and US. (5) There was a striking discrepancy between the decrease in the soft tissue lesions as demonstrated by clinical findings, MRI, and US, and the significant increase in erosive bone lesions, which were primarily evident at MRI and US.

CONCLUSIONS

Despite clinical improvement and a regression of inflammatory soft tissue lesions, erosive bone lesions were increased at the two year follow up, which were more pronounced with 3D MRI and less pronounced with US. The results of our study suggest that owing to the inadequate depiction of erosions and soft tissue lesions, conventional radiography alone has limitations in the intermediate term follow up of treatment. US has a high sensitivity for depicting inflammatory soft tissue lesions, but dynamic 3D MRI is more sensitive in differentiating minute erosions.

Pathogenesis of bone erosions in rheumatoid arthritis

Focal marginal joint erosions represent the radiographic hallmark of rheumatoid arthritis (RA). These bone changes are characteristically localized to the joint margins, but in addition, regions of focal bone resorption can be detected in the subchondral bone adjacent to the bone marrow space into which the synovial inflammatory tissues have extended. Because progressive destruction of the periarticular bone contributes significantly to joint dysfunction and disability in patients with RA, there is considerable interest in developing a better understanding of the pathologic mechanisms involved in this process and in developing therapies that can arrest these events. Previous analysis of joint tissues from patients with RA have provided morphologic evidence that osteoclasts are the cell types that mediate the focal bone resorption associated with the rheumatoid synovial lesion. Additional recent data from animal models have helped to further implicate these cells in the pathogenesis of focal bone erosions. Furthermore, analysis of RA synovium and joint tissues from animal models of inflammatory arthritis, as well as cell and tissues culture studies, have helped to define the cytokines and inflammatory mediators that are involved in the recruitment and activation of bone resorbing cells associated with focal bone erosions. These findings provide a rational framework for developing targeted therapies that can specifically inhibit or slow the progressive focal bone destruction associated with the rheumatoid synovial lesion.

Pathogenesis of bone lesions in rheumatoid arthritis

Histopathologic characterization of bone erosions from patients with rheumatoid arthritis (RA) and studies performed in animal models of inflammatory arthritis provide strong evidence that osteoclasts play an important role in focal marginal and subchondral bone loss in inflammatory arthritis. Much has been learned concerning the factors responsible for the induction and activation of osteoclasts associated with the bone erosions in RA. Therapies that target these osteoclast-inducing factors or other aspects of osteoclast-mediated bone resorption represent potential targets for blocking or at least attenuating bone destruction in RA. The demonstration of the role of the newly described osteoclastogenic factor receptor activator of nuclear factor kappaB ligand in RA synovial tissues and the successful prevention of bone erosions in animal models of arthritis with its inhibitor osteoprotegerin provide hope that specific therapies can be developed for preventing bone and joint destruction in RA, particularly in situations in which disease-modifying agents are ineffective in controlling disease activity.

Early referral recommendation for newly diagnosed rheumatoid arthritis: evidence based development of a clinical guide

BACKGROUND

Effective treatment of active rheumatoid arthritis (RA) requires early diagnosis and early disease modifying antirheumatic drug (DMARD) treatment to have an impact on long term morbidity and mortality. Clinical criteria would facilitate early referral of the patient with suspected RA to a rheumatologist for definitive diagnosis and initiation of DMARD treatment at that point in the disease most likely to have an impact on the long term outcome.

OBJECTIVE

To develop a referral recommendation that may serve as a clinical guide for primary care doctors, enabling them to identify patients with suspected RA during the early inflammatory stages.

METHODS

Key points of the referral criteria were formed based on a thorough literature review targeting early RA, early arthritis clinics, DMARD treatment for early RA, prognostic factors of disease progression, early RA clinical trials, and quality of life. Evidence was graded using the methods defined by Shekelle et al. A draft version of the criterion was circulated among the authors for critical evaluation. A consensus integrated these comments.

RESULTS

Clinical evidence strongly supports the observations that structural damage occurs early in active RA and that early DMARD treatment improves the long term outcome of the disease. The observations indicate that rapid referral to a rheumatologist is advised when RA is suspected. This may be supported by the presence of any of the following: >or=3 swollen joints, metatarsophalangeal/metacarpophalangeal involvement, and morning stiffness of >or=30 minutes.

CONCLUSION

The proposed early referral recommendation is a viable tool for primary care doctors to identify potential patients with active RA early in the disease. Early referral to a rheumatologist for definitive diagnosis and early DMARD treatment should improve the long term outcome of RA.

Comparative assessment of leflunomide and methotrexate for the treatment of rheumatoid arthritis, by dynamic enhanced magnetic resonance imaging

OBJECTIVE

Ethical constraints on the conduct of placebo-controlled trials evaluating new therapies for serious chronic diseases, such as rheumatoid arthritis (RA), indicate the need for discerning methods to assess treatment effect in active-controlled clinical trials. Dynamic gadolinium-enhanced magnetic resonance imaging (DEMRI) is a sensitive technique for the detection of synovial inflammation in RA. Therefore, this investigation was undertaken to evaluate DEMRI as an efficacy assessment tool for differentiating treatment effect in a randomized, active-controlled trial comparing leflunomide and methotrexate.

METHODS

Patients with active RA (n = 39) were randomized in a 2-center, prospective, double-blind clinical trial to receive either leflunomide (n = 18) or methotrexate (n = 21) therapy for 4 months. DEMRI scans were obtained at baseline and at 4 months, and the initial rate of enhancement (IRE) and the maximal signal intensity (SI) enhancement (ME) were calculated from the SI curves. Clinical improvement was assessed by conventional outcome measures.

RESULTS

Thirty-four patients (17 treated with leflunomide and 17 with methotrexate) had usable baseline and end point DEMRI scans. Leflunomide treatment was associated with a significantly greater improvement in IRE compared with methotrexate treatment (P < 0.05). Average values of ME indicated reduction of inflammation with both leflunomide and methotrexate. The improvement in clinical signs and symptoms, as measured by traditional assessments, was comparable for both active treatments.

CONCLUSION

Results of this study validate the sensitivity of DEMRI in detecting inflammatory changes in active RA in response to treatment. Improvement in synovial inflammation as measured by IRE was significantly better with leflunomide than with methotrexate over 4 months of therapy.

Efficacy of anakinra in bone: comparison to other biologics

Three biologic therapies significantly slow radiographic progression in active rheumatoid arthritis. This paper compares the effects of anakinra, a recombinant human interleukin-1 receptor antagonist, with those of etanercept and infliximab, two drugs that target tumor necrosis factor-alpha. A Medline search identified controlled clinical trials that included radiographic progression as an endpoint. Anakinra 30 to 150 mg subcutaneously each day for 24 weeks was significantly more effective than placebo in slowing progression of erosion, joint-space narrowing, and total composite scores, as assessed by the Genant method, and erosive joint count, as assessed by the Larsen method. Erosion scores were slowed even further during a 24-week extension. Etanercept 25 mg subcutaneously twice weekly and infliximab 3 to 10 mg/kg intravenously every 4 or 8 weeks also slowed progressive joint damage, but these agents were studied under different study designs, patient populations, and radiographic assessments than those used in the anakinra study. Despite these differences, however, each biologic therapy appeared to slow progressive joint damage. In some studies, control of clinical symptoms did not correlate with slowing of radiographic progression. Agents that block interleukin-1 or tumor necrosis factor-alpha appear similarly effective in slowing radiographic progression in patients with active rheumatoid arthritis. Treatment strategies for this disease may need to consider clinical symptoms, progressive joint damage, and long-term safety effects separately.

Magnetic resonance imaging and miniarthroscopy of metacarpophalangeal joints: sensitive detection of morphologic changes in rheumatoid arthritis

OBJECTIVE

To evaluate and characterize magnetic resonance imaging (MRI) findings in the metacarpophalangeal (MCP) joints of rheumatoid arthritis (RA) patients macroscopically, using miniarthroscopy (MA; needle arthroscopy).

METHODS

The second MCP joint of the dominant hand of 22 RA patients (13 with various RA activities/stages; 9 with early RA [< or = 1.5 years' duration]) was examined by MRI followed by MA. Findings were evaluated by standardized semiquantitative measures of synovial and bony pathologic changes of the MCP joint, and were compared with the clinical and conventional radiologic findings.

RESULTS

Erosions and pre-erosions were detected in 17 of 22 patients by MRI; 2 of the other 5 patients (all early RA) displayed bony changes on MA. All 10 joints with pre-erosions on MRI (grade I bony alterations on MRI) exhibited significant cartilaginous and bony pathology on MA. Synovial membrane pathology was detected in all but 1 patient by MRI and in all patients by MA, although findings of plain radiography were normal in 6 of the 22 patients and another 9 patients had a Larsen score of 1. Semiquantitative analysis of synovial findings of MRI revealed gadolinium diethylenetriaminepentaacetic acid enhancement as a significant marker of macroscopically varied synovial vascularity and hyperemia, both of which strongly correlated with clinical activity (as measured by the Disease Activity Score). The extent of synovitis/synovial proliferation shown by MA and MRI were significantly correlated with each other, but not with any other activity or damage parameter analyzed.

CONCLUSION

In RA, both MRI and MA findings support early detection and staging of synovial changes. Ongoing longitudinal studies are aimed at evaluating the value of synovial proliferation as visualized by both methods.

Rheumatoid arthritis

Rheumatoid arthritis is a systemic inflammatory disorder that mainly affects the diarthrodial joint. It is the most common form of inflammatory arthritis, and has a substantial societal effect in terms of cost, disability, and lost productivity. Although the pathogenesis of rheumatoid arthritis remains incompletely understood, much insight into the cellular and molecular mechanisms involved has been gained in the past decade. On the basis of these insights, new therapies have been developed, and clinical trials have shown the efficacy of aggressive treatment of patients with active disease. In this review, we discuss improvements in our understanding of the pathophysiology of inflammatory synovitis in rheumatoid arthritis, and improvements in therapy for patients with the disorder. The past decade has seen substantial advances in these areas. Future studies will be directed at improving methods for early diagnosis and identification of patients with progressive disease, and at improving methods to identify candidates for subclasses of disease-modifying antirheumatic drugs (DMARDs). Long-term safety and efficacy data for the new DMARD agents and combination regimens will also further delineate efficacy and toxicity and thus the appropriate clinical context for use of these therapeutic approaches. The continuing elucidation of pathophysiological pathways relevant in rheumatoid arthritis, coupled with continuing advances in biotechnology and rational drug design, offer substantial hope for the continued development of increasingly potent and specific pharmacotherapy for treatment of rheumatoid arthritis.

Synovial tissue protease gene expression and joint erosions in early rheumatoid arthritis

OBJECTIVE

To relate the expression of proteases in the lining and sublining layers of the synovial membrane to the rate of joint damage during 1 year in patients with early inflammatory arthritis.

METHODS

Samples of synovial membrane were obtained by closed-needle biopsy or needle arthroscopy from inflamed knees of 20 patients with early inflammatory polyarthritis (mean disease duration 9.6 months, range 2 weeks to 18 months). Expression of matrix metalloproteinase 1 (MMP-1), cathepsin B (CB), and cathepsin L (CL) was examined using in situ hybridization. Immunohistochemistry was used to identify infiltrating mononuclear cell populations. Radiographs of the hands and feet, performed at presentation and after 1 year, were evaluated for the development of new erosions.

RESULTS

Twelve patients had rheumatoid arthritis (RA), 6 had psoriatic arthritis (PsA), 1 had gout, and 1 had an undifferentiated arthritis. Six patients had erosions at presentation. Eleven patients (10 with RA, 1 with PsA) demonstrated at least 1 new erosion after 1 year of followup. MMP-1, CB, and CL messenger RNA (mRNA) were expressed in the synovial membrane of all patients and were present throughout the lining layer, as well as in perivascular cellular infiltrates and endothelial cells in the sublining layer. In the lining layer, the mean percentages of protease mRNA-positive cells per high-power field were higher in those patients who developed new joint erosions than in those without evidence of joint damage. A similar pattern was observed in the sublining layer, where mean numbers of protease mRNA-positive cells were also greater in patients with new joint erosions. There were significant differences between the two groups in MMP-1 mRNA expression in both the lining and sublining layers (P = 0.0007 and P = 0.0027, respectively), as well as in sublining layer CL mRNA expression (P = 0.017), but not in CB mRNA expression. Numbers of lining layer CD68+ cells correlated positively with lining layer MMP-1 mRNA expression (P = 0.043) and with the development of new joint erosions (P = 0.002).

CONCLUSION

The detection of MMP-1, CB, and CL in the synovium soon after the onset of symptoms highlights the potential for early joint destruction in patients with RA. High levels of MMP-1 mRNA expression in the lining layer distinguished patients with more rapidly progressive erosive disease. This is the first study to demonstrate features of early synovial pathophysiology that may identify patients at increased risk of developing new joint erosions.

Low field dedicated magnetic resonance imaging in untreated rheumatoid arthritis of recent onset

OBJECTIVE

To compare a low field dedicated extremity magnetic resonance imaging system (E-MRI) with x ray and clinical examination, in the detection of inflammation and erosive lesions in wrist and metacarpophalangeal (MCP) joints in newly diagnosed, untreated rheumatoid arthritis (RA).

PATIENTS AND METHODS

Twenty five patients (disease duration < or =1 year) and three healthy controls entered the study. An x ray examination and MRI (before and after intravenous injection of a contrast agent) of the 2nd-5th MCP joints and the wrist was performed. The number of erosions on x ray examination and MRI was calculated, and synovitis in the MCP joints and wrists was graded semiquantitatively.

RESULTS

E-MRI detected 57 bone erosions, whereas only six erosions were disclosed by x ray examination (ratio 9.5:1). Synovial hypertrophy grades were significantly higher in RA joints with clinical signs of joint inflammation-that is, swelling and/or tenderness (median 3, 5th-95th centile 1-4) than without these clinical signs (median 2, 5th-95th centile 1-3), p < 0.001. 51% of the joints without clinical signs of synovitis showed synovial hypertrophy on E-MRI. There was a positive correlation between MRI scores of synovitis and the number of erosions detected by MRI in the MCP joints (Spearman r(s) = 0.31, p < 0.01). No healthy controls had erosions or synovitis on MRI.

CONCLUSION

Joint destruction starts very early in RA and E-MRI allows detailed evaluation of inflammatory and destructive changes in wrists and MCP joints in patients with incipient RA.

How do you diagnose rheumatoid arthritis early?

There are difficulties in making an accurate diagnosis of rheumatoid arthritis in its early stages, a principal problem being the fact that its most defining feature is chronicity, which, by definition, takes time to identify. There is substantial evidence that patients with rheumatoid arthritis should be treated early, and the majority are now commenced on therapy when first diagnosed. A logical implication of the early therapy approach is that treatment before rheumatoid arthritis is fully developed may have even greater benefits. This requires patients who are likely to have a persistent, more severe disease to be identified and treated effectively in the very earliest stages. This requires a system of the early specialist referral of suitable patients and the use of effective predictors of patient outcome. This text discusses the early arthritis clinic approach and the current evidence base available for use in constructing management guidelines for such patients.

Magnetic resonance imaging of rheumatoid arthritis: the evolution of clinical applications through clinical trials

Powerful techniques are being developed for evaluating rheumatoid arthritis with magnetic resonance imaging (MRI). Much of this development is being driven by the pharmaceutical and biotechnology industries searching for novel therapies for this disease. Accordingly, the imaging tools that ultimately will be used to direct patients to specific therapies and then to monitor treatment effectiveness and safety are currently being refined and validated in rigorous multicenter and multinational clinical trials aimed at gaining regulatory approval of these new therapies. As these trials approach completion, rheumatologists can anticipate an increased demand for expertise and experience in evaluating disease progression and treatment response with these techniques and the emergence of MRI systems specifically designed for this market. The following discussion reviews this novel pathway for evolving imaging techniques for clinical use through clinical drug trials, lists the most promising MRI markers available today for evaluating joint destruction in rheumatoid arthritis, and speculates on how these techniques will find their way into clinical practice.

Imaging the joints in early rheumatoid arthritis

Radiography is the most widely utilized imaging modality for early rheumatoid arthritis, determination of radiographic progression remaining a crucial part of the evaluation of therapy. Conventional radiography is, however, insensitive for showing bone damage in early disease and is totally unsuitable for assessing synovial inflammation. The recognition of these limitations has led to intense interest in the multiplanar imaging capabilities of magnetic resonance imaging in rheumatoid arthritis and to an increasing use of ultrasonography for assessing synovitis and bone damage. This chapter discusses the role of radiography in early rheumatoid arthritis and the emerging use and role of magnetic resonance imaging and ultrasonography in evaluating synovitis and bone damage. The relationship between synovitis and bone damage is also addressed in the light of recent magnetic resonance imaging observations.

Where is imaging going in rheumatology?

Four new approaches to imaging are now becoming available. First is filmless radiology, with flat detectors that 'permit access' to PACS, the picture archiving communication system, and teleteaching. Second is ultrasonography (US), involving three-dimensional volume, harmonic Doppler energy and digital technology techniques, with contrast agents and biopsy needles. Next is computer tomography (CT), using volume acquisition multislices, spiral reconstruction and solid detectors, as well as multidetectors. Finally comes magnetic resonance imaging (MRI). A low magnetic field with an open MRI scan permits interventional radiology in musculoskeletal disease. High magnetic fields are mainly used for clinical research and permit rapid examination, in approximately 10 minutes. In interventional radiology, many procedures can be performed with the guidance of digital radiography, US or MRI. Two areas of localization have to be considered: the spine and the peripheral joints, particularly the shoulder, wrist and foot. Guidelines contribute to good medical practice, but there are other considerations, such as machine accessibility, the nature of the treatment, the personality of the patient and the role of the hospital. Overinvestigation has to be avoided for four reasons: an increase in patient anxiety, the cost of health-care management, the risk of irradiation and sometimes the lack of diagnostic value of these procedures. In rheumatoid arthritis, MRI can detect lesions at an earlier stage of their development and identify subtle lesions and synovitis. Imaging (using x-rays, MRI and US) is important in the assessment of the effectiveness of slow-acting drugs in rheumatoid arthritis, especially since joint damage can progress in spite of a clinical improvement in joint inflammation. In the future, teletransmission, by the Internet or intranet and using PACS, will change our approach to the diagnosis of musculoskeletal disease. Future developments therefore include PACS, filmless radiology, the Internet and intranet, harmonic US, multidetector CT scanning and open MRI on the technical side, as well as the study of cartilage and international radiology on the clinical side.

The value of sonography in the detection of bone erosions in patients with rheumatoid arthritis: a comparison with conventional radiography

OBJECTIVE

The ability to make an early, accurate diagnosis of rheumatoid arthritis (RA) has become increasingly important with the availability of new, expensive, and targeted therapies. However, plain radiography, the traditional method of detecting the characteristic bone erosions and an important adjunct in establishing a diagnosis of RA, is known to be insensitive. This study compared sonography, a modern imaging technique, with conventional radiography for the detection of erosions in the metacarpophalangeal (MCP) joints of patients with RA.

METHODS

One hundred RA patients (including 40 with early disease) underwent posteroanterior radiography and sonography of the MCP joints of the dominant hand. Twenty asymptomatic control subjects also underwent sonography. Erosion sites were recorded and subsequently compared using each modality. Magnetic resonance imaging (MRI) was performed on the second MCP joint in 25 patients with early RA to confirm the pathologic specificity of sonographic erosions. Intraobserver reliability of sonography readings was assessed using video recordings of 55 MCP joint scans of RA patients, and interobserver reliability was assessed by comparing 160 MCP joint scans performed sequentially by 2 independent observers.

RESULTS

Sonography detected 127 definite erosions in 56 of 100 RA patients, compared with radiographic detection of 32 erosions (26 [81%] of which coincided with sonographic erosions) in 17 of 100 patients (P < 0.0001). In early disease, sonography detected 6.5-fold more erosions than did radiography, in 7.5-fold the number of patients. In late disease, these differences were 3.4-fold and 2.7-fold, respectively. On MRI, all sonographic erosions not visible on radiography (n = 12) corresponded by site to MRI abnormalities. The Cohen-kappa values for intra- and interobserver reliability of sonography were 0.75 and 0.76, respectively.

CONCLUSION

Sonography is a reliable technique that detects more erosions than radiography, especially in early RA. Sonographic erosions not seen on radiography corresponded to MRI bone abnormalities. This technology has potential in the management of patients with early RA/inflammatory arthritis and is likely to have major implications for the future practice of rheumatology.

Magnetic resonance imaging, radiography, and scintigraphy of the finger joints: one year follow up of patients with early arthritis. The TIRA Group

OBJECTIVES

To evaluate synovial membrane hypertrophy, tenosynovitis, and erosion development of the 2nd to 5th metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints by magnetic resonance imaging in a group of patients with rheumatoid arthritis (RA) or suspected RA followed up for one year. Additionally, to compare the results with radiography, bone scintigraphy, and clinical findings.

PATIENTS AND METHODS

Fifty five patients were examined at baseline, of whom 34 were followed up for one year. Twenty one patients already fulfilled the American College of Rheumatology (ACR) criteria for RA at baseline, five fulfilled the criteria only after one year's follow up, whereas eight maintained the original diagnosis of early unclassified polyarthritis. The following MRI variables were assessed at baseline and one year: synovial membrane hypertrophy score, number of erosions, and tenosynovitis score.

RESULTS

MRI detected progression of erosions earlier and more often than did radiography of the same joints; at baseline the MRI to radiography ratio was 28:4. Erosions were exclusively found in patients with RA at baseline or fulfilling the ACR criteria at one year. At one year follow up, scores of MR synovial membrane hypertrophy, tenosynovitis, and scintigraphic tracer accumulation had not changed significantly from baseline; in contrast, swollen and tender joint counts had declined significantly (p<0.05).

CONCLUSIONS

MRI detected more erosions than radiography. MR synovial membrane hypertrophy and scintigraphy scores did not parallel the changes seen over time in clinically assessed swollen and tender joint counts. Although joint disease activity may be assessed as quiescent by conventional clinical methods, a more detailed evaluation by MRI may show that a pathological condition is still present within the synovium.

Mechanisms of bone loss in inflammatory arthritis: diagnosis and therapeutic implications

Rheumatoid arthritis represents an excellent model in which to gain insights into the local and systemic effects of joint inflammation on skeletal tissues. Three forms of bone disease have been described in rheumatoid arthritis. These include: focal bone loss affecting the immediate subchondral bone and bone at the joint margins; periarticular osteopenia adjacent to inflamed joints; and generalized osteoporosis involving the axial and appendicular skeleton. Although these three forms of bone loss have several features in common, careful histomorphometric and histopathological analysis of bone tissues from different skeletal sites, as well as the use of urinary and serum biochemical markers of bone remodeling, provide compelling evidence that different mechanisms are involved in their pathogenesis. An understanding of these distinct pathological forms of bone loss has relevance not only with respect to gaining insights into the different pathological mechanisms, but also for developing specific and effective strategies for preventing the different forms of bone loss in rheumatoid arthritis.