Association of HLA alleles and clinical features in patients with synovitis of recent onset

Multicentric Reticulohistiocytosis Exhibiting Positive HLA-B*07 and HLA-B*08: A Case Report

Multicentric reticulohistiocytosis (MRH) is a rare cause of destructive inflammatory arthritis involving both small, as well as larger joints. We report the case of a 40-year-old Caucasian female with a family history of neoplasia who was referred to our service witha two-month history of inflammatory joint pain. On examination, the patient had inflammatory arthritis, mainly involving the peripheral joints, sacroiliac joint pain, and numerous papulonodular mucocutaneous lesions, including periungual “coral beads”. Imaging tests revealed erosive arthritis with synovitis and tenosynovitis, sacroiliac joint changes, as well as papulonodular mucosal lesions in the nasal vestibule, the oropharyngeal mucosa, and supraglottic larynx. She tested positive for HLA-B*07 (Human Leukocyte Antigen B*07) and HLA-B*08, ANA (antinuclear antibodies), RF (rheumatoid factor), anti-Ro52, anti-SSA/Ro, and anti-SSB/La antibodies. The skin biopsy was suggestive of MRH, showing a histiocyte infiltrate and frequent giant multinucleated cells. The patient exhibited favorable outcomes under Methotrexate, then Leflunomide. However, she displayed worsening clinical symptoms while under Azathioprine. To our knowledge, this is the first case of MRH to exhibit positive HLA-B*07 together with HLA-B*08. The rarity of MRH, its unknown etiology and polymorphic clinical presentation, as well as its potential neoplastic/paraneoplastic, and autoimmune nature demand extensive investigation.

Is HLA-B27 Increased in Patients Diagnosed with Undifferentiated Arthritis? Results from the Leiden Early Arthritis Cohort

Objective.

Undifferentiated arthritis (UA) is a common form of arthritis. According to the Assessment of Spondyloarthritis international Society (ASAS) criteria for peripheral spondyloarthritis (pSpA), HLA-B27 can be used to help classify patients with pSpA. We tested whether HLA-B27 is increased in patients diagnosed with UA.

Methods.

Prevalence of HLA-B27 was compared between healthy controls and patients with UA. SpA features were compared between HLA-B27-positive and -negative UA, and SpA.

Results.

We found 10.1% of UA (38/375) versus 7.2% (403/5584) of controls were HLA-B27-positive (OR 1.5, 95% CI 1.0–2.1; p = 0.037). HLA-B27-positive patients with UA had more SpA features than HLA-B27-negative patients (mean 1.6, SD 1.0, and 0.9 SD 0.6; p < 0.001), but patients with SpA had significantly more SpA features (mean 4.5, SD 1.5; p < 0.001). Family history and preceding infection were features more common in HLA-B27-positive than in HLA-B27-negative UA (15.8% vs 1.3%, p = 0.04 and 15.8% vs 2.6%, p = 0.04). After HLA-B27 testing, 21 additional patients (5.6%) with UA could potentially have been classified with pSpA according to the ASAS criteria.

Conclusion.

HLA-B27 is more common in patients with UA than in controls. However, the yield of HLA-B27 testing in UA is low. Our results suggest that HLA-B27 testing should be reserved for patients with additional SpA features.

[Evidence-based recommendations for the management of undifferentiated peripheral inflammatory arthritis (UPIA). The German perspective on the international 3e initiative]

INTRODUCTION

Peripheral arthritis is the most common presenting complaint in clinical rheumatology. Unequivocal identification of the underlying entity can be difficult, particularly at an early stage. Such cases are commonly referred to as undifferentiated peripheral inflammatory arthritis (UPIA). Since evidence-based recommendations for the clinical management of UPIA are lacking, this international 3e initiative convened 697 rheumatologists from 17 countries to develop appropriate recommendations.

METHODS

Based on a systematic literature research in Medline, EMBASE, Cochrane Library, and the ACR/EULAR abstracts of 2007/2008, 10 multinational recommendations were developed by 3 rounds of a Delphi process. In Germany, a national group of experts worked on 3 additional recommendations using the same method. The recommendations were discussed among the members of the 3e initiative and the degree of consensus was analyzed as well as the potential impact of the recommendations on clinical practice.

RESULTS

A total of 39,756 references were identified, of which 250 were systematically reviewed for the development of 10 multinational recommendations concerning differential diagnosis, diagnostic and prognostic value of clinical assessments, laboratory tests and imaging techniques, and monitoring of UPIA. In addition, 3 national recommendations on the diagnostic and prognostic value of a response to anti-inflammatory therapy on the analysis of synovial fluid and on enthesitis were developed by the German experts based on 35 out of 5542 references.

CONCLUSIONS

The article translates the 2011 published original paper of the international 3e initiative (Machado et al., Ann Rheum Dis 70:15-24, 2011) and reports the methods and results of the national vote and the additional 3 national recommendations.

Australian and New Zealand national evidence-based recommendations for the investigation and follow-up of undifferentiated peripheral inflammatory arthritis: an integration of systematic literature research and rheumatological expert opinion

AIM

To develop Australian and New Zealand (ANZ) recommendations for the investigation and follow-up of undifferentiated peripheral inflammatory arthritis (UPIA) using an evidence-based approach.

METHODS

Ten questions pertaining to the investigation and follow-up of patients with UPIA in daily rheumatological practice were defined by clinicians using a modified Delphi approach. A systematic literature search was conducted for each of the final questions. The results were presented to a workshop of 54 ANZ rheumatologists in May 2009. Discussions were held to develop consensus statements for each question, based on published evidence and clinical experience/expertise.

RESULTS

Ten recommendations were made on diagnostic value of clinical features in the patient's history and examination, predictors of poor prognosis and persistence, synovial fluid analysis, serology, imaging and human leukocyte antigen B27 testing. The lack of specific research to inform recommendations presented a challenge. Dynamic discussion groups outlined individual experience in areas without good quality clinical trial evidence. The median strength of support for the final set of recommendations was 7/10 (interquartile range 6-8), ranging from 6 to 9 for individual statements.

CONCLUSION

Ten ANZ recommendations for the investigation and follow-up of UPIA were formulated, based on available evidence and extensive clinical experience. The systematic literature review was of limited value while animated discussion of individual experience, with subsequent information exchange, highlighted the importance of merging clinical expertise with published literature to establish practical recommendations that can improve quality of care in rheumatology.

Ultrasonographic assessment of enthesitis in HLA-B27 positive patients with rheumatoid arthritis, a matched case-only study

Introduction

HLA-B27 has a modifier effect on the phenotype of multiple diseases, both associated and non-associated with it. Among these effects, an increased frequency of clinical enthesitis in patients with Rheumatoid Arthritis (RA) has been reported but never explored again. We aimed to replicate this study with a sensitive and quantitative assessment of enthesitis by using standardized ultrasonography (US).

Methods

The Madrid Sonography Enthesitis Index (MASEI) was applied to the US assessment of 41 HLA-B27 positive and 41 matched HLA-B27 negative patients with longstanding RA. Clinical characteristics including explorations aimed to evaluate spondyloarthrtitis and laboratory tests were also done.

Results

A significant degree of abnormalities in the entheses of the patients with RA were found, but the MASEI values, and each of its components including the Doppler signal, were similar in HLA-B27 positive and negative patients. An increase of the MASEI scores with age was identified. Differences in two clinical features were found: a lower prevalence of rheumatoid factor and a more common story of low back pain in the HLA-B27 positive patients than in the negative. The latter was accompanied by radiographic sacroiliitis in two HLA-B27 positive patients. No other differences were detected.

Conclusion

We have found that HLA-B27 positive patients with RA do not have more enthesitis as assessed with US than the patients lacking this HLA allele. However, HLA-B27 could be shaping the RA phenotype towards RF seronegativity and axial involvement.

Selective IgA deficiency in autoimmune diseases

Selective immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. It has previously been suggested to be associated with a variety of concomitant autoimmune diseases. In this review, we present data on the prevalence of IgAD in patients with Graves disease (GD), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), celiac disease (CD), myasthenia gravis (MG) and rheumatoid arthritis (RA) on the basis of both our own recent large-scale screening results and literature data. Genetic factors are important for the development of both IgAD and various autoimmune disorders, including GD, SLE, T1D, CD, MG and RA, and a strong association with the major histocompatibility complex (MHC) region has been reported. In addition, non-MHC genes, such as interferon-induced helicase 1 (IFIH1) and c-type lectin domain family 16, member A (CLEC16A), are also associated with the development of IgAD and some of the above diseases. This indicates a possible common genetic background. In this review, we present suggestive evidence for a shared genetic predisposition between these disorders.

Multinational evidence-based recommendations on how to investigate and follow-up undifferentiated peripheral inflammatory arthritis: integrating systematic literature research and expert opinion of a broad international panel of rheumatologists in the 3E Initiative

Objective

To develop evidence-based recommendations on how to investigate and follow-up undifferentiated peripheral inflammatory arthritis (UPIA).

Methods

697 rheumatologists from 17 countries participated in the 3E (Evidence, Expertise, Exchange) Initiative of 2008–9 consisting of three separate rounds of discussions and modified Delphi votes. In the first round 10 clinical questions were selected. A bibliographic team systematically searched Medline, Embase, the Cochrane Library and ACR/EULAR 2007–2008 meeting abstracts. Relevant articles were reviewed for quality assessment, data extraction and synthesis. In the second round each country elaborated a set of national recommendations. Finally, multinational recommendations were formulated and agreement among the participants and the potential impact on their clinical practice was assessed.

Results

A total of 39 756 references were identified, of which 250 were systematically reviewed. Ten multinational key recommendations about the investigation and follow-up of UPIA were formulated. One recommendation addressed differential diagnosis and investigations prior to establishing the operational diagnosis of UPIA, seven recommendations related to the diagnostic and prognostic value of clinical and laboratory assessments in established UPIA (history and physical examination, acute phase reactants, autoantibodies, radiographs, MRI and ultrasound, genetic markers and synovial biopsy), one recommendation highlighted predictors of persistence (chronicity) and the final recommendation addressed monitoring of clinical disease activity in UPIA.

Conclusions

Ten recommendations on how to investigate and follow-up UPIA in the clinical setting were developed. They are evidence-based and supported by a large panel of rheumatologists, thus enhancing their validity and practical use.

General characteristics of an early arthritis cohort in Argentina

OBJECTIVE

The aim of the present study is to describe the general characteristics of a cohort of patients with early arthritis in Argentina.

METHODS

CONAART (Consorcio Argentino de Artritis Temprana--Argentine Consortium for Early Arthritis) is an initiative of seven rheumatology centres across Argentina. Patients were included if they had at least one or more swollen joints and <2 years of disease duration. Social, demographic, familiar, hereditary, clinical and laboratory data were recollected. At first visit and every year, X-rays of hands and feet were performed and working characteristics and pharmaco-economic data were re-collected.

RESULTS

A total of 413 patients were included. Of them, 327 (79.2%) were women with a median age of 49 years and a median disease duration of 6 months. Of the total, 183 (44.3%) had RA (ACR 1987) and 167 (40.4%) undifferentiated arthritis (UA). Other diagnoses included: 12 crystalics, 11 PsA, 6 uSpA, 6 other CTD, 1 AS and 27 other diagnosis. As 85% of our population had RA and UA, we only compared these two groups of patients. Patients with RA had significantly worse activity parameters of the disease (DAS of 28 joints), functional capacity (HAQ) and quality of life (Rheumatoid Arthritis Quality of Life) than patients with UA. The frequency of RF and anti-CCP, and symmetrical distribution were also significantly higher in patients with RA compared with UA patients. All patients with RA initiated early specific treatment, in a period no longer than 6 months from the beginning of the disease.

CONCLUSION

Early arthritis clinics are a useful tool to identify and treat patients with different forms of joint involvement.

The Value of HLA-DRB1 Shared Epitope, −308 Tumor Necrosis Factor-α Gene Promoter Polymorphism, Rheumatoid Factor, Anti-Citrullinated Peptide Antibodies, and Early Erosions for Predicting Radiological Outcome in Recent-Onset Rheumatoid Arthritis

Objective.

To study the value of HLA-DRB1 shared epitope (SE), −308 tumor necrosis factor-α (TNF-α) gene promoter polymorphism, rheumatoid factor (RF), anti-citrullinated peptide antibodies (anti-CCP), and baseline erosions for predicting radiological outcome at 1 year in patients with recent-onset rheumatoid arthritis (RA).

Methods.

Radiological damage was assessed by radiographs at baseline and at 1 year in an inception cohort of 134 RA patients with disease duration ≤ 1 year at study entry. Radiographs were scored with the modified Sharp/van der Heijde (SvdH) erosion score for hands, wrists, and feet. The predictive value of the variables was studied by multiple linear regression analysis, using immunogenetic factors, baseline SvdH erosion score, and type of treatment during the followup period as independent variables, and SvdH erosion score at 1 year as the dependent variable.

Results.

The SvdH erosion score increased from the baseline visit to the 1-year visit in 49 patients (36.6%). In multiple linear regression analysis, radiological outcome was significantly predicted by SE homozygosity (ß coefficient 1.75; 95% CI 1.54, 2.96; p = 0.005) and baseline SvdH erosion score (ß coefficient 1.56; 95% CI 1.4, 1.71; p < 0.001). This model explained 78% of the variability of the dependent variable (R2 = 0.779).

Conclusion.

Erosive damage at 1 year in patients with recent-onset RA is significantly influenced by SE homozygosity and the presence of baseline erosions, but not by RF status, anti-CCP status, or −308 TNF-α genotype.

Enhanced MRI in early undifferentiated oligoarthritis of the knee joints: improvements already visible after 2 months of DMARDs treatment

To describe (1) the findings with MRI in a series of patients with early undifferentiated oligoarthritis of the knee joint(s) and (2) the early effect after 2 months of treatment with only methotrexate (MTX) and hydroxychloroquine (HCQ) as disease-modifying antirheumatic drugs (DMARDs), 15 consecutive patients with undifferentiated oligoarthritis of the knee joint(s) were recruited. The mean age was 31.7 years (SD = 8.1 years), and the mean disease duration was 15.3 months (SD = 12.2 months). In all patients, synovial fluid analysis, RF, anti-CCP2 antibodies, ANA, CRP, ESR, and routine laboratory investigations were performed. Enhanced MRI was done at initial evaluation and after 2 months treatment. Four of the 15 patients had positive RF and 6 had positive anti-CCP2. After treatment with DMARDs, a regression was seen regarding effusion and synovitis in all patients; in one of three patients, the bone edema had regressed. Synovial thickening as measured by enhanced MRI decreased significantly (p < 0.01) and correlated significantly with the improved ESR and CRP (p < 0.01). After 2 months treatment with MTX and HCQ, the MRI improved considerably especially regarding synovial thickening.

The association of anti-CCP antibodies with disease activity in rheumatoid arthritis

Antibodies to citrullinated proteins have been described in patients with rheumatoid arthritis (RA) and these appear to be the most specific markers of the disease. Our objective was to determine the frequency of antibodies to cyclic citrullinated peptides (CCPs) in patients with RA and the association of anti-CCP antibodies with disease activity, radiological erosions and HLA DR genotype. Forty patients with RA and 38 patients with fibromyalgia were included in this study. Serum samples were collected from both patient groups with RA and fibromyalgia. Anti-CCP was measured by the corresponding enzyme-linked immunosorbent assay. Additionally, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), disease activity score (DAS), visual analog scala (VAS), HLA genotype and radiographic information were determined in patients with RA. The rate of sensitivity and specificity of anti-CCP reactivity for the diagnosis RA were measured (sensitivity 50%, specificity 100%). There is no significant difference between anti-CCP (+) and anti-CCP (-) RA patients for DAS28, VAS, ESR, CRP, disease duration, HLA genotype, and radiological assessment of hand. However, there was a significant difference between anti-CCP (+) and anti-CCP (-) RA patients for RF and the radiological assessment of left and right wrists (respectively, P < 0.05, P = 0.04, P = 0.01). There was no significant correlation between anti-CCP antibody and ESR, CRP, VAS, DAS 28 or radiological assessment. A small but significant correlation was found between RF and anti-CCP antibody (P = 0.02, r = 0.35).

Established rheumatoid arthritis: clinical assessments

Clinical assessment of established rheumatoid arthritis (RA) can have several purposes. It can be used to evaluate prognosis, disease course or interventions at both the individual and the group level (i.e. in a clinical trial), over the short or long term. The instruments used for the different purposes are not always the same. For example, information on prognosis is very useful when assessing the risk:benefit ratio of early aggressive pharmacotherapy; however, established prognostic factors are currently of limited use in individual patients with established RA. As, at the individual patient level, disease activity, disability and joint damage have variable courses, the course of the disease should be evaluated regularly both with process (i.e. erythrocyte sedimentation rate, joint counts) and with outcome (i.e. radiological progression, sum of past process) measures. For the evaluation of interventions, 'core sets' of valid measures to assess disease activity, outcome and specific criteria for improvement are used; these can, to some extent, be useful in clinical practice.

Independent associations of anti-cyclic citrullinated peptide antibodies and rheumatoid factor with radiographic severity of rheumatoid arthritis

Several recent publications have established a strong association between anti-cyclic citrullinated peptide antibody (anti-CCP)-positive rheumatoid arthritis (RA) and carriage of shared epitope (SE) alleles. Although anti-CCP have also been associated with more severe RA, the issue of whether this is independent of rheumatoid factor (RF) has not been addressed. To identify associations between RF, anti-CCP, SE status and radiological damage, we studied a large cross-sectional cohort with longstanding RA. Individuals (n = 872) enrolled in the study all fulfilled the American College of Rheumatology criteria for RA, had a minimum disease duration of 3 years, and at least one definite radiographic erosion was present in hands or feet. Radiographs were scored blind at study entry by a single musculoskeletal radiologist using a modified Larsen's score. Anti-CCP and RF levels were determined using enzyme-linked immunosorbent assay, and DRB1 typing was performed using polymerase chain reaction based methodology. Both anti-CCP and RF levels were strongly associated with radiographic severity (P < 0.0001). In subgroups stratified for both anti-CCP and RF status, evidence of independent associations of both antibodies with radiographic outcome was found (P < 0.0001). An association of SE alleles with radiographic severity was present only in RF-negative individuals. Anti-CCP positivity was associated with SE status with evidence of a gene-dose effect, most markedly in RF-negative individuals (P < 0.01). Anti-CCP and RF status are independent severity factors for RA, with SE alleles playing at most a secondary role. Our data support the view that previously described associations between SE and radiological severity, especially in RF-negative patients, may be indirect and due to an association with anti-CCP.

Inflammatory synovitis due to underlying lipoma arborescens (gadolinium-enhanced MRI features): report of two cases

Lipoma arborescens (synovial lipomatosis) is a rare, benign intra-articular lesion of unknown etiology. It is a very rare primary benign tumour of the synovium, which usually affects the knee joint and can lead to slowly progressive chronically swollen knee. In this report we described two cases with this rare entity with initial presentation of inflammatory synovitis. We also described the Gadolinium (Gd-DTPA)-enhanced MRI features. To the best of our knowledge, this is the first report that described inflammatory synovitis in association with this rare entity.

Regulation of anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis: contrasting effects of HLA-DR3 and the shared epitope alleles

OBJECTIVE

To examine the association between HLA-DRB1 alleles and the production of anti-cyclic citrullinated peptide (anti-CCP) and rheumatoid factor (RF) autoantibodies in patients with rheumatoid arthritis (RA).

METHODS

We studied 1,723 Caucasian RA patients enrolled in the North American Rheumatoid Arthritis Consortium (NARAC) family cohort and the Study of New Onset Rheumatoid Arthritis (SONORA) cohort. All patients were tested for anti-CCP antibodies (by enzyme-linked immunosorbent assay), RF (by nephelometry), and HLA-DR genotype (by polymerase chain reaction and sequence-specific oligonucleotide hybridization).

RESULTS

When controlled for the presence of RF, anti-CCP positivity was strongly associated with the HLA-DRB1 shared epitope (SE). In RF+ patients, the presence of the SE was very significantly associated with anti-CCP positivity, with an odds ratio (OR) of 5.8 and a 95% confidence interval (95% CI) of 4.1-8.3. This relationship was also seen in RF- patients (OR 3.1 [95% CI 1.8-5.3]). In contrast, RF positivity was not significantly associated with presence of the SE independently of anti-CCP antibodies. Strikingly, HLA-DRB1*03 was strongly associated with reduced anti-CCP titers, even after controlling for the presence of the SE and restricting the analysis to anti-CCP+ patients. HLA-DR3 was also associated with anti-CCP- RA in our population.

CONCLUSION

The HLA-DRB1 SE is strongly associated with the production of anti-CCP antibodies, but not RF. In contrast, HLA-DR3 alleles are associated with anti-CCP- disease and with lower levels of anti-CCP antibodies, even when controlling for the SE. These data emphasize the complexity of the genetic effects of the major histocompatibility complex on the RA phenotype.

Association of tumor necrosis factor α polymorphism, but not the shared epitope, with increased radiographic progression in a seropositive rheumatoid arthritis inception cohort

OBJECTIVE

To determine whether the tumor necrosis factor alpha (TNFA) -308 guanine-to-adenosine polymorphism and/or the shared epitope (SE) is associated with radiographic damage in patients with early rheumatoid arthritis (RA).

METHODS

The cohort consisted of 189 patients with early seropositive RA (median 5.6 months since symptom onset) who had active disease, no previous disease-modifying antirheumatic drug treatment, and >or=2 sets of scored radiographs of the hands/wrists and forefeet. TNFA -308 polymorphism was analyzed by polymerase chain reaction pyrosequencing. The SE was defined as presence of any 1 of the following HLA-DRB1 alleles: *0101, *0102, *0401, *0404, *0405, *0408, *0410, *1001, *1402, or *1406. Radiographic progression was assessed by the total Sharp score.

RESULTS

Using a weighted least-squares regression analysis, patients with the -308 TNFA AA plus AG genotypes (n=49) had significantly higher rates of progression in erosion scores (median 0.84 versus 0.48 units/year), joint space narrowing (JSN) scores (0.42 versus 0.04), and total Sharp scores (1.70 versus 0.61) compared with patients with the TNFA GG genotype (n=140). Presence of the SE (n=137) was associated with significantly lower progression rates (per year) for total Sharp scores (median 0.9 versus 1.25 units/year) and JSN scores (0.04 versus 0.41), but not for erosion scores (0.50 versus 0.61) compared with patients without the SE (n=52). In a least-squares multiple linear regression model, the presence of the AA plus AG genotypes was associated with a significantly higher progression rate after adjusting for the presence of the SE, interaction between the SE and the AA plus AG genotypes, baseline log C-reactive protein level, Health Assessment Questionnaire Disability Index, total Sharp score, swollen joint count, and presence of osteophytes (osteoarthritis). There was a strong linkage disequilibrium between DRB1*0301 and TNFA polymorphism (D'=0.84, r2=0.45, P<0.001).

CONCLUSION

This study showed an association between the TNFA -308 polymorphism and progression of radiographic damage in patients with early seropositive RA. This association appeared to be independent of the SE, but might be dependent on other genetic variants in linkage disequilibrium with the -308 TNFA A allele and DRB1*0301. Further studies should be conducted to validate these results in both longitudinal observational cohorts and randomized clinical trials.

Association of HLA-DR3 with anti-cyclic citrullinated peptide antibody-negative rheumatoid arthritis

OBJECTIVE

Recent data have shown that the most prominent and longest known genetic risk factors for rheumatoid arthritis (RA), HLA-DRB1 shared epitope alleles, are only associated with RA that is characterized by the presence of antibodies against cyclic citrullinated peptide (anti-CCP antibodies) and not with anti-CCP-negative RA. We undertook this study to investigate whether anti-CCP-negative RA is associated with other HLA-DRB1 alleles.

METHODS

HLA typing was performed for 377 patients from the Leiden Early Arthritis Clinic who were diagnosed as having RA within the first year of followup (206 anti-CCP-positive patients and 171 anti-CCP-negative patients), 235 patients who, after 1 year, had undifferentiated arthritis (UA) (28 anti-CCP-positive patients and 207 anti-CCP-negative patients), and 423 healthy control subjects. Odds ratios (ORs) with 95% confidence intervals (95% CIs) for HLA-DRB1 allele frequencies were determined for all patient groups compared with the healthy control group.

RESULTS

HLA-DR3 was more frequently present in the anti-CCP-negative RA group than in the control group (OR 1.84, 95% CI 1.26-2.67). This was not the case for anti-CCP-positive RA (OR 0.92, 95% CI 0.60-1.40). HLA-DR3 was also more frequently present in anti-CCP-negative UA patients (OR 1.59, 95% CI 1.10-2.28), but not in anti-CCP-positive UA patients (OR 0.68, 95% CI 0.17-1.92).

CONCLUSION

HLA-DR3 is associated with anti-CCP-negative arthritis and not with anti-CCP-positive arthritis. These data show that distinct genetic risk factors are associated with the presence of anti-CCP antibodies in RA and indicate that different pathogenetic mechanisms underlie anti-CCP-positive and anti-CCP-negative RA.

Early Undifferentiated Arthritis

Patients who cannot be classified as having a well-defined arthropathy typically are labeled as having undifferentiated arthritis. Some patients develop sufficient features to permit classification, whereas others remain undifferentiated, but with persistent joint inflammation, functional disability, and development of radiographic damage. Identifying the subset of patients destined to develop rheumatoid arthritis, spondyloarthropathy, or a more severe and persistent form of undifferentiated arthritis and choosing appropriate treatment strategies remain challenges for clinicians. Numerous investigative strategies are available with which to characterize undifferentiated arthritis and assess prognosis. This article discusses the characteristics of undifferentiated arthritis at presentation and the investigative strategies that can be used to predict prognosis and outcome early in the disease course. Therapeutic strategies also are explored.

Clinical, laboratory and genetic markers associated with erosions and remission in patients with early inflammatory arthritis: a prospective cohort study

We investigated the relationship between clinical, laboratory and genetic markers and outcome measures in 159 patients with recent onset of inflammatory arthritis (IA). The majority of patients were managed in community-based rheumatology practice. Median duration of arthritis at baseline was 3 months with median follow-up of 4.0 years (range 0-10). Markers of disease activity and 1987 ACR criteria for rheumatoid arthritis (RA) were estimated every 6 months for the first 2 years and annually thereafter. Presence of shared epitopes (SE) was established by PCR-based method. Main outcome variables were attainment of remission and presence of erosions on X-rays of hands and feet at 3 years. Remission was seen in 34.3% of patients and was independently related to age 60 and older (odds ratio (OR) 3.2; 95% confidence interval (CI), 1.2-8.7) and inversely to the presence of rheumatoid factor (RF) (OR 8.3; 95% CI, 3.2-21.3 for persistent arthritis). Patients with two SE were likely to have persistent arthritis (P=0.006), but this was not significant when corrected for RF. Independent predictors for erosions at 3 years were RF (OR 7.5; 95% CI, 1.9-29.5) and area under the curve for number of swollen joints (OR 1.08; 95% CI, 1.02-1.16). SE status was not predictive of erosions at 3 years (OR 1.6; 95% CI, 0.7-3.7). In univariate analysis, patients possessing DERAA motif on DRB1 were less likely to have erosive disease than without this motif at 4 years (OR 0.21; 95% CI, 0.0-0.9, P=0.037) but this finding was partly explained by adjusting for RF (adjusted OR 0.24; 95% CI 0.04-1.37). In this study of recent onset IA, active disease and RF were associated with poor outcome. Whilst SE did not predict erosive disease, patients with DERAA motif may be protected against erosions whilst the presence of two SE alleles suggests persistence of arthritis.

Elevated levels of IgM and IgA antibodies to Proteus mirabilis and IgM antibodies to Escherichia coli are associated with early rheumatoid factor (RF)-positive rheumatoid arthritis

OBJECTIVE

Antibodies to Proteus mirabilis were previously detected in patients with established rheumatoid arthritis (RA). We examined the prevalence of antibodies to P. mirabilis and their associations with RA in early synovitis patients.

METHODS

Two hundred and forty-six patients with inflammatory arthritis for less than 1 yr were prospectively evaluated for 1 yr. Of these patients, 30% had rheumatoid factor (RF)-positive RA, 16% RF-negative RA, 17% a spondyloarthropathy and 37% undifferentiated arthritis. Serum antibodies to P. mirabilis, Escherichia coli and other potentially arthritogenic organisms (Chlamydia, Salmonella, Shigella, Campylobacter, Yersinia and parvovirus B19) and for antibodies specific for immunoglobulin (Ig) G damaged with advanced glycation end-products (anti-IgG-AGE) were measured.

RESULTS

IgM and IgA anti-Proteus antibodies were significantly higher in patients with RF-positive RA compared with all other patient groups (P < 0.0005 and P < 0.005). Anti-P. mirabilis IgG, and IgG, IgA, and IgM antibodies to other potentially arthritogenic pathogens did not differ in the patient groups. IgM antibodies to E. coli were elevated in RF-positive RA patients. Anti-P. mirabilis IgM and IgA results were not explained by false-positive reactions, because after absorption of RF there was no decrease in antibodies to Proteus in 10 of 12 patients. Proteus and E. coli antibodies were highest in patients positive for both RF and anti-IgG-AGE antibodies (P<0.001). Patients with erosions tended to have higher IgA anti-Proteus titres, but no association with the shared HLA epitope or treatment was detected.

CONCLUSION

Anti-P. mirabilis IgM and IgA and anti-E. coli IgM antibody elevations are associated with early seropositive RA and the presence of anti-IgG-AGE antibodies. The role that P. mirabilis or E. coli plays in early RF-positive RA requires further investigation.

Raised granzyme B levels are associated with erosions in patients with early rheumatoid factor positive rheumatoid arthritis

BACKGROUND

Raised granzyme B in serum and synovium of patients with rheumatoid arthritis suggests a role for cytotoxic T cells and natural killer cells in the pathogenesis of this disease.

OBJECTIVE

To evaluate serum granzyme B in patients with early arthritis and correlate it with specific diagnosis and clinical indices of disease severity.

METHODS

257 patients with inflammatory arthritis for less than one year (46% rheumatoid arthritis, 17% spondyloarthropathy, 37% undifferentiated arthritis) had a prospective clinical, serological, and radiographic evaluation. Granzyme B was measured in initial sera by ELISA. Patients were HLA typed for DR alleles using sequence specific primers. A logistic regression model was used to evaluate the potential prognostic value of serum granzyme B in predicting radiographic erosions after one year of follow up.

RESULTS

Granzyme B values were similar in rheumatoid arthritis, spondyloarthropathy, and undifferentiated arthritis. Concentrations were higher in rheumatoid factor (RF) positive patients than in RF negative patients (mean (SD): 3.15 (0.92) v 2.89 (0.71) pg/ml; p<0.05). After one year, erosions were present in 30% of patients in the overall cohort, and in 44% of patients with rheumatoid arthritis. In the entire cohort, serum granzyme B did not predict erosions independently. However, high granzyme B was an independent predictor of early erosions in patients with RF positive rheumatoid arthritis (odds ratio = 4.83 (95% confidence interval, 1.13 to 20.59)) (p<0.05).

CONCLUSIONS

Granzyme B may be a useful prognostic marker in early rheumatoid arthritis and may provide important clues to the pathogenesis of this disease.

Outcome of patients with undifferentiated chronic monoarthritis: retrospective study of 46 cases

OBJECTIVE

To determine the natural history of undifferentiated monoarthritis of more than 3 months' duration and to evaluate the usefulness of classic diagnostic tools for identifying factors associated with outcomes.

METHOD

Retrospective study of 46 patients with undifferentiated monoarthritis of more than 3 months' duration.

RESULTS

Full resolution was the outcome in 50% of cases. Rheumatoid arthritis and spondyloarthropathy were the most common diagnoses in the remaining patients. HLA-B27 status was the only significant predictor of outcome: progression to spondyloarthropathy was significantly more common (P = 0.05) among HLA-B27-positive patients. Mean time to full recovery was significantly shorter than mean time to disease progression (12 vs. 45 months, P = 0.0015). Intraarticular glucocorticoid injections were effective in over 50% of patients. Arthritis relief during the month following the injection was associated with self-limited disease. The role for magnetic resonance imaging in managing patients with undifferentiated monoarthritis remains unclear.

CONCLUSION

In patients with undifferentiated monoarthritis, the likelihood of a full recovery is 50%. The only significant predictor of outcome was positive HLA-B27 status, which was associated with progression to spondyloarthropathy.

Diagnostic usefulness of synovial vascular morphology in chronic arthritis. A systematic survey of 100 cases

OBJECTIVES

To assess the diagnostic usefulness of the systematic analysis of synovial vascular morphology in various inflammatory, early, and longstanding arthropathies, and to examine the validity of the vascular patterns in predicting the evolution of a group of patients with undifferentiated arthritis (UA).

METHODS

One hundred patients who underwent rheumatologic arthroscopy of a symptomatic joint (85 knees, 11 wrists, 3 elbows, 1 metacarpophalangeal joint) were evaluated. The same observer, blinded to patient diagnosis, analyzed the video recordings of the arthroscopies. Vascular morphology was classified into 3 patterns: straight, tortuous, and mixed.

RESULTS

Eighty-one patients had inflammatory arthritis: 35 rheumatoid arthritis (RA), 16 psoriatic arthritis (PsA), 13 spondyloarthropathies (SpA), and 17 UA. Forty-nine percent of patients with RA had a straight pattern, 28% a mixed, and 23% a tortuous one. The sensitivity rate of the straight pattern for RA was 77% and the specificity rate was 70%. Seventy-six percent of RA patients with a straight pattern were rheumatoid factor positive (RF+) against 25% of RA patients with a tortuous pattern. The odds ratio for RA associated to straight compared with tortuous pattern was 57.3 (95% confidence interval, 6.6 to 499.5; P <.001). Patients with PsA and SpA shared the same pattern and were analyzed as 1 group. Ninety-three percent of patients with PsA/SpA had a tortuous pattern, 4% a straight pattern, and 3% a mixed pattern. The sensitivity rate of the tortuous pattern for PsA/SpA was 61% and the specificity rate was 95%. During 2 years of follow-up, 6 of 17 patients with UA were definitely diagnosed: 4 RA (2 RF+ and straight pattern; 2 with a tortuous pattern, 1 with RF+ and HLA-B27+); 1 SpA and 1 PsA, both with a tortuous pattern. No differences in vascular patterns were observed according to disease duration. Our results indicate that vascular patterns are not modified by disease modifying antirheumatic drug (DMARD) treatment. The other 19 patients had osteoarthritis (n = 8) and calcium pyrophosphate dihydrate crystal deposition disease (n = 11) and their predominant vascular pattern was tortuous-like.

CONCLUSIONS

Arthroscopic assessment of synovial vascular changes in chronic arthritis may be of diagnostic and pathogenetic interest, although differences between published studies suggest a need for consensus in evaluating vascular patterns. A straight pattern is strongly associated with RF + RA whereas a tortuous pattern is generally associated with PsA or SpA; these associations are independent of disease duration. The vascular pattern likely does not change qualitatively with DMARD therapy. The application of this technique to the diagnosis or prognosis of patients with UA may be a complementary tool for the treatment of these patients, but larger, prospective studies are necessary to confirm this hypothesis.

HLA-DR2 dose effect on susceptibility to multiple sclerosis and influence on disease course

Models of disease susceptibility in multiple sclerosis (MS) often assume a dominant action for the HLA-DRB1*1501 allele and its associated haplotype (DRB1*1501-DQB1*0602 or DR2). A robust and phenotypically well-characterized MS data set was used to explore this model in more detail. A dose effect of HLA-DR2 haplotypes on MS susceptibility was revealed. This observation suggests that, in addition to the role of HLA-DR2 in MS, two copies of a susceptibility haplotype further increase disease risk. Second, we report that DR2 haplotypes modify disease expression. There is a paucity of benign MS and an increase of severe MS in individuals homozygous for DR2. Concepts of the molecular mechanisms that underlie linkage and association of the human leukocyte antigen (HLA) region to MS need to be revised to accommodate these data.

Seronegative spondyloarthritides

Epidemiological studies on the spondyloarthritides have been hindered in the past by the lack of adequate classification criteria for the whole group of these diseases. Using the Amor and the European Spondyloathropathy Study Group (ESSG) criteria the total prevalence of such diseases has been found to be higher than estimated in the past. The prevalence of ankylosing spondylitis varies across populations, but closely parallels the frequency of HLA B27-associated subtypes. The lack of well established criteria for reactive arthritis and the varying expression of its clinical manifestations are the principal reasons for the under-reporting of the true prevalence and incidence of this type of spondyloarthritis. Few data exist on the prevalence and incidence of psoriatic arthritis. A recent European study on an inception cohort of patients having inflammatory bowel disease has evaluated the prevalence of spondyloarthritis using the ESSG criteria. Of the patients studied, 18% met these criteria. Undifferentiated spondyloarthritis is one of the most frequent spondyloarthritides. It also includes a number of different subtypes.

Relationship among the HLA-DRB1 shared epitope, smoking, and rheumatoid factor production in rheumatoid arthritis

OBJECTIVE

Rheumatoid factor (RF) production in rheumatoid arthritis (RA) is generally associated with more severe disease. In some studies, RF production has been associated with carriage of HLA-DRB1 alleles encoding the RA-associated shared epitope (SE). Patients who smoke are also more likely to be RF positive. In this study, we investigated whether the association between RF production and smoking was influenced by carriage of the SE.

METHODS

The smoking histories of 371 RA patients attending a hospital clinic were recorded. RF levels and SE status were determined for every patient, and the associations between the SE, smoking, and RF production were examined. HLA-DRB1 typing was performed using polymerase chain reaction. Results were analyzed using chi-square tests and logistic regression analysis.

RESULTS

Patients who had ever smoked were significantly more likely to be RF positive than nonsmokers (odds ratio 2.2, P < 0.0001). This remained significant (P = 0.003) after correction for age, sex, and disease duration in a logistic regression model. An association was also found between RF positivity and carriage of the SE (P = 0.03, after correction for age, sex, and disease duration), but significance was reduced or lost after correction for previous or current smoking (P = 0.05 and 0.09, respectively). Examination of the major SE phenotypes in this RA population by multivariate logistic regression analysis revealed that only DRB1*0401 was associated with RF positivity, and that this was independent of the influence of smoking.

CONCLUSION

Our data confirm that RF production in RA patients is associated with smoking. This does not appear to depend on an HLA-DR-restricted immune response. The association of the SE with RF positivity is primarily due to HLA-DRB1*0401. This appears to be independent of the association with smoking, although smoking further increases the likelihood of RF production in DRB1*0401 patients.

Value of laboratory tests in early prediction of rheumatoid arthritis

OBJECTIVE

To determine which laboratory test or tests at presentation best predicted a diagnosis of rheumatoid arthritis (RA) 2 years later.

METHODS

Two hundred seventy patients with early arthritis seen in 7 hospitals underwent comprehensive evaluations at 6-month intervals for 2 years, when the diagnosis of RA was assessed by 5 rheumatologists. The sensitivity and specificity of each test at the first visit for discriminating between RA (38%, n = 98) and non-RA patients were determined. Optimal cutoffs for continuous tests were derived from receiver operating characteristic curves. Sensitivity and specificity of test combinations selected by multiple logistic regression were determined.

RESULTS

IgM rheumatoid factor (RF) by enzyme-linked immunosorbent assay, IgG-antikeratin antibody (AKA), and latex test had the strongest associations with RA. These 3 tests formed the most powerful combination for distinguishing RA from non-RA.

CONCLUSION

IgM-RF, IgG-AKA, and the latex test are the best laboratory tests for discriminating between patients with and without RA. Combining these tests slightly improves diagnostic value.

Reshaping the shared epitope hypothesis: HLA-associated risk for rheumatoid arthritis is encoded by amino acid substitutions at positions 67-74 of the HLA-DRB1 molecule

OBJECTIVE

To further analyze the association of HLA-DRB1 alleles with disease susceptibility in recent-onset rheumatoid arthritis (RA).

METHODS

One hundred sixty-seven Caucasian RA patients and 166 healthy controls were typed for HLA-DRB1.

RESULTS

The association of susceptibility to RA with the group of alleles encoding the shared epitope susceptibility sequences (SESSs) was confirmed in recent-onset RA. Among non-SESS alleles, DRB1*07, *1201, *1301, and *1501 showed significant protective effects. Even after correction for the influence of SESS alleles, significant independent protective effects of DRB1 alleles were observed. Protective alleles shared a third hypervariable region motif. Independent homozygosity effects were observed both for susceptibility and for protective alleles.

CONCLUSION

Nonsusceptibility alleles differ significantly with regard to RA risk. Protective alleles show clear homology at positions 67-74, often encoding isoleucine at position 67 or aspartic acid at position 70. Susceptibility and protective alleles both show homozygosity effects. Based on these results and on data reported in the literature, in order to incorporate the finding of differential risks among nonsusceptibility alleles, we propose to reshape the shared epitope hypothesis as follows: HLA-associated risk for RA is encoded by amino acid substitutions at positions 67-74 of the HLA-DRB1 molecule.

Genetic studies, clinical heterogeneity, and disease outcome studies in rheumatoid arthritis

HLA haplotypes influence various clinical RA features considered to reflect severity in case-control and cohort studies. Of particular note is the fact that HLA generally influences the development of erosive and sometimes seropositive and nodular disease; in prospective studies, it noticeably affects joint surgical intervention. These are valuable clues indicating that HLA influences RA severity and chronicity. Nevertheless, HLA influences are generally weak enough so as to require large study subject numbers for detection. As a result, HLA genotyping has restricted usefulness for prediction of clinical severity in individual patients.

Human leukocyte antigen-DQ and DR polymorphisms predict rheumatoid arthritis outcome better than DR alone

Conflicting data have been published on the value of the shared epitope (SE) hypothesis in predicting disease outcome in rheumatoid arthritis (RA). Recently we have proposed an alternative hypothesis, referred to as the RA protection (RAP) model. In this model, the HLA-DQ loci carry predisposition while HLA-DRB1 alleles encoding the motif DERAA provide protection against severe RA. In the present study, we have compared the respective values of the models in predicting both remission and erosions in early RA patients. We made use of an early arthritis clinic in which 158 RA patients and 138 patients with undifferentiated arthritis were enrolled. Patients were typed for HLA-DQ and -DR using high resolution DNA typing methods. Homozygosity for predisposing HLA-DQ alleles was associated with no remission and high erosion score. The presence of DERAA-bearing DRB1 alleles was negatively associated with erosions in otherwise predisposed individuals and increased the chance of being in remission. We found that the RAP model was significantly better than the SE model in predicting remission rate and erosion scores at one and two years in early RA patients. We conclude that HLA polymorphism does not only affect RA susceptibility, but also protects against severe disease at early stage.

Prognostic factors for radiographic damage in early rheumatoid arthritis: a multiparameter prospective study

OBJECTIVE

To determine prognostic factors of radiologic damage and radiologic progression in early rheumatoid arthritis (RA).

METHODS

A cohort of 191 patients with RA whose disease duration was shorter than 1 year were prospectively followed up for 3 years. Radiologic scores (as determined by Sharp's method, modified by van der Heijde) and radiologic progression were used as outcome measures. Numerous baseline clinical, laboratory, genetic, and radiographic data were obtained.

RESULTS

The change in the total radiologic score for the patients followed up over 3 years was a mean +/- SD increase of 6.1 +/- 6.2. Radiologic progression was observed in 71 of the 172 patients for whom there were data at the end of the study. By univariate analysis with Fisher's exact test, radiologic scores and progression at followup were closely correlated with the baseline values of the erythrocyte sedimentation rate (ESR), C-reactive protein level, IgM and IgA rheumatoid factor positivity, antiperinuclear antibody positivity, radiologic scores, duration of morning stiffness, and RA-associated HLA-DRB1*04 genes. No correlation was demonstrated with sex, age, Disease Activity Score, swollen or tender joint counts, extraarticular manifestations, Health Assessment Questionnaire score, Ritchie Articular Index, patient's assessment of pain, positivity for anti-heat-shock protein 90-kd antibodies, anticalpastatin antibodies, anti-RA33 antibodies, antinuclear antibodies, YKL-40, or antikeratin antibodies, and HLA-DRB1*01 genes. The logistic regression analysis revealed that the only baseline values that were predictive of the 3-year radiologic scores were IgM rheumatoid factor positivity, DRB1*04 genes, pain score, and total radiologic score. Progression of joint damage was predicted by the ESR, IgM rheumatoid factor positivity, DRB1*04 genes, and erosions score at baseline.

CONCLUSION

Prognostic factors for radiographic damage in early RA were identified. A combination of these baseline values allowed us to draw up a predictive arithmetic score that could be used to predict radiologic damage at 3 years and radiologic progression in individual patients.

On the organization of an early arthritis clinic

Early active treatment with disease-modifying anti-rheumatic drugs has become standard management for patients with recent-onset rheumatoid arthritis. A number of questions, however, remain unresolved for practising clinicians, for example how early and how actively to treat and what the treatment goals should be. This chapter summarizes some recent data that have added important empirical evidence on these issues. It has thus been demonstrated that the formal organization of an early arthritis clinic shortens the referral time from primary care, that a delay in the institution of disease-modifying drug treatment leads to decreased long-term function and that early active treatment with pharmacotherapy as well as team-based care may increase occupational capacity. It is argued that adopting a day care approach in the initial encounter with specialist care may increase the possibility for patients actively to understand the disease and their own potentials to diminish and cope with its effects. The further development of care for early arthritis patients with new, potentially efficient but also expensive drugs will increase the requirement for a structured documentation of outcomes, systems for such documentation being discussed in the chapter.

Independent association of rheumatoid factor and the HLA-DRB1 shared epitope with radiographic outcome in rheumatoid arthritis

OBJECTIVE

Findings of a recent study suggested that HLA-DRB1 alleles encoding the rheumatoid arthritis (RA) "shared epitope" (SE) were not predictive of erosive damage at 2 years in patients with early inflammatory arthritis who were rheumatoid factor (RF) positive, but were predictive in those who were RF negative. The present study was undertaken to determine whether RF status was also important in the association between the SE and radiographic outcome in patients with longstanding RA.

METHODS

The association between radiographic outcome, HLA-DRBI, and RF status was examined in 299 RA patients with established disease (5-30 years). Radiographic outcome was measured by scoring radiographs of the hands and feet using the standard radiographs of Larsen. HLA-DRB1 typing was performed using polymerase chain reaction methodology. Results were stratified by RF status and analyzed by multiple regression.

RESULTS

An association between radiographic severity and the SE was found in RF-, but not RF+, patients. RF- patients carrying an SE allele had higher Larsen scores than RF- patients lacking the SE, although there was no association with SE dosage. The mean Larsen score was significantly higher in RF+ patients than in RF- patients, but there were no differences between RF+ patients with 0, 1, or 2 SE alleles. Multiple regression analysis confirmed independent associations of RF and SE positivity with radiographic outcome. No significant associations were found between RF and the SE, or RF and individual SE alleles.

CONCLUSION

Our data indicate that RF and the SE are independently associated with radiographic outcome in RA. In RF+ patients with longstanding RA, there is no apparent association between the presence of the SE and radiographic damage. However, in RF-patients, although radiographic outcome is generally less severe, there is an association between severity and presence of the SE.

Early rheumatoid arthritis: can we predict its outcome?

The continuing trend towards more aggressive treatment of rheumatoid arthritis (RA) has seen an increasing interest in the early phase of this chronic inflammatory disease. Optimal benefit from present and emerging therapies is limited by our prognostic abilities during this period. The present review attempts to outline first the many methodological issues encountered in studies of early RA, and second the extent to which each major outcome measure can be explained, both by readily available clinical variables and by HLA-DR genotyping. The evidence supporting the clinical usefulness of genotyping is discussed separately. Based on this information, a clinically appropriate approach to the management of early RA and the identification of patients suitable for experimental therapies is suggested.

Frequency of triggering bacteria in patients with reactive arthritis and undifferentiated oligoarthritis and the relative importance of the tests used for diagnosis

OBJECTIVE

Reactive arthritis (ReA) triggered by Chlamydia trachomatis or enteric bacteria such as yersinia, salmonella, Campylobacter jejuni, or shigella is an important differential diagnosis in patients presenting with the clinical picture of an undifferentiated oligoarthritis (UOA). This study was undertaken to evaluate the best diagnostic approach.

PATIENTS AND METHODS

52 patients with ReA, defined by arthritis and a symptomatic preceding infection of the gut or the urogenital tract, and 74 patients with possible ReA, defined by oligoarthritis without a preceding symptomatic infection and after exclusion of other diagnoses (UOA), were studied. The following diagnostic tests were applied for the identification of the triggering bacterium: for yersinia induced ReA-stool culture, enzyme immunoassay (EIA), and Widal's agglutination test for detection of antibodies to yersinia; for salmonella or campylobacter induced ReA-stool culture, EIA for the detection of antibodies to salmonella and Campylobacter jejuni; for infections with shigella-stool culture; for infections with Chlamydia trachomatis-culture of the urogenital tract, microimmunofluorescence and immunoperoxidase assay for the detection of antibodies to Chlamydia trachomatis.

RESULTS

A causative pathogen was identified in 29/52 (56%) of all patients with ReA. In 17 (52%) of the patients with enteric ReA one of the enteric bacteria was identified: salmonella in 11/33 (33%) and yersinia in 6/33 (18%). Chlamydia trachomatis was the causative pathogen in 12/19 (63%) of the patients with urogenic ReA. In patients with the clinical picture of UOA a specific triggering bacterium was also identified in 35/74 (47%) patients: yersinia in 14/74 (19%), salmonella in 9/74 (12%), and Chlamydia trachomatis in 12/74 (16%).

CONCLUSIONS

Chlamydia trachomatis, yersinia, and salmonella can be identified as the causative pathogen in about 50% of patients with probable or possible ReA if the appropriate tests are used.

Evidence for a protective role of the human leukocyte antigen class II region in early rheumatoid arthritis

OBJECTIVE

To analyse the distribution of predisposing DQ3 (DQB1*03(*04)/DQA1*03) and DQ5 (DQB1*0501/DQA1*01), shared epitope encoding and protective DRB1 alleles in patients with early rheumatoid arthritis (RA) and undifferentiated arthritis (UA).

METHODS

Consecutive patients enrolled in an early arthritis clinic were DNA-typed for HLA-DQ and DR. RA patients (n=195), UA patients (n=160) and controls from the same region (n=306) were sorted according to their DQ-DR phenotypes: DQ3 vs DQ5 and the presence or absence of a protective DERAA-positive DRB1 molecule. The three groups were also sorted according to the shared epitope (SE) hypothesis.

RESULTS

We observed the association of both DQ3 and DQ5 with RA. DQ3/3 homozygous individuals had the highest risk of developing disease [odds ratio (OR)=20.00]. Conversely DQ5, but not DQ3, was associated with undifferentiated arthritis (OR=2.15 vs 1.25). Consistent with these differences, DQ3-positive individuals had significantly more active disease at the first visit at the outpatient clinic than DQ5-positive patients. DRB1 alleles encoding a DERAA motif in their third hypervariable region provided a strong dominant protection against RA among DQ5-positive individuals and decreased arthritis activity among DQ3-positive patients. Individuals with SE-positive DR1, DR4 and DR10 alleles were also predisposed to RA, DR4/4 homozygous individuals having the highest risk of developing RA (OR=11.00).

CONCLUSION

The DQ3-DR4/9 haplotypes are associated with RA. The DQ5-DR1/10 haplotypes are associated with less active disease, i.e. UA, and DERAA encoding DRB1 alleles modulate either predisposition to or the severity of RA. We propose that HLA polymorphism influences not only the initiation or perpetuation of RA but also protection against the disease.

The telomeric part of the HLA region predisposes to rheumatoid arthritis independently of the class II loci

We have evaluated the possible contribution of genes besides DQ and DR to the association of HLA with rheumatoid arthritis (RA). To this end, we have looked at the allele distributions of six microsatellites, D6S1014, D6S2673, TNFalpha, MIB, C1-2-5, and C1-3-2 among 132 RA patients and 254 controls. We have defined 19 microsatellite clusters corresponding to previously described ancestral haplotypes. One of them was D6S1014*143-D6S273*139-TNFalpha*99-MIB*350-C1-2-5*196-C1-3-2*354, often found associated with DQB1*0201-DRB1*0301. As part of this microsatellite cluster, the allele MIB*350 was found to be a RA-predisposing factor, independent of DRB1*0301 and RA-predisposing haplotypes DQB1*03-DRB1*04 and DQB1*0501-DRB1*01. We conclude that the telomeric part of the HLA region contains a locus conferring predisposition to RA independently of HLA class II.

The genetics of rheumatoid arthritis and the need for animal models to find and understand the underlying genes

The causes of rheumatoid arthritis (RA) are largely unknown. However, RA is most probably a multifactorial disease with contributions from genetic and environmental factors. Searches for genes that influence RA have been conducted in both human and experimental model materials. Both types of study have confirmed the polygenic inheritance of the disease. It has become clear that the features of RA complicate the human genetic studies. Animal models are therefore valuable tools for identifying genes and determining their pathogenic role in the disease. This is probably the fastest route towards unravelling the pathogenesisis of RA and developing new therapies.

Insights into rheumatoid arthritis derived from the Sa immune system

The Sa system is a recently described immune system that has a specificity and positive predictive value of nearly 100% for rheumatoid arthritis (RA) in Asia, Europe and the Americas. Its sensitivity of 30-40% suggests that it identifies a subset of RA patients. Anti-Sa antibodies are present from disease onset and are predictive of disease severity. The immune reactants are plentiful in the target tissue: antigen is present in the synovium, IgG antibody in the fluid. Immunologically, Sa is a hapten-carrier antigen in which vimentin is the carrier and citrulline is the hapten. The citrullination of vimentin is closely related to apoptosis, and citrullinated vimentin is extremely sensitive to digestion by the ubiquitous calpains. Nevertheless, Sa is found in only a few cell lines. Calpastatin, the natural specific inhibitor of calpains, is also a RA-associated, albeit non-specific, autoimmune system. Is it possible that calpain-related apoptotic pathways could be prominent in cells containing Sa? The task is to reconcile the specificity of Sa/citrullinated proteins in a multifactorial and polygenic disease such as RA.

Rheumatoid arthritis associated autoantibodies in patients with synovitis of recent onset

STATEMENT OF FINDINGS: An inception cohort of 238 patients having peripheral joint synovitis of less than 12 months duration was evaluated clinically and followed prospectively for 1 year to determine the clinical significance of a number of rheumatoid arthritis (RA) associated autoantibodies. Serum samples collected at the time of the initial evaluation were tested for rheumatoid factor (RF) and antibodies to Sa (anti-Sa), RA-33, (pro)filaggrin [antifilaggrin antibody (AFA)], cyclic citrullinated peptide (anti-CCP), calpastatin, and keratin [antikeratin antibody (AKA)]. RF had a sensitivity of 66% and a specificity of 87% for RA. Anti-Sa, AFA, and anti-CCP all had a specificity of more than 90%, but a sensitivity of less than 50% for this diagnosis. Overall, there was a high degree of correlation between AFA, AKA, anti-Sa or anti-CCP, this being highest between anti-Sa and anti-CCP (odds ratio, 13.3; P < 0.001). Of the 101 patients who were positive for at least one of these four autoantibodies, 57% were positive for only one. Finally, anti-SA identified a subset of predominantly male RA patients with severe, erosive disease. Anti-SA, AFA and anti-CCP are all specific for early RA but, overall, have little additional diagnostic value over RF alone. Although these antibodies may preferentially recognize citrullinated antigens, the modest degree of concordance between them in individual patient sera suggests that it is unlikely a single antigen is involved in generating these responses.