Spondyloarthritis Group Research Articles

Epidemiology, genetics and management of psoriatic arthritis 2013: focus on developments of who develops the disease, its clinical features, and emerging treatment options

The picture of elements comprising the genetic susceptibility to develop psoriatic arthritis, especially those involving human leukocyte antigen alleles, is emerging in much greater clarity because of improvements in the methods of psoriatic arthritis ascertainment and in the technology of genetic typing. This new knowledge suggests there is genetic heterogeneity in the psoriasis phenotype, and that there are several genetically and clinically different forms of psoriatic arthritis. These genetic studies on psoriatic arthritis further reinforce the relationship of psoriatic arthritis to the other spondyloarthritides, but also raise novel questions of whether the effect of certain susceptibility genes may differ among them. Considerable evidence indicates that the clinical features reflect a CD8 T lymphocyte-driven immune response is present that is characterized by clonal expansion and differentiation towards memory-effector phenotypes. With the aid of new classification criteria, the typical clinical features of psoriatic arthritis involving different joints, entheses, and their related compartments are being better defined as distinctive characteristics of psoriatic arthritis or of the spondyloarthritis group of disorders. In the evaluation of an individual with psoriatic arthritis, taking a patient-focused perspective is recommended, which has the potential to enhance their quality of life significantly. The choice of current and emerging therapeutic agents from an increasing realm of conventional and biologic agents is becoming much better rationalized and more firmly based on evidence from clinical trials.

Increased Levels of IgG Antibodies against Human HSP60 in Patients with Spondyloarthritis

Spondyloarthritis (SpA) comprises a heterogeneous group of inflammatory diseases, with strong association to human leukocyte antigen (HLA)-B27. A triggering bacterial infection has been considered as the cause of SpA, and bacterial heat shock protein (HSP) seems to be a strong T cell antigen. Since bacterial and human HSP60, also named HSPD1, are highly homologous, cross-reactivity has been suggested in disease initiation. In this study, levels of antibodies against bacterial and human HSP60 were analysed in SpA patients and healthy controls, and the association between such antibodies and disease severity in relation to HLA-B27 was evaluated.Serum samples from 82 patients and 50 controls were analysed by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (Ig)G1, IgG2, IgG3 and IgG4 antibodies against human HSP60 and HSP60 from Chlamydia trachomatis, Salmonella enteritidis and Campylobacter jejuni. Disease severity was assessed by the clinical scorings Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Metrology Index (BASMI).Levels of IgG1 and IgG3 antibodies against human HSP60, but not antibodies against bacterial HSP60, were elevated in the SpA group compared with the control group. Association between IgG3 antibodies against human HSP60 and BASMI was shown in HLA-B27+ patients. Only weak correlation between antibodies against bacterial and human HSP60 was seen, and there was no indication of cross-reaction.These results suggest that antibodies against human HSP60 is associated with SpA, however, the theory that antibodies against human HSP60 is a specific part of the aetiology, through cross-reaction to bacterial HSP60, cannot be supported by results from this study. We suggest that the association between elevated levels of antibodies against human HSP60 and disease may reflect a general activation of the immune system and an increased expression of human HSP60 in the synovium of patients with SpA.

Espondiloartritis anquilosante

Ankylosing spondylitis (AS) is the prototype of the diseases that make up the group of spondyloarthritis (ESA), is the most common and characteristic of the group.EA is expressed clinically by combining four syndromes: axial syndrome, peripheral, and extraskeletal entesitico. The sacroiliitis is the mark of the disease is usually bilateral and symmetrical. Radiological findings are pseudoensanchamiento, sclerosis, bone bridge formation and, in more advanced stages, the complete fusion or ankylosis.The goal of treatment is to control the patient's symptoms and improve physical function and to prevent structural damage. It is based on non-pharmacological measures, primarily exercise and physical therapy, along with self-help groups and associations, and drug therapy, including nonsteroidal antiinflammatory drugs (NSAIDs), corticosteroids, drugs disease modifying antirheumatic drugs (DMARDs) and anti-TNF alpha. The latter have been one of the most important milestones in the field that, because they are highly effective in the different manifestations of the disease and even known to be more effective the more early used, therefore, but the indication was established in AD, has now been extended to use any form of that.

Radiographic progression in ankylosing spondylitis/axial spondyloarthritis

Radiographic progression in the axial skeleton is considered as an important outcome in ankylosing spondylitis (AS) and in the whole group of axial spondyloarthritis (SpA). Recently new data on the rates and predictors of radiographic progression from observational cohorts have become available. Here we summarize recent data and discuss their clinical relevance and directions for further investigations. Nonradiographic axial SpA progresses to AS with a rate of about 12% over 2 years; elevated C-reactive protein (CRP) is an important predictor of such a progression. The rate of radiographic progression in the spine is strongly dependent on the presence of the following risk factors: syndesmophytes at baseline, elevated acute phase reactants (CRP and/or erythrocyte sedimentation rate) and smoking. The presence of radiographic damage in the spine has a strong impact on spinal mobility and functional status, although the association of radiographic sacroiliitis progression with the functional status remains unclear. Radiographic progression in the spine and, to a lesser extent, in the sacroiliac joint represents a clinically relevant clinical outcome and treatment target in AS/axial SpA.

Performance of classification criteria for peripheral spondyloarthritis and psoriatic arthritis in the Leiden early arthritis cohort

ObjectivesThe performance of spondyloarthritis (SpA) classification criteria is not well-established in general early arthritis cohorts. Therefore, the authors tested their performance in the Leiden Early Arthritis Clinic (EAC) cohort and...

Off-Label-Therapie bei rheumatoider Arthritis und Spondyloarthritiden

For rheumatoid arthritis (RA) and diseases of the spondyloarthritis group (SpA) a large number of approved medications are available. Nevertheless, in Germany even for these diseases several off-label risks exist for the rheumatologist prescribing antirheumatic drugs which have recently led to a series of recourses or threats of recourse. In RA as well as SpA first of all biologicals are the target of recourse imposed mainly by health insurances. In RA monotherapy (when labeled only in combination with methotrexate), combination with leflunomide (instead of methotrexate) and dose deviations are the most important causes. In SpA TNF inhibitors are labeled only for the definite diagnosis of ankylosing spondylitis (AS) and psoriatic arthritis (PsA) leaving aside patients with severe peripheral spondyloarthritis including enthesitis which does not exactly meet the diagnostic criteria of AS and PsA. The same applies to early AS not fulfilling the 1984 New York criteria which still lacks labeled use of TNF inhibitors. In these cases, however, based on successful randomized controlled trials and changed diagnostic criteria a label extension is expected in the near future. Until then it seems suitable to apply for permission for this treatment from insurers in each case.

Tailored Treatment of Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic rheumatic disease of the axial skeleton (spine and sacroiliac joints). Only nonsteroidal anti-inflammatory drugs (NSAIDs) and tumor necrosis factor (TNF) α inhibitors have currently been shown as effective for the treatment of signs and symptoms of active AS with predominant axial involvement. In contrast to rheumatoid arthritis (RA), disease-modifying anti-rheumatic drugs (DMARDs) play only a minor role in the management of AS and only in cases with peripheral joint involvement. Herein, this review describes the pharmacological and nonpharmacological management of AS, based on recent international recommendations for the management of AS by the Assessment of Spondyloarthritis (ASAS) group. Despite the overall demonstrated efficacy of currently available treatments for AS, up to 40% of treated patients do not achieve an acceptable clinical improvement during therapy. Therefore, this article also reviews the evidence regarding the potential role for new 강직성 척추염의 맞춤치료 Tailored Treatment of Ankylosing Spondylitis agents targeting B-cells, T-cells, interleukin (IL)-1, IL-6, IL17, and IL-12/23 in patients with AS.

Current therapeutics for spondyloarthritis

Introduction:Ankylosing spondylitis (AS) belongs to a clinically related group of disorders named spondyloarthritis (SpA) that mainly affect the axial skeleton and present with specific extra-articular manifestations. The therapeutic management of AS and other SpA has considerably progressed over the past 10 years.Areas covered:This paper provides a review of the available treatments for AS including traditional treatments (NSAIDs, sulfasalazine and methotrexate, local corticosteroids) and biological therapies (TNF-α antagonists), as well as nonpharmacological procedures (education and physical therapy) and specific recommendations for this therapeutic management.Expert opinion:NSAIDs remain the first-line treatment in patients with AS, especially with axial disease. There is an increasing amount of evidence showing the short-term and long-term efficacy of TNF-α antagonists in AS, with the control of pain, extra-articular manifestations and spinal inflammation as evidenced by MRI. By contrast, there is no proof for the control of radiographic progression at the spine with these agents. An early diagnosis is now possible using the new classification criteria for SpA. However, it remains to be established if an early intervention might control the progression of the disease. Since about 20 – 25% of patients are considered as nonmajor responders to TNF-α blockers, there is an unmet need for developing new biological therapies. Targeting the IL-17 pathway may be an interesting option. International recommendations for the management of AS by the Assessment of Spondyloarthritis (ASAS) group were recently updated and discussed the respective place of each current therapeutic option in AS.

Quel est l’intérêt du bilan de thrombophilie au cours du SAPL obstétrical ?

Ankylosing spondylitis is the prototype of immune-mediated inflammatory rheumatic diseases grouped under the term spondyloarthritis (SpA). An early diagnosis has now become increasingly important because effective therapies are available and anti-TNF drugs are even more effective if used in early stages of the disease. In ankylosing spondylitis, the 1984 modified New York criteria have been used widely in clinical studies and daily practice but are not applicable in early disease when the characteristic radiographic signs of sacroiliitis are not visible but active sacroiliitis is readily detectable by magnetic resonance imaging (MRI). Thus there has been a need for new classification or diagnostic criteria to identify inflammatory spondyloarthritis at early stage of the disease. This led to the concept of axial SpA to include the entire spectrum of patients with axial disease both, with and without radiographic damage. New classification criteria for the wider group of SpA have been proposed by ASAS (Assessment of Spondylo Arthritis International Society); and the patients are sub-grouped into (1) a predominantly axial disease, termed axial SpA including AS and non-radiographic axial SpA; (2) peripheral SpA. The clinical course and disease process of non-radiographic axial spondyloarthritis remains unclear. However the development of the SpA criteria by ASAS particularly for axial SpA, is an important step for early diagnosis and better management of these patients.

Prevalence of Thyroid Autoimmunity in Patients with Spondyloarthropathies

To evaluate the prevalence of chronic autoimmune thyroiditis or Hashimoto's thyroiditis (HT) in a group of patients with spondyloarthritis (SpA). We evaluated serum levels of thyroid-stimulating hormone, free triiodothyronine, and free thyroxine, and titers of antithyroglobulin and antithyroid peroxidase (anti-TPO) antibodies in 357 consecutive patients with SpA. We also recruited 318 healthy age-matched controls. Ultrasonography of the thyroid gland was performed in all subjects and rheumatic activity was evaluated. Indices of thyroid autoimmunity were significantly more frequent in patients with SpA than in controls (24.09% vs 10.69%, respectively; p < 0.05). In the SpA group, a higher prevalence of HT was found in patients with an active disease than in those with low-moderate disease levels. Also in the SpA group, patients with a disease duration > 2 years had a higher prevalence of HT and anti-TPO antibodies positivity than patients with a disease duration ≤ 2 years. Ultrasonography detected a significantly higher frequency of thyroid nodules and hypoechoic pattern in patients with SpA than in controls. Among patients with SpA, HT and anti-TPO antibodies positivity were significantly more frequent in patients with peripheral involvement (68.6%) than in patients with axial involvement (31.4%; p < 0.05). Our study shows a significantly higher prevalence of thyroid autoimmunity in patients with SpA as compared to controls. Thyroiditis occurs more frequently in patients with longer disease duration and active rheumatic disease. We suggest that thyroid function tests be part of the clinical evaluation in patients with SpA.

Anti-Saccharomyces cerevisiae (ASCA) and anti-endomysial antibodies in spondyloarthritis

Spondyloarthritis (SpA) are diseases with increased gut inflammation. To search for (anti-Saccharomyces cerevisiae) ASCA IgA, ASCA IgG, and anti-endomysial antibodies (EmA-IgA) in a cohort of 70 patients with SpA, we found 18.6% (13/70) positive for IgA-ASCA in the SpA group and 3/57 (5.2%) in the control group (P=0.031). ASCA IgG and EmA-IgA were found at the same frequency in SpA and controls. No relationship of ASCA IgA positivity could be established with disease activity (measured by ESR, C-reactive protein, and BASDAI), presence of uveitis, or peripheral arthritis neither with functional status measured by BASFI. SpA patients present an increase in the IgA-ASCA positivity without any relationship to disease activity, functional index, clinical profile or the presence of HLA-B27. There is no evidence of higher prevalence of EmA-IgA in SpA patients in the studied sample.

Validation of ultrasound imaging for Achilles entheseal fibrocartilage in bovines and description of changes in humans with spondyloarthritis

BackgroundEntheseal fibrocartilage (EF) derangement is hypothesised to be pivotal to the pathogenesis of spondyloarthritis. Ultrasound is useful for visualisation of the enthesis but its role in EF visualisation is uncertain....

From Retrospective Analysis of Patients with Undifferentiated Spondyloarthritis (SpA) to Analysis of Prospective Cohorts and Detection of Axial and Peripheral SpA

Spondyloarthritis (SpA) refers to a group of HLA-B27-positive associated rheumatic diseases that share clinical and genetic features. The diseases and conditions that constitute the SpA group are defined by signs, symptoms, and radiographic findings, and consist of ankylosing spondylitis (AS), reactive arthritis (ReA), the SpA subsets psoriatic arthritis (PsA), Crohn’s disease (CD) and ulcerative colitis, and a subgroup of undifferentiated forms1. Traditionally, patients with SpA may be classified according to Amor, et al 2 and the European Spondylarthropathy Study Group (ESSG)3 criteria. Patients fulfilling such criteria may then be classified or diagnosed according to specific criteria, clinical picture, or diagnostic tests for AS, ReA and SpA subsets PsA, CD and ulcerative colitis, for example. In general, patients with SpA that do not fulfill such classification or diagnostic-specific criteria remain unclassified and comprise the subgroup known as undifferentiated SpA (USpA). USpA accounts for a significant but variable proportion of patients with SpA in the open population4,5, in a group of relatives of probands with AS6,7, and in hospital-based registries of SpA8–10. As a group, USpA are mostly characterized by isolated episodes of peripheral arthritis and enthesitis, axial symptoms, and by a lower incidence of HLA-B27 versus AS. As a group, SpA are characterized by overlapping of clinical manifestations over the disease course11. For example, patients with AS may develop psoriasis and CD, patients with ReA may develop psoriasis, and patients with psoriasis may developed CD and AS. Similarly, patients with USpA may develop any specific clinical manifestation and fulfill specific diagnostic criteria some time later. In this context, it is clear that patients with SpA fulfilling specific criteria of more than 2 SpA constitute a “true SpA overlap,” while patients presenting with nonspecific or …

Megacolon and arthritis

In the present report the authors describe four cases with megacolon and arthritis. The etiology of these unique associations is known in only one case. The musculoskeletal pictures belong to the group of seronegative spondyloarthritis. A huge resistance with great scibalas was detected in the left iliac region by physical examination in all cases. Surgical procedures of the colon resulted in complete remission of arthritis in one case, in the others, chronic obstipation with intermittent relapse of arthritis persisted.

An epidemiological survey of low back pain and axial spondyloarthritis in a Chinese Han population

Objective: To investigate the prevalence of low back pain (LBP) and axial spondyloarthritis (SpA) in a Chinese Han population.Methods: A face-to-face investigation was performed in the Han population of Dalang Town, Yangshan County, Guangdong Province, China, using a questionnaire established in France in 1999. First the clinical features associated with SpA were investigated, then the human leucocyte antigen (HLA)-B27 and sacroiliac joint radiographic examinations were carried out. Finally, the diagnosis of SpA was determined by rheumatologists.Results: A total of 13 315 subjects participated in the study and 10 921 were aged >16 years; of these, 787 (7.21%) had LBP. There were 92 axial SpA patients (0.782% in subjects >16 years old and 11.96% in subjects with LBP). There were 29 (0.253%) cases of ankylosing spondylitis (AS), 60 (0.507%) undifferentiated axial SpA (USpA), and three (0.022%) psoriatic arthritis (PsA). Patients in the SpA groups had higher percentages in onset <40 years, insidious onset, morning stiffness, and affected for >3 months compared with those in other LBP groups. Simultaneous symptoms associated with spondylitis, such as buttock pain, heel pain, psoriasis, and SpA family history, were more commonly present. Of the axial SpA patients, 82.67% were HLA-B27 positive, clearly a greater percentage than those (11.65%) in other LBP groups.Conclusions: The survey questionnaire for SpA in this study is useful for axial SpA screening in China. In southern China, the prevalence of LBP is 7.21%. The prevalence of axial SpA is 0.782%. USpA is the most common subtype of SpA, followed by AS.

Spectrum of rheumatological disorders: an experience of 337 cases in a tertiary care hospital in Pokhara valley, Nepal

AbstractAim: To reveal the commonly occurring important types of rheumatological disorders, as well as various clinico‐epidemiological aspects, concurrent medical illnesses, and the ancillary medications used, along with their side‐effects.Method: A total of 365 patients with various rheumatological disorders were studied at the Rheumatology Department of Manipal Teaching Hospital, Pokhara, Nepal from September 2001 to September 2004. The diagnosis was based on the criteria of the American College of Rheumatology (1988). A pro forma was prepared for 30 common rheumatological disorders, listing patient identification, clinical characteristics, disease duration, objective and subjective assessment of the progress of the diseases, monitoring the response of treatment and side‐effects of medications. Patients aged 15–75 years, men and women suffering from various musculoskeletal disorders, fulfilling the ACR criteria, were studied. Each patient was followed up at 1–3 monthly interval and data recorded systematically to monitor the progress of joint function and evaluating the effects of medications.Results: Out of the 365 patients recorded, only 337 fulfilled the criteria laid down by ACR. Most common rheumatological disorders in order of frequency were soft tissue rheumatism (40.0%), inflammatory arthritis (21.36%) and bone and cartilage diseases (21.06%). Connective tissue disorders were only 4.74%. Seronegative spondyloarthritis group was only 2.67% and least common disease was gout at 3.85%. Rheumatoid arthritis was the most common inflammatory arthritis observed in 20.17% of total cases. Fibromyalgia was the most common soft tissue rheumatism seen in 19.88%. Osteoarthritis of knee, hand and hip were the most common degenerative disorder of the bone and cartilage, constituting 10.38%. Lumbago, lumbar spondylolisthesis and spinal canal stenosis together comprised 14.24% of patients with low back pain. Cervical spondylosis and all types of shoulder joint pain syndromes comprised 5.93% and 5.34%, respectively. Patients were mostly in the age group 20–60 years. The most common type of drug used in all rheumatic conditions was non‐steroidal anti‐inflammatory drugs in 81.6% of cases followed by steroids in 26.7%, disease‐modifying and cytotoxic drugs in 18.6% and 17.2% of cases, respectively. Chronic obstructive airway disease and hypertension constituted the major concurrent illness in 23.63% and 18.78%, respectively.Conclusion: This unique type of clinico‐epidemiological study on rheumatological disorders, the first in Nepal, will provide a rich database for future investigations into rheumatology and would plan for all levels of prevention and therapy in the future.

Tumor Necrosis Factor-α Promoter Polymorphisms in Mexican Patients With Spondyloarthritis

To evaluate the role of tumor necrosis factor–α (TNF-α) gene as susceptibility marker for spondyloarthritis (SpA), two polymorphisms (−238 and −308 positions) were analyzed in 229 patients with SpA (113 with ankylosing spondylitis [AS], 92 with undifferentiated SpA [U-SpA], 24 with reactive arthritis), and 169 ethnically matched healthy control subjects. The HLA-B alleles were detected by PCR-SSP technique and the TNF-α polymorphism by PCR-RFLP. In comparison with healthy control subjects, the frequencies of TNF-238 in SpA were similar. In contrast, the analysis of −308 polymorphism showed increased frequencies of the T2(A) allele in the whole SpA group ( p < 0.05, pC = NS, OR = 1.83) as well as the T2(A) allele ( pC < 0.05, OR = 2.4) and T1T2(AG) genotype ( p < 0.05, pC = NS, OR = 2.25) in U-SpA patients. Comparison of B27-negative patients and healthy control subjects yielded similar results. There was no significant correlation between TNF genotypes and clinical data. The present study demonstrates that TNF-α −308 polymorphism appears to be associated with the genetic susceptibility U-SpA. The association seems independent of the susceptibility conferred by the HLA-B27 in this group of patients.

Frühdiagnose von Spondyloarthritiden mit besonderer Betonung auf die axialen Formen

The axial spondyloarthritis (SpA) is the most important disease out of the whole group of SpA. If a sacroiliits is clearly detectable by x-rays a diagnosis of ankylosing spondylitis can be made. However, there is still a delay of 5-10 years from the first symptoms until a final diagnosis is made. An important reason for this is the fact that radiological changes are often only detectable after several years of disease, despite the presence of inflammation as detected by MRI and the presence of clinical manifestations such as pain and stiffness. An early diagnosis becomes more and more important because effective therapies have become available which are probably even more effective if given early. New strategies how to make an early diagnosis and how primary care physicians can screen for these patients are discussed.

Association study of LMP gene polymorphisms in Mexican patients with spondyloarthritis

To evaluate the role of LMP (low molecular weight protein) genes as susceptibility markers for spondyloarthritis (SpA), LMP gene polymorphisms were analyzed in 223 Mexican patients with SpA (81 undifferentiated SpA [U-SpA], 117 with ankylosing spondylitis [AS], 25 with reactive arthritis) and in 139 ethnically matched healthy individuals. LMP genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism. The LMP2 and LMP7 allele frequencies were similar in patients and healthy controls. Genotype analysis revealed an increased frequency of LMP2 R/R genotype in the whole group of SpA ( pC = 0.003, OR = 2.06, 95%CI = 1.3–3.25) and in the clinical subgroups of AS ( pC = 0.039, OR = 1.88, 95%CI = 1.1–3.22) and U-SpA ( pC = 0.003, OR = 2.56, 95%CI = 1.37–4.8) compared with healthy controls. Analysis in the LMP7 did not reveal significant differences in patients and healthy controls. The HLA-B27-negative AS subgroup also showed an increased frequency of LMP2 R/R genotype ( pC = 0.027, OR = 4.81, 95%CI = 1.21–22.13). The LMP2-R/R AS patients were younger than LMP2-H/R and H/H patients at onset of the disease (16.0 ± 6.8 years for R/R, 22.0 ± 11.2 years for H/R and 28.6 ± 10.9 years for H/H) ( p < 0.05). The data suggest that, besides HLA-B27, LMP2 genotypes are also involved in the genetic susceptibility to develop AS in Mexicans. Furthermore, the age at onset of this disease might also be influenced by genotypes of this gene.

Tumour necrosis factor-alpha polymorphism and the HLA-Cw*0602 allele in psoriatic arthritis.

To investigate polymorphisms in the genes for tumour necrosis factor alpha (TNFA), interleukin 10 (IL10) and tumour necrosis factor receptor II (TNFRII) in patients with psoriatic arthritis (PsA) and their relationship to the HLA-Cw*0602 allele and to the ages at onset of psoriasis and arthritis and the pattern of joint involvement. One hundred and twenty-four well-characterized patients with PsA were studied. Controls were 101 cadaveric organ donors. All were genotyped for single-nucleotide polymorphisms in TNFA (positions -308, -238, +488), IL10 (-1082, -819, -592) and in the 3'-untranslated region of TNFRII (+1663, +1668, +1690). The HLA-Cw*0602 allele was detected by polymerase chain reaction-based techniques. The frequencies of the respective variants were compared between patients and controls and in relation to the ages at onset of psoriasis and arthritis, to clinical subsets of the disease and to the presence of erosions. HLA-Cw*0602 was significantly increased in frequency in PsA (40 vs 26%; P<0.05) and was associated with younger age of onset of psoriasis (P<0.05). There was no significant increase in any of the polymorphisms studied within TNFA, IL10 or TNFRII in the total PsA group. Although the frequency of TNFA allele -238A was not increased in the total PsA group or in patients with a younger age of onset of psoriasis, TNFA allele -238A was absent in the spondyloarthritis group and increased in frequency in patients with peripheral polyarthritis. However, these latter findings could be explained by linkage disequilibrium as all TNFA -238A alleles (23/23) in patients with PsA were HLA-Cw*0602-positive (P<0.0001). An association between young age of onset of psoriasis and HLA-Cw*0602 is confirmed in patients with PsA. The uncommon TNFA -238A allele is strongly linked to HLA-Cw*0602 and as such is associated with the development of peripheral polyarthritis rather than spondylitis. Further investigation of possible HLA-Cw*0602 linked genes in PsA is warranted.