ABSTRACT
Antisynthease syndrome (ASSD) is a rare, complex and understudied autoimmune disease. Internet-based studies can overcome barriers of traditional on-site research and are therefore very appealing for rare diseases. The aim of this study was to investigate patient-reported symptoms, diagnostic delay, symptoms, medical care, health status, working status, disease knowledge and willingness to participate in research of ASSD patients by conducting an international web-based survey. The multilingual questionnaire was created by an international group of rheumatologists and patients and distributed online. 236 participants from 22 countries completed the survey. 184/236 (78.0%) were female, mean age (SD) was 49.6 years (11.3) and most common antisynthetase antibody was Jo-1 (169/236, 71.6%). 79/236 (33.5%) reported to work full-time. Median diagnostic delay was one year. The most common symptom at disease onset was fatigue 159/236 (67.4%), followed by myalgia 130/236 (55.1%). The complete triad of myositis, arthritis and lung involvement verified by a clinician was present in 42/236 (17.8%) at disease onset and in 88/236 (37.3%) during the disease course. 36/236 (15.3%) reported to have been diagnosed with fibromyalgia and 40/236 (16.3%) with depression. The most reported immunosuppressive treatments were oral corticosteroids 179/236 (75.9%), followed by rituximab 85/236 (36.0%). 73/236 (30.9%) had received physiotherapy treatment. 71/236 (30.1%) reported to know useful online information sources related to ASSD. 223/236 (94.5%) were willing to share health data for research purposes once a year. Our results reiterate that internet-based research is invaluable for cooperating with patients to foster knowledge in rare diseases.
Subject(s)
Autoantibodies , Myositis , Humans , Female , Middle Aged , Male , Rare Diseases , Delayed Diagnosis , Myositis/diagnosis , Myositis/therapy , Syndrome , Patient Acceptance of Health CareSubject(s)
COVID-19 , SARS-CoV-2 , Antibody Formation , COVID-19 Vaccines , Humans , Immunologic Factors , VaccinationABSTRACT
OBJECTIVES: To determine prevalence and co-existence of myositis specific autoantibodies (MSAs) and myositis associated autoantibodies (MAAs) and associated clinical characteristics in a large cohort of idiopathic inflammatory myopathy (IIM) patients. METHODS: Adult patients with confirmed IIM recruited to the EuroMyositis registry (nâ¯=â¯1637) from four centres were investigated for the presence of MSAs/MAAs by radiolabelled-immunoprecipitation, with confirmation of anti-MDA5 and anti-NXP2 by ELISA. Clinical associations for each autoantibody were calculated for 1483 patients with a single or no known autoantibody by global linear regression modelling. RESULTS: MSAs/MAAs were found in 61.5% of patients, with 84.7% of autoantibody positive patients having a sole specificity, and only three cases (0.2%) having more than one MSA. The most frequently detected autoantibody was anti-Jo-1 (18.7%), with a further 21 specificities each found in 0.2-7.9% of patients. Autoantibodies to Mi-2, SAE, TIF1, NXP2, MDA5, PMScl and the non-Jo-1 tRNA-synthetases were strongly associated (pâ¯<â¯0.001) with cutaneous involvement. Anti-TIF1 and anti-Mi-2 positive patients had an increased risk of malignancy (OR 4.67 and 2.50 respectively), and anti-SRP patients had a greater likelihood of cardiac involvement (OR 4.15). Interstitial lung disease was strongly associated with the anti-tRNA synthetases, anti-MDA5, and anti-U1RNP/Sm. Overlap disease was strongly associated with anti-PMScl, anti-Ku, anti-U1RNP/Sm and anti-Ro60. Absence of MSA/MAA was negatively associated with extra-muscular manifestations. CONCLUSIONS: Myositis autoantibodies are present in the majority of patients with IIM and identify distinct clinical subsets. Furthermore, MSAs are nearly always mutually exclusive endorsing their credentials as valuable disease biomarkers.
Subject(s)
Autoantibodies/immunology , Disease Susceptibility/immunology , Myositis/epidemiology , Myositis/immunology , Adult , Aged , Cohort Studies , Comorbidity , Dermatomyositis/epidemiology , Dermatomyositis/immunology , Europe/epidemiology , Female , Humans , Male , Middle Aged , Myositis/diagnosis , Odds Ratio , Polymyositis/epidemiology , Polymyositis/immunology , PrevalenceABSTRACT
BACKGROUND: Many patients with psoriasis have undiagnosed psoriatic arthritis. Low specificity is found with many PsA screening tools. A new instrument, the CONTEST questionnaire, was developed utilizing the most discriminative items from existing instruments. OBJECTIVE: The aim of this study was to compare the CONTEST and PEST screening tools. METHODS: People attending secondary care clinics with psoriasis, but not PsA, completed the questionnaires, were assessed for function and quality of life, and had a physical examination. Patients thought to have PsA were compared to those without. The performance of CONTEST and PEST was compared using area under the receiver operating curve (AUC), and sensitivity and specificity at the previously published cut-offs. RESULTS: A total of 451 dermatology patients were approached, 35% were reviewed and 27 (17%, 95% CI 12.3-21.7) had unidentified psoriatic arthritis. The sensitivity and specificity (95% CI) of PEST were 0.60 (0.42-0.78)/0.76 (0.69-0.83) and for CONTEST 0.53 (0.34-0.72)/0.71 (0.63-0.79). The confidence limits for the AUC overlapped (AUC for PEST 0.72 (0.61-0.84), for CONTEST 0.66 (0.54-0.77). CONCLUSIONS: PEST and CONTEST questionnaires performed equally well, with no superiority of the new CONTEST tool.
Subject(s)
Arthritis, Psoriatic/diagnosis , Mass Screening/methods , Surveys and Questionnaires , Adult , Area Under Curve , Arthritis, Psoriatic/complications , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Physical Examination , Psoriasis/complications , Quality of Life , ROC CurveABSTRACT
OBJECTIVES: Autoantibodies directed against cytosolic 5'-nucleotidase 1A have been identified in many patients with inclusion body myositis. This retrospective study investigated the association between anticytosolic 5'-nucleotidase 1A antibody status and clinical, serological and histopathological features to explore the utility of this antibody to identify inclusion body myositis subgroups and to predict prognosis. MATERIALS AND METHODS: Data from various European inclusion body myositis registries were pooled. Anticytosolic 5'-nucleotidase 1A status was determined by an established ELISA technique. Cases were stratified according to antibody status and comparisons made. Survival and mobility aid requirement analyses were performed using Kaplan-Meier curves and Cox proportional hazards regression. RESULTS: Data from 311 patients were available for analysis; 102 (33%) had anticytosolic 5'-nucleotidase 1A antibodies. Antibody-positive patients had a higher adjusted mortality risk (HR 1.89, 95% CI 1.11 to 3.21, p=0.019), lower frequency of proximal upper limb weakness at disease onset (8% vs 23%, adjusted OR 0.29, 95% CI 0.12 to 0.68, p=0.005) and an increased prevalence of excess of cytochrome oxidase deficient fibres on muscle biopsy analysis (87% vs 72%, adjusted OR 2.80, 95% CI 1.17 to 6.66, p=0.020), compared with antibody-negative patients. INTERPRETATION: Differences were observed in clinical and histopathological features between anticytosolic 5'-nucleotidase 1A antibody positive and negative patients with inclusion body myositis, and antibody-positive patients had a higher adjusted mortality risk. Stratification of inclusion body myositis by anticytosolic 5'-nucleotidase 1A antibody status may be useful, potentially highlighting a distinct inclusion body myositis subtype with a more severe phenotype.
Subject(s)
5'-Nucleotidase/immunology , Autoantibodies/blood , Muscle Fibers, Skeletal/pathology , Myositis, Inclusion Body/blood , Myositis, Inclusion Body/diagnosis , Age of Onset , Aged , Aged, 80 and over , Biomarkers/blood , Cytosol , Electron Transport Complex IV/analysis , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Muscle Fibers, Skeletal/chemistry , Muscle Weakness/etiology , Myositis, Inclusion Body/pathology , Prognosis , Proportional Hazards Models , Retrospective Studies , Self-Help Devices/statistics & numerical data , Survival Rate , Time FactorsABSTRACT
BACKGROUND: There is limited evidence as to whether biologic therapy should be stopped or continued in patients with psoriasis and/or psoriatic arthritis (PsA) who are undergoing surgical procedures. Current guidelines of care recommend a planned break from biologic therapy in those undergoing major surgical procedures. OBJECTIVE: To audit current practice of managing biologic therapy peri-operatively in a tertiary referral psoriasis clinic against guidelines of care and to investigate the effects of continuing/stopping biologic therapy in psoriasis and PsA patients. METHODS: A retrospective audit of psoriasis and PsA patients who had a surgical procedure whilst on biologic therapy. A proforma was used to collect information on the biologics used, whether they were stopped peri-operatively and whether patients developed post-operative complications and/or disease flare. RESULTS: A total of 42 patients who had 77 procedures were identified. Procedures ranged from skin surgery to orthopaedic and cardiothoracic surgery. Biologic therapy was continued in the majority of procedures (76%). There was no significant difference in post-operative risk of infection and delayed wound healing between those patients who continued and those who stopped biologic therapy, including those undergoing major surgery. Interrupting biologic therapy peri-operatively was associated with a significant (P = 0.003) risk of flare of psoriasis or PsA. CONCLUSION: Continuing biologic therapy in psoriasis and PsA patients peri-operatively did not increase the risk of post-operative complications. Interrupting biologic therapy peri-operatively significantly increased the risk of disease flare. This study is limited by cohort size and requires replication, ideally in a prospective randomized controlled manner.
Subject(s)
Biological Factors/therapeutic use , Postoperative Complications/etiology , Psoriasis/drug therapy , Surgical Procedures, Operative , Adult , Aged , Arthritis, Psoriatic/drug therapy , Female , Humans , Male , Middle Aged , Retrospective Studies , RiskABSTRACT
Autoimmune muscle diseases (myositis) comprise a group of complex phenotypes influenced by genetic and environmental factors. To identify genetic risk factors in patients of European ancestry, we conducted a genome-wide association study (GWAS) of the major myositis phenotypes in a total of 1710 cases, which included 705 adult dermatomyositis, 473 juvenile dermatomyositis, 532 polymyositis and 202 adult dermatomyositis, juvenile dermatomyositis or polymyositis patients with anti-histidyl-tRNA synthetase (anti-Jo-1) autoantibodies, and compared them with 4724 controls. Single-nucleotide polymorphisms showing strong associations (P<5×10(-8)) in GWAS were identified in the major histocompatibility complex (MHC) region for all myositis phenotypes together, as well as for the four clinical and autoantibody phenotypes studied separately. Imputation and regression analyses found that alleles comprising the human leukocyte antigen (HLA) 8.1 ancestral haplotype (AH8.1) defined essentially all the genetic risk in the phenotypes studied. Although the HLA DRB1*03:01 allele showed slightly stronger associations with adult and juvenile dermatomyositis, and HLA B*08:01 with polymyositis and anti-Jo-1 autoantibody-positive myositis, multiple alleles of AH8.1 were required for the full risk effects. Our findings establish that alleles of the AH8.1 comprise the primary genetic risk factors associated with the major myositis phenotypes in geographically diverse Caucasian populations.
Subject(s)
Alleles , HLA Antigens/genetics , Myositis/genetics , Adolescent , Adult , Autoantibodies/immunology , Case-Control Studies , Dermatomyositis/genetics , Female , Genetic Association Studies , Genetic Predisposition to Disease , Genome-Wide Association Study , Haplotypes , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Polymyositis/genetics , Risk Factors , White PeopleABSTRACT
Statins are widely used lipid-lowering drugs that are effective in reducing cardiovascular disease risk. Although they are generally well tolerated, they can cause muscle toxicity, which can lead to severe rhabdomyolysis. Research in this area has been hampered to some extent by the lack of standardized nomenclature and phenotypic definitions. We have used numerical and descriptive classifications and developed an algorithm to define statin-related myotoxicity phenotypes, including myalgia, myopathy, rhabdomyolysis, and necrotizing autoimmune myopathy.
Subject(s)
Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects , Muscular Diseases/chemically induced , Autoimmune Diseases/chemically induced , Autoimmune Diseases/classification , Humans , Muscular Diseases/classification , Myalgia/chemically induced , Myalgia/classification , Myositis/chemically induced , Myositis/classification , Phenotype , Rhabdomyolysis/chemically induced , Rhabdomyolysis/classification , Risk Factors , Terminology as Topic , Time FactorsABSTRACT
BACKGROUND: Multiple questionnaires to screen for psoriatic arthritis (PsA) have been developed but the optimal screening questionnaire is unknown. OBJECTIVES: To compare three PsA screening questionnaires in a head-to-head study using CASPAR (the Classification Criteria for Psoriatic Arthritis) as the gold standard. METHODS: This study recruited from 10 U.K. secondary care dermatology clinics. Patients with a diagnosis of psoriasis, not previously diagnosed with PsA, were given all three questionnaires. All patients who were positive on any questionnaire were invited for a rheumatological assessment. Receiver operating characteristic (ROC) curves were used to compare the sensitivity, specificity and area under the curve of the three questionnaires according to CASPAR criteria. RESULTS: In total, 938 patients with psoriasis were invited to participate and 657 (70%) patients returned the questionnaires. One or more questionnaires were positive in 314 patients (48%) and 195 (62%) of these patients attended for assessment. Of these, 47 patients (24%) were diagnosed with PsA according to the CASPAR criteria. The proportion of patients with PsA increased with the number of positive questionnaires (one questionnaire, 19·1%; two, 34·0%; three, 46·8%). Sensitivities and specificities for the three questionnaires, and areas under the ROC curve were, respectively: Psoriatic Arthritis Screening Evaluation (PASE), 74·5%, 38·5%, 0·594; Psoriasis Epidemiology Screening Tool (PEST), 76·6%, 37·2%, 0·610; Toronto Psoriatic Arthritis Screen (ToPAS), 76·6%, 29·7%, 0·554. The majority of patients with a false positive response had degenerative or osteoarthritis. CONCLUSION: Although the PEST and ToPAS questionnaires performed slightly better than the PASE questionnaire at identifying PsA, there is little difference between these instruments. These screening tools identify many cases of musculoskeletal disease other than PsA.
Subject(s)
Psoriasis/diagnosis , Surveys and Questionnaires/standards , Adult , Aged , Arthritis, Psoriatic/complications , Arthritis, Psoriatic/diagnosis , Early Diagnosis , Female , Humans , Male , Middle Aged , Psoriasis/complications , ROC Curve , Young AdultABSTRACT
OBJECTIVES: HLA-DRB1*03 is strongly associated with anti-Jo-1-positive idiopathic inflammatory myopathies (IIM) and there is now increasing evidence that Jo-1 antigen is preferentially expressed in lung tissue. This study examined whether smoking was associated with the development of anti-Jo-1 antibodies in HLA-DRB1*03-positive IIM. METHODS: IIM cases were selected with concurrent information regarding HLA-DRB1 status, smoking history and anti-Jo-1 antibody status. DNA was genotyped at DRB1 using a commercial sequence-specific oligonucleotide kit. Anti-Jo-1 antibody status was established using a line blot assay or immunoprecipitation. RESULTS: 557 Caucasian IIM patients were recruited from Hungary (181), UK (99), Sweden (94) and Czech Republic (183). Smoking frequency was increased in anti-Jo-1-positive IIM cases, and reached statistical significance in Hungarian IIM (45% Jo-1-positive vs 17% Jo-1-negative, OR 3.94, 95% CI 1.53 to 9.89, p<0.0001). A strong association between HLA-DRB1*03 and anti-Jo-1 status was observed across all four cohorts (DRB1*03 frequency: 74% Jo-1-positive vs 35% Jo-1-negative, OR 5.55, 95% CI 3.42 to 9.14, p<0.0001). The frequency of HLA-DRB1*03 was increased in smokers. The frequency of anti-Jo-1 was increased in DRB1*03-positive smokers vs DRB1*03-negative non-smokers (42% vs 8%, OR 7.75, 95% CI 4.21 to 14.28, p<0.0001) and DRB1*03-positive non-smokers (42% vs 31%, p=0.08). In DRB1*03-negative patients, anti-Jo-1 status between smokers and non-smokers was not significantly different. No significant interaction was noted between smoking and DRB1*03 status using anti-Jo-1 as the outcome measure. CONCLUSION: Smoking appears to be associated with an increased risk of possession of anti-Jo-1 in HLA-DRB1*03-positive IIM cases. The authors hypothesise that an interaction between HLA-DRB1*03 and smoking may prime the development of anti-Jo-1 antibodies.
Subject(s)
Antibodies, Antinuclear/immunology , HLA-DRB1 Chains/immunology , Myositis/epidemiology , Myositis/immunology , Smoking/epidemiology , Smoking/immunology , Adult , Age of Onset , Antibodies, Antinuclear/blood , Europe/epidemiology , Female , Genotype , HLA-DRB1 Chains/genetics , Humans , Male , Middle Aged , Myositis/genetics , Risk Factors , Seroepidemiologic Studies , Smoking/genetics , White People/genetics , White People/statistics & numerical dataABSTRACT
Significant changes to the structure and entry into specialist training continue to be implemented. This is likely to have had a long-term impact on rheumatology service provision and the proportion of trainees undertaking academic medicine. An online questionnaire was sent to all trainees on the Joint Royal Colleges Postgraduate Training Board (JRCPTB) database. Out of 211 trainees, 141 responded (66.8%). Of these, 33 (23%) were registered for, or had been awarded, an MD or PhD with a wide variety of funding sources. Mainstream funding sources included Arthritis Research UK, the Medical Research Council, the National Institute for Health Research and the Wellcome Trust, but a substantial number of trainees (n = 17, 51.5%) also utilised other sources of funding. The data from this study will be valuable in the planning of future rheumatology training and academic career pathways and provide useful comparative data for other medical specialties.
Subject(s)
Education, Medical, Graduate/organization & administration , Rheumatology/education , Adult , Female , Humans , Male , Research Support as Topic , Training Support , United KingdomABSTRACT
The idiopathic inflammatory myopathies (IIMs) comprise polymyositis, myositis overlapping with another connective tissue disease, dermatomyositis (DM) and inclusion-body myositis (IBM). IIMs are characterized by the presence of proximal muscle weakness, increased levels of muscle-specific enzymes, specific electromyographic abnormalities, and the presence of inflammatory cell infiltrates in skeletal muscle. Clinical, serological and histological criteria can be used to define individual IIM subtypes. In the first of this two-part review series, we examine the evidence for the existence of cancer-associated myositis (CAM), and in part 2, we discuss recent discoveries that provide insight into identification of patients with DM, who may be most at risk of developing CAM.
Subject(s)
Dermatomyositis/complications , Neoplasms/complications , Dermatomyositis/diagnosis , Dermatomyositis/epidemiology , Evidence-Based Medicine , Female , Humans , Male , Neoplasms/epidemiology , Polymyositis/complications , Polymyositis/epidemiology , Risk FactorsABSTRACT
In part 1 of this review, we examined the evidence behind the association between idiopathic inflammatory myopathies (IIM) and cancers. In view of the well-recognized association between cancer and myositis (hence the term cancer-associated myositis, or CAM), clinicians responsible for the management of patients with myositis must make important decisions regarding how intensively they undertake searches for malignancy. Clinicians must also decide how often such searches are repeated, and again how intensively, to optimize both cancer detection and treatment, and thus patient survival. As the risks of CAM are greatest in dermatomyositis, this is an issue of obvious importance to dermatologists. In this second of two reviews, we examine the role of autoantibodies as potential predictors of cancer risk in patients with IIM.
Subject(s)
Biomarkers, Tumor/blood , Dermatomyositis/complications , Neoplasms , Autoantibodies/blood , Humans , Mass Screening/methods , Neoplasms/diagnosis , Neoplasms/etiology , Risk Assessment/methodsABSTRACT
OBJECTIVE: The identification of novel autoantibodies in juvenile dermatomyositis (DM) may have etiologic and clinical implications. The aim of this study was to describe autoantibodies to a 140-kd protein in children recruited to the Juvenile DM National Registry and Repository for UK and Ireland. METHODS: Clinical data and sera were collected from children with juvenile myositis. Sera that recognized a 140-kd protein by immunoprecipitation were identified. The identity of the p140 autoantigen was investigated by immunoprecipitation/immunodepletion, using commercial monoclonal antibodies to NXP-2, reference anti-p140, and anti-p155/140, the other autoantibody recently described in juvenile DM. DNA samples from 100 Caucasian children with myositis were genotyped for HLA class II haplotype associations and compared with those from 864 randomly selected UK Caucasian control subjects. RESULTS: Sera from 37 (23%) of 162 patients with juvenile myositis were positive for anti-p140 autoantibodies, which were detected exclusively in patients with juvenile DM and not in patients with juvenile DM-overlap syndrome or control subjects. No anti-p140 antibody-positive patients were positive for other recognized autoantibodies. Immunodepletion suggested that the identity of p140 was consistent with NXP-2 (the previously identified MJ autoantigen). In children with anti-p140 antibodies, the association with calcinosis was significant compared with the rest of the cohort (corrected P < 0.005, odds ratio 7.0, 95% confidence interval 3.0-16.1). The clinical features of patients with anti-p140 autoantibodies were different from those of children with anti-p155/140 autoantibodies. The presence of HLA-DRB1*08 was a possible risk factor for anti-p140 autoantibody positivity. CONCLUSION: This study has established that anti-p140 autoantibodies represent a major autoantibody subset in juvenile DM. This specificity may identify a further immunogenetic and clinical phenotype within the juvenile myositis spectrum that includes an association with calcinosis.
Subject(s)
Autoantibodies/blood , Calcinosis/blood , Calcinosis/etiology , Dermatomyositis/blood , Dermatomyositis/complications , Adult , Autoantigens/immunology , Calcinosis/immunology , Case-Control Studies , Child , Child, Preschool , Dermatomyositis/immunology , Female , HLA-DR Antigens/blood , HLA-DRB1 Chains , Humans , Ireland , Male , Registries , Risk Factors , United KingdomABSTRACT
OBJECTIVES: Autoantibodies to a novel autoantigen small ubiquitin-like modifier activating enzyme (SAE) associated with dermatomyositis (DM) have previously been identified. The aim of this study was to establish the frequency of anti-SAE autoantibodies in a UK myositis cohort and investigate clinicoimmunogenetic associations. METHODS: Clinical data and sera were studied from 266 patients recruited to the Adult Onset Myositis Immunogenetic Collaboration. Myositis sera, control sera including 250 patients with other connective tissue diseases and 50 healthy participants were screened using radio-immunoprecipitation. Immunodepletion was performed on all sera immunoprecipitating 40 and 90 kDa bands to confirm the presence of anti-SAE. DNA from 202 patients with myositis was genotyped for human leucocyte antigen (HLA)-DRB1 and DQB1; DQA1 data were inferred. RESULTS: Out of 266 patients with myositis, 11 (4%) were positive for anti-SAE, which was found exclusively in DM with a frequency of 8%. Patients with anti-SAE had a high frequency of cutaneous lesions including heliotrope (82%) and Gottron rash (82%). Of the 11, 9 (82%) had systemic features and 7 of 9 (78%) developed dysphagia. Of those nine, seven (78%) presented with skin disease before myositis onset. All patients with anti-SAE possessed at least one copy of HLA-DQB1*03. HLA-DRB1*04-DQA1*03-DQB1*03 was a significant risk factor in anti-SAE positive versus patients who were anti-SAE negative (haplotype frequency 18% vs 6%, p<0.001, OR 5.7, 95% CI 1.9 to 17.3). CONCLUSIONS: Anti-SAE is a myositis-specific autoantibody that identifies a subset of patients with adult DM. The majority of patients with anti-SAE presented with cutaneous disease and progressed to myositis with systemic features including dysphagia. This novel autoantibody has a strong association with the HLA-DRB1*04-DQA1*03-DQB1*03 haplotype.
Subject(s)
Autoantibodies/blood , HLA-D Antigens/genetics , Myositis/immunology , Small Ubiquitin-Related Modifier Proteins/immunology , Aged , Autoantigens/immunology , Cohort Studies , Dermatomyositis/epidemiology , Dermatomyositis/genetics , Dermatomyositis/immunology , Female , Haplotypes , Histocompatibility Testing , Humans , Male , Middle Aged , Myositis/epidemiology , Myositis/genetics , United Kingdom/epidemiologyABSTRACT
OBJECTIVE: To examine single-nucleotide polymorphisms (SNPs) of the protein tyrosine phosphatase N22 gene (PTPN22) and to study the relationship between PTPN22 and the HLA region in patients with idiopathic inflammatory myopathies (IIMs). METHODS: PTPN22 SNPs were assessed in a large, cross-sectional, case-control study from the UK involving patients with adult or juvenile IIM, comprising patients with polymyositis (PM) (n=114), dermatomyositis (DM) (n=102), myositis associated with another connective tissue disease (myositis-CTD overlap syndrome) (n=64), or juvenile DM (n=101), in comparison with 748 control subjects. Seventeen PTPN22 SNPs were genotyped using the Sequenom MassArray iPLEX platform. Serotyping for myositis-specific/myositis-associated autoantibodies (MSAs/MAAs) was performed by radioimmunoprecipitation. RESULTS: A significant association was noted between the R620W variant (rs2476601) and IIM (corrected P [Pcorr]=0.0009 versus controls), and specifically with the clinical subgroup of PM (Pcorr=0.003 versus controls). A weaker association was noted with juvenile DM (Pcorr=0.009 versus controls). No significant associations were noted after stratification by serologic subgroups. The association with the R620W variant was independent of alleles forming the HLA 8.1 haplotype. No other PTPN22 SNPs were associated with IIM. The PTPN22 haplotype containing the R620W T allele was the only haplotype significantly associated with IIM. CONCLUSION: The R620W variant is a significant risk factor for IIM, independent of the HLA 8.1 haplotype. Unlike that in the HLA region, risk is not increased in individuals possessing MSAs/MAAs. These results are further evidence that the PTPN22 gene confers autoimmune susceptibility.