Hector Chinoy

Clinical associations of autoantibodies to a p155/140 kDa doublet protein in juvenile dermatomyositis

OBJECTIVESnMyositis-specific autoantibodies (MSAs) may define homogeneous clinical subsets of adult patients with dermatomyositis (DM). Recently, there have been descriptions of novel autoantibodies in DM. This study was conducted to establish the clinical significance of anti-p155/140 autoantibodies in juvenile DM (JDM).nnnMETHODSnThe first 116 children recruited to the JDM National Registry and Repository (UK and Ireland) were studied. Comprehensive clinical features were recorded and sera screened for anti-p155/140 autoantibodies using radio-immunoprecipitation. Sera from adults with DM (n = 20), PM (n = 25), SSc (n = 150), SLE (n = 40) and healthy subjects (n = 50) were used for comparison. Immunodepletion experiments were used to establish whether the p155/140 kDa targets recognized by JDM sera were the same as adult DM sera.nnnRESULTSnTwenty-seven out of 116 (23%) JDM cases were positive for anti-p155/140 in comparison with 6/20 (30%) adults with DM. Immunodepletion confirmed that the 155/140 kDa proteins recognized by JDM and adult DM sera were the same targets. All other adult control sera were negative for anti-p155/140 autoantibodies. There was a higher frequency of males in the anti-p155/140-positive JDM group (P = 0.02). JDM patients with anti-p155/140 autoantibodies had significantly more cutaneous involvement including Gottrons papules (P = 0.003), ulceration (P = 0.005) and oedema (P = 0.013). The distribution of skin lesions was more extensive particularly periorbitally (P = 0.014) and over the small (P < 0.001) and large joints (P = 0.003).nnnCONCLUSIONSnAnti-p155/140 autoantibodies are clinically significant in JDM and may define a clinical subset in terms of disease severity and outcome. The same autoantigen target is detected in adult DM patients.

Autoantibodies to a 140‐kd protein in juvenile dermatomyositis are associated with calcinosis

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.

Clinical and human leucocyte antigen class II haplotype associations of autoantibodies to small ubiquitin-like modifier enzyme, a dermatomyositis-specific autoantigen target, in UK Caucasian adult-onset myositis

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.

HLA–DPB1 associations differ between DRB1*03 positive anti-Jo-1 and anti-PM-Scl antibody positive idiopathic inflammatory myopathy

OBJECTIVEnThe HLA 8.1 ancestral haplotype (HLA-B*08/DRB1*03/DQA1*05/DQB1*02) is associated with adult/juvenile idiopathic inflammatory myopathy (IIM), but confers a greater strength of association in patients possessing anti-Jo-1 or anti-PM-Scl antibodies. The HLA-DPB1 gene is centromeric to other HLA class II loci and separated by a recombination hotspot. We investigated whether HLA-DPB1 associations differ between anti-Jo-1 and anti-PM-Scl antibody-positive IIM cases.nnnMETHODSnTwo hundred and thirty-three adult IIM patients (73% females, 49.4 +/- 13.6 years) with PM (n = 89), DM (n = 88) and myositis associated with another CTD (n = 55) and 85 juvenile DM patients (75% females, 6.2 +/- 3.6 years) were compared with 678 UK Caucasian controls. Patients/controls were genotyped for HLA-DPB1 and DRB1 alleles. Myositis-specific and associated antibodies were identified in cases using immunoprecipitation.nnnRESULTSnHLA-DPB1*0101 was associated with IIM overall [22 vs 13% controls, corrected probability (P(corr)) = 2 x 10(-03); odds ratio (OR) 2.0; 95% CI 1.4, 2.9], PM (P(corr) = 7 x 10(-03); OR 2.5; 95% CI 1.5, 4.4) and anti-Jo-1 (P(corr) = 3 x 10(-5); OR 4.1; 95% CI 2.1, 7.8). No significant DPB1*0101 difference was present between anti-PM-Scl cases and controls. The HLA-DPB1*0101 association in IIM overall cases was dependent on the presence of DRB1*03. A number of HLA-DRB1*03/DPB1 haplotypes were identified, but only DRB1*03/DPB1*0101 was associated with anti-Jo-1 antibody-positive cases.nnnCONCLUSIONSnThe HLA-DRB1*03/DPB1*0101 haplotype is a risk factor for anti-Jo-1 antibody-positive IIM. Thus, although DRB1*03 is strongly associated with possession of either anti-Jo-1 or anti-PM-Scl, differing antibody associations are observed at the HLA-DPB1 locus.

Cytosolic 5′-nucleotidase 1A autoantibody profile and clinical characteristics in inclusion body myositis

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.

Genetic association study of NF-κB genes in UK Caucasian adult and juvenile onset idiopathic inflammatory myopathy

Objective. Treatment-resistant muscle wasting is an increasingly recognized problem in idiopathic inflammatory myopathy (IIM). TNF-α is thought to induce muscle catabolism via activation of nuclear factor-kappa B (NF-κB). Several genes share homology with the NF-κB family of proteins. This study investigated the role of NF-κB-related genes in disease susceptibility in UK Caucasian IIM. Methods. Data from 362 IIM cases [274 adults, 49 (±14.0) years, 72% female; 88 juveniles, 6 (±3.6) years, 73% female) were compared with 307 randomly selected Caucasian controls. DNA was genotyped for 63 single nucleotide polymorphisms (SNPs) from NF-κB-related genes. Data were stratified by IIM subgroup/serotype. Results. A significant allele association was observed in the overall IIM group vs controls for the IKBL-62T allele (rs2071592, odds ratio 1.5, 95% CI 1.21, 1.89, corrected Pu2009=u20090.0086), which strengthened after stratification by anti-Jo-1 or -PM-Scl antibodies. Genotype analysis revealed an increase for the AT genotype in cases under a dominant model. No other SNP was associated in the overall IIM group. Strong pairwise linkage disequilibrium was noted between IKBL-62T, TNF-308A and HLA-B*08 (D′u2009=u20091). Using multivariate regression, the IKBL-62T IIM association was lost after adjustment for TNF-308A or HLA-B*08. Conclusion. An association was noted between IKBL-62T and IIM, with increased risk noted in anti-Jo-1- and -PM-Scl antibody-positive patients. However, the IKBL-62T association is dependent on TNF-308A and HLA-B*08, due to strong shared linkage disequilibrium between these alleles. After adjustment of the 8.1 HLA haplotype, NF-κB genes therefore do not independently confer susceptibility in IIM.

Clinical, serological and HLA profiles in non-Caucasian UK idiopathic inflammatory myopathy.

Clinical, serological and HLA profiles in non-Caucasian UK idiopathic inflammatory myopathy SIR, Since 2000, the UK Adult Onset Myositis Immunogenetic Collaboration (AOMIC) has recruited idiopathic inflammatory myopathy (IIM) cases across the UK. In this brief report, we summarize the clinical, serological and HLA Class II status of non-Caucasian IIM cases, to ascertain whether differences are observed among UK IIM ethnic populations. DNA was available from 28 UK non-Caucasian IIM cases. Adult IIM patients, aged 518 years of age at disease onset, with probable or definite myositis [1] were recruited through AOMIC [2]. Data were also available from 303 UK Caucasian IIM cases previously described [2, 3]. The collaborating AOMIC physicians confirmed interstitial lung disease (ILD) and cancer-associated myositis (CAM) [4] by relevant investigations. Radio-immunoprecipitation was used for determination of myositis-specific antibodies (anti-previously described [2, 4]. This study was approved by the local research ethics committee and informed consent was obtained according to the Declaration of Helsinki. A Wilcoxon–Mann– Whitney test was used to compare the age of onset between Caucasians and non-Caucasians. Associations were calculated from 2 Â 2 contingency tables using the chi-squared test. Of the 28 non-Caucasian IIM cases, 14 were Asian, 12 African/ Afro-Caribbean and 2 of mixed-race origin (Table 1). Sixty-four percent of the non-Caucasian IIM cases were females, compared with 71% female Caucasian cases (P ¼ 0.46). The median age of onset of the non-Caucasian cohort was significantly lower than that of the Caucasian cohort [non-Caucasians, 37 years (inter-After stratification by gender, this observation was only significantly lower in non-Caucasian females [non-Caucasians females, 33 years (27, 41) vs Caucasian females, 49 years (38, 60), P ¼ 0.0001]. No significant difference for age of onset was noted between African/Afro-Caribbean or Asian cases. CAM was not detected in the non-Caucasian cohort, but was present in 6% of the Caucasian IIM cohort, and in 15% of the DM cases [4]. With respect to ILD, there were eight (29%) non-Caucasian IIM cases and six of seven (86%) anti-synthetase antibody-positive cases. Although a higher frequency of ILD was observed in African/Afro-Caribbean (35%) compared with Asian (18%) cases, due to the small sample size this was not statistically significant (P ¼ 0.24). This difference was not attributable to differences in anti-synthetase antibody frequency. In comparison, the overall frequency of ILD in the Caucasian cohort was 20%, and 44% in anti-synthetase positive cases. Within the non-Caucasian cohort, only PM cases possessed anti-Jo-1 …

A microcosting study of immunogenicity and tumour necrosis factor alpha inhibitor drug level tests for therapeutic drug monitoring in clinical practice

Objectives. To identify and quantify resource required and associated costs for implementing TNF-α inhibitor (TNFi) drug level and anti-drug antibody (ADAb) tests in UK rheumatology practice. Methods. A microcosting study, assuming the UK National Health Service perspective, identified the direct medical costs associated with providing TNFi drug level and ADAb testing in clinical practice. Resource use and costs per patient were identified via four stages: identification of a patient pathway with resource implications; estimation of the resources required; identification of the cost per unit of resource (2015 prices); and calculation of the total costs per patient. Univariate and multiway sensitivity analyses were performed using the variation in resource use and unit costs. Results. Total costs for TNFi drug level and concurrent ADAb testing, assessed using ELISAs on trough serum levels, were £152.52/patient (range: £147.68–159.24) if 40 patient samples were tested simultaneously. For the base–case analysis, the pre-testing phase incurred the highest costs, which included booking an additional appointment to acquire trough blood samples. The additional appointment was the key driver of costs per patient (67% of the total cost), and labour accounted for 10% and consumables 23% of the total costs. Performing ELISAs once per patient (rather than in duplicate) reduced the total costs to £133.78/patient. Conclusion. This microcosting study is the first assessing the cost of TNFi drug level and ADAb testing. The results could be used in subsequent cost-effectiveness analyses of TNFi pharmacological tests to target treatments and inform future policy recommendations.

SAT0355 Risk and Characteristics of Drug Induced Vasculitis in Patients Exposed to Tumour Necrosis Factor α Inhibitor Therapy: Results from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis

Background Several reports have suggested an association between tumour necrosis factor inhibitor (TNFi) therapies and vasculitis as an immune mediated adverse event related to autoantibody formation; however, the incidence of this manifestation is unknown. Objectives The aims of this study were to (i) compare the incidence of vasculitis in rheumatoid arthritis (RA) patients treated with TNFi to those receiving non-biologic drugs (nbDMARDs) and (ii) characterise these adverse events. Methods The British Society for Rheumatology Biologics Register for RA (BSRBR-RA) is a prospective cohort study assessing the safety of biologic therapy. This analysis included two cohorts: (i) patients starting TNFi (adalimumab, etanercept, infliximab, certolizumab) as their first biologic (ii) a biologic-naïve comparison cohort receiving nbDMARDs. Patients were recruited to the study between 2001 and 2014. Additional information from consultants was sought for vasculitis episodes. Events were excluded in patients with (i) baseline systemic/nailfold vasculitis or (ii) receiving TNFi for RA vasculitis. Only patients who were biologic-naïve at baseline were included. The risk of an event was compared between the two cohorts using Cox proportional hazard models, adjusted using deciles of propensity scores. Events were attributed to TNFi therapy if they occurred within 90 days of being on drug. Follow-up was censored at first episode of vasculitis, switching to another biologic, death, last returned clinical follow-up or 31/05/2014, whichever came first. Results There were 72 incident cases: 12 in 3673 nbDMARD patients and 60 in 12,289 first TNFi-treated subjects generating crude incidence rates of 6/10,000 and 12/10,000 person years respectively (Table). After adjusting for propensity score, the hazard ratio of vasculitis in patients on TNFi vs. nbDMARD was 1.13 (95% CI 0.51-2.49). The majority of cases were limited to cutaneous involvement (Table). Other common systemic manifestations included digital infarction, neurological involvement and simultaneous arterial/venous thromboembolism (Table). One patient in the TNFi cohort died after developing haemorrhagic alveolitis (leukocytoclastic vasculitis on lung biopsy) and bilateral episcleritis (cANCA, PR3+ve). Conclusions In this large UK study, the incidence of TNFi induced vasculitis was not significantly higher compared with the nbDMARD treated comparator group after adjustment and the absolute risk in both groups was low. Cutaneous disease predominated in over half of the cases that occurred and TNFi induced systemic vasculitis was rare. Acknowledgements MJ is a Medical Research Council Clinical Training Fellow supported by the North West England Medical Research Council Fellowship Scheme in Clinical Pharmacology and Therapeutics (funded by the Medical Research Council [grant number G1000417/94909], ICON, GlaxoSmithKline, AstraZeneca and the Medical Evaluation Unit). This abstract includes independent research supported by the National Institute for Health Research Biomedical Research Unit Funding Scheme. Disclosure of Interest M. Jani Speakers bureau: Pfizer, W. Dixon: None declared, L. Kearsley-Fleet: None declared, I. Bruce Grant/research support from: GSK, Roche, Pfizer, UCB, Genzyme/Sanofi, H. Chinoy Grant/research support from: Novartis, Pfizer, Abbvie, Speakers bureau: Pfizer, Roche, MSD, Janssen, Abbvie, UCB, Servier, A. Barton Grant/research support from: Abbvie, Pfizer, Eli-Lilly and Sanofi-Aventis, M. Lunt: None declared, D. Symmons: None declared, K. Hyrich Grant/research support from: Pfizer, Speakers bureau: Abbvie

OP0110 Association of pharmacological biomarkers with treatment response and long-term disability in patients with psoriatic arthritis: results from outpass

Background Up to 40% of patients with inflammatory arthritis on TNF-α inhibitor (TNFi) treatment fail to respond either due to primary inefficacy or loss of response. One explanation is immunogenicity leading to the development of anti-drug antibodies (ADAb) and subsequent low drug levels. Few data exist on whether such pharmacological tests correlate with treatment response in psoriatic arthritis (PsA). The clinical utility of whether such tests should be incorporated into practice is in question. Objectives To identify (i) whether the presence of ADAbs/drug levels predict treatment response and disability in TNFi-treated PsA patients (ii) the factors associated with drug levels (iii) a drug level threshold for optimal therapeutic response. Methods 75 patients were available from the Outcomes of Treatment in PsA Study Syndicate (OUTPASS) [n=49 adalimumab; n=26 etanercept], a national UK prospective observational cohort. Serum samples were collected at 3, 6 and 12 months following initiation of TNFi therapy. ADAbs were measured using radioimmunoassay (RIA) and random (non-trough) drug levels using ELISA assays at 3, 6 and 12 months. Disease activity (DAS28) scores were measured at each visit. Patient self-reported adherence to TNFi was measured at each time-point. Generalised estimating equation (GEE) was used to test the association between ADAbs and drug levels, both biomarkers and treatment response [as assessed by change in DAS28 score between pre-treatment and 12 months post-treatment (ΔDAS28)], Health assessment Questionnaire (HAQ) and the association between longitudinal/baseline factors with drug levels. Results 264 serial samples were suitable for pharmacological testing (n=174 adalimumab; n=90 etanercept). Mean age was 51±12 years; 61% were female; median BMI 28.9 (IQR 26.0–34.9). 20% (n=10/49) of adalimumab-treated patients were positive for ADAbs, but none were detected in etanercept-treated patients. There was no significant association between etanercept drug levels and ΔDAS over 12 months [β= -0.039 (95% CI -0.31, 0.23), p=0.77]. Using GEE, adalimumab drug levels were significantly associated with ΔDAS28 over 12 months [β=0.055 (95% CI: 0.011, 0.099) p=0.014] and inversely with HAQ scores over 12 months [β= -0.022 (95% CI: -0.043, -0.00063]. ΔDAS28 was not independently associated with ADAb level [β=-0.0015 (95% CI: -0.0031, 0.000047), p=0.057]. Adalimumab concentrations between 4.5–8.5 mg/L were associated with an optimal treatment response at 6 months using concentration-effect curves. Factors that were significantly associated with adalimumab drug levels were ADAb level [β=-0.0073 (95% CI: -0.0014, 0.18), p<0.0001] and BMI [β=-0.15 (-0.29, -0.00450, p=0.043] in the final GEE model (adjusting for age, gender, adherence, BMI). Conclusions TNFi drug-level testing in adalimumab-initiated PsA patients may be useful in determining treatment response and disability over 12 months; interestingly, both the presence of ADAbs and BMI were inversely associated with drug levels. Identification of a drug level threshold for optimal response may help tailor adalimumab therapy for PsA patients in the future. Acknowledgements This work was funded from a grant awarded by the National Institute of Health and Research, Manchester Musculoskeletal BRU to MJ, AB. Disclosure of Interest M. Jani Grant/research support from: Abbvie, UCB, Pfizer, H. Chinoy Grant/research support from: Novartis, Abbvie, Consultant for: Eli-Lilly and Novartis, Speakers bureau: UCB, A. Barton Grant/research support from: Eli-Lilly, Speakers bureau: Roche Chugai and Pfizer