Nail psoriasis dynamics during biologic treatment and withdrawal in patients with psoriasis who may be at high risk of developing psoriatic arthritis: a post hoc analysis of the VOYAGE 2 randomized trial.

BACKGROUND: Nail psoriasis is a common, physiologically, and psychologically disruptive, and yet often under-treated manifestation of psoriasis. The objectives of this analysis were to investigate the trajectory of nail psoriasis, a risk factor for psoriatic arthritis (PsA), with guselkumab vs adalimumab treatment followed by withdrawal, and determine characteristics associated with nail response in patients treated with guselkumab. METHODS: This post hoc analysis of the phase III trial VOYAGE 2 included patients with moderate-to-severe plaque psoriasis and baseline nail involvement. Nail Psoriasis Severity Index (NAPSI) and Psoriasis Area and Severity Index (PASI) were analyzed through week 48 in patients randomized to guselkumab or adalimumab. Multiple logistic regression analyzed factors associated with NAPSI 0/1 at week 24/week 48 following guselkumab treatment. In a separate analysis, patients were stratified by prior biologic experience. RESULTS: Overall, 272 vs 132 patients receiving guselkumab vs adalimumab had nail psoriasis at baseline. Lower baseline NAPSI and week 16 PASI were associated with achieving NAPSI 0/1 at week 24 (NAPSI, odds ratio 0.685 [95% confidence interval: 0.586, 0.802]; week 16 PASI, 0.469 [0.281, 0.782]) and week 48 (NAPSI, 0.784 [0.674, 0.914]; week 16 PASI, 0.557 [0.331, 0.937]) with guselkumab. Previous biologic experience did not impact NAPSI response. Following treatment withdrawal at week 28, mean NAPSI was maintained in the guselkumab arm (week 24 1.7, week 48 1.9) and increased slightly in the adalimumab arm (week 24 1.4, week 48 2.3). Mean PASI increased across both treatment arms. CONCLUSIONS: Higher skin efficacy at week 16 was associated with better nail responses during guselkumab treatment. Nail psoriasis improvements reflected skin improvements. Following guselkumab withdrawal, nail response was maintained longer than skin response. Future studies should investigate whether such improvements in nail response reduce patients' risk of later PsA development. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02207244. Registered July 31, 2014.

Contribution of Rare Genetic Variation to Disease Susceptibility in a Large Scandinavian Myositis Cohort.

OBJECTIVE: Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of complex autoimmune conditions characterized by inflammation in skeletal muscle and extramuscular compartments, and interferon (IFN) system activation. We undertook this study to examine the contribution of genetic variation to disease susceptibility and to identify novel avenues for research in IIMs. METHODS: Targeted DNA sequencing was used to mine coding and potentially regulatory single nucleotide variants from ~1,900 immune-related genes in a Scandinavian case-control cohort of 454 IIM patients and 1,024 healthy controls. Gene-based aggregate testing, together with rare variant- and gene-level enrichment analyses, was implemented to explore genotype-phenotype relations. RESULTS: Gene-based aggregate tests of all variants, including rare variants, identified IFI35 as a potential genetic risk locus for IIMs, suggesting a genetic signature of type I IFN pathway activation. Functional annotation of the IFI35 locus highlighted a regulatory network linked to the skeletal muscle-specific gene PTGES3L, as a potential candidate for IIM pathogenesis. Aggregate genetic associations with AGER and PSMB8 in the major histocompatibility complex locus were detected in the antisynthetase syndrome subgroup, which also showed a less marked genetic signature of the type I IFN pathway. Enrichment analyses indicated a burden of synonymous and noncoding rare variants in IIM patients, suggesting increased disease predisposition associated with these classes of rare variants. CONCLUSION: Our study suggests the contribution of rare genetic variation to disease susceptibility in IIM and specific patient subgroups, and pinpoints genetic associations consistent with previous findings by gene expression profiling. These features highlight genetic profiles that are potentially relevant to disease pathogenesis.

Corrigendum to: Persistence of biologic treatments in psoriatic arthritis: a population-based study in Sweden.

[This corrects the article DOI: 10.1093/rap/rkaa070.][This corrects the article DOI: 10.1093/rap/rkaa070.].

Performance of the new EULAR/ACR classification criteria for idiopathic inflammatory myopathies (IIM) in a large monocentric IIM cohort.

BACKGROUND: In 2017, the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) published new classification criteria for idiopathic inflammatory myopathies (IIM). OBJECTIVES: To [1] assess the performance of the EULAR/ACR criteria in a monocentric cohort of consecutive patients with IIM, compare them with the Bohan and Peter (BP) criteria, and with the physician's diagnosis; and [2] evaluate the effect of including the presence of interstitial lung disease (ILD) as variable in the criteria. METHODS: 439 consecutive patients with a diagnosis of IIM followed at the Rheumatology Clinic, Karolinska University Hospital, Sweden were enrolled. The patients were diagnosed as IIM and subclassified by expert physicians. Clinical, laboratory, serological and histopathological data were collected from existing databases (Euromyositis registry and Swedish Rheumatology quality registry) and clinical charts of the patients. The sensitivity of the EULAR/ACR and the BP criteria was calculated. RESULTS: The EULAR/ACR criteria had a higher sensitivity (87.7%) compared to the BP criteria (80.4%). The concordance between the two sets of criteria was low (k = 0.253 p<0.001). The EULAR/ACR criteria showed a very high specificity (>98%) for the major IIM subgroups polymyositis, dermatomyositis, and inclusion body myositis. The sensitivity was variable and was high in inclusion body myositis (98%), dermatomyositis (90%) and lower in polymyositis (73%). When including ILD in the variables of the criteria, six more patients were classified as IIM cases (1.3%). CONCLUSION: The EULAR/ACR criteria for IIM are applicable with high sensitivity and specificity using data available from existing databases and clinical charts and represent a major step forward from the previous criteria for IIM and its subgroups. Their application will improve the quality of clinical trials and research studies with IIM patients.

Persistence of biologic treatments in psoriatic arthritis: a population-based study in Sweden.

OBJECTIVES: TNF inhibitors (TNFis) and IL inhibitors are effective treatments for PsA. Treatment non-persistence (drug survival, discontinuation) is a measure of effectiveness, tolerability and patient satisfaction or preferences in real-world clinical practice. Persistence on these treatments is not well understood in European PsA populations. The aim of this study was to compare time to non-persistence for either ustekinumab (IL-12/23 inhibitor) or secukinumab (IL-17 inhibitor) to a reference group of adalimumab (TNFi) treatment exposures in PsA patients and identify risk factors for non-persistence. METHODS: A total of 4649 exposures of adalimumab, ustekinumab, and secukinumab in 3918 PsA patients were identified in Swedish longitudinal population-based registry data. Kaplan-Meier curves were constructed to measure treatment-specific real-world risk of non-persistence and adjusted Cox proportional hazards models were estimated to identify risk factors associated with non-persistence. RESULTS: Ustekinumab was associated with a lower risk of non-persistence relative to adalimumab in biologic-naïve [hazard ratio (HR) 0.48 (95% CI 0.33, 0.69)] and biologic-experienced patients [HR 0.65 (95% CI 0.56, 0.76)], while secukinumab was associated with a lower risk in biologic-naïve patients [HR 0.65 (95% CI 0.49, 0.86)] but a higher risk of non-persistence in biologic-experienced patients [HR 1.20 (95% CI 1.03, 1.40)]. Biologic non-persistence was also associated with female sex, axial involvement, recent disease onset, biologic treatment experience and no psoriasis. CONCLUSION: Ustekinumab exhibits a favourable treatment persistency profile relative to adalimumab overall and across lines of treatment. The performance of secukinumab is dependent on biologic experience. Persistence and risk factors for non-persistence should be accounted for when determining an optimal treatment plan for patients.

Abatacept in the treatment of adult dermatomyositis and polymyositis: a randomised, phase IIb treatment delayed-start trial.

OBJECTIVES: To study the effects of abatacept on disease activity and on muscle biopsy features of adult patients with dermatomyositis (DM) or polymyositis (PM). METHODS: Twenty patients with DM (n=9) or PM (n=11) with refractory disease were enrolled in a randomised treatment delayed-start trial to receive either immediate active treatment with intravenous abatacept or a 3 month delayed-start. The primary endpoint was number of responders, defined by the International Myositis Assessment and Clinical Studies Group definition of improvement (DOI), after 6 months of treatment. Secondary endpoints included number of responders in the early treatment arm compared with the delayed treatment arm at 3 months. Repeated muscle biopsies were investigated for cellular markers and cytokines. RESULTS: 8/19 patients included in the analyses achieved the DOI at 6 months. At 3 months of study, five (50%) patients were responders after active treatment but only one (11%) patient in the delayed treatment arm. Eight adverse events (AEs) were regarded as related to the drug, four mild and four moderate, and three serious AEs, none related to the drug. There was a significant increase in regulatory T cells (Tregs), whereas other markers were unchanged in repeated muscle biopsies. CONCLUSIONS: In this pilot study, treatment of patients with DM and PM with abatacept resulted in lower disease activity in nearly half of the patients. In patients with repeat muscle biopsies, an increased frequency of Foxp3+ Tregs suggests a positive effect of treatment in muscle tissue.

2017 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Adult and Juvenile Idiopathic Inflammatory Myopathies and Their Major Subgroups.

OBJECTIVE: To develop and validate new classification criteria for adult and juvenile idiopathic inflammatory myopathies (IIM) and their major subgroups. METHODS: Candidate variables were assembled from published criteria and expert opinion using consensus methodology. Data were collected from 47 rheumatology, dermatology, neurology, and pediatric clinics worldwide. Several statistical methods were utilized to derive the classification criteria. RESULTS: Based on data from 976 IIM patients (74% adults; 26% children) and 624 non-IIM patients with mimicking conditions (82% adults; 18% children), new criteria were derived. Each item is assigned a weighted score. The total score corresponds to a probability of having IIM. Subclassification is performed using a classification tree. A probability cutoff of 55%, corresponding to a score of 5.5 (6.7 with muscle biopsy) "probable IIM," had best sensitivity/specificity (87%/82% without biopsies, 93%/88% with biopsies) and is recommended as a minimum to classify a patient as having IIM. A probability of ≥90%, corresponding to a score of ≥7.5 (≥8.7 with muscle biopsy), corresponds to "definite IIM." A probability of <50%, corresponding to a score of <5.3 (<6.5 with muscle biopsy), rules out IIM, leaving a probability of ≥50-<55% as "possible IIM." CONCLUSION: The European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for IIM have been endorsed by international rheumatology, dermatology, neurology, and pediatric groups. They employ easily accessible and operationally defined elements, and have been partially validated. They allow classification of "definite," "probable," and "possible" IIM, in addition to the major subgroups of IIM, including juvenile IIM. They generally perform better than existing criteria.

EULAR/ACR classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups: a methodology report.

OBJECTIVE: To describe the methodology used to develop new classification criteria for adult and juvenile idiopathic inflammatory myopathies (IIMs) and their major subgroups. METHODS: An international, multidisciplinary group of myositis experts produced a set of 93 potentially relevant variables to be tested for inclusion in the criteria. Rheumatology, dermatology, neurology and paediatric clinics worldwide collected data on 976 IIM cases (74% adults, 26% children) and 624 non-IIM comparator cases with mimicking conditions (82% adults, 18% children). The participating clinicians classified each case as IIM or non-IIM. Generally, the classification of any given patient was based on few variables, leaving remaining variables unmeasured. We investigated the strength of the association between all variables and between these and the disease status as determined by the physician. We considered three approaches: (1) a probability-score approach, (2) a sum-of-items approach criteria and (3) a classification-tree approach. RESULTS: The approaches yielded several candidate models that were scrutinised with respect to statistical performance and clinical relevance. The probability-score approach showed superior statistical performance and clinical practicability and was therefore preferred over the others. We developed a classification tree for subclassification of patients with IIM. A calculator for electronic devices, such as computers and smartphones, facilitates the use of the European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria. CONCLUSIONS: The new EULAR/ACR classification criteria provide a patient's probability of having IIM for use in clinical and research settings. The probability is based on a score obtained by summing the weights associated with a set of criteria items.

2017 European League Against Rheumatism/American College of Rheumatology classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups.

OBJECTIVE: To develop and validate new classification criteria for adult and juvenile idiopathic inflammatory myopathies (IIM) and their major subgroups. METHODS: Candidate variables were assembled from published criteria and expert opinion using consensus methodology. Data were collected from 47 rheumatology, dermatology, neurology and paediatric clinics worldwide. Several statistical methods were used to derive the classification criteria. RESULTS: Based on data from 976 IIM patients (74% adults; 26% children) and 624 non-IIM patients with mimicking conditions (82% adults; 18% children), new criteria were derived. Each item is assigned a weighted score. The total score corresponds to a probability of having IIM. Subclassification is performed using a classification tree. A probability cut-off of 55%, corresponding to a score of 5.5 (6.7 with muscle biopsy) 'probable IIM', had best sensitivity/specificity (87%/82% without biopsies, 93%/88% with biopsies) and is recommended as a minimum to classify a patient as having IIM. A probability of ≥90%, corresponding to a score of ≥7.5 (≥8.7 with muscle biopsy), corresponds to 'definite IIM'. A probability of <50%, corresponding to a score of <5.3 (<6.5 with muscle biopsy), rules out IIM, leaving a probability of ≥50 to <55% as 'possible IIM'. CONCLUSIONS: The European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for IIM have been endorsed by international rheumatology, dermatology, neurology and paediatric groups. They employ easily accessible and operationally defined elements, and have been partially validated. They allow classification of 'definite', 'probable' and 'possible' IIM, in addition to the major subgroups of IIM, including juvenile IIM. They generally perform better than existing criteria.

Use of biologic agents in idiopathic inflammatory myopathies in Sweden: a descriptive study of real life treatment.

OBJECTIVES: Biologic treatment has revolutionised treatment in rheumatology in the last decades. Patients with idiopathic inflammatory myopathies (IIM) have so far only been treated with biologics off-label, with little published follow-up on those who are treated and how they are treated. We therefore set out to characterise the Swedish IIM patients who have been treated with biologics. METHODS: By linking Swedish registers we identified 95 patients with IIM who were treated with biologics between 2000 and 2011. Via chart review the diagnoses were validated and clinical characteristics extracted. RESULTS: In total, 95 individuals with IIM and biologic treatment were identified. Median disease duration was 5.5 years at start of biologics. All patients had been treated with prednisolone and failed at least one previous DMARD before the start of first biologic. Rituximab was the most common biologic drug, followed by anakinra and TNFinhibitors. Median overall treatment length was 10 months and varied between 5 and 12.5 months or the different therapies. CONCLUSIONS: Off-label treatment of IIMs is often tried and seldom successful. This study shows a large unmet need for novel treatments and therapies in IIM. It is therefore important to follow these patients in a structured way to learn about effects and potential risks for different subgroups of IIM associated with different therapies.

Dysfunction of endothelial progenitor cells is associated with the type I IFN pathway in patients with polymyositis and dermatomyositis.

OBJECTIVE: Alterations in phenotype and function of endothelial progenitor cells (EPCs) have been associated with poor vascular outcomes and impaired vascular repair in various conditions. Our hypothesis was that patients with PM and DM have dysregulation of EPCs driven by type I IFN and IL-18 similar to other autoimmune diseases. METHODS: Quantification of circulating EPCs was performed by flow cytometry in patients with PM/DM and matched healthy controls. The ability of EPCs to differentiate into mature endothelial cells was investigated by light and fluorescence microscopy quantification in the presence or absence of PM/DM or control serum, neutralizing antibodies to type I IFN receptor or IL-18. Serum type I IFN activity was quantified by induction of type I IFN-inducible genes in HeLa cells. Circulating IL-18 concentrations were assessed by ELISA. RESULTS: Circulating EPCs were significantly lower in PM/DM patients compared with controls. PM/DM EPCs displayed a decreased capacity to differentiate into mature endothelial cells and PM/DM serum significantly inhibited differentiation of control EPCs. This effect was reversed in the majority of samples with neutralizing antibodies to IL-18 or to type I IFN receptor or by a combination of these antibodies. Patients with associated impairments in EPC function had higher type I IFN serum activity. CONCLUSION: PM/DM is associated with dysregulation of EPC phenotype and function that may be attributed, at least in part, to aberrant IL-18 and type I IFN pathways. The implication of these vasculopathic findings for disease prognosis and complications remains to be determined.

Development of autoantibodies against muscle-specific FHL1 in severe inflammatory myopathies.

Mutations of the gene encoding four-and-a-half LIM domain 1 (FHL1) are the causative factor of several X-linked hereditary myopathies that are collectively termed FHL1-related myopathies. These disorders are characterized by severe muscle dysfunction and damage. Here, we have shown that patients with idiopathic inflammatory myopathies (IIMs) develop autoimmunity to FHL1, which is a muscle-specific protein. Anti-FHL1 autoantibodies were detected in 25% of IIM patients, while patients with other autoimmune diseases or muscular dystrophies were largely anti-FHL1 negative. Anti-FHL1 reactivity was predictive for muscle atrophy, dysphagia, pronounced muscle fiber damage, and vasculitis. FHL1 showed an altered expression pattern, with focal accumulation in the muscle fibers of autoantibody-positive patients compared with a homogeneous expression in anti-FHL1-negative patients and healthy controls. We determined that FHL1 is a target of the cytotoxic protease granzyme B, indicating that the generation of FHL1 fragments may initiate FHL1 autoimmunity. Moreover, immunization of myositis-prone mice with FHL1 aggravated muscle weakness and increased mortality, suggesting a direct link between anti-FHL1 responses and muscle damage. Together, our findings provide evidence that FHL1 may be involved in the pathogenesis not only of genetic FHL1-related myopathies but also of autoimmune IIM. Importantly, these results indicate that anti-FHL1 autoantibodies in peripheral blood have promising potential as a biomarker to identify a subset of severe IIM.