Serum Jo-1 Autoantibody and Isolated Arthritis in the Antisynthetase Syndrome: Review of the Literature and Report of the Experience of AENEAS Collaborative Group

A Review of Antisynthetase Syndrome-Associated Interstitial Lung Disease

Our objective in this review article is to present a clinical case of a patient with antisynthetase syndrome (ASyS) and provide an overview of the pathogenesis, classification criteria, antibody profiles, clinical features, and current knowledge of treatment options, focusing on interstitial lung disease (ILD). ASyS is an uncommon autoimmune disease with a heterogenous clinical presentation characterized by the presence of autoantibodies against an aminoacyl-tRNA synthetase and manifested by myositis, fever, inflammatory arthritis, Raynaud's phenomenon, mechanics hands, and ILD. ASyS-associated ILD (ASyS-ILD) is the most serious complication of ASyS, which may evolve to rapidly progressive ILD; therefore, it often requires thorough clinical and radiologic evaluation including recognition of a specific clinical phenotype associated with the antisynthetase antibodies (ASAbs) to guide therapeutic interventions.

Dermatomyositis: Practical Guidance and Unmet Needs

Dermatomyositis is a heterogeneous idiopathic inflammatory myopathy associated with various cutaneous manifestations and variable presence of myositis, interstitial lung disease, and other visceral organ involvement. An accurate diagnosis of dermatomyositis requires correlating clinical examination findings with serological and histological findings. Familiarity with pathognomonic and common cutaneous manifestations of dermatomyositis, which are highlighted here, can be especially helpful in making an accurate diagnosis. Additionally, evaluating patients for presence of myositis-specific autoantibodies can further support or refute a dermatomyositis diagnosis. When present, myositis-specific autoantibodies can also help guide workups for various dermatomyositis-associated manifestations, as each is associated with relatively distinct clinical characteristics. Evaluating patients for various systemic manifestations often relies on expert opinion recommendations; however, societal guideline statements concerning the evaluation of some manifestations have recently been described. Although malignancy-associated dermatomyositis is a well-accepted subtype, there is limited evidence to support extensive malignancy screening has a favorable benefit-risk ratio in most dermatomyositis patients. However, recent research has uncovered novel associations between dermatomyositis and malignancy, suggesting the possibility of identifying high-risk subsets of dermatomyositis patients in whom malignancy screening may have a high value. Treatment for dermatomyositis has remained largely unchanged over the past several decades. Although many dermatomyositis patients can be effectively treated with current options, either as monotherapy or with combination regimens, there is a need for more targeted and effective DM therapies, in general, and for MDA5(+) dermatomyositis-associated rapidly progressive interstitial lung disease. Fortunately, significant current and emerging research activities evaluating various novel medications for dermatomyositis provide hope for exciting future advances in patients with this intriguing immune-mediated disease.

Joint and muscle inflammatory disease: A scoping review of the published evidence

OBJECTIVES

Polyarthritis is commonly reported in idiopathic inflammatory myositis patients, but few studies have focused on the overlap of myositis with rheumatoid arthritis which is a difficult diagnosis in the absence of well-defined diagnostic criteria. The primary objective of this scoping review was to map the field of research to explore the potential diagnoses in patients presenting with both myositis and polyarthritis.

METHODS

Two electronic databases (MEDLINE/PubMed® and Web of Science®) were systematically searched using the terms (myositis OR 'inflammatory idiopathic myopathies') AND (polyarthritis OR 'rheumatoid arthritis') without any publication date limit.

RESULTS

Among individual records, 280 reports met inclusion criteria after full-text review. There was heterogeneity in the definition of overlap myositis as well as the characteristics of rheumatoid arthritis. In many studies, key data were lacking; rheumatoid factor status was reported in 56.8% (n=151), anti-citrullinated proteins antibodies status in 18.8% (n=50), and presence or absence of bone erosions in 45.1% (n=120) of the studies. Thirteen different diagnoses were found to associate myositis with polyarthritis: antisynthetase syndrome (29.6%, n=83), overlap myositis with rheumatoid arthritis (16.1%, n=45), drug-induced myositis (20.0%, n=56), rheumatoid myositis (7.5%, n=21), inclusion body myositis (1.8%, n=5), overlap with connective tissue disease (20.0%, n=56), and others (5.0%, n=14).

CONCLUSION

The spectrum of joint and muscle inflammatory diseases encompasses many diagnoses including primitive and secondary myositis associated with RA or arthritis mimicking RA. This review highlights the need for a consensual definition of OM with RA to better individualise this entity from the numerous differential diagnoses.

Diagnosis and Management of Myositis-Associated Lung Disease

Although interstitial lung disease (ILD) is a leading cause of morbidity and mortality in patients with inflammatory myopathies, the current definition and diagnostic criteria of autoimmune myositis remain inadequate to capture the large proportion of patients with lung-dominant disease. As a result, these patients present unique diagnostic and treatment challenges for even the most experienced clinicians. This article highlights the emerging role of autoantibodies in the diagnosis, classification, and management of patients with ILD. We propose alternative nomenclature to facilitate research on this unique patient population. Additionally, evidence supporting the various therapies used in the treatment of myositis-associated ILD is reviewed. The classification and treatment of patients with myositis-associated ILD remains challenging. A standardized therapeutic approach to these patients is lacking, and prospective studies in the field are needed to determine optimal treatment regimens.

[Myositis]

Extensive research work in the field of inflammatory myopathies over the past years has given us new insights into the classification and treatment of myositis. The myositis drug pipeline has never been stronger, although it is too early to know which products will eventually reach the market. Furthermore, in our review we try to summarize the latest German guidelines and recommendations on myositis that were recently published in June 2022. After reading this article, you should be able to describe practical considerations regarding the diagnosis, classification, and management of inflammatory myopathies. Additionally, you will be able to recognize myositis subgroups with a poor prognosis.

Coexistence of Multiple Myositis-Specific Antibodies in Patients with Idiopathic Inflammatory Myopathies

The mutual exclusivity of myositis-specific antibodies (MSAs) has been reported before, but the coexistence of 2 or more MSAs was still found in a few case reports. This study aims to confirm the existence and prevalence of double MSAs in patients with idiopathic inflammatory myopathy (IIM) and to clarify the clinical features of these patients. One hundred fifty-one patients with IIM diagnosed from 1 July 2018 to 31 July 2022, at National Cheng Kung University Hospital, Taiwan, were enrolled and divided into two groups, patients with ≤1 MSA (n = 128, 84.8%) and those with ≥2 MSAs (n = 23, 15.2%) according to the initial serology results. After being re-examined by ANA-IIF assay, 8 out of 23 patients were confirmed to have ≥2 MSAs. The demographic data and clinical features were presented. The prevalence of double-positive MSAs among IIM was 5.3% in this cohort. The coexistence of two MSAs in an IIM patient does exist but is rare. Patients with two MSAs belonging to two distinct IIM subtypes presented clinical features skewed to one subtype instead of "mixed phenotypes". No apparent difference in clinical severity was found between patients with ≥2 MSAs and ≤1 MSA. Longer follow-ups and more studies are required to characterize the patients of IIM with ≥2 MSAs.

A multidisciplinary approach to the diagnosis of antisynthetase syndrome

Antisynthetase syndrome is a subtype of idiopathic inflammatory myopathy, strongly associated with the presence of interstitial lung disease. Diagnosis is made by identifying myositis-specific antibodies directed against aminoacyl tRNA synthetase, and relevant clinical and radiologic features. Given the multisystem nature of the disease, diagnosis requires the careful synthesis of subtle clinical and radiological features with the interpretation of specialized autoimmune serological testing. This is provided in a multidisciplinary environment with input from rheumatologists, respiratory physicians, and radiologists. Differentiation from other idiopathic interstitial lung diseases is key; treatment and prognosis differ between patients with antisynthetase syndrome and idiopathic interstitial lung disease. In this review article, we look at the role of the multidisciplinary team and its individual members in the initial diagnosis of the antisynthetase syndrome, including the role of physicians, radiologists, and the wider team.

Even if it looks like COVID-19, think again: the importance of differential diagnosis during a pandemic

INTRODUCTION

Antisynthetase syndrome (ASSD) is a rare auto-immune condition that can present as interstitial lung disease (ILD) and progress into Acute Respiratory Distress Syndrome (ARDS).

IMPORTANCE

The purpose of this clinical case is to highlight the importance of considering less prevalent causes of ARDS amid the COVID-19 pandemic.

CASE REPORT

We present a 56-year-old Belgian female of African descent without past medical history who demonstrated typical signs of COVID-19 at the start of the pandemic. Based on the disease course as well as CT-scan findings, a diagnosis of COVID-19 was made. She progressed to ARDS for which she got intubated and was started on venovenous membrane oxygenation (VV-ECMO). Despite initial negative screening for antinuclear antibodies, further analysis revealed anti-Jo-antibodies. Diagnosis of ASSD was eventually retained and immunosuppressive therapy was started. However, pulmonary fibrosis had evolved too far and therapy was halted shortly after.

Role of MUC1 rs4072037 polymorphism and serum KL-6 levels in patients with antisynthetase syndrome

Mucin 1/Krebs von den Lungen-6 (KL-6) is proposed as a serum biomarker of several interstitial lung diseases (ILDs), including connective tissue disorders associated with ILD. However, it has not been studied in a large cohort of Caucasian antisynthetase syndrome (ASSD) patients. Consequently, we assessed the role of MUC1 rs4072037 and serum KL-6 levels as a potential biomarker of ASSD susceptibility and for the differential diagnosis between patients with ILD associated with ASSD (ASSD-ILD +) and idiopathic pulmonary fibrosis (IPF). 168 ASSD patients (149 ASSD-ILD +), 174 IPF patients and 523 healthy controls were genotyped for MUC1 rs4072037 T > C. Serum KL-6 levels were determined in a subgroup of individuals. A significant increase of MUC1 rs4072037 CC genotype and C allele frequencies was observed in ASSD patients compared to healthy controls. Likewise, MUC1 rs4072037 TC and CC genotypes and C allele frequencies were significantly different between ASSD-ILD+ and IPF patients. Additionally, serum KL-6 levels were significantly higher in ASSD patients compared to healthy controls. Nevertheless, no differences in serum KL-6 levels were found between ASSD-ILD+ and IPF patients. Our results suggest that the presence of MUC1 rs4072037 C allele increases the risk of ASSD and it could be a useful genetic biomarker for the differential diagnosis between ASSD-ILD+ and IPF patients.

Clinical profile and treatment outcomes in antisynthetase syndrome: a tertiary centre experience

OBJECTIVES

The aim was to describe the clinical profile and outcomes in patients with antisynthetase syndrome (ASS) from a tertiary care centre.

METHODS

The clinical data and investigations of all patients classified as ASS by Connors criteria over 5 years were recorded, and they were followed up prospectively. The median (interquartile range) was used for descriptive statistics. Clinical variables between the Jo-1 and non-Jo-1 groups and between patients with and without anti-Ro52 antibodies were compared using the χ2 test. Survival analysis was done using the log rank test.

RESULTS

The 28 patients (23 females) had a median age of 42.5 (34.8-52.3) years, with a disease duration of 1.75 (0.6-3.8) years at diagnosis, and had a follow-up of 2 (0.25-4.25) years. Seronegative arthritis was seen in 23 of 28 patients. Non-specific interstitial pneumonia was seen in 19 patients with interstitial lung disease (ILD). Antibodies to Jo-1 (n = 17) were more frequent than non-Jo-1 antibodies (n = 11; five anti-PL-12, four anti-PL-7 and two anti-EJ). There was no significant difference in the prevalence of myositis (P = 0.07) or ILD (P = 0.11) between groups. Anti-Ro52 antibodies were more frequently found in the non-Jo-1 group (P = 0.006, ϕ = 0.51). A partial or complete improvement with treatment was seen in three-quarters of the patients. Five patients succumbed to the illness. Better survival was seen in the Jo-1 group (P = 0.05).

CONCLUSION

The most typical presenting manifestation of ASS in our cohort was isolated seronegative arthritis. Non-specific interstitial pneumonia was the commonest ILD pattern. Patients with antibodies to Jo-1 had better survival compared with non-Jo-1. The non-Jo-1 aminoacyl-transfer RNA synthetases had a strong association with anti-Ro52 antibodies.

The combined prevalence of classified rare rheumatic diseases is almost double that of ankylosing spondylitis

BACKGROUND

Rare diseases (RDs) affect less than 5/10,000 people in Europe and fewer than 200,000 individuals in the United States. In rheumatology, RDs are heterogeneous and lack systemic classification. Clinical courses involve a variety of diverse symptoms, and patients may be misdiagnosed and not receive appropriate treatment. The objective of this study was to identify and classify some of the most important RDs in rheumatology. We also attempted to determine their combined prevalence to more precisely define this area of rheumatology and increase awareness of RDs in healthcare systems. We conducted a comprehensive literature search and analyzed each disease for the specified criteria, such as clinical symptoms, treatment regimens, prognoses, and point prevalences. If no epidemiological data were available, we estimated the prevalence as 1/1,000,000. The total point prevalence for all RDs in rheumatology was estimated as the sum of the individually determined prevalences.

RESULTS

A total of 76 syndromes and diseases were identified, including vasculitis/vasculopathy (n = 15), arthritis/arthropathy (n = 11), autoinflammatory syndromes (n = 11), myositis (n = 9), bone disorders (n = 11), connective tissue diseases (n = 8), overgrowth syndromes (n = 3), and others (n = 8). Out of the 76 diseases, 61 (80%) are classified as chronic, with a remitting-relapsing course in 27 cases (35%) upon adequate treatment. Another 34 (45%) diseases were predominantly progressive and difficult to control. Corticosteroids are a therapeutic option in 49 (64%) syndromes. Mortality is variable and could not be determined precisely. Epidemiological studies and prevalence data were available for 33 syndromes and diseases. For an additional eight diseases, only incidence data were accessible. The summed prevalence of all RDs was 28.8/10,000.

CONCLUSIONS

RDs in rheumatology are frequently chronic, progressive, and present variable symptoms. Treatment options are often restricted to corticosteroids, presumably because of the scarcity of randomized controlled trials. The estimated combined prevalence is significant and almost double that of ankylosing spondylitis (18/10,000). Thus, healthcare systems should assign RDs similar importance as any other common disease in rheumatology.

Idiopathische inflammatorische Myopathien: Aktuelles zu Diagnose und Klassifikation

Auf dem Sektor der Kollagenosen ist der wissenschaftliche Fortschritt bei der Myositis in den letzten 15–20 Jahren bemerkenswert. Durch kontinuierliche Forschung und intensive Vernetzung der Myositis-Experten ist es gelungen, neue Untergruppen zu identifizieren und somit für die Prognose wichtige Organmanifestationen rechtzeitig zu erkennen. Vor dem Hintergrund dieser Neuerungen verfolgt diese Übersichtsarbeit sowohl das Ziel, möglichst alle Facetten der Erkrankung zu präsentieren, als auch die moderne Einteilung der idiopathischen inflammatorischen Myopathien zu erläutern. Außerdem werden die neuen Klassifikationskriterien vorgestellt, die die Kriterien von Bohan und Peter aus dem Jahr 1975 abgelöst haben. Im Artikel werden ihre Stärken und Schwächen sowie ihr Optimierungspotenzial diskutiert.

The aetiopathogenic significance, clinical relevance and therapeutic implications of vasculopathy in idiopathic inflammatory myopathy

It is 120 years since 'angiomyositis' was included alongside 'polymyositis' and 'dermatomyositis' in an attempt to propose a taxonomy that reflected the major clinical characteristics of idiopathic inflammatory myopathy (IIM). Endothelial injury, perivascular inflammation and capillary loss are important histological findings in affected tissues in IIM. Overt vascular clinical features including RP and abnormal nailfold capillaroscopy (NC) are also common in IIM. Despite the presence of endothelial injury, perivascular inflammation and capillary loss in affected tissues in IIM, and the presence of clinical features such as RP and NC abnormalities, the pathogenic and therapeutic implications of vasculopathy in IIM have been somewhat overlooked. RP and NC abnormalities are not always present, providing a valuable opportunity to explore aetiopathogenic factors driving vasculopathy within autoimmune rheumatic disease. The present review examines the aetiopathogenic, prognostic and therapeutic significance of vasculopathy in IIM. We describe the prevalence and clinical relevance of vasculopathy in IIM, and consider how vasculopathy may be better utilized to support improved IIM diagnosis and disease classification. Areas of unmet research need are highlighted where relevant.

HLA association with the susceptibility to anti-synthetase syndrome

OBJECTIVE

To investigate the human leukocyte antigen (HLA) association with anti-synthetase syndrome (ASSD).

METHODS

We conducted the largest immunogenetic HLA-DRB1 and HLA-B study to date in a homogeneous cohort of 168 Caucasian patients with ASSD and 486 ethnically matched healthy controls by sequencing-based-typing.

RESULTS

A statistically significant increase of HLA-DRB1*03:01 and HLA-B*08:01 alleles in patients with ASSD compared to healthy controls was disclosed (26.2% versus 12.2%, P=1.56E-09, odds ratio-OR [95% confidence interval-CI]=2.54 [1.84-3.50] and 21.4% versus 5.5%, P=18.95E-18, OR [95% CI]=4.73 [3.18-7.05]; respectively). Additionally, HLA-DRB1*07:01 allele was significantly decreased in patients with ASSD compared to controls (9.2% versus 17.5%, P=0.0003, OR [95% CI]=0.48 [0.31-0.72]). Moreover, a statistically significant increase of HLA-DRB1*03:01 allele in anti-Jo-1 positive compared to anti-Jo-1 negative patients with ASSD was observed (31.8% versus 15.5%, P=0.001, OR [95% CI]=2.54 [1.39-4.81]). Similar findings were observed when HLA carrier frequencies were assessed. The HLA-DRB1*03:01 association with anti-Jo-1 was unrelated to smoking history. No HLA differences in patients with ASSD stratified according to the presence/absence of the most representative non-anti-Jo-1 anti-synthetase autoantibodies (anti-PL-12 and anti-PL-7), arthritis, myositis or interstitial lung disease were observed.

CONCLUSIONS

Our results support the association of the HLA complex with the susceptibility to ASSD.

Early predominant inflammatory myopathy in anti-glycyl-tRNA synthetase (EJ) antibody positive antisynthetase syndrome

It is important to consider antisynthetase syndrome in the differential diagnosis of patients presenting with weakness, respiratory distress, and a constellation of complaints spanning multiple organ systems, as this will change clinical management.

Antisynthetase Syndrome-Associated Interstitial Lung Disease: Monitoring of Immunosuppressive Treatment Effects by Chest Computed Tomography

Background: Antisynthetase syndrome (ASyS) is a rare autoimmune disease characterized by inflammatory myopathy, arthritis, fever, and interstitial lung disease (ILD). Pulmonary involvement in ASyS significantly increases morbidity and mortality and, therefore, requires prompt and effective immunosuppressive treatment. Owing to the rarity of ASyS, limited data exists on progression and prognosis of ILD under immunosuppression.

Objectives: The objective of the study was to evaluate the radiological progression and outcome measures of ILD with immunosuppressive therapy in patients with ASyS.

Methods: Twelve patients with ASyS-associated ILD (ASyS-ILD) were included. Demographic and clinical data, including organ involvement, pulmonary function tests (PFT), laboratory parameters, imaging studies, and treatment regimens were retrospectively analyzed from routinely collected data. The extent of ground glass opacities, fibrotic changes and honeycombing was analyzed and scored using high-resolution chest computed tomography (HRCT) scans. HRCT findings were compared between baseline and follow-up examinations. In addition, patients were stratified depending on whether they had received rituximab (RTX) or not.

Results: Pulmonary function tests revealed stable lung function and follow-up HRCT scans showed an improvement of radiological alterations in the majority of ASyS patients under immunosuppressive therapy. We did not detect significant differences between the RTX- and non-RTX-treated groups, but the RTX-treated patients more frequently had myositis and relapsing disease.

Conclusions: Radiographic alterations in ASyS-associated ILD respond to immunosuppressive treatment. RTX is a feasible treatment option with similar clinical and radiographic outcomes in patients with relapsing disease and clinically apparent myositis.

Clinicoserological features of antisynthetase syndrome (ASyS)-associated interstitial lung disease presenting to respiratory services: comparison with idiopathic pulmonary fibrosis and ASyS diagnosed in rheumatology services

INTRODUCTION

Antisynthetase syndrome (ASyS) is a rare autoimmune connective tissue disease (CTD), associated with autoantibodies targeting tRNA synthetase enzymes, that can present to respiratory (interstitial lung disease (ILD)) or rheumatology (myositis, inflammatory arthritis and systemic features) services. The therapeutic management of CTD-associated ILD and idiopathic pulmonary fibrosis (IPF) differs widely, thus accurate diagnosis is essential.

METHODS

We undertook a retrospective, multicentre observational cohort study designed to (1) evaluate differences between ASyS-associated ILD with IPF, (2) phenotypic differences in patients with ASyS-ILD presenting to respiratory versus rheumatology services, (3) differences in outcomes between ASySassociated with Jo-1 versus non-Jo-1 autoantibodies and (4) compare long-term outcomes between these groups.

RESULTS

We identified 76 patients with ASyS-ILD and 78 with IPF. Patients with ASyS were younger at presentation (57 vs 77 years, p<0.001) with a female predominance (57% vs 33%, p=0.006) compared with IPF. Cytoplasmic staining on indirect immunofluorescence was a differentiating factor between ASyS and IPF (71% vs 0%, p<0.0001). Patients with ASyS presenting initially to respiratory services (n=52) had a higher prevalence of ASyS non-Jo-1 antibodies and significantly fewer musculoskeletal symptoms/biochemical evidence of myositis, compared with those presenting to rheumatology services (p<0.05), although lung physiology was similar in both groups. There were no differences in high-resolution CT appearances or outcomes in those with Jo-1 versus non-Jo-1 ASyS-ILD.

CONCLUSIONS

Extended autoimmune serology is needed to evaluate for ASyS autoantibodies in patients presenting with ILD, particularly in younger female patients. Musculoskeletal involvement is common in ASyS (typically Jo-1 autoantibodies) presenting to rheumatology but the burden of ILD is similar to those presenting to respiratory medicine.

Interstitial lung disease in patients with antisynthetase syndrome: a retrospective case series study

PURPOSE

Antisynthetase syndrome (ASS) is a rare systemic autoimmune condition associated to the presence of anti-aminoacyl-tRNA synthetase antibodies. Interstitial lung disease (ILD) is the most prevalent manifestation of ASS and is a major determinant of morbidity and mortality. The aim of this study was to describe the radiological characteristics of patients with ASS-associated-ILD in our institution.

MATERIALS AND METHODS

Medical records from 2014 to 2020 were retrospectively reviewed and patients with a diagnosis of ASS and evidence of ILD on HRCT were included. HRCT images were reviewed by two thoracic radiologists in consensus. Five HRCT patterns were defined: cellular non-specific interstitial pneumonia (NSIP), organizing pneumonia (OP), mixed NSIP/OP pattern, acute interstitial pneumonia (AIP) pattern and fibrotic pattern. Descriptive statistics was calculated for all variables.

RESULTS

Twenty-two patients with ASS who met inclusion criteria were included. The disease presented with the typical triad of ASS in 45% of patients, 55% had ILD only at the onset. Cellular NSIP was present in 27% of patients, OP in 23%, mixed NSIP/OP in 9%, AIP in 18% and a fibrotic pattern in 23%.

CONCLUSION

HRCT findings in ASS-associated ILD are often non-specific; nevertheless, it is important to consider this diagnosis, especially in patients presenting with acute onset of symptoms.

Antisynthetase syndrome - much more than just a myopathy

The aim of the study was to summarize current knowledge on antisynthetase syndrome (ASS), including its epidemiology, pathogenesis, proposed so far diagnostic criteria, heterogeneity of clinical manifestations, prognostic factors and therapeutic possibilities. PubMed database was screened for "antisynthetase syndrome" OR "antisynthetase antibodies" between February and April 2020. Aminoacyl-tRNA synthetases participate in the immune system activation as antigens, but also serve chemoattractive and cytokine-resembling roles, initiating innate and adaptive pathways. Exposure to various inhaled antigens may induce the autoimmune cascade leading to ASS. NK cells with its impaired INF-y production as well as formation of NETs by neutrophils contribute to pathogenesis. The prevalence of symptoms vary significantly depending on the study with muscular, articular and pulmonary involvement being the most frequently observed. Although classified as subtype of idiopathic inflammatory myopathies, myositis may not necessarily be the prominent manifestation. Since clinical presentation is heterogeneous and symptoms can emerge gradually, ASS could be considered as a heterogeneous spectrum rather than a homogenous disease entity. The currently available classification criteria do not fully correspond with the clinical patterns of the disease. Therapy is based on glucocorticosteroids and other immunosuppressive agents. Randomized controlled trials, dedicated for patients with ASS, are needed to form treatment algorithms.

Increased Levels of Soluble CD206 Associated with Rapidly Progressive Interstitial Lung Disease in Patients with Dermatomyositis

Objective

Soluble CD206 (sCD206) is considered a macrophage activation marker, and a previous study proved it as a potential biomarker to predict the severity of anti-melanoma differentiation-associated gene 5- (anti-MDA-5-) positive dermatomyositis- (DM-) associated interstitial lung disease (ILD). To investigate the role of sCD206 in various subtypes of DM, we evaluated the serum level of sCD206 in patients with different myositis-specific autoantibodies besides anti-MDA-5 and clarified its clinical significance.

Methods

Commercial enzyme-linked immunosorbent assay kits were used to detect serum concentrations of sCD206 in 150 patients with DM and 52 healthy controls (HCs). Correlations between sCD206 levels and clinical features, laboratory examinations, and pulmonary function test parameters were analysed.

Results

The median concentrations of serum sCD206 in DM patients were significantly higher than those in HCs (p < 0.0001). Furthermore, median sCD206 levels were elevated in patients with ILD (p = 0.001), especially in those with rapidly progressive ILD (RP-ILD) (p < 0.0001). In addition, sCD206 levels were negatively correlated with the pulmonary function test results, including the percent predicted forced vital capacity (r = −0.234, p = 0.023), percent predicted forced expiratory volume in one second (r = −0.225, p = 0.030), and percent predicted carbon monoxide diffusion capacity (r = −0.261, p = 0.014). Age- and gender-adjusted multivariable analysis showed that sCD206 was an independent prognostic factor for RP-ILD in patients with DM. A longitudinal study showed that sCD206 levels were positively correlated with the physician global assessment visual analog scale scores (β = 54.201, p = 0.001).

Conclusion

Serum sCD206 levels were significantly increased in patients with DM and significantly associated with RP-ILD, suggesting that sCD206 is an important biological predictor of RP-ILD in patients with DM.

Antisynthetase syndrome: A distinct disease spectrum

The discovery of novel autoantibodies related to idiopathic inflammatory myopathies (collectively referred to as myositis) has not only advanced our understanding of the clinical, serological, and pathological correlation in the disease spectrum but also played a role in guiding management and prognosis. One group of the myositis-specific autoantibodies is anti-aminoacyl-tRNA synthetase (anti-ARS or anti-synthetase) which defines a syndrome with predominant interstitial lung disease, arthritis, and myositis. Autoantibodies to eight aminoacyl-tRNA synthetases have been identified with anti-Jo1 the most common in all of idiopathic inflammatory myopathies. Disease presentation and prognosis vary depending on which anti-aminoacyl-tRNA synthetase antibody is present. In this review, we will discuss the clinical characteristics, overlap features with other autoimmune diseases, prognostic factors, and management of the antisynthetase syndrome.

Nailfold Videocapillaroscopy is a Useful Tool to Recognize Definite Forms of Systemic Sclerosis and Idiopathic Inflammatory Myositis in Interstitial Lung Disease Patients

Nailfold videocapillaroscopy (NVC) is an easy tool used for the assessment of patients with Raynaud's phenomenon (RP) as possibly associated with systemic sclerosis (SSc). Recent insights have also highlighted its role in the diagnostic assessment of idiopathic inflammatory myopathies (IIMs). The aim of this study is to describe the diagnostic role of NVC in a series of 361 consecutive patients with interstitial lung disease (ILD). All the patients were assessed by clinical pulmonary and rheumatic examinations, blood exams, high-resolution computed tomography and NVC. NVC was considered positive only in the presence of avascular areas or giant capillaries, but also, the presence of bushy capillaries (BCs) was recorded. NVC was positive in 17.7% of ILD patients and in 78.1% of ILD patients associated with a diagnosis of connective tissue disease (CTD). In 25% of SSc-ILD patients, NVC proved necessary for a correct diagnosis. The presence of BCs and/or NVC positivity in ILD patients with normal levels of creatine phosphokinase is associated with amyopathic IIM, regardless the presence of RP. In conclusion, NVC is useful for the diagnostic assessment of incomplete forms of CTD and in amyopathic IIMs. NVC should be considered in the diagnostic assessment of ILD patients regardless of the presence of RP.

Patients with Interstitial Lung Disease Secondary to Autoimmune Diseases: How to Recognize Them?

The diagnostic assessment of patients with Interstitial Lung Disease (ILD) can be challenging due to the large number of possible causes. Moreover, the diagnostic approach can be limited by the severity of the disease, which may not allow invasive exams. To overcome this issue, the referral centers for ILD organized Multidisciplinary Teams (MDTs), including physicians and experts in complementary discipline, to discuss the management of doubtful cases of ILD. MDT is currently considered the gold standard for ILD diagnosis, but it is not often simple to organize and, furthermore, rheumatologists are still not always included. In fact, even if rheumatologic conditions represent a common cause of ILD, they are sometimes difficult to recognize, considering the variegated clinical features and their association with all possible radiographic patterns of ILD. The first objective of this review is to describe the clinical, laboratory, and instrumental tests that can drive a diagnosis toward a possible rheumatic disease. The secondary objective is to propose a set of first-line tests to perform in all patients in order to recognize any possible rheumatic conditions underlying ILD.

PL-7 Antisynthetase Syndrome in Association with Sjögren's, Systemic Lupus Erythematosus, and Rheumatoid Arthritis

We present a rare case of PL-7 antisynthetase syndrome (ASS) in association with Sjögren's, systemic lupus erythematosus (SLE), and seropositive rheumatoid arthritis (RA). Initially, the patient was diagnosed with Sjögren's followed by Sjögren's/SLE overlap and then Sjögren's/SLE/RA overlap. She was eventually diagnosed with Sjögren's/SLE/RA overlap with PL-7 ASS with interstitial lung disease (ILD). ILD was discovered after complaints of pleuritic chest pain with subsequent workup with coronary computed tomography (CT) revealing pulmonary fibrosis. This case demonstrates the ambiguity with which symptoms of ASS can present; given the high respiratory morbidity and mortality of ASS especially in non-Jo-1 patients, those who present with Raynaud's, myositis, or joint pain, whether together or in isolation, should be assessed for presence of additional features of ASS and potentially undergo testing for ASS antibodies if appropriate.

Multidisciplinary Approach in the Early Detection of Undiagnosed Connective Tissue Diseases in Patients With Interstitial Lung Disease: A Retrospective Cohort Study

Interstitial lung disease (ILD) encompasses a wide range of parenchymal lung pathologies with different clinical, histological, radiological, and serological features. Follow-up, treatment, and prognosis are strongly influenced by the underlying pathogenesis. Considering that an ILD may complicate the course of any connective tissue disease (CTD) and that CTD's signs are not always easily identifiable, it could be useful to screen every ILD patient for a possible CTD. The recent definition of interstitial pneumonia with autoimmune features is a further confirmation of the close relationship between CTD and ILD. In this context, the multidisciplinary approach is assuming a growing and accepted role in the correct diagnosis and follow-up, to as early as possible define the best therapeutic strategy. However, despite clinical advantages, until now, the pathways of the multidisciplinary approach in ILD patients are largely heterogeneous across different centers and the best strategy to apply is still to be established and validated. Aims of this article are to describe the organization of our multidisciplinary group for ILD, which is mainly focused on the early identification and management of CTD in patients with ILD and to show our results in a 1 year period of observation. We found that 15% of patients referred for ILD had an underlying CTD, 33% had interstitial pneumonia with autoimmune feature, and 52% had ILD without detectable CTD. Furthermore, we demonstrated that the adoption of a standardized strategy consisting of a screening questionnaire, specific laboratory tests, and nailfold videocapillaroscopy in all incident ILD proved useful in making the right diagnosis.

Inflammatory muscle disease - An update

Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of inflammatory myopathies whose common feature is immune-mediated muscle injury. There are distinct subgroups including dermatomyositis (DM), polymyositis (PM), inclusion body myositis, and immune-mediated necrotizing myopathy. Antisynthetase syndrome is also emerging as a distinct subgroup with its unique muscle histopathological characteristic of perifascicular necrosis. While the newly updated EULAR/ACR Classification Criteria for IIM have brought advancements in diagnosis and the exclusion of mimickers, the use of only one autoantibody in the derivation of the schema limits its use. Similarly, while the advent of multiple novel therapeutics in the treatment of myositis has been exciting, it has also highlighted the scarcity of validated outcome measures. The purpose of our review is to highlight the updated classification criteria of myositis, newly reported clinical phenotypes associated with myositis autoantibodies, the measurement of outcomes, and emerging treatments in the field.

Aminoacyl-tRNA synthetases as therapeutic targets

Aminoacyl-tRNA synthetases (ARSs) are essential enzymes for protein synthesis with evolutionarily conserved enzymatic mechanisms. Despite their similarity across organisms, scientists have been able to generate effective anti-infective agents based on the structural differences in the catalytic clefts of ARSs from pathogens and humans. However, recent genomic, proteomic and functionomic advances have unveiled unexpected disease-associated mutations and altered expression, secretion and interactions in human ARSs, revealing hidden biological functions beyond their catalytic roles in protein synthesis. These studies have also brought to light their potential as a rich and unexplored source for new therapeutic targets and agents through multiple avenues, including direct targeting of the catalytic sites, controlling disease-associated protein-protein interactions and developing novel biologics from the secreted ARS proteins or their parts. This Review addresses the emerging biology and therapeutic applications of human ARSs in diseases including autoimmune and rare diseases, and cancer.

Influence of MUC5B gene on antisynthetase syndrome

MUC5B rs35705950 (G/T) is strongly associated with idiopathic pulmonary fibrosis (IPF) and also contributes to the risk of interstitial lung disease (ILD) in rheumatoid arthritis (RA-ILD) and chronic hypersensitivity pneumonitis (CHP). Due to this, we evaluated the implication of MUC5B rs35705950 in antisynthetase syndrome (ASSD), a pathology characterised by a high ILD incidence. 160 patients with ASSD (142 with ILD associated with ASSD [ASSD-ILD+]), 232 with ILD unrelated to ASSD (comprising 161 IPF, 27 RA-ILD and 44 CHP) and 534 healthy controls were genotyped. MUC5B rs35705950 frequency did not significantly differ between ASSD-ILD+ patients and healthy controls nor when ASSD patients were stratified according to the presence/absence of anti Jo-1 antibodies or ILD. No significant differences in MUC5B rs35705950 were also observed in ASSD-ILD+ patients with a usual interstitial pneumonia (UIP) pattern when compared to those with a non-UIP pattern. However, a statistically significant decrease of MUC5B rs35705950 GT, TT and T frequencies in ASSD-ILD+ patients compared to patients with ILD unrelated to ASSD was observed. In summary, our study does not support a role of MUC5B rs35705950 in ASSD. It also indicates that there are genetic differences between ILD associated with and that unrelated to ASSD.

Impact of a systematic evaluation of connective tissue disease on diagnosis approach in patients with interstitial lung diseases

To date, there is no clear agreement regarding which is the best method to detect a connective tissue disease (CTD) during the initial diagnosis of interstitial lung diseases (ILD). The aim of our study was to explore the impact of a systematic diagnostic strategy to detect CTD-associated ILD (CTD-ILD) in clinical practice, and to clarify the significance of interstitial pneumonia with autoimmune features (IPAF) diagnosis in ILD patients.Consecutive patients evaluated in an ILD Diagnostic Program were divided in 3 groups: IPAF, CTD-ILD, and other ILD forms. Clinical characteristics, exhaustive serologic testing, high resolution computed tomography (HRCT) images, lung biopsy specimens, and follow-up were prospectively collected and analyzed.Among 139 patients with ILD, CTD was present in 21 (15.1%), 24 (17.3%) fulfilled IPAF criteria, and 94 (67.6%) were classified as other ILD forms. Specific systemic autoimmune symptoms such as Raynaud phenomenon (19%), inflammatory arthropathy (66.7%), and skin manifestations (38.1%) were more frequent in CTD-ILD patients than in the other groups (all P < .001). Among autoantibodies, antinuclear antibody was the most frequently found in IPAF (42%), and CTD-ILD (40%) (P = .04). Nonspecific interstitial pneumonia, detected by HRCT scan, was the most frequently seen pattern in patients with IPAF (63.5%), or CTD-ILD (57.1%) (P < .001). In multivariate analysis, a suggestive radiological pattern by HRCT scan (odds ratio [OR] 15.1, 95% confidence interval [CI] 4.7-48.3, P < .001) was the strongest independent predictor of CTD-ILD or IPAF, followed by the presence of clinical features (OR 14.6, 95% CI 4.3-49.5, P < .001), and serological features (OR 12.4, 95% CI 3.5-44.0, P < .001).This systematic diagnostic strategy was useful in discriminating an underlying CTD in patients with ILD. The defined criteria for IPAF are fulfilled by a considerable proportion of patients referred for ILD.

Arthritis in Idiopathic Inflammatory Myopathies

PURPOSE OF REVIEW

Arthritis is a well-recognized symptom of idiopathic inflammatory myopathies (IIM). We provide a summary of available data regarding the epidemiology, clinical characteristics, and autoantibody associations of joint involvement in various forms of IIM.

RECENT FINDINGS

Arthritis is reported in 18-55% of patients with IIM. It is particularly frequent (20-70%) in those with antisynthetase syndrome (ASS); highest prevalence is associated with anti-Jo-1 positivity. Most common manifestation is non-erosive polyarthritis. X-ray erosions may be found occasionally in ASS, particularly in patients with overlap with rheumatoid arthritis (RA). Arthritis is often present at the time of IIM diagnosis and it may even precede the onset of muscle weakness. Arthritis may in some cases be the main disease manifestation responsible for the disease burden in patients with IIM. Arthritis is a frequent symptom of IIM. Polyarthritis of small joints of the hands is the most frequent clinical manifestation. Arthritis may be the first or dominant symptom in IIM and therefore patients may be initially misdiagnosed as having RA. Particularly in seronegative RA patients with interstitial lung disease or Raynaud's phenomenon, the possibility of IIM should be considered.

Influence of Antisynthetase Antibodies Specificities on Antisynthetase Syndrome Clinical Spectrum Time Course

Antisynthetase syndrome (ASSD) is a rare clinical condition that is characterized by the occurrence of a classic clinical triad, encompassing myositis, arthritis, and interstitial lung disease (ILD), along with specific autoantibodies that are addressed to different aminoacyl tRNA synthetases (ARS). Until now, it has been unknown whether the presence of a different ARS might affect the clinical presentation, evolution, and outcome of ASSD. In this study, we retrospectively recorded the time of onset, characteristics, clustering of triad findings, and survival of 828 ASSD patients (593 anti-Jo1, 95 anti-PL7, 84 anti-PL12, 38 anti-EJ, and 18 anti-OJ), referring to AENEAS (American and European NEtwork of Antisynthetase Syndrome) collaborative group’s cohort. Comparisons were performed first between all ARS cases and then, in the case of significance, while using anti-Jo1 positive patients as the reference group. The characteristics of triad findings were similar and the onset mainly began with a single triad finding in all groups despite some differences in overall prevalence. The “ex-novo” occurrence of triad findings was only reduced in the anti-PL12-positive cohort, however, it occurred in a clinically relevant percentage of patients (30%). Moreover, survival was not influenced by the underlying anti-aminoacyl tRNA synthetase antibodies’ positivity, which confirmed that antisynthetase syndrome is a heterogeneous condition and that antibody specificity only partially influences the clinical presentation and evolution of this condition.

Disease Specific Autoantibodies in Idiopathic Inflammatory Myopathies

Idiopathic inflammatory myopathies represent still a diagnostic and therapeutic challenge in different disciplines including neurology, rheumatology, and dermatology. In recent years, the spectrum of idiopathic inflammatory myopathies has been significantly extended and the different manifestations were described in more detail leading to new classification criteria. A major breakthrough has also occurred with respect to new biomarkers especially with the characterization of new autoantibody-antigen systems, which can be separated in myositis specific antibodies and myositis associated antibodies. These markers are detectable in approximately 80% of patients and facilitate not only the diagnostic procedures, but provide also important information on stratification of patients with respect to organ involvement, risk of cancer and overall prognosis of disease. Therefore, it is not only of importance to know the significance of these markers and to be familiar with the optimal diagnostic tests, but also with potential limitations in detection. This article focuses mainly on antibodies which are specific for myositis providing an overview on the targeted antigens, the available detection procedures and clinical association. As major tasks for the near future, the need of an international standardization is discussed for detection methods of autoantibodies in idiopathic inflammatory myopathies. Furthermore, additional investigations are required to improve stratification of patients with idiopathic inflammatory myopathies according to their antibody profile with respect to response to different treatment options.

Sonographic findings from inflammatory arthritis due to antisynthetase syndrome

Inflammatory arthritis is a common feature of antisynthetase syndrome. Ultrasonography is able to characterize important features of bone and tendon pathology but has not been evaluated in this setting. We review the sonographic findings in a series of patients with antisynthetase syndrome and inflammatory arthritis. A retrospective chart review was performed of patients with antisynthetase syndrome-associated inflammatory arthritis who had undergone ultrasound imaging for joint pathology. Seventeen sonographic assessments of eight patients were included. Synovial hypertrophy was seen in all eight patients, with active Doppler signal present in six patients (13 of 17 ultrasound locations). Tendon involvement was common, with tenosynovitis in seven patients (11 of 17 ultrasound locations). Erosions were present in five patients. Musculoskeletal ultrasound showed significant joint pathology including proliferative synovitis and tenosynovitis. This may be severe and associated with erosive disease. Further systematic studies are needed to better understand the articular involvement of antisynthetase syndrome. Key points • Marked inflammatory change-with proliferative synovitis, tenosynovitis, and erosions-can be seen in selected patients with antisynthetase syndrome (ASyS). • Inflammatory arthritis from ASyS can be severe and erosive in the absence of RF and ACPA and can be refractory to immunosuppressive therapy used to manage the myositis and interstitial lung disease. • Systematic sonographic evaluation of patients with ASyS is needed to further evaluate pathology and treatment response of inflammatory arthritis.

Clinical characteristics and outcome in patients with antisynthetase syndrome associated interstitial lung disease: a retrospective cohort study

Background and objective: To describe the clinical characteristics including the bronchoalveolar lavage fluid (BALF) characteristics of patients with antisynthetase syndrome (AS) associated interstitial lung disease (ILD) in a tertiary ILD outpatient clinic, their medical therapy and outcome.

Methods: Retrospective cohort study of patients with AS-ILD. All available data of clinical characteristics, pulmonary function tests, laboratory parameters, BALF analysis, histology, high-resolution computed tomography (HRCT) and treatment were collected from the patient files.

Results and conclusions: Twelve patients with AS-ILD were identified. Mean age at diagnosis was 55 years (range 45–69), 67% were female. Mean follow-up time was 7 years. The anti-aminoacyl tRNA-synthetase antibodies presented were anti-Jo1 (n = 6), anti-PL7 (n = 3), anti-PL12 (n = 2) and anti-EJ (n = 1). HRCT patterns were mainly non-specific interstitial pneumonia (75%). Four patients had BALF-eosinophilia (two of four anti-Jo1 patients) and two anti-PL12 positive patients had BALF-neutrophilia. Two AS-ILD patients improved on rituximab (RTX) as induction treatment and three out of four patients were stabilised on RTX as maintenance treatment. Two patient obtained remission by cyclophosphamide. Four patients were stabilised on azathioprine alone or in combination with oral corticosteroids.

Our cohort of AS-ILD patients showed clinical characteristics in accordance with previous reports at baseline and was comparable to other cohorts. Most patients can be stabilised with immunosuppressive treatment.

Effect of Genetic and Laboratory Findings on Clinical Course of Antisynthetase Syndrome in a Hungarian Cohort

The aim of this study was to determine the clinical, serological, and genetic features of anti-Jo-1 positive antisynthetase patients followed by a Hungarian single centre to identify prognostic markers, which can predict disease phenotypes and disease progression. It was a retrospective study using clinical database of 49 anti-Jo-1 positive patients. 100% of patients exhibited myositis, 73% interstitial lung disease, 88% arthritis, 65% Raynaud's phenomenon, 43% fever, 33% mechanic's hand, and 12% dysphagia. We could detect significant correlation between anti-Jo-1 titer and the CK and CRP levels at disease onset and during disease course. HLA DRB1⁎03 positivity was present in 68.96% of patients, where the CK level at diagnosis was significantly lower compared to the HLA DRB1⁎03 negative patients. HLA DQA1⁎0501-DQB1⁎0201 haplotype was found in 58.62% of patients, but no significant correlation was found regarding any clinical or laboratory features. Higher CRP, ESR level, RF positivity, and the presence of fever or vasculitic skin lesions at the time of diagnosis indicated a higher steroid demand and the administration of higher number of immunosuppressants during the follow-up within anti-Jo-1 positive patients. The organ involvement of the disease was not different in HLA-DRB1⁎0301 positive or negative patients who were positive to the anti-Jo-1 antibody; however, initial CK level was lower in HLA-DRB1⁎0301 positive patients. Distinct laboratory and clinical parameters at diagnosis could be considered as prognostic markers.

Prevalence and clinical correlates of rheumatoid factor and anticitrullinated protein antibodies in patients with idiopathic inflammatory myopathy

Objective

As rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPAs) are not routinely tested in idiopathic inflammatory myositis (IIM), little is known about their prevalence and clinical implications in this patient group. In antisynthetase syndrome (ASS), presence of ACPA is reportedly associated with more severe and erosive arthritis. We aim to retrospectively determine the prevalence of RF and ACPA in a cross-sectional cohort of 121 patients diagnosed with IIM and to assess clinical associations.

Methods

Serum samples from 121 patients diagnosed with polymyositis (n=30), dermatomyositis (n=41), ASS (n=37), inclusion body myositis (n=1), necrotising autoimmune myopathy (n=5) or overlap myositis (n=7) were analysed. RF was evaluated by nephelometry (Immage 800, Beckman–Coulter); anti-CCP antibodies were identified using fluoro enzyme immunoassays (Immuno-Cap 250, Thermo Fisher). Values above 40 IU/mL and 7 U/mL were considered positive for RF and ACPA, respectively.

Results

The prevalence of RF and ACPA was 9.09% and 4.96%, respectively. No significant differences were observed between RF/ACPA positive versus negative patients. There was a numerical trend for RF-positive IIM patients to be older and have lower forced expiratory volume in 1 s levels.

Conclusions

RF and ACPA are prevalent in IIM, although we detected a lower prevalence than reported in previous studies. Presence of these antibodies in patients with IIM patients is not clinically relevant in our cohort.

Clinical spectrum of anti-Jo-1-associated disease

PURPOSE OF REVIEW

To provide the most recent evidence on anti-Jo-1 syndrome.

RECENT FINDINGS

Several new evidences on anti-Jo-1 syndrome have recently emerged. It has been clearly established that, at disease onset, the classic clinical triad (arthritis, myositis and interstitial lung disease - ILD) is only rarely observed. Indeed, disease onset with an isolated arthritis is common. Patients presenting with an isolated manifestation are at high risk for the subsequent occurrence of initially lacking triad findings. Moreover, the ex-novo occurrence of accompanying features such as Raynaud's phenomenon, mechanic's hands and fever during follow-up is a strong risk factor for the occurrence of overt antisynthetase syndrome (ASSD) with further triad manifestations. Several contributions on ILD involvement and prognosis have been published, as well as the distinctive muscle MRI characteristics compared with healthy controls, and a novel definition of a rare skin manifestation (hiker's feet).

SUMMARY

Recent evidence has shed a light on the need for a better understanding of the clinical course, imaging modalities and prognosis of anti-Jo-1 syndrome, providing some relevant elements to allow early diagnosis of this often unrecognized disease.

Aromatase inhibitors and anti-synthetase syndrome

Adjuvant therapy in postmenopausal women with endocrine-responsive breast cancer (BC) is actually centered on the use of anti-aromatase inhibitors (AI). Several reports, however, are emerging in literature associating the use of this drugs to rheumatic disorders. This case report describes the first case of anti-synthetase syndrome diagnosis after treatment with anti-estrogen agents in a patient with pre-existing rheumatoid arthritis.