Sera from anti-Jo-1-positive patients with polymyositis and interstitial lung disease induce expression of intercellular adhesion molecule 1 in human lung endothelial cells

Review of Pulmonary Manifestations in Antisynthetase Syndrome

Antisynthetase syndrome (ASyS) is now a widely recognized entity within the spectrum of idiopathic inflammatory myopathies. Initially described in patients with a triad of myositis, arthritis, and interstitial lung disease (ILD), its presentation can be diverse. Additional common symptoms experienced by patients with ASyS include Raynaud's phenomenon, mechanic's hand, and fever. Although there is a significant overlap with polymyositis and dermatomyositis, the key distinction lies in the presence of antisynthetase antibodies (ASAs). Up to 10 ASAs have been identified to correlate with a presentation of ASyS, each having manifestations that may slightly differ from others. Despite the proposal of three classification criteria to aid diagnosis, the heterogeneous nature of patient presentations poses challenges. ILD confers a significant burden in patients with ASyS, sometimes manifesting in isolation. Notably, ILD is also often the initial presentation of ASyS, requiring pulmonologists to remain vigilant for an accurate diagnosis. This article will comprehensively review the various aspects of ASyS, including disease presentation, diagnosis, management, and clinical course, with a primary focus on its pulmonary manifestations.

Association of anti-Ro52 autoantibody with interstitial lung disease in autoimmune diseases: a systematic review and meta-analysis

OBJECTIVES

Interstitial lung disease (ILD) is an important manifestation of autoimmune diseases that can lead to morbidity and mortality. Although several autoantibodies have been linked with ILD presentation and adverse outcomes, the association of anti-Ro52 antibody with ILD is less studied. Hence, we investigated this association in various autoimmune diseases in the current study.

DESIGN

We designed a systematic review and meta-analysis and did a comprehensive search from inception until 2 January 2023.

DATA SOURCES

A systematic search was conducted in four electronic databases: PubMed, Web of Science, Scopus and Embase.

ELIGIBILITY CRITERIA

Observational studies that reported ILD diagnosis (outcome) and anti-Ro antibody (exposure) status in any autoimmune conditions (population) were included. The association between rapidly progressive ILD (RP-ILD) and anti-Ro52 was studied in idiopathic inflammatory myopathies (IIM).

DATA EXTRACTION AND SYNTHESIS

Collected data included study characteristics and ORs with 95% CIs. Quality assessment was performed using a modified version of the Newcastle-Ottawa Scale for cross-sectional studies. Random effects meta-analysis was used to pool the effect estimates.

RESULTS

A total of 2353 studies were identified, from which 59 articles met the eligibility criteria. Anti-Ro52/SSA positivity was associated with ILD in all autoimmune disease subgroups: IIM (OR=3.08; 95% CI: 2.18 to 4.35; p value<0.001; I2=49%), systemic lupus (OR=2.43; 95% CI: 1.02 to 5.79; p=0.046; I2=71%), Sjogren (OR=1.77; 95% CI: 1.09 to 2.87; p=0.021; I2=73%), systemic sclerosis (OR=1.71; 95% CI: 1.04 to 2.83; p=0.036; I2=43%), mixed connective tissue disease (OR=3.34; 95% CI: 1.82 to 6.13; p<0.001; I2=0%). Additionally, anti-Ro52-positive myopathy patients were more likely to have simultaneous RP-ILD (OR=2.69; 95% CI:1.50 to 4.83; p<0.001; I2=71%).

CONCLUSION

Anti-Ro52/SSA positivity is associated with a higher frequency of ILD diagnosis in various autoimmune diseases. Anti-Ro52/SSA is also linked with a more severe lung involvement (RP-ILD). Future studies can investigate the benefits of screening for anti-Ro52 and its association with ILD development.

PROSPERO REGISTRATION NUMBER

CRD42022381447.

Echocardiographic Characteristics of Patients with Anti‐synthetase Syndrome

Right ventricular (RV) dysfunction and pulmonary hypertension (PH) occurs in approximately one‐third of patients with interstitial lung disease (ILD) and is associated with reduced 6‐minute walk distance (6MWD), and increased hospitalizations and mortality. Although the impact of RV dysfunction and PH has been well described in several types of ILD, data is scarce on antisynthetase syndrome. Therefore, we sought to examine the presence of RV dysfunction and PH in patients with antisynthetase syndrome and the impact on clinical outcomes. We conducted a retrospective study of patients with antisynthetase syndrome. Seventy‐five subjects were identified. Fifty‐one (68%) subjects had echocardiographic data. Patients were grouped into those with normal fractional area change (FAC) ≥ 35% and reduced FAC < 35%. Clinical, echocardiographic, and right heart catheterization data were compared between the two groups. Subjects with FAC < 35% had lower diffusion capacity of the lung for carbon monoxide (29% vs. 47%, p = 0.004), fibrotic features on computed tomography of the chest (79% vs. 33%, p = 0.005), larger RV diameter (5.4 vs. 3.9 cm, p < 0.001), higher right atrial pressures (8 vs. 5 mmHg, p = 0.02), and required supplemental oxygen more frequently (100% vs. 44%, p < 0.001) compared to those with FAC ≥ 35%. We found no difference in 6MWD and hospitalizations between the two groups. The presence of RV dysfunction in antisynthetase syndrome may identify patients at risk of poor outcomes.

Myositis Antibodies and Interstitial Lung Disease

BACKGROUND

Interstitial lung disease (ILD) comprises a heterogeneous group of inflammatory and fibrotic conditions, often resulting in progressive lung function decline and increased mortality. Connective tissue disease (CTD) should be considered in all patients with ILD, as distinguishing between CTD-ILD and other forms of fibrotic lung disease has important therapeutic and prognostic implications. The idiopathic inflammatory myopathies (IIM) represent a CTD subtype of growing interest to ILD experts. The expansion and availability of myositis-specific and myositis-associated antibody testing has allowed for improved disease detection and characterization.

CONTENT

In this review, we highlight the relationship between myositis antibodies and ILD. Select forms of IIM, such as the antisynthetase syndrome and clinically amyopathic dermatomyositis can present with rapidly progressive ILD, warranting timely disease diagnosis and management. Disease phenotypes, prevalence, laboratory testing, prognosis, and management strategies are described according to select myositis antibodies.

SUMMARY

Myositis antibodies provide valuable information for clinicians managing patients with ILD. This review aims to increase awareness of their role in disease detection, pathophysiology, and possibly therapeutics.

High- density lipoprotein function is abnormal in idiopathic inflammatory myopathies

OBJECTIVE

Damage to the vascular endothelium is strongly implicated in the pathogenesis of idiopathic inflammatory myopathies (IIM). Normally, high-density lipoprotein (HDL) protects the vascular endothelium from damage from oxidized phospholipids, which accumulate under conditions of oxidative stress. The current work evaluated the antioxidant function of HDL in IIM patients.

METHODS

HDL's antioxidant function was measured in IIM patients using a cell-free assay, which assesses the ability of isolated patient HDL to inhibit oxidation of low-density lipoproteins and is reported as the HDL inflammatory index (HII). Cholesterol profiles were measured for all patients, and subgroup analysis included assessment of oxidized fatty acids in HDL and plasma MPO activity. A subgroup of IIM patients was compared with healthy controls.

RESULTS

The antioxidant function of HDL was significantly worse in patients with IIM (n = 95) compared with healthy controls (n = 41) [mean (S.d.) HII 1.12 (0.61) vs 0.82 (0.13), P < 0.0001]. Higher HII associated with higher plasma MPO activity [mean (S.d.) 13.2 (9.1) vs 9.1 (4.6), P = 0.0006] and higher oxidized fatty acids in HDL. Higher 5-hydroxyeicosatetraenoic acid in HDL correlated with worse diffusion capacity in patients with interstitial lung disease (r = -0.58, P = 0.02), and HDL's antioxidant function was most impaired in patients with autoantibodies against melanoma differentiation-associated protein 5 (MDA5) or anti-synthetase antibodies. In multivariate analysis including 182 IIM patients, higher HII was associated with higher disease activity and DM diagnosis.

CONCLUSION

The antioxidant function of HDL is abnormal in IIM patients and may warrant further investigation for its role in propagating microvascular inflammation and damage in this patient population.

Pulmonary arterial hypertension, a novelty in idiopathic inflammatory myopathies: insights and first experiences with vasoactive therapy

To characterise the different types of pulmonary hypertension (PH) among idiopathic inflammatory myopathy (IIM). A retrospective case series with assessment of PH by right heart catheterisation, extent of interstitial lung disease (ILD) and outcome of vasoactive therapy.The group of patients with IIM with PH (n=9) showed a median age at PH diagnosis of 62 years (IQR 48–71 years; eight women), seven diagnosed with polymyositis and two with dermatomyositis; median disease duration of 5.7 years and five patients with a positive anti-Jo1 antibody. We found one patient to be classified in PH WHO group 2 (left heart disease), five patients in WHO group 3 (lung disease) and three patients in WHO group 1 (pulmonary arterial hypertension (PAH)). During median observed follow-up of 24 months, mortality for the total group was 44%. Surprisingly, we found a relevant group (33%) of patients with IIM who suffered from non-ILD-PH, which reflects the presence of PAH phenotype. This result should lead to more awareness among treating physicians that complaints of dyspnoea among patient with IIM could be related to PAH and not only ILD. The role of vasoactive therapy remains to be defined in patients with IIM suffering from PAH or PH-ILD.

Role of Jo-1 in the Immunopathogenesis of the Anti-synthetase Syndrome

Histidyl-tRNA synthetase (HRS = Jo-1) represents a key autoantibody target in the anti-synthetase syndrome that is marked by myositis as well as extra-muscular organ complications including interstitial lung disease (ILD). Over the last 25 years, a wealth of clinical, epidemiological, genetic, and experimental data have collectively supported a role for Jo-1 in mediating deleterious cell-mediated, adaptive immune responses contributing to the disease phenotype of the anti-synthetase syndrome. Complementing these studies, more recent work suggests that unique, non-enzymatic functional properties of Jo-1 also endow this antigen with the capacity to activate components of the innate immune system, particularly cell surface as well as endosomal Toll-like receptors and their downstream signaling pathways. Combining these facets of Jo-1-mediated immunity now supports a more integrated model of disease pathogenesis that should lead to improved therapeutic targeting in the anti-synthetase syndrome and related subsets of idiopathic inflammatory myopathy.

[Antisynthetase syndrome with pulmonary hypertension: 4 original observations]

INTRODUCTION

Pulmonary hypertension (PH) may occur in patients with antisynthetase syndrome (ASS) but this association is poorly studied. In this article, we report 4 new cases of PH associated with ASS, and we discuss PH mechanisms in this specific disease.

CASES

Four patients (3 females, 1 male) with confirmed ASS associated with anti-Jo1 (n=3), anti-PL7 (n=1), and anti-Ro52 (n=3) antibodies were analyzed. They presented with subacute dyspnea in average ten years after they were first diagnosed as ASS. Diagnosis of pre-capillary PH was made (mean of mPAP: 34mmHg): PAH (n=1), group 3 PH (n=2) and PH associated to hyperthyroidism (n=1). Among three patients who received specific PAH therapy, two had significant improvement in both clinical and hemodynamic parameters.

CONCLUSION

During ASS, PH may occur in 5 to 10 % of cases, caused by various mechanisms. Unexplained dyspnea may be due to PH among ASS patients.

Brief report: antisynthetase syndrome-associated myocarditis

BACKGROUND

The antisynthetase (AS) syndrome is characterized by autoimmune myopathy, interstitial lung disease, cutaneous involvement, arthritis, fever, and antibody specificity. We describe 2 patients with AS syndrome who also developed myocarditis, depressed biventricular function, and congestive heart failure.

METHODS AND RESULTS

Both patients were diagnosed with AS syndrome based on clinical manifestations, detection of serum AS antibodies, and myositis confirmation with the use of skeletal muscle magnetic resonance imaging and skeletal muscle biopsy. In addition, myocarditis resulting in heart failure was confirmed with the use of cardiac magnetic resonance imaging and from endomyocardial biopsy findings. After treatment for presumed AS syndrome-associated myocarditis, one patient recovered and the other patient died.

CONCLUSIONS

AS syndrome is a rare entity with morbidity and mortality typically attributed to myositis and lung involvement. This is the first report of AS syndrome-associated myocarditis leading to congestive heart failure in 2 patients. Given the potentially fatal consequences, myocarditis should be considered in patients with AS syndrome presenting with heart failure.

Clinical heterogeneity and outcomes of antisynthetase syndrome

The autoimmune connective tissue disease antisynthetase syndrome (ASS) is an inflammatory myopathy associated with myositis-specific autoantibodies, e.g. anti-tRNA-synthetase antibodies (ASA). Since 1976 eight different ASA have been rigorously identified, of which anti-hystidyl-tRNA synthetase (anti-Jo1) is the most prevalent. Other phenotype features of ASS include interstitial lung disease (ILD), Raynaud's phenomenon, polyarthritis, fever, and mechanic's hands. The clinical presentation of ASS varies greatly, as does the severity of involvement of different organs-both among patients and/or over the course of the disease. ILD has been associated with poor outcomes, but in general the heterogeneity of ASS prevents identification of robust prognosis indicators. Early identification of patients requiring aggressive immunosuppressive treatment is very challenging, and there are very few prospective trials available to help match treatment management to ASS clinical characteristics. This review will focus on the biological, clinical, functional, and morphological features of ASS associated with patient outcome. Our objective is to use compiled data on these subjects to discuss the usefulness of patient stratification in developing future prospective therapeutic trials.

[Clinical phenotypes and prognosis of antisynthetase syndrome]

Antisynthetase syndrome (ASS) was first described in 1989 as an inflammatory myopathy associated with the presence of specific auto-antibodies, namely the anti-tRNA-synthetase antibodies (ASA). To date, the ASA family comprises eight different auto-antibodies, among which anti-hystidyl-tRNA-synthetase (anti-Jo1) is the most prevalent. In addition to myositis, a constellation of clinical features has also been described in ASS, including interstitial lung disease, Raynaud's phenomenon, polyarthritis, fever and mechanic's hands. Large variations in the distribution and the severity of each of these symptoms are reported from one patient to another, and also over the course of the disease. The heterogeneity of this autoimmune connective tissue disease has led to difficulties in the early identification of patients with a poor outcome (those who will require the most intensive treatments). Additionally, very few prospective trials have so far compared the efficacy of the different immunosuppressive drugs available, and evidence is lacking to help adapting therapeutic strategies to all of the different ASS clinical situations. We will review the different characteristics of ASS (namely biological, clinical, functional, and morphological ASS parameters) that have recently been shown to correlate with patients' outcome, our aim being to discuss the usefulness of patient stratification for elaborating targeted therapeutic trials for ASS in the future.

Interstitial lung disease outcomes by high-resolution computed tomography (HRCT) in Anti-Jo1 antibody-positive polymyositis patients: a single centre study and review of the literature

Interstitial lung disease (ILD) is a frequent complication of inflammatory myopathies with high rates of morbidity and mortality. Antibodies against aminoacyl-tRNA-synthetases are the strongest predictive factors in ILD. In this study, we reviewed the literature and we retrospectively analysed high-resolution computed tomography (HRCT) findings in a cohort of 131 consecutive subjects: 75 with polymyositis (PM), 43 with dermatomyositis (DM), one with amyophatic PM, two with paraneoplastic syndromes, and 10 with overlapping syndromes. The inclusion criteria were PM/DM, anti-Jo1 antibody positivity, and HRCT-assessed ILD. The effect of 12 months' treatment with cyclophosphamide (CYC) or cyclosporin A (CsA) plus steroids was assessed by comparing baseline and follow-up HRCT scans for evidence of stability, improvement or worsening. Fifteen patients (11.5%) had ILD and were Jo-1 positive. They were all women with PM, and had a mean age of 47.33 years and a median duration of symptoms of 7.26 months. At baseline, HRCT showed ground-glass attenuations in eight cases, septal thickening in seven, and honeycombing in four. Twelve months after diagnosis, ILD had worsened in nine patients (60%; exact confidence interval [ECI] 32-84) and was stable in four (two patients were lost to follow-up). Seven of the 15 patients were treated with CsA, and 12-month HRCT revealed a worsening in ILD in five cases (71%; ECI 0.29-0.96); ILD also worsened (ECI 16-84) in four of the eight patients treated with CYC pulses (50%). The evolution of the HRCT findings was not significantly different between the two groups. Our findings confirm that ILD is a common early manifestation in patients with Jo1-positive PM. Over twelve months, HRCT showed worsening ILD in most of our patients, with no difference in the HRCT changes between those treated with CYC or CsA.

Antisynthetase syndrome

Autoantibodies to eight of the aminoacyl-transfer RNA synthetases-the most well-recognized of which is anti-histidyl (Jo-1)-have all been implicated in the pathogenesis of antisynthetase syndrome (AS). AS is characterized by varying degrees of interstitial lung disease, myositis, arthropathy, fever, Raynaud's phenomenon, and mechanic's hands, and the morbidity and mortality of the disease are usually linked to the pulmonary findings. The value of a lung biopsy in AS cannot be overemphasized, as it serves to describe the underlying etiology of the interstitial lung disease, guide therapy, and estimate prognosis. Muscle disease shares many clinical features of polymyositis, yet histologically, the inflammatory involvement resembles that of dermatomyositis. Because inflammatory arthritis mimics rheumatoid arthritis, AS should be considered in atypical cases. Corticosteroids are the mainstay of acute therapy, although treatment often requires immunosuppressant medications such as cyclophosphamide, azathioprine, mycophenolate mofetil, cyclosporine, tacrolimus, or rituximab.

Polymyositis and dermatomyositis: pathophysiology

Recent advances have increased the understanding of the pathogenesis of polymyositis and dermatomyositis. Clearly, the pathogenesis is complex, and adaptive (eg, autoimmune) and innate and nonimmune pathways play a role in the disease mechanisms, but the relative contribution may vary between patients and in different phases of the disease. Phenotyping patients using autoantibody profiling has resulted in information on molecular pathways that may be relevant in certain subsets of patients with polymyositis or dermatomyositis, but combining the autoantibody profiles with molecular signatures of innate and nonimmune mechanisms would enhance our ability to classify, diagnose, and treat these disorders more effectively.

Novel autoantibodies and clinical phenotypes in adult and juvenile myositis

Autoantibodies targeting intracellular proteins involved in key processes are detected in patients with idiopathic inflammatory myopathies. These myositisspecific autoantibodies have been increasingly demonstrated to correlate with distinct clinical phenotypes within the myositis spectrum. This review highlights the clinical associations of the myositisspecific autoantibodies, with particular attention to the recently identified and characterized novel myositis autoantibodies: p155/140, p140 (MJ), CADM-140 (MDA5), SAE, and 200/100.

Interstitial Lung Disease in Idiopathic Inflammatory Myopathy

The lung is one of the most common extra-muscular targets in idiopathic inflammatory myopathies (IIM) and interstitial lung disease (ILD) is a prevalent and often devastating manifestation of IIM. IIM-associated ILD (IIM-ILD) contributes to nearly 80% of the mortality in IIM with a reported prevalence of 65% of newly diagnosed IIM cases. Although ILD frequently accompanies clinical and laboratory findings of myositis, overt signs of muscle disease may be absent in the setting of significant lung disease. Understanding the varied scope of presentation of these diseases is essential to providing optimal patient care. This review will provide an in depth examination of ILD in IIM both from a rheumatologic and pulmonary perspective and will discuss the scope of disease, presenting features, genetic associations, pathogenesis, diagnosis, radiographic and histopathologic findings, along with biomarker assessment and a rationale for therapeutic intervention.

The type I interferon system in idiopathic inflammatory myopathies

Polymyositis (PM), dermatomyositis (DM) and inclusion body myositis (IBM) are chronic inflammatory diseases that are characterized by muscle weakness and inflammatory cells in muscle tissue. Autoantibodies are common, some of them are specific for myositis, the most frequent being the anti-Jo-1 antibody which is associated not only with myositis but also with interstitial lung disease and arthritis. A role of type I interferons in disease mechanisms of myositis was first supported by the reported onset of PM and DM during treatment with type I interferon. More recently an interferon signature has been reported in muscle tissue of DM and PM patients both as gene and protein expression, and type I IFN expression in peripheral blood cells seems to correlate with disease activity. Different mechanisms could induce type I interferon in PM and DM like viral infections or endogenous factors as suggested by the observation that sera from myositis patients with anti-Jo-1 antibodies as well as anti-SSA and anti-SSB antibodies have an interferon inducible capacity. Accumulating data indicate a role of the type I interferon in myositis, particularly in juvenile and adult DM and in anti-Jo-1 or anti-SSA positive PM.