The clinical phenotype associated with myositis-specific and associated autoantibodies: A meta-analysis revisiting the so-called antisynthetase syndrome

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.

Pathologic Features of Anti-Ku Myositis

OBJECTIVE

Characteristics of myositis with anti-Ku antibodies are poorly understood. The purpose of this study was to elucidate the pathologic features of myositis associated with anti-Ku antibodies, compared with immune-mediated necrotizing myopathy (IMNM) with anti-signal recognition particle (SRP) and anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies, in muscle biopsy-oriented registration cohorts in Japan and Germany.

METHODS

We performed a retrospective pathology review of patients with anti-Ku myositis samples diagnosed in the Japanese and German cohorts. We evaluated histologic features and performed HLA phenotyping.

RESULTS

Fifty biopsied muscle samples in the Japanese cohort and 10 in the German cohort were obtained. After exclusion of myositis-specific autoantibodies or other autoimmune connective tissue diseases, 26 samples (43%) of anti-Ku antibody-positive myositis were analyzed. All the samples shared some common features with IMNM, whereas they showed expression of MHC class II and clusters of perivascular inflammatory cells more frequently than the anti-SRP/HMGCR IMNM samples (71% vs 7%/16%; p < 0.005/<0.005; 64% vs 0%/0%; p < 0.005/<0.005). Anti-Ku myositis biopsies could be divided into 2 subgroups based on the extent of necrosis and regeneration. The group with more abundant necrosis and regeneration showed a higher frequency of MHC class II expression and perivascular inflammatory cell clusters. HLA phenotyping in the 44 available patients showed possible associations of HLA-DRB1*03:01, HLA-DRB1*11:01, and HLA-DQB1*03:01 (p = 0.0045, 0.019, and 0.027; odds ratio [OR] 50.2, 4.6, and 2.8; 95% CI 2.6-2942.1, 1.1-14.5, and 1.0-7.0) in the group with less conspicuous necrosis and regeneration. On the contrary, in the group of more abundant necrosis and regeneration, the allele frequencies of HLA-A*24:02, HLA-B*52:01, HLA-C*12:02, and HLA-DRB1*15:02 were lower than those of healthy controls (p = 0.0036, 0.027, 0.016, and 0.026; OR = 0.27, 0, 0, and 0; 95% CI 0.1-0.7, 0-0.8, 0-0.8, and 0-0.8). However, these HLA associations did not remain significant after statistical correction for multiple testing.

DISCUSSION

While anti-Ku myositis shows necrotizing myopathy features, they can be distinguished from anti-SRP/HMGCR IMNM by their MHC class II expression and clusters of perivascular inflammatory cells. The HLA analyses suggest that anti-Ku myositis may have different subsets associated with myopathologic subgroups.

[Pulmonary involvement in idiopathic inflammatory myopathies]

Idiopathic inflammatory myopathies are rare systemic diseases with different types of pulmonary manifestations depending on the underlying aetiology; here, interstitial lung diseases (ILD) are the most frequently found patterns depending on the underlying disorder. There is a lack of sufficient prospective studies on this heterogeneous group of patients, particularly in case of ILD being involved. The diagnosis is based upon guideline recommendations for ILD and requires a multidisciplinary discussion within a team with specific expertise in this field. Myositis specific antibodies and myositis associated antibodies form an essential part of the diagnostic tools and may also be associated with a certain phenotype or disease progression. Anti-t-RNA-synthetase antibodies (Anti-ARS) and anti-melanoma differentiation-associated gene 5 antibodies (MDA5) play an important clinical role for treatment the estimation of response and prognosis. The most common ILD patterns are nonspecific interstitial pneumonia (NSIP) and organising pneumonia (OP) or a mixed pattern of both. Treatment is based on systemic steroids and early initiation of other immunosuppressant drugs. Evidence for this is, however, sparse, since most of the studies having investigated treatment modalities are of retrospective nature, even though some new prospective data may be useful for the establishment of treatment pathways in the future.

Novel endotypes of antisynthetase syndrome identified independent of anti-aminoacyl transfer RNA synthetase antibody specificity that improve prognostic stratification

OBJECTIVES

To systemically analyse the heterogeneity in the clinical manifestations and prognoses of patients with antisynthetase syndrome (ASS) and evaluate the transcriptional signatures related to different clinical phenotypes.

METHODS

A total of 701 patients with ASS were retrospectively enrolled. The clinical presentation and prognosis were assessed in association with four anti-aminoacyl transfer RNA synthetase (ARS) antibodies: anti-Jo1, anti-PL7, anti-PL12 and anti-EJ. Unsupervised machine learning was performed for patient clustering independent of anti-ARS antibodies. Transcriptome sequencing was conducted in clustered ASS patients and healthy controls.

RESULTS

Patients with four different anti-ARS antibody subtypes demonstrated no significant differences in the incidence of rapidly progressive interstitial lung disease (RP-ILD) or prognoses. Unsupervised machine learning, independent of anti-ARS specificity, identified three endotypes with distinct clinical features and outcomes. Endotype 1 (RP-ILD cluster, 23.7%) was characterised by a high incidence of RP-ILD and a high mortality rate. Endotype 2 (dermatomyositis (DM)-like cluster, 14.5%) corresponded to patients with DM-like skin and muscle symptoms with an intermediate prognosis. Endotype 3 (arthritis cluster, 61.8%) was characterised by arthritis and mechanic's hands, with a good prognosis. Transcriptome sequencing revealed that the different endotypes had distinct gene signatures and biological processes.

CONCLUSIONS

Anti-ARS antibodies were not significant in stratifying ASS patients into subgroups with greater homogeneity in RP-ILD and prognoses. Novel ASS endotypes were identified independent of anti-ARS specificity and differed in clinical outcomes and transcriptional signatures, providing new insights into the pathogenesis of ASS.

Defining criteria for disease activity states in juvenile dermatomyositis based on the Juvenile Dermatomyositis Activity Index

OBJECTIVES

To develop and validate the cut-offs in the Juvenile DermatoMyositis Activity Index (JDMAI) to distinguish the states of inactive disease (ID), low disease activity (LDA), moderate disease activity (MDA) and high disease activity (HDA) in children with juvenile dermatomyositis (JDM).

METHODS

For cut-off definition, data from 139 patients included in a randomised clinical trial were used. Among the six versions of the JDMAI, JDMA1 (score range 0-40) and JDMAI2 (score range 0-39) were selected. Optimal cut-offs were determined against external criteria by calculating different percentiles of score distribution and through receiver operating characteristic curve analysis. External criteria included the modified Pediatric Rheumatology International Trials Organization (PRINTO) criteria for clinically ID in JDM (for ID) and PRINTO levels of improvement in the clinical trial (for LDA and HDA). MDA cut-offs were set at the score interval between LDA and HDA cut-offs. Cut-off validation was conducted by assessing construct and discriminative ability in two cohorts including a total of 488 JDM patients.

RESULTS

The calculated JDMAI1 cut-offs were ≤2.4 for ID, ≤6.6 for LDA, 6.7-11 for MDA and >11 for HDA. The calculated JDMAI2 cut-offs were ≤5.2 for ID, ≤8.5 for LDA, 8.6-11.3 for MDA and >11.3 for HDA. The cut-offs discriminated strongly among disease activity states defined subjectively by caring physicians and parents, parents' satisfaction or non-satisfaction with illness outcome, levels of pain, fatigue, physical functional impairment and physical well-being.

CONCLUSIONS

Both JDMAI1 and JDMAI2 cut-offs revealed good metrologic properties in validation analyses and are, therefore, suited for application in clinical practice and research.

New aspects of clinical and immunological characteristics in patients with anti-asparaginyl tRNA synthetase (anti-KS) autoantibody

OBJECTIVES

Anti-asparaginyl tRNA synthetase (anti-KS) antibody is present in patients with interstitial lung disease (ILD) accompanied by polymyositis/dermatomyositis. We examined clinical/immunological features of these patients.

METHODS

Polymyositis/dermatomyositis or ILD patients were screened for autoantibodies, and clinical/immunological data were collected retrospectively. ILD was diagnosed by computed tomography, and clinical/immunological features of anti-KS-positive patients were compared with those of anti-Jo-1-positive patients.

RESULTS

Sixteen anti-KS-positive patients [female = 11; male = 5; average age 63.6 years (range, 40-81) years] were diagnosed: seven had ILD, four had clinically amyopathic DM (CADM) and ILD, three had Sjögren's syndrome (SS) and ILD one each had rheumatoid arthritis and ILD, or CADM/SS overlap and ILD. All patients had ILD with chronic onset and clinical course; 11/16 (69%) had nonspecific interstitial pneumonia, and five (31%) had usual interstitial pneumonia pattern. Regarding skin manifestations, 4 (27%) had typical DM rash and 11 (69%) had mechanic's hands. All anti-KS-positive patients had no clinical muscle weakness or serum creatine kinase elevation; 8/16 patients (50%) had sicca symptoms at a significantly high frequency compared with anti-Jo-1-positive patients (50% vs 11%, P = 0.01).

CONCLUSIONS

Anti-KS-positive patients might form a distinguishable subset closely associated with sicca symptoms, CADM and chronic-type ILD with a relatively favourable prognosis.

Anti-EJ antibody-positive interstitial pneumonia with breast cancer improved by combining immunosuppressive therapy and chemotherapy

We present a case of a 45-year-old woman diagnosed with interstitial pneumonia (IP) during a comprehensive breast cancer evaluation. Although the patient showed no obvious clinical symptoms of polymyositis or dermatomyositis, the presence of anti-glycyl-transfer ribonucleic acid synthetase antibodies confirmed anti-synthetase syndrome. The patient began methylprednisolone for treatment of the IP. She then received preoperative chemotherapy with epirubicin and cyclophosphamide before undergoing a mastectomy. A significant improvement was seen in the patient's IP during treatment. This case emphasizes the potential advantages of personalized immunosuppressive therapy for patients who are simultaneously diagnosed with anti-synthetase syndrome and cancer.

Prevalence of anti-synthetase antibodies among systemic sclerosis patients

BACKGROUND

we aimed to estimate the prevalence of Amino acyl-transfer ribonucleic acid synthetase antibodies (Anti-ARS); myositis specific antibodies, among patients with systemic sclerosis (SSc), to evaluate the clinical associations of anti-ARS antibodies in SSc patients and to identify risk factors for development of interstitial lung disease (ILD) in SSc.

METHODS

A prospective study of 71 systemic sclerosis patients in our rheumatology clinic in Israel. Sera were tested for myositis antibodies. Data on patients clinical and serological manifestations and treatment were collected and compared according to anti-ARS antibodies and ILD.

RESULTS

Prevalence of anti-ARS antibodies was 6% (4/71) with anti PL-7, anti- OJ and Jo-1 positivity. Anti Ro-52 was found in 27%, anti-PM/Scl 75, anti-PM/Scl 100 and anti-SRP in 6%, anti-Ku in 3%, anti-Mi-2 beta and anti-Mi-2 alfa in 4%, anti- NXP2 and anti-TIF1gamma in 1%. ILD complication was observed in 42% of patients and was associated with anti RNAP-III, anti Scl-70 and Anti-ARS antibodies. In multiple logistic regression, anti Scl-70 was associated with 6-fold higher risk for ILD.

CONCLUSION

Anti-ARS antibodies were observed in 6% of SSc patients. All of them had ILD. Due to the low prevalence of anti-ARS, this study could not describe clinical associations of anti-ARS antibodies in SSc patients.

What should we expect when two myositis-specific antibodies coexist in a patient

BACKGROUND

The coexistence of two myositis-specific autoantibodies (MSA) is considered extremely rare. We describe three patients with both anti-signal recognition particle (SRP) antibodies and another MSA in serum.

METHODS

We performed a retrospective clinical data collection and follow-up studies of the clinical manifestations and treatment outcome of three patients positive with anti-SRP antibodies and other MSAs. IgG antibodies against MSAs were detected using commercial line immunoblot assay.

RESULTS

The tests of MSA showed positive result of anti-SRP antibodies and another one MSA including anti-TIF1-γ, anti-Jo1, or anti-EJ antibodies, respectively. The proximal muscle weakness appeared in 2 patients; interstitial lung disease presented in 2 patients. The serum CK level was elevated in 1 patient. The muscle biopsy showed necrotizing myopathy in 1 patient and deposition of membrane attack complex on scattered myofibers in the other one patient. One of the two patients with interstitial lung disease died because of respiratory failure. One patient had completely improved and the other one showed partial remission after immunosuppressive therapy.

CONCLUSIONS

The patients with anti-SRP antibodies co-occurred with the other MSA may have various clinical characteristics. The clinicopathological phenotypes of these patients seem to be mainly caused by one of the MSAs, namely the responsible antibody.

Polymyositis: A Case Report

Inflammatory myopathies are a group of diseases whose common pathway is immune-mediated muscle damage, one of which is polymyositis. The definition of polymyositis is controversial, with proponents advocating a definition based on immunohistochemical and histopathological findings in muscle biopsies, while other proponents advocate a definition based on clinical manifestations and histopathological findings. Polymyositis is a quite rare disease that is clinically characterized by progressive proximal muscle weakness with a symmetric distribution. Within the diagnostic approach, laboratory studies show elevation of sarcoplasmic enzymes; nerve conduction tests are performed, which may aid in distinguishing myopathic causes of weakness from neuropathic disorders; and muscle biopsy is considered the gold standard to diagnose inflammatory myopathy and to distinguish the subclasses. We report the case of a 61-year-old male patient who presented generalized symmetrical weakness, predominantly in the upper extremities, and dysphagia, whose laboratory studies, autoantibodies, and muscle biopsy were confirmatory of this entity.

Prediction of progressive pulmonary fibrosis in patients with anti-synthetase syndrome-associated interstitial lung disease

OBJECTIVE

Interstitial lung disease (ILD) is a common extramuscular manifestation of the anti-synthetase syndrome (ASS). Patients with ASS-ILD are at risk in developing a progressive fibrosing phenotype despite appropriate treatments. This study investigated the risk factors and the predictive value of multiple risk factors for progressive pulmonary fibrosis (PPF) in patients with ASS-ILD.

METHODS

Ninety patients with a diagnosis of ASS and evidence of ILD on high-resolution computed tomography (HRCT) were recruited. Among them, 72 participants completed follow-up for more than 12 months. These patients were further divided into a PPF-ASS group (n = 18) and a non-PPF-ASS group (n = 54). Logistic regression analysis was performed to investigate the risk factors for PPF. The predictive value of the combined risk factors for predicting PPF were analyzed by a ROC curve.

RESULTS

The PPF-ASS group had a higher rate of positive non-Jo-1 antibodies, a significantly higher neutrophil-to-lymphocyte ratio (NLR) and serum lactate dehydrogenase (LDH), and a significantly lower PaO2/FiO2 ratio and diffusing capacity for carbon monoxide (DLCO%pred) than the non-PPF-ASS group. In addition, elevated serum Krebs von den Lungen-6 (KL-6) level and reticular opacities were significantly more common, and corticosteroid monotherapy at onset was administered more frequently in the PPF-ASS group. The median duration of follow-up was 37.4 months, survival was poorer in the PPF-ASS group, and the overall survival was 88.9%. Multivariate regression analysis further revealed that positive non-Jo-1 antibodies, NLR, and KL-6 were independent risk factors for PPF. These combined indexes had good accuracy (area under the curve = 0.874) in predicting PPF in patients with ASS-ILD.

CONCLUSION

Positive non-Jo-1 antibodies, NLR, and serum KL-6 are independent risk factors for PPF in patients with ASS-ILD. Monitoring these markers can potentially predict PPF in this group of patients. Key Points • Positive non-Jo-1 antibodies, NLR, and serum KL-6 are independent risk factors associated with PPF in patients with ASS-ILD. • Monitoring non-Jo-1 antibodies, NLR, and serum KL-6 can potentially predict PPF in patients with ASS-ILD.

Antisynthetase Syndrome: The Classical Phenotype With a Twist

Antisynthetase syndrome is a systemic autoimmune rheumatic disease characterized by multiple organ involvement, including interstitial lung disease, myositis, non-erosive arthritis, fever, Raynaud's phenomenon, "mechanic's hands," and the presence of autoantibodies against aminoacyl-tRNA synthetases, mainly anti-Jo1 (histidyl) antibodies. Patients with antisynthetase syndrome and active muscle inflammation are usually presented with elevated creatine phosphokinase levels, even in the range of acute rhabdomyolysis. Despite that, the presence of myoglobinuric acute kidney injury is rarely seen in patients with myositis-associated rhabdomyolysis. Herein, we report the case of a 64-year-old man who presented with acute kidney injury due to severe rhabdomyolysis in the setting of antisynthetase syndrome diagnosed by the classical clinical triad of (1) interstitial lung disease, (2) non-erosive arthritis, and (3) active myositis and the presence of anti-Jo1 antibodies. The diagnosis was confirmed by muscle biopsy histological findings as well as electromyography. In this case report, we also discuss the classical clinical manifestations of antisynthetase syndrome and a twist toward this unusual complication associated with active muscle inflammation.

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.

Anti-synthetase syndrome-associated interstitial lung disease possibly caused by atezolizumab in a patient with lung adenocarcinoma: a case report

BACKGROUND

Anti-aminoacyl-tRNA synthetase (ARS) antibody-positive patients present with a variety of symptoms, including interstitial lung disease (ILD), which is termed anti-synthetase syndrome (ASS). But it is rare that ASS-ILD is considered an immune-related adverse event after the use of immune checkpoint inhibitors (ICIs).

CASE PRESENTATION

A 47-year-old male with advanced lung adenocarcinoma was treated with platinum and ICI combination immunotherapy and was followed up as an outpatient. Nine months after the start of treatment, he developed a fever and cough, and imaging findings showed lung consolidations in the bilateral lower lung fields. The patient was positive for anti- ARS antibodies and was considered to have developed ASS-ILD due to ICIs remitted with steroid therapy. The patient was found to be positive for anti-ARS antibodies before ICI administration, and the antibody titer was elevated compared to that before ICI administration.

CONCLUSIONS

The examination of anti-ARS antibodies pior to the administration of ICIs may be useful in predicting the development of ASS-ILD.

Predictive factors for progressive fibrosing interstitial lung disease in anti-synthetase syndrome

OBJECTIVES

Interstitial lung disease (ILD) is common in anti-synthetase syndrome (ASS). Progressive fibrosing ILD (PF-ILD) may develop in ILD with autoimmune features. Data on PF-ILDs in ASS as a group are scarce. This study aimed to explore the characteristics and predictors of PF-ILD in ASS patients.

METHODS

This retrospective study enrolled 96 ASS-ILD patients. Baseline clinical data were collected. PF-ILD assessments were conducted at every hospital visit during windows of 24 months after initial diagnosis. Phenotypic, survival features and predictors of PF-ILD were estimated through SPSS 22.0.

RESULTS

The results revealed that 35.42% (34/96) were evaluated to be PF-ILD with a median interval time of 14.73 months. Nonspecific interstitial pneumonia was the most common radiological pattern of PF-ILD. Ground glass opacity (GGO), traction bronchiectasis and reticulation were representative high-resolution computed tomography findings of this group. Compared with the non-progressive group, PF-ILD patients had higher frequencies of anti-Ro-52 antibodies (91.18% vs 66.13%, P = 0.007) and GGO in the lower + middle and lower + middle + upper zones of the left lung, as well as lower + middle zones in the right lung (85.30% vs 54.84%, P = 0.003; 64.71% vs 38.71%, P = 0.015; 82.35% vs 58.06%, P = 0.016). Multivariate Cox analysis identified that anti-Ro-52 antibody (hazards ratio [HR] 3.55, 95% CI 1.06-11.90, P = 0.040) and GGO in left lower + middle lung zones (HR 22.11, 95% CI 1.95-250.90, P = 0.012) were independent risk factors for PF-ILD.

CONCLUSIONS

PF-ILD was associated with poor prognosis. Over one-third of ASS-ILD patients may develop to PF-ILD. Anti-Ro-52 antibody positivity and GGO in left lower + middle lung zones were independent risk factors for PF-ILD in ASS patients.

Successful baricitinib treatment of refractory anti-synthetase syndrome associated with interstitial lung disease

A 47-year-old Japanese man was admitted with dyspnoea on exertion (DOE), skin rash and myalgia. Clinical findings of Gottron's sign and mechanic's hands were observed, with increased serum levels of Krebs von den Lungen-6, surfactant protein-D, creatine kinase, and anti-EJ on laboratory tests. In both lungs, chest computed tomography revealed diffuse reticular opacities and lower lobe predominance. The patient was diagnosed with anti-synthetase syndrome (ASS) and associated interstitial lung disease. Despite repeated administration of high-dose intravenous corticosteroids, cyclophosphamide and immunoglobulin, his skin rash, myalgia, and DOE followed a relapsing and remitting course. He was then given rituximab therapy. This was initially successful, but disease activity increased approximately 12 months after starting rituximab therapy. Finally, in addition to prednisolone and cyclosporine A, we administered baricitinib. There has been no relapse of the disease in the 12 months since he began baricitinib treatment.

[Profiles of autoimmune myositis with or without pulmonary involvement: A retrospective single-center study of 40 patients]

INTRODUCTION

Idiopathic inflammatory myopathies (IMM) are rare diseases with clinico-biological heterogeneity. Pulmonary involvement is frequent and associated with some distinctive manifestations. The aim of this study was to describe the clinico-biological profile of patients with autoimmune myositis with and without pulmonary involvement.

METHODS

This retrospective descriptive study included patients with idiopathic inflammatory myopathies and a positive antibody test performed at Grenoble Alpes University Hospital between 2010 and 2020.

RESULTS

Forty patients were included, the majority were women. The anti-Jo1 autoantibody was the most frequently found (37.5%). The prevalence of pulmonary involvement was 70%. Mechanics' hands and Raynaud's syndrome were the extra-respiratory signs significantly more present in the group with lung involvement (P <0.05), in contrast to creatine kinase levels which were lower in this group (P <0.05). Glucocorticoids and rituximab were significantly more often used in the group with lung involvement (P <0.05). The 5-year survival rate was 76.2% in patients with lung involvement and 100% in patients without lung involvement (P=0.50).

CONCLUSION

We report a high prevalence of lung involvement probably explained by the presence of many patients with anti-synthetase syndrome. Our study highlights a lower severity of muscle involvement in myositis patients with lung disease, which deserves to be confirmed in a larger study.

A prognostic analysis of antisynthetase syndrome-related interstitial lung disease

OBJECTIVE

To analyze prognostic factors of antisynthetase syndrome (ASS)-related interstitial lung disease (ILD).

METHODS

We retrospectively collected the data of 77 inpatients with ASS-ILD at our hospital from January 1, 2018, to January 1, 2021. The improvement/stability group and deterioration/death group were defined according to their follow-up outcome. Clinical data of the 2 groups were compared. Univariate analysis was adopted to screen the possible prognostic factors and then logistic regression was used for multivariate analysis.

RESULT

After 6 to 42 months of follow-up, 52 patients (67.5%) were classified into the improvement/stability group, and 25 patients (32.5%) were classified into the deterioration/death group. According to the multivariate stepwise logistic regression analysis, respiratory failure (odds ratio [OR] = 6.71, 95% CI: 1.64-27.38, P = .008) and elevated muscle enzymes (OR = 4.31, 95% CI: 1.03-18.05, P = .045) were found to be independent risk factors, while mechanic's hands (OR = 0.06, 95% CI: 0.01-0.37, P = .003) and anti-Jo-1 antibody (OR = 0.24, 95% CI: 0.06-0.93, P = .039) were protective factors.

CONCLUSION

The prognostic assessment of ASS-ILD patients should be emphasized. Patients with a poor prognosis should be identified early based on their risk factors to guide clinical management decisions.

Clinical and Radiological Features of Interstitial Lung Diseases Associated with Polymyositis and Dermatomyositis

Polymyositis and dermatomyositis are autoimmune idiopathic systemic inflammatory diseases, characterized by various degrees of muscle inflammation and typical cutaneous lesions-the latter found in dermatomyositis. The underlying pathogenesis is characterized by a high level of uncertainty, and recent studies suggest diseases may have different immunopathological mechanisms. In polymyositis, components of the cellular immune system are involved, whereas in dermatomyositis, the pathogenesis is mainly mediated by the humoral immune response. The interstitial lung disease occurs in one-third of polymyositis and dermatomyositis patients associated with worse outcomes, showing an estimated excess mortality rate of around 40%. Lung involvement may also appear, such as a complication of muscle weakness, mainly represented by aspiration pneumonia or respiratory insufficiency. The clinical picture is characterized, in most cases, by progressive dyspnea and non-productive cough. In some cases, hemoptysis and chest pain are found. Onset can be acute, sub-acute, or chronic. Pulmonary involvement could be assessed by High Resolution Computed Tomography (HRCT), which may identify early manifestations of diseases. Moreover, Computed Tomography (CT) appearances can be highly variable depending on the positivity of myositis-specific autoantibodies. The most common pathological patterns include fibrotic and cellular nonspecific interstitial pneumonia or organizing pneumonia; major findings observed on HRCT images are represented by consolidations, ground-glass opacities, and reticulations. Other findings include honeycombing, subpleural bands, and traction bronchiectasis. In patients having Anti-ARS Abs, HRCT features may develop with consolidations, ground glass opacities (GGOs), and reticular opacities in the peripheral portions; nonspecific interstitial pneumonia or nonspecific interstitial pneumonia mixed with organizing pneumonia have been reported as the most frequently encountered patterns. In patients with anti-MDA5 Abs, mixed or unclassifiable patterns are frequently observed at imaging. HRCT is a sensitive method that allows one not only to identify disease, but also to monitor the effectiveness of treatment and detect disease progression and/or complications; however, radiological findings are not specific. Therefore, aim of this pictorial essay is to describe clinical and radiological features of interstitial lung diseases associated with polymyositis and dermatomyositis, emphasizing the concept that gold standard for diagnosis and classification-should be based on a multidisciplinary approach.

Predictors of progression in idiopathic inflammatory myopathies with interstitial lung disease

The idiopathic inflammatory myopathies (IIMs) are a group of connective tissue diseases that afect multiple organ systems, including the lungs. Interstitial lung disease (ILD) is the most common and heterogeneous complication of IIMs, with its degree ranging from mild to fatal. Thus, it is critical to identify clinical features and validated biomarkers for predicting disease progression and prognosis, which could be beneficial for therapy adjustment. In this review, we discuss predictors for rapid progression of IIM-ILD and propose guidance for disease monitoring and implications of therapy. Systematic screening of myositis-specific antibodies, measuring serum biomarker levels, pulmonary function tests, and chest high-resolution computer tomography will be beneficial for the evaluation of disease progression and prognosis.

Positive Autoantibody Is Associated with Malignancies in Patients with Idiopathic Interstitial Pneumonias

Various autoantibodies are associated with clinical outcomes in patients with idiopathic interstitial pneumonias (IIPs). We retrospectively analyzed the association between autoantibodies and malignancies in IIP patients. Comprehensive analyses of autoantibodies were performed using immunoprecipitation and enzyme-linked immunosorbent assays in 193 consecutive IIP patients. Cancer-related factors were analyzed using logistic regression analysis. In total, 22 of 193 patients (11.4%) with IIP had malignant disease. In univariate analysis, positivity for any autoantibody (odds ratio (OR), 3.1; 95% confidence interval (CI), 1.2-7.7; p = 0.017) and antinuclear antibody titer ≥1:320 (OR, 3.4; CI, 1.2-9.8; p = 0.024) were significantly associated with malignancies. Positive anti-aminoacyl tRNA synthetase (ARS) (OR, 3.7; CI, 0.88-15.5; p = 0.074) and anti-Ro52 antibody (OR, 3.2; CI, 0.93-11.2; p = 0.065) tended to be associated with malignancies. In multivariate analysis, independent risk factors were male sex (OR, 3.7; CI, 1.0-13.5; p = 0.029) and positivity for any autoantibody (OR, 3.9; CI, 1.5-10.1; p = 0.004) in model 1, and male sex (OR, 3.9; CI, 1.0-15.3; p = 0.049), antinuclear antibody titer ≥1:320 (OR, 4.2; CI, 1.4-13.3; p = 0.013), and positivity for anti-ARS antibody (OR, 6.5; CI, 1.2-34.1; p = 0.026) in model 2. Positivity for any autoantibody, antinuclear and anti-ARS antibodies, and male sex were independent risk factors for malignancies in IIP patients. Testing autoantibodies in IIP patients might help the early diagnosis of malignancies.

Prevention of Adverse Outcomes and Treatment Side Effects in Patients with Neuromuscular Disorders

In this article, we review prevention of serious adverse clinical outcomes and treatment side effects in patients with neuromuscular disorders including myopathies and myasthenia gravis. While neither of these entities is preventable, their course can often be modified, and severe sequelae may be prevented, with the identification of risk factors and proactive attention toward treatment planning.

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.

Profile of specific and associated autoantibodies in patients with idiopathic inflammatory myopathies in a Colombian population

Objectives

Idiopathic inflammatory myopathies (IIMs) are chronic, autoimmune diseases with several forms of presentation. Diagnosis is mostly clinical in our region. Our aim was to evaluate the autoantibody profile of patients with IIMs.

Methods

This study is a cross-sectional study with a prospective recollection of data, conducted between 2019–2021, in a single center in Cali, Colombia. Patients with a clinical diagnosis or suspicion of IIM were included. The presence of myositis-specific/associated antibodies was evaluated by immunoblotting in serum samples. Phenotypic characterization was performed.

Results

A total of 36 patients were included. The mean age was 50.6 (16.7) years, and 20 (55.6%) were female. Eighteen (50%) patients were seropositive, of which 11 (30.5%) presented one positive antibody, with anti-TIF1ɣbeing the most frequent (n = 4, 11.1%), followed by anti-Ro52 (n = 2, 5.6%). Seven patients (19.4%) showed >1 positive antibody. Dermatomyositis was the most frequent type of IIM in seropositive patients (n = 8, 44.4%), followed by anti-synthetase syndrome (n = 4, 22.2%). Weakness was symmetric and presented in the upper and lower extremities in 11 (61.1%) patients each. Both respiratory insufficiency and weight loss were seen in 7 (38.9%) patients, Gottron papules in six (33.3%) patients, and heliotrope rash, esophageal dysmotility, and myalgia in 5 (27.8%) patients. Pulmonary interstitial disease was seen in 4 (22.2%, with antibodies for anti-Ro52, anti-MDA5 + anti-Jo1 + anti-TIF1ɣ, anti-MDA5 + anti-SAE1 + anti-NXP2, and anti-cN1A + anti-Ro52) patients, and malignancy was seen in 2 (11.1%) patients (1 with anti-Mi2β and 1 with anti-TIF1ɣ + anti-Mi2α). In all, 7 (19.4%) patients required intensive care (2 seropositive, 1 with anti-PL7, 1 with anti-MDA5 + anti-Jo1 + anti-TIF1ɣ), and 1 (2.8%) (seronegative) patient died.

Conclusion

This study is the first study in the Southwest of Colombia that evaluates myositis-specific/associated antibodies in IIM. Half of the patients were seropositive. Anti-TIF1ɣwas the most frequent MSA and anti-Ro52 was the most frequent MAA. Several patients presented antibody combinations. Further studies are needed to fully associate phenotypes with antibodies.

Myositis-specific autoantibodies and their clinical associations in idiopathic inflammatory myopathies: results from a cohort from China

OBJECTIVES

The purpose of this study was to determine the incidence of myositis-specific autoantibodies (MSAs) in a cohort of Chinese patients with idiopathic inflammatory myopathies (IIMs) and to examine their associations with clinical characteristics and long-term prognosis.

METHODS

Adult patients with confirmed IIMs (n = 515) were studied using the EUROLINE Autoimmune Inflammatory Myopathies 16 Ag (IgG) commercial line blot test to detect MSAs/myositis-associated autoantibodies. We collected the laboratory data and clinical features. The frequencies of MSAs and their associations with clinical phenotypes were evaluated using SPSS 25.0 software.

RESULTS

At least one MSA was found in 88.2% of the 515 IIM patients studied. The most frequently detected MSAs were anti-MDA5 (25.4%), anti-Jo-1(15.1%), and anti-EJ (9.5%). Autoantibodies against MDA5, TIF1-γ, and NXP2 were significantly correlated with cutaneous involvement (P < 0.001 or P < 0.01). Anti-TIF1-γ-positive patients had an enhanced risk of malignancy (OR = 3.51). Rapidly progressive interstitial lung disease (RP-ILD) was significantly correlated with anti-MDA5 (P < 0.0001). Anti-MDA5-positive patients had increased risks of elevated ferritin and decreased lymphocyte counts (OR = 5.65 and OR = 5.74, respectively). Kaplan-Meier survival revealed that individuals positive for anti-MDA5, especially anti-MDA5 combined with anti-Ro52, had the worst prognosis (P = 0.03). Male, old age, RP-ILD, and elevated ferritin were identified as predictors of poor prognosis in IIM patients.

CONCLUSIONS

MSAs were present in the majority of the IIM patients. Numerous MSAs were independent factors for identifying exceptional clinical phenotypes. Key Points • This is a large Chinese cohort of IIM patients to analyze possible associations of MSA profiles with clinical characteristics, aiming to provide valuable data for clinical work. • MSAs were present in approximately 90% of IIM patients with distinct clinical subsets. Patients with anti-Jo-1 and non-anti-Jo-1 ASAs exhibited similar characteristics. • The association of anti-TIF1-γ with malignancy was confirmed in adult patients. Patients with IIMs who were positive for both anti-Ro52 and anti-MDA5 had a worse prognosis. • Male, RP-ILD, and heliotrope rash were independent risk factors for a poor prognosis in patients with IIMs.

Myositis-associated Interstitial Lung Disease: Clinical Characteristics and Factors Related to Pulmonary Function Improvement: A Latin-American Multicenter Cohort Study

BACKGROUND AND OBJECTIVES

ILD patients can be positive to highly specific autoantibodies of connective tissue diseases (CTD). Among them stand out myositis-specific and associated autoantibodies (MSA/MAA). There is limited knowledge about treatment response and prognosis of ILD patients positive to MSA/MAA (MSA/MAA-ILD). Our aim was to describe clinical, radiological and pulmonary function (PF) of MSA/MAA-ILD Latin-American patients and risk factors associated to PF at onset and long term follow up.

METHODS

Multicentric retrospective study of MSA/MAA-ILD patients evaluated between 2016 and 2018 in 3 ILD clinics in Latin America. Clinical, functional and tomographic variables were described. Variables associated with poor baseline PF and associated with functional improvement (FI) were analyzed in a multivariate logistic regression model.

RESULTS

We included 211 patients, 77.4% female, mean age 57 years old. Most frequent MSA/MAA were Ro-52 and Jo-1. Poor baseline PF was associated to ILD as initial diagnosis and NSIP/OP HRCT pattern. 121 patients were included in the follow up PF analysis: 48.8% remained stable and 33% had a significant FI. In multivariate analysis, OP pattern on HRCT was associated with FI. Systemic symptoms from the beginning and the absence of sclerodactyly showed a trend to be associated with FI.

CONCLUSIONS

Worse baseline PF could be related to the absence of extra-thoracic symptoms and "classic" antibodies in CTD (ANA), which causes delay in diagnosis and treatment. In contrast, FI could be related to the presence of extra-thoracic signs that allow timely diagnosis and therapy, and more acute and subacute forms of ILD, such as OP pattern.

Inflammatory myopathies: an update for neurologists

Idiopathic inflammatory myopathies (IIM) are a heterogenous group of treatable myopathies. Patients present mainly to the rheumatologist and neurologists, complaining of acute or subacute onset of proximal weakness. Extramuscular manifestations may occur, including involvement of the lungs, skin, and joints. Classically, the diagnosis used to be made based on the creatine kinase level increase, abnormalities in electroneuromyography and presence of inflammatory infiltrates in the muscle biopsy. Recently, the importance of autoantibodies has increased, and now they may be identified in more than half of IIM patients. The continuous clinicoseropathological improvement in IIM knowledge has changed the way we see these patients and how we classify them. In the past, only polymyositis, dermatomyositis and inclusion body myopathy were described. Currently, immune-mediated necrotizing myopathy, overlap myositis and antisynthetase syndrome have been considered the most common forms of IIM in clinical practice, increasing the spectrum of classification. Patients previously considered to have polymyositis, in fact have these other forms of seropositive IIM. In this article, we reviewed the new concepts of classification, a practical way to make the diagnosis and how to plan the treatment of patients suffering from IIM.

High-Dimensional Analysis Reveals Distinct Endotypes in Patients With Idiopathic Inflammatory Myopathies

The idiopathic inflammatory myopathies (IIM) are a rare clinically heterogeneous group of conditions affecting the skin, muscle, joint, and lung in various combinations. While myositis specific autoantibodies are well described, we postulate that broader immune endotypes exist in IIM spanning B cell, T cell, and monocyte compartments. This study aims to identify immune endotypes through detailed immunophenotyping of peripheral blood mononuclear cells (PBMCs) in IIM patients compared to healthy controls. We collected PBMCs from 17 patients with a clinical diagnosis of inflammatory myositis and characterized the B, T, and myeloid cell subsets using mass cytometry by time of flight (CyTOF). Data were analyzed using a combination of the dimensionality reduction algorithm t-distributed stochastic neighbor embedding (t-SNE), cluster identification, characterization, and regression (CITRUS), and marker enrichment modeling (MEM); supervised biaxial gating validated populations identified by these methods to be differentially abundant between groups. Using these approaches, we identified shared immunologic features across all IIM patients, despite different clinical features, as well as two distinct immune endotypes. All IIM patients had decreased surface expression of RP105/CD180 on B cells and a reduction in circulating CD3+CXCR3+ subsets relative to healthy controls. One IIM endotype featured CXCR4 upregulation across all cellular compartments. The second endotype was hallmarked by an increased frequency of CD19+CD21loCD11c+ and CD3+CD4+PD1+ subsets. The experimental and analytical methods we describe here are broadly applicable to studying other immune-mediated diseases (e.g., autoimmunity, immunodeficiency) or protective immune responses (e.g., infection, vaccination).

AC-X: Characteristic Antinuclear Antibody Patterns of Two Anti-Mi-2 Autoantibody-Positive Dermatomyositis Patients—A Case Report

Here we reported two anti-Mi-2 autoantibody-positive dermatomyositis (DM) patients with a characteristic antinuclear antibody (ANA) immunofluorescence pattern. Autoantibodes were screened by indirect immunofluorescence (IIF) on HEp-2 cells (Euroimmun, Lübeck, Germany) and confirmed by line immunoblot (ANA Profile 3—Euroimmun, Germany). These two patients were positive for ANA (speckled, titer 1:320), followed by confirmation of positive anti-Mi-2α and anti-Mi-2β positive and negative for all other antibodies. We found a characteristic ANA pattern of the anti-Mi-2 antibody that differed from the AC-4 pattern, especially in the morphology of mitotic cells (metaphase, anaphase, and telophase). Thus, we would like to suggest reporting this characteristic antinuclear antibody pattern as a new AC type, as AC-X.

Myositis-specific Antibodies: Overview and Clinical Utilization

Purpose of review-To review autoantibodies associated with different subtypes of idiopathic inflammatory myopathy (IIM) and their clinical applications. IIM are a heterogenous group of autoimmune disorders characterized by muscle weakness, cutaneous features, and internal organ involvement. The diagnosis and classification, which is often challenging, is made using a combination of clinical features, muscle enzyme levels, imaging, and biopsy. The landmark discoveries of novel autoantibodies specific to IIM subtypes have been one of the greatest advancements in the field of myositis. The specificity of these autoantibodies has simplified the diagnostic algorithm of IIM with their heterogenous presentation and outdated the earlier diagnostic criteria. Myositis-specific antibodies (MSAs) have improved diagnostics, clinical phenotyping, and prognostic stratification of the subtypes of IIMs. Furthermore, the levels of certain MSAs correlate with disease activity and muscle enzyme levels such that titers may be able to be used to predict disease course and treatment response.

Myositis-Specific Autoantibodies and QTc Changes by ECG in Idiopathic Inflammatory Myopathies

OBJECTIVES

The aim of this study was to investigate cardiac involvement detected by electrocardiography (ECG) in patients with idiopathic inflammatory myopathies (IIM) and to evaluate possible associations between autoantibody profile and ECG changes in these patients.

METHODS

In a Scandinavian cross-sectional study, patients were included from two Danish centres and one Swedish centre. Resting 12-lead ECG was investigated in 261 patients with IIM compared with 102 patients with systemic sclerosis (SSc) and 48 healthy controls (HCs). ECG changes were correlated to clinical manifestations and myositis-specific (MSAs) and myositis-associated (MAAs) autoantibodies.

RESULTS

Patients with IIM had longer mean QTc duration and more frequently presented with prolonged QTc (≥ 450 ms; p= 0.038) compared with HCs. Longer QTc duration was recorded in SSc compared with IIM (433 ± 23 ms vs 426 ± 24 ms, p= 0.011), yet, no significant difference in the fraction with prolonged QTc (SSc: 22%, IIM: 16%; p= 0.19). In multivariable regression analyses, anti-Mi2 (p= 0.01, p= 0.035) and anti-Pl-7 (p= 0.045, p= 0.014) were associated with QTc duration and prolonged QTc in IIM. Elevated CRP was associated with prolonged QTc (p= 0.041).

CONCLUSION

Presence of QTc abnormalities was as common in patients with IIM as in patients with SSc, including prolonged QTc seen in almost one fifth of the patients. Anti-Mi2, anti-Pl-7, and elevated CRP may serve as biomarkers for cardiac disease in IIM, but needs to be confirmed in a larger prospective study.

The manifestation of myositis in tick-borne encephalitis as a prophet of severe disease course: a rare case report

Tick-borne encephalitis (TBE) is one of the most serious neurological tick-transmitted diseases. The initial phase usually occurs with non-specific symptoms such as fever, headache, and muscular pain. The clinical spectrum of the second phase of the disease typically ranges from mild meningitis to severe meningoencephalitis. Our case demonstrates a rare clinical case of acute myositis as manifestation of TBE virus infection. A 33-year-old female was admitted to the Rheumatology centre with a fever followed by proximal muscle pain and weakness. Despite the tick bite history and marginally positive anti-TBE virus IgM titre, the patient did not present any neurological symptoms. Laboratory test results showed elevated creatine kinase (CK) and myoglobin. Other infections, idiopathic inflammatory myopathies, were excluded. TBE virus infection was confirmed by rapid seroconversion of specific IgG class antibodies in serum. The second phase of the disease was followed by neurological symptoms and a repeated increase of CK and myoglobin. We suggest that in the case of acute myositis of unknown cause and the history of thick bite, TBE virus infection should be considered and creatine kinase might be considered as a laboratory marker of disease activity that correlates with the severity of the disease.

Autoantibodies in Common Connective Tissue Diseases: A Primer for Laboratory Professionals

Background

Autoimmune connective tissue disorders are a significant health concern throughout the world with an estimated prevalence of 3% to 5%. They are associated with a variety of autoantibodies that play roles in their diagnosis, risk stratification, prognostication, and/or management. While some autoantibodies have been well-characterized for use in clinical laboratories, many more are in the research stage. Rapid transition from research to clinical practice, lack of clinical guidelines, and harmonization across a rapidly growing number of commercially available tests create numerous challenges to clinicians and laboratories.

Content

This article briefly discusses common connective tissue disorders and their association with well-known autoantibodies, describes current methods used in clinical laboratories, and outlines their advantages and limitations in the context of these diseases.

Summary

Understanding the role of specific autoantibodies and various methodologies for autoantibody testing are important for laboratory professionals who may be introducing/repatriating new tests, updating existing tests, or advising clinicians/patients about testing options/results. Collaboration between laboratory professional staff and clinicians, around the advantages and limitations of each methodology, is also important in their appropriate clinical utilization.

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.

Development and validation of a nomogram risk prediction model for malignancy in dermatomyositis patients: a retrospective study

Background

Dermatomyositis accompanied with malignancy is a common poor prognostic factor of dermatomyositis. Thus, the early prediction of the risk of malignancy in patients with dermatomyositis can significantly improve the prognosis of patients. However, the identification of antibodies related to malignancy in dermatomyositis patients has not been widely implemented in clinical practice. Herein, we established a predictive nomogram model for the diagnosis of dermatomyositis associated with malignancy.

Methods

We retrospectively analyzed 240 cases of dermatomyositis patients admitted to Sun Yat-sen Memorial Hospital, Sun Yat-sen University from January 2002 to December 2019. According to the year of admission, the first 70% of the patients were used to establish a training cohort, and the remaining 30% were assigned to the validation cohort. Univariate analysis was performed on all variables, and statistically relevant variables were further included in a multivariate logistic regression analysis to screen for independent predictors. Finally, a nomogram was constructed based on these independent predictors. Bootstrap repeated sampling calculation C-index was used to evaluate the model’s calibration, and area under the curve (AUC) was used to evaluate the model discrimination ability.

Results

Multivariate logistic analysis showed that patients older than 50-year-old, dysphagia, refractory itching, and elevated creatine kinase were independent risk factors for dermatomyositis associated with malignancy, while interstitial lung disease was a protective factor. Based on this, we constructed a nomogram using the above-mentioned five factors. The C-index was 0.780 (95% CI [0.690–0.870]) in the training cohort and 0.756 (95% CI [0.618–0.893]) in the validation cohort, while the AUC value was 0.756 (95% CI [0.600–0.833]). Taken together, our nomogram showed good calibration and was effective in predicting which dermatomyositis patients were at a higher risk of developing malignant tumors.

Tryptophanyl tRNA Synthetase from Human Macrophages Infected by Porphyromonas gingivalis Induces a Proinflammatory Response Associated with Atherosclerosis

Porphyromonas gingivalis is the most common microorganism associated with adult periodontal disease, causing inflammation around the subgingival lesion. In this study, we investigated tryptophanyl tRNA synthase (WRS) production by THP-1 cells infected with P. gingivalis. Cytokine production, leukocyte adhesion molecules, and low-density lipoprotein receptor (LDLR) expressions in cultured cells were examined. WRS was detected in THP-1 cell culture supernatants stimulated with P. gingivalis from 1 to 24 h, and apparent production was observed after 4 h. No change in WRS mRNA expression was observed from 1 to 6 h in THP-1 cells, whereas its expression was significantly increased 12 h after stimulation with P. gingivalis. Lactate dehydrogenase (LDH) activity was observed from 4 to 24 h. The TNF-α, IL-6, IL-8, and CXCL2 levels of THP-1 cells were upregulated after treatment with recombinant WRS (rWRS) and were significantly reduced when THP-1 cells were treated with C29. The MCP-1, ICAM-1, and VCAM-1 levels in human umbilical vein endothelial cells were upregulated following treatment with rWRS, and TAK242 suppressed these effects. Additionally, unmodified LDLR, macrophage scavenger receptor A, and lectin-like oxidized LDLRs were upregulated in THP-1 cells treated with rWRS. These results suggest that WRS from macrophages infected with P. gingivalis is associated with atherosclerosis.

Advances with pharmacotherapy for the treatment of interstitial lung disease

INTRODUCTION

In recent decades, the primary focus of pharmaceutical research in interstitial lung diseases (ILD) has been on idiopathic pulmonary fibrosis (IPF). Recently, pharmaceutical development has also focused on other forms of ILDs, including connective tissue diseases associated ILD, fibrotic hypersensitivity pneumonitis, and sarcoidosis.

AREAS COVERED

The authors summarize the advances in pharmacotherapy for the treatment of ILD. Specifically, the authors review the most recent studies and discuss the most recent research findings and future prospects.

EXPERT OPINION

Data collected over the past years have confirmed the efficacy of antifibrotic drugs on slowing disease progression in IPF. The usual strategy for CTD-ILD management is represented by the combined use of corticosteroids and immunosuppressive agents. There is an urgent need for new target therapies. The concept of progressive fibrosing ILD has emerged in the ILD community in recent years, which has led to grouping several diseases with a common disease behavior to find an effective treatment . At present, selecting the best therapy in ILDs should be reasonably performed on a case-by-case basis through a multidisciplinary team discussion in tertiary ILD centers, taking into consideration patients' symptoms, lung functional trends, and radiological changes.

Role of antifibrotics in the management of idiopathic inflammatory myopathy associated interstitial lung disease

The antifibrotic therapies nintedanib and pirfenidone were first approved by the United States for the treatment of idiopathic pulmonary fibrosis in 2014. In 2020, nintedanib received U.S. Food and Drug Administration (FDA) approval for the treatment of all progressive fibrosing interstitial lung disease (ILD). Given that a major cause of mortality and morbidity in the idiopathic inflammatory myopathies (IIM) is progressive interstitial lung disease and respiratory failure, antifibrotic therapies may be useful as adjuvant to traditional immunosuppression. However, randomized controlled trials of antifibrotic therapies in IIM are lacking. The purpose of this review is to (1) summarize the mechanism of action of nintedanib and pirfenidone in ILD with possible role in IIM-ILD, (2) review the clinical data supporting their use in interstitial lung disease in general, and more specifically in connective tissue disease associated ILD, and (3) discuss the evidence and remaining challenges for using antifibrotic therapies in IIM-ILD.

Myositis-Specific Antibodies and Myositis-Associated Antibodies in Patients With Idiopathic Inflammatory Myopathies From the PANLAR Myositis Study Group

BACKGROUND

Dermatomyositis (DM) and polymyositis (PM) are forms of idiopathic inflammatory myopathies (IIMs), which are associated with the production of autoantibodies that are useful in the diagnosis and prognosis of the disease.

OBJECTIVE

The aim of this study was to determine the frequency of antinuclear autoantibodies (ANAs), myositis-specific autoantibodies (MSAs), and myositis-associated autoantibodies (MAAs) in 6 Latin American countries.

METHODS

Two hundred ten patients with IIM were included in this cross-sectional study from 2014 to 2017: 112 from Mexico, 46 from Colombia, 20 from Peru, 16 from the Dominican Republic, 10 from Argentina, and 6 from Guatemala. Antinuclear autoantibodies were detected by indirect immunofluorescence on HEp-2 cells. MSAs and MAAs were tested by a line immunoassay method. Mann-Whitney U and χ2 tests were used for statistical analysis.

RESULTS

Of the 210 IIM patients, 139 (66.2%) had DM, 59 (28%) PM, and 12 (5.7%) juvenile DM. The mean age was 43.5 (6-79 years); 158 (75.2%) were female, and 52 (24.8%) were male. The overall frequency of ANA was 60%. The most frequent patterns were fine speckled (AC-4) (78.3%) and cytoplasmic (AC-19) (6.45%). The most frequent MSA were anti-Mi-2 (38.5%) and anti-Jo-1 (11.9%). Anti-Mi-2 was more frequent in patients from Colombia (40.1%). The MAA more frequent were anti-Ro-52/TRIM21 (17.6%) and anti-PM-Scl75 (7.5%).

CONCLUSIONS

This is the first study of ANA, MSA, and MAA in patients from 6 countries from the Panamerican League against Rheumatism myositis study group. We observed a general prevalence of 60% of ANA. In relation to MSA and MAA, anti-Mi-2 was the more frequent (38.5%).

Dermatomyositis With Anti-MDA5 Antibodies: Bioclinical Features, Pathogenesis and Emerging Therapies

Anti-MDA5 dermatomyositis is a rare systemic autoimmune disease, historically described in Japanese patients with clinically amyopathic dermatomyositis and life-threatening rapidly progressive interstitial lung disease. Subsequently, the complete clinical spectrum of the disease was enriched by skin, articular and vascular manifestations. Depending on the predominance of these symptoms, three distinct clinical phenotypes with different prognosis are now defined. To date, the only known molecular component shared by the three entities are specific antibodies targeting MDA5, a cytosolic protein essential for antiviral host immune responses. Several biological tools have emerged to detect these antibodies, with drawbacks and limitations for each of them. However, the identification of this highly specific serological marker of the disease raises the question of its role in the pathogenesis. Although current knowledge on the pathogenic mechanisms that take place in the disease are still in their enfancy, several lines of evidence support a central role of interferon-mediated vasculopathy in the development of skin and lung lesions, as well as a possible pathogenic involvement of anti-MDA5 antibodies. Here, we review the clinical and biological evidences in favor of these hypothesis, and we discuss the contribution of emerging therapies that shed some light on the pathogenesis of the disease.

A narrative review of interstitial lung disease in anti-synthetase syndrome: a clinical approach

Anti-synthetase syndrome (AS) is a rare autoimmune disorder characterized by the presence of aminoacyl-transfer RNA synthetase antibodies in conjunction with clinical features such as interstitial lung disease (ILD), Raynaud's phenomenon, nonerosive arthritis, and myopathy. AS distinguishes itself from other inflammatory myopathies by its significant lung involvement and rapidly progressive interstitial lung disease (AS-ILD), therefore the management of AS-ILD requires careful clinical, serologic and radiologic assessment. Glucocorticoids are considered the mainstay of therapy; however, additional immunosuppressive agents are often required to achieve disease control. Patient prognosis is highly dependent on early diagnosis and symptom recognition as the antibody profile is thought to influence therapy response. Since progressive ILD is the leading cause of morbidity and mortality, this review will discuss the clinical approach to patient with suspected AS, with particular emphasis on diagnosis and management of AS-ILD.

Description and Analysis of a Novel Subtype of the Anti-Synthetase Syndrome Characterized by Frequent Attacks of Fever and Systemic Inflammation in a Single-Center Cohort Study

Objectives

The aim of this study was to investigate anti-synthetase syndrome (ASyS) patients who presented with recurrent episodes of fever and systemic inflammation.

Methods

A retrospective cohort of Chinese ASyS patients (n=126) in our center (between January 2013 and January 2020) was included. Patients presenting with concomitant autoimmune rheumatic diseases or malignancies were subsequently excluded. The number of non-infectious fever attacks and attack frequency were recorded and calculated. Patients with two or more attacks and within the upper three quartiles of attack frequency were defined as high-inflammation group. Univariate and multivariate analyses were carried out to characterize the high-inflammation subtype.

Results

Out of 113 eligible patients with an average of 5 years follow up, 25 patients were defined as the high-inflammation group (16 for anti-Jo1, 9 for anti-PL7), with an average of 1.12 attack/patient-year. Compared to low-inflammation group (0-1 attack only and a frequency lower than 0.5 attack/patient-year), the high-inflammation group had higher occurrence of fever and rapid progressive interstitial lung disease (RPILD) as the first presentation (84% vs. 21% and 40% vs. 9%, respectively, both p<0.01). Anti-PL-7 was related to the more inflammatory phenotype (p=0.014). Cumulative disease-modifying agent exposures (>=3) were much higher in the high-inflammation group (60% vs. 26%), while biological agents, i.e., rituximab and tocilizumab, showed better "drug survival" for Jo-1+ and PL-7+ ASyS patients with high inflammation, respectively, in our cohort.

Conclusions

ASyS with recurrent systemic inflammatory episodes reflects a subtype of more aggressive and refractory disease in the spectrum of ASyS. Increased awareness of this subtype might lead to more appropriate management.

2020 guide for the diagnosis and treatment of interstitial lung disease associated with connective tissue disease

The prognosis of patients with connective tissue disease (CTD) has improved significantly in recent years, but interstitial lung disease (ILD) associated with connective tissue disease (CTD-ILD) remains a refractory condition, which is a leading cause of mortality. Because it is an important prognostic factor, many observational and interventional studies have been conducted to date. However, CTD is a heterogeneous group of conditions, which makes the clinical course, treatment responses, and prognosis of CTD-ILD extremely diverse. To summarize the current understanding and unsolved questions, the Japanese Respiratory Society and the Japan College of Rheumatology collaborated to publish the world's first guide focusing on CTD-ILD, based on the evidence and expert consensus of pulmonologists and rheumatologists, along with radiologists, pathologists, and dermatologists. The task force members proposed a total of 27 items, including 7 for general topics, 9 for disease-specific topics, 3 for complications, 4 for pharmacologic treatments, and 4 for non-pharmacologic therapies, with teams of 2-4 authors and reviewers for each item to prepare a consensus statement based on a systematic literature review. Subsequently, public opinions were collected from members of both societies, and a critical review was conducted by external reviewers. Finally, the task force finalized the guide upon discussion and consensus generation. This guide is expected to contribute to the standardization of CTD-ILD medical care and is also useful as a tool for promoting future research by clarifying unresolved issues.

The Risk Factors of Exacerbation in Interstitial Pneumonia With Autoimmune Features: A Single-Center Observational Cohort Study

Objectives

To investigate the long-term outcomes, including risk factors, for exacerbation between monotherapy and combination therapy in patients with interstitial pneumonia with autoimmune features (IPAF).

Methods

We assessed 672 patients between April 2009 and March 2019 who were evaluated using high-resolution computed tomography (HRCT) of the chest. We applied the IPAF criteria. Fifty-two patients who visited our department for at least 6 months were diagnosed with IPAF. Clinical, laboratory, and imaging data were collected from medical records and statistically analyzed.

Results

Among the 52 cases of IPAF, we compared the characteristics at diagnosis between treated (n = 28) and untreated patients (n = 24). The exacerbation rates were 42.9% (n = 12) and 8.3% (n = 2) (P = 0.0051), respectively. Among the treated patients, smoking history, high titer of KL-6, and the duration from diagnosis to the start of treatment were significant risk factors for exacerbation (P = 0.0062, 0.011, and 0.019, respectively). The number of risk factors was significantly and positively associated with exacerbation rate (P = 0.0053). Among the treated patients, glucocorticoid (GC) monotherapy was used in 13 cases, and GC and immunosuppressant (IS) combination therapy was used in 14 patients. There was no significant difference in the treatment methods between patients with and without risk factors (P = 0.47). When comparing the long-term outcomes between the monotherapy and combination therapy groups, the 3-year non-exacerbation rates were 72.9 and 45.9% (P = 0.020), respectively.

Conclusions

IPAF patients with risk factors had a high exacerbation rate, regardless of the type of treatment. New interventions aimed at preventing exacerbations in these patients are required.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00371-3.

Diagnosis of myositis-associated interstitial lung disease: Utility of the myositis autoantibody line immunoassay

OBJECTIVES

The detection of myositis autoantibodies (MA) in patients with interstitial lung disease (ILD) has major implications for diagnosis and management, especially amyopathic and forme frustes of idiopathic inflammatory myositis-associated ILD (IIM-ILD). Use of the MA line immunoblot assay (MA-LIA) in non-rheumatological cohorts remains unvalidated. We assessed the diagnostic performance of the MA-LIA and explored combined models with clinical variables to improve identification of patients with IIM-ILD.

METHODS

Consecutive patients referred to a specialist ILD clinic, with ILD-diagnosis confirmed at multidisciplinary meeting, and MA-LIA performed within six months of baseline were included. Pre-specified MA-LIA thresholds were evaluated for IIM-ILD diagnosis.

RESULTS

A total 247 ILD patients were included (IIM-ILD n = 12, non-IIM connective tissue disease-associated ILD [CTD-ILD] n = 52, idiopathic interstitial pneumonia [IIP] n = 115, other-ILD n = 68). Mean age was 64.8 years, with 45.3% female, mean FVC 75.5% and DLCO 59.2% predicted. MA were present in 13.8% overall and 83.3% of IIM-ILD patients. The most common MA in IIM-ILD and non-IIM ILD patients were anti-Jo-1 (prevalence 40%) and anti-PMScl (29.2%) autoantibodies respectively. The pre-specified low-positive threshold (>10 signal intensity) had the highest discriminative capacity for IIM-ILD (AUC 0.86). Combining MA-LIA with age, gender, clinical CTD-manifestations and an overlap non-specific interstitial pneumonia/organising pneumonia pattern on HRCT improved discrimination for IIM-ILD (AUC 0.96).

CONCLUSION

The MA-LIA is useful to support a diagnosis of IIM-ILD as a complement to multi-disciplinary ILD assessment. Clinical interpretation is optimised by consideration of the strength of the MA-LIA result together with clinical and radiological features of IIM-ILD.

Biomarker und Histologie bei idiopathischen inflammatorischen Myopathien

Die idiopathischen inflammatorischen Myopathien (IIM) sind eine Gruppe entzündlicher Muskelerkrankungen für deren Diagnosestellung, Verlaufsbeurteilung, Prognoseabschätzung und Risikostratifizierung Biomarker eine jeweils essentielle Rolle spielen. Biomarker in diesem Kontext können sowohl „herkömmliche“ serologische Marker wie Muskelenzyme oder Autoantikörper, histologische Marker wie entitätsspezifische inflammatorische Muster, aber auch genomische und genetische Marker sein. Der vorliegende Artikel gibt einen Überblick über bewährte und innovative Marker.

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.

Role of Immunoglobulins in Muscular Dystrophies and Inflammatory Myopathies

Muscular dystrophies and inflammatory myopathies are heterogeneous muscular disorders characterized by progressive muscle weakness and mass loss. Despite the high variability of etiology, inflammation and involvement of both innate and adaptive immune response are shared features. The best understood immune mechanisms involved in these pathologies include complement cascade activation, auto-antibodies directed against muscular proteins or de-novo expressed antigens in myofibers, MHC-I overexpression in myofibers, and lymphocytes-mediated cytotoxicity. Intravenous immunoglobulins (IVIGs) administration could represent a suitable immunomodulator with this respect. Here we focus on mechanisms of action of immunoglobulins in muscular dystrophies and inflammatory myopathies highlighting results of IVIGs from pre-clinical and case reports evidences.