Idiopathic inflammatory myopathies and the lung

High Prevalence of Myositis-Specific and Associated Antibodies in Patients with Pulmonary Hypertension

Pulmonary hypertension (PH) is a serious condition linked to immune-system dysfunction. Myositis-specific/associated antibodies (MSAs/MAAs) play a role in idiopathic inflammatory myopathy (IIM) and interstitial lung disease (ILD), but their significance in PH remains unclear. We believe the presence of these antibodies may be underestimated. This study analyzed adult PH patients without pre-existing IIM for MSA/MAA prevalence using a line-blot assay. We compared PH patients with and without ILD signs to a cohort clinically suspected of IIM/ILD (n = 558). Our PH cohort (n = 121) showed a significantly higher prevalence of overall weak positive MSAs/MAAs and positive overlap syndrome-associated MAAs than the suspected IIM/ILD group (p < 0.001). Notably, MSAs/MAAs were found in PH patients both with and without ILD, though more prevalent in those with ILD. Anti-synthetase and anti-overlap syndrome antibodies were the most common. Our study is the first to systematically show a high MSA/MAA prevalence in PH without IIM presentation. This highlights the need to consider PH when diagnosing MSA/MAA-associated conditions. We recommend MSA/MAA screening for newly diagnosed PH, especially in those with ILD, for early detection and potential immunomodulatory treatment. Further research should explore the link between MSAs/MAAs and PH, and the value of monitoring patients with weak MSA/MAA positivity over time.

Rapid Progression of Acute Interstitial Pneumonia in a Patient with Low MDA-5 Antibody Titer

BACKGROUND Melanoma differentiation associated gene-5 antibody (MDA-5 Ab) is one of the diagnostic autoantibodies that appears in idiopathic inflammatory myopathies (IIMs). Unlike when other autoantibodies are positive, when this antibody is positive, there is less characteristic muscle involvement. However, this MDA-5 Ab-positive myopathy presents extremely rapid progression of interstitial lung disease, resulting in a high mortality rate. Previous studies reported that the prognosis of this lung disease will be determined by the titer and suggest that low titers of MDA-5 antibody can indicate a good prognosis in associated interstitial lung disease. CASE REPORT Our case describes a 55-year-old woman who presented with acute respiratory symptoms and dyspnea. After hospitalization, symptoms and chest imaging worsened rapidly, and the radiology image of lung disease featured interstitial changes not seen in typical infections. We treated the patient with a high-flow oxygen nasal cannula, empirical antibiotics, and a systemic steroid. While treatment for a disease of unknown cause was continued, low titer of MDA-5 antibody was identified. CONCLUSIONS This case suggests 2 points to consider about non-infectious interstitial changes with acute respiratory distress syndrome. First, when treating rapidly progressing interstitial pneumonia of an unknown cause, it is recommended to consider lung involvement of MDA-5 Ab dermatomyositis. Second, a low titer of MDA-5 Ab can be associated with better prognosis in this MDA-5 Ab dermatomyositis-related lung disease.

Clinical profiles and treatment outcomes of outpatients with interstitial lung disease and mechanic's hands: A retrospective and observational cohort

Idiopathic inflammatory myopathies, especially antisynthetase syndrome, often appear outside of the muscles as interstitial lung disease (ILD). Another typical finding is the presence of mechanic's hands. The aim of the present study was to describe the clinical, functional, tomographic, and serological data of patients with ILD and mechanic's hands and their response to treatment and survival rates. This is a retrospective study of ILD with concurrent myopathy. Among the 119 patients initially selected, 51 had mechanic's hands. All the patients were screened for anti-Jo-1 antibodies. An expanded panel of myopathy autoantibodies was also performed in 27 individuals. Of the 51 patients, 35 had 1 or more antibodies. The most common were anti-Jo-1, anti-PL-7, and anti-PL-12, while of the associated antibodies, anti-Ro52 was present in 70% of the 27 tested individuals. A significant response to treatment was characterized by an increase in predicted forced vital capacity (FVC) of at least 5% in the last evaluation done after 6 to 24 months of treatment. A decrease in predicted FVC of at least 5%, the need for oxygen therapy, or death were all considered treatment failures. All patients were treated with corticosteroids, and 71% with mycophenolate. After 24 months, 18 patients had an increase in FVC, 11 had a decrease, and 22 remained stable. After a median follow-up of 58 months, 48 patients remained alive and three died. Patients with honeycombing on high-resolution chest tomography (log-rank = 34.65; P < .001) and a decrease in FVC ≥5% (log-rank = 18.28, P < .001) had a poorer survival rate. Patients with ILD and mechanic's hands respond well to immunosuppressive treatment.

Undercover lung damage in pediatrics - a hot spot in morbidity caused by collagenoses

Connective tissue represents the support matrix and the connection between tissues and organs. In its composition, collagen, the major structural protein, is the main component of the skin, bones, tendons and ligaments. Especially at the pediatric age, its damage in the context of pathologies such as systemic lupus erythematosus, scleroderma or dermatomyositis can have a significant negative impact on the development and optimal functioning of the body. The consequences can extend to various structures (e.g., joints, skin, eyes, lungs, heart, kidneys). Of these, we retain and reveal later in our manuscript, mainly the respiratory involvement. Manifested in various forms that can damage the chest wall, pleura, interstitium or vascularization, lung damage in pediatric systemic inflammatory diseases is underdeveloped in the literature compared to that described in adults. Under the threat of severe evolution, sometimes rapidly progressive and leading to death, it is necessary to increase the popularization of information aimed at physiopathological triggering and maintenance mechanisms, diagnostic means, and therapeutic directions among medical specialists. In addition, we emphasize the need for interdisciplinary collaboration, especially between pediatricians, rheumatologists, infectious disease specialists, pulmonologists, and immunologists. Through our narrative review we aimed to bring up to date, in a concise and easy to assimilate, general principles regarding the pulmonary impact of collagenoses using the most recent articles published in international libraries, duplicated by previous articles, of reference for the targeted pathologies.

Pulmonary Hypertension in Connective Tissue Diseases Other than Systemic Sclerosis

Pulmonary hypertension (PH) is a known complication of certain connective tissue diseases (CTDs), with systemic sclerosis (SSc) being the most common in the Western world. However, PH in association with non-SSc CTD such as systemic lupus erythematous, mixed connective tissue disease, and primary Sjögren's syndrome constitutes a distinct subset of patients with inherently different epidemiologic profiles, pathophysiologic mechanisms, clinical features, therapeutic options, and prognostic implications. The purpose of this review is to inform a practical approach for clinicians evaluating patients with non-SSc CTD-associated PH.The development of PH in these patients involves a complex interplay between genetic factors, immune-mediated mechanisms, and endothelial cell dysfunction. Furthermore, the broad spectrum of CTD manifestations can contribute to the development of PH through various pathophysiologic mechanisms, including intrinsic pulmonary arteriolar vasculopathy (pulmonary arterial hypertension, Group 1 PH), left-heart disease (Group 2), chronic lung disease (Group 3), chronic pulmonary artery obstruction (Group 4), and unclear and/or multifactorial mechanisms (Group 5). The importance of diagnosing PH early in symptomatic patients with non-SSc CTD is highlighted, with a review of the relevant biomarkers, imaging, and diagnostic procedures required to establish a diagnosis.Therapeutic strategies for non-SSc PH associated with CTD are explored with an in-depth review of the medical, interventional, and surgical options available to these patients, emphasizing the CTD-specific considerations that guide treatment and aid in prognosis. By identifying gaps in the current literature, we offer insights into future research priorities that may prove valuable for patients with PH associated with non-SSc CTD.

Pleural Diseases in Connective Tissue Diseases

Connective tissue diseases (CTD) are heterogeneous, immune-mediated inflammatory disorders often presenting with multiorgan involvement. With the advent of high-resolution computed tomography, CTD-related pleuritis-pleural thickening and effusion-is now increasingly recognized early in the disease trajectory. The natural history of CTD-related pleural effusions varies from spontaneous resolution to progressive fibrothorax with ventilatory impairment. Treatment of the underlying CTD is necessary to manage the pleural disease. Depending on the degree of symptom burden and physiological insult, specific treatment of pleural disease can include monitoring, repeated aspirations, systemic anti-inflammatory medication, and surgical decortication.

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.

FAPi PET/CT for assessment and visualisation of active myositis-related interstitial lung disease: a prospective observational pilot study

Background

Interstitial lung disease (ILD) is a common manifestation of idiopathic inflammatory myopathies (IIM) and a substantial contributor to hospitalisation, increased morbidity, and mortality. In-vivo evidence of ongoing tissue remodelling in IIM-ILD is scarce. We aimed to evaluate fibroblast activation in lungs of IIM-patients and control individuals using ⁶⁸Ga-labelled inhibitor of Fibroblast-Activation-Protein (FAPi) based positronic emission tomography and computed tomography imaging (PET/CT).

Methods

In this prospective observational pilot study, consecutive patients with IIM and participants without rheumatic conditions or ILD serving as a control group were recruited at the Medical University of Vienna, Austria, and underwent FAPi PET/CT imaging. Standard-of-care procedures including clinical examination, assessment of severity of dyspnoea, high-resolution computed tomography (HR-CT), and pulmonary function testing (PFT) were performed on all patients with IIM at baseline and for patients with IIM-ILD at follow-up of 12 months. Baseline pulmonary FAPi-uptake was assessed by the maximum (SUVmax) and mean (SUVmean) standardized uptake values (SUV) over the whole lung (wl). SUV was corrected for blood pool background activity and target-to-background ratios (TBR) were calculated. We compared pulmonary FAPi-uptake between patients with IIM-ILD and those without ILD, as well as controls, and correlated baseline FAP-uptake with standard diagnostic tools such as HR-CT and PFT. For predictive implications, we investigated whether patients with IIM and progressive ILD exhibited higher baseline FAPi-uptake compared to those with stable ILD. Metrics are reported as mean with standard deviation (±SD).

Findings

Between November 16, 2021 and October 10, 2022, a total of 32 patients were enrolled in the study. Three participants from the control group were excluded due to cardiopulmonary disease. In individuals with IIM-ILD (n = 14), wlTBRmax and wlTBRmean were significantly increased as compared with both non-ILD-IIM patients (n = 5) and the control group (n = 16): wlTBRmax: 2.06 ± 1.04 vs. 1.04 ± 0.22 (p = 0.019) and 1.08 ± 0.19 (p = 0.0012) and wlTBRmean: 0.45 ± 0.19 vs. 0.26 ± 0.06 (p = 0.025) and 0.27 ± 0.07 (p = 0.0024). Similar values were observed in wlTBRmax or wlTBRmean between non-ILD IIM patients and the control group. Patients with progressive ILD displayed significantly enhanced wlTBRmax and wlTBRmean values at baseline compared to patients with stable ILD: wlTBRmax: 1.30 ± 0.31 vs. 2.63 ± 1.04 (p = 0.0084) and wlTBRmean: 0.32 ± 0.08 vs. 0.55 ± 0.19 (p = 0.021). Strong correlations were found between FAPi-uptake and disease extent on HR-CT (wlTBRmax: R = 0.42, p = 0.07; wlTBRmean: R = 0.56, p = 0.013) and severity of respiratory symptoms determined by the New York Heart Association (NYHA) classification tool (wlTBRmax: R = 0.52, p = 0.022; wlTBRmean: R = 0.59, p = 0.0073). Further, pulmonary FAPi-uptake showed inverse correlation with forced vital capacity (FVC) (wlTBRmax: R = -0.56, p = 0.012; wlTBRmean: R = -0.64, p = 0.0033) and diffusing capacity of the lungs for carbon monoxide (DLCO) (wlTBRmax: R = -0.52, p = 0.028; wlTBRmean: R = -0.68, p = 0.0017).

Interpretation

Our study demonstrates higher fibroblast activation in patients with IIM-ILD compared to non-ILD patients and controls. Intensity of pulmonary FAPi accumulation was associated with progression of ILD. Considering that this study was carried out on a small population, FAPi PET/CT may serve as a useful non-invasive tool for risk stratification of lung disease in IIM.

Funding

The Austrian Research Fund.

Prognostic Role of Interferon-λ3 in Anti-Melanoma Differentiation-Associated Gene 5-Positive Dermatomyositis-Associated Interstitial Lung Disease

OBJECTIVE

Interferon-λ3 (IFNλ3) is a cytokine with antiviral functions on barrier surfaces, and it is associated with disease activity in autoimmune diseases. This study assessed the clinical significance of serum IFNλ3 levels in polymyositis/dermatomyositis (PM/DM)-associated interstitial lung disease (ILD).

METHODS

We measured serum IFNλ3 levels in 221 patients with PM/DM-ILD (155 in the derivation cohort, 66 in the validation cohort) and 38 controls. We evaluated factors associated with mortality risk among 79 patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive DM-ILD.

RESULTS

Serum IFNλ3 levels at diagnosis were significantly higher in patients with PM/DM-ILD than in healthy controls. Remarkably, serum IFNλ3 levels were specifically increased in patients with anti-MDA5 antibody-positive DM-ILD in both the derivation and validation cohorts. In anti-MDA5 antibody-positive DM-ILD, patients with high IFNλ3 levels (>120 pg/mL) had significantly lower survival rates than those with low IFNλ3 levels (≤120 pg/mL). A multivariate analysis revealed that high IFNλ3 levels, as well as old age and low Pao2, were significantly associated with poor prognoses in patients with anti-MDA5 antibody-positive DM-ILD. In a classification analysis of patients with anti-MDA5 antibody-positive DM-ILD based on age, IFNλ3 level, and Pao2, patients with old age (>53 years), high IFNλ3 levels (>120 pg/mL), and low Pao2 (<75 mm Hg) had the worst survival. In lung pathologic analyses, IFNλ3-positive staining was observed in macrophages, airway epithelial cells, the pleural region, and intrapulmonary veins in patients with anti-MDA5 antibody-positive DM-ILD.

CONCLUSION

Serum IFNλ3 is a promising biomarker for identifying patients at high risk of poor outcomes in anti-MDA5 antibody-positive DM-ILD.

Pretreatment mortality risk prediction model in patients with polymyositis/dermatomyositis-associated interstitial lung disease

OBJECTIVES

Risk prediction for patients with polymyositis/dermatomyositis-associated interstitial lung disease (PM/DM-ILD) is challenging due to heterogeneity in the disease course. We aimed to develop a mortality risk prediction model for PM/DM-ILD.

METHODS

This prognostic study analysed patients with PM/DM-ILD admitted to Nanjing Drum Hospital from 2016 to 2021. The primary outcome was mortality within 1 year. We used a least absolute shrinkage and selection operator (LASSO) logistic regression model to identify predictive laboratory indicators. These indicators were used to create a laboratory risk score, and we developed a mortality risk prediction model by incorporating clinical factors. The evaluation of model performance encompassed discrimination, calibration, clinical utility and practical application for risk prediction and prognosis.

RESULTS

Overall, 418 patients with PM/DM-ILD were enrolled and randomly divided into development (n=282) and validation (n=136) cohorts. LASSO logistic regression identified four optimal features in the development cohort, forming a laboratory risk score: C reactive protein, lactate dehydrogenase, CD3+CD4+ T cell counts and PO2/FiO2. The final prediction model integrated age, arthralgia, anti-melanoma differentiation-associated gene 5 antibody status, high-resolution CT pattern and the laboratory risk score. The prediction model exhibited robust discrimination (area under the receiver operating characteristic: 0.869, 95% CI 0.811 to 0.910), excellent calibration and valuable clinical utility. Patients were categorised into three risk groups with distinct mortality rates. The internal validation, sensitivity analyses and comparative assessments against previous models further confirmed the robustness of the prediction model.

CONCLUSIONS

We developed and validated an evidence-based mortality risk prediction model with simple, readily accessible clinical variables in patients with PM/DM-ILD, which may inform clinical decision-making.

Radiological and histopathological features and treatment response by subtypes of interstitial pneumonia with autoimmune features: A prospective, multicentre cohort study

BACKGROUND

Patients with idiopathic interstitial pneumonia (IIP) have a favourable prognosis when they have interstitial pneumonia with autoimmune features (IPAF). However, precise IPAF-related findings from high-resolution computed tomography (HRCT) and lung histopathological specimens and the treatment response have not been fully determined. Therefore, this study was conducted to evaluate the relationship between findings on HRCT or lung histopathological specimens and the progression of interstitial pneumonia in patients with IPAF.

METHODS

This multicentre cohort study prospectively enrolled consecutive patients with IIP. At the diagnosis of IIP, we systematically evaluated 74 features suggestive of connective tissue diseases and followed them up. HRCT, lung specimens, serum antibodies, and the clinical course were also evaluated.

RESULTS

Among 222 patients with IIP, 26 (11.7%) fulfilled the IPAF criteria. During a median observation period of 36 months, patients with IPAF showed better survival than those without IPAF (p = 0.034). While histopathological findings were not related to IPAF, nonspecific interstitial pneumonia (NSIP) with organizing pneumonia (OP) overlap was the most prevalent HRCT pattern (p < 0.001) and the consolidation opacity was the most common radiological finding in IPAF (p = 0.017). Furthermore, in patients with IPAF, the diagnosis of COP or NSIP with OP overlap was associated with a higher increase in %FVC in 1 year than in those with idiopathic pulmonary fibrosis, NSIP, or unclassifiable IIP (p = 0.002).

CONCLUSIONS

This study shows the presence of consolidation opacity on HRCT and the diagnosis of COP or NSIP with OP overlap are associated with IPAF and its favourable treatment response in patients with IPAF.

Microarray analysis of microrna expression in peripheral blood mononuclear cells of patients with polymyositis and dermatomyositis

Background and Objectives

MicroRNAs (miRNAs) represent a new class of biomarkers in the context of connective tissue disorders. The miRNA expression profiles in peripheral blood mononuclear cells (PBMCs) of patients with polymyositis (PM) and dermatomyositis (DM) have not been fully elucidated. The objective is to investigate miRNAs expression profile in PBMCs of patients with PM/DM.

Methods

Microarray technology was used to identify differentially expressed miRNAs in PBMCs obtained from 6 untreated PM/DM patients and 3 healthy controls (HCs). TaqMan-based stem-loop real-time PCR detection was used for validation in a cohort of 34 PM/DM patients and 20 HCs.

Results

Microarray analysis revealed 38 differentially expressed miRNAs (24 up-regulated and 14 down-regulated) in PM/DM patients compared to HCs. Four miRNAs (miR-320a, miR-335-3p, miR-34a-5p and miR-454-3p) were chosen for real-time PCR validation. The expression of miR-34a-5p was significantly upregulated in PM/DM group (P < 0.05). In subgroup analysis, miR-34a-5p was significantly upregulated in interstitial lung disease (ILD) group and DM group (P < 0.001). The level of SIRT1, a validated target of miR-34a, was significantly lower in PBMCs of PM/DM patients compared with HCs.

Conclusions

MiR-34a-5p may potentially participate in the pathogenesis of PM/DM through SIRT1, and may serve as a potential new biomarker for PM/DM-ILD.

[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.

Clinical Features and Outcomes of Patients with Idiopathic Inflammatory Myositis-Associated Interstitial Lung Disease in Rural Appalachia: A Cross-Sectional Study

BACKGROUND

Idiopathic inflammatory myopathies (IIMs) are a group of autoimmune disorders often complicated by interstitial lung disease (ILD). The clinical characteristics and outcomes of IIM-associated ILD have been reported variably, but the literature on rural populations is scarce.

METHODS

A retrospective cross-sectional study was conducted at a rural tertiary academic medical center. Twenty-nine patients met the final inclusion criteria. The primary outcome was to assess the disease state and immunological and radiographic features of IIM-associated ILD. Secondary outcomes included disease progression, ILD exacerbation, mortality rate, and factors associated with poor outcome.

RESULTS

Dermatomyositis (n = 15, 51.72%) followed by polymyositis (n = 8, 27.58%) were predominant myopathies. The most common autoantibodies were anti-Jo1 antibodies (n = 11, 37.93%). Indeterminate usual interstitial pneumonitis (41.30%, n = 12) was the most common radiographic pattern followed by non-specific interstitial pneumonia (n = 5, 17.24%). ILD exacerbation (n = 14, 66.66%) and mortality rate (n = 6, 20.69%) were high. Albumin levels were significantly lower in patients who died.

CONCLUSIONS

The clinical characteristics of patients with IIM-associated ILD in rural Appalachia exhibit notable distinctions, and outcomes are worse compared to other populations. Larger studies are needed to investigate other prognostics factors and longitudinal trends of clinical characteristics and outcomes of IIM-associated ILD in rural populations.

Anti-MDA5 antibody-associated clinically amyopathic dermatomyositis diagnosed after the onset of pulmonary hypertension

Idiopathic inflammatory myopathies (IIM) are a group of highly heterogeneous systemic autoimmune diseases, of which clinically amyopathic dermatomyositis (CADM) is a distinct sub-type. Pulmonary hypertension (PH) is a life-threatening medical condition that can occur as a complication of connective tissue diseases. Herein, our report first suggests that PH can develop in CADM. A 48-year-old woman came to our hospital due to a 3 months history of facial edema and shortness of breath. Relevant examinations revealed Gottron's sign, normal creatinine kinase levels, elevated levels of mean pulmonary artery pressure, double-positive anti-MDA5 and anti-Ro52 antibodies, and typical pathological changes associated with myositis. The diagnosis of CADM combined with PH was considered. The patient responded well to the immunosuppression therapy and PH-related drug therapy. We provide further insights that patients with IIM need to undergo regular assessment of PH.

Prevalence of myositis specific and associated antibodies in a cohort of patients affected by idiopathic NSIP and no hint of inflammatory myopathies

The presence of interstitial lung disease (ILD) is a common and fearsome feature of idiopathic inflammatory myopathies (IIM). Such patients show radiological pattern of non-specific interstitial pneumonia (NSIP). The present study aimed to assess the prevalence of myositis-specific and myositis-associated antibodies (MSA and MAA) in a cohort of patients with a previous diagnosis of NSIP and no sign or symptom of IIM. Secondly, it will be assessed whether patients displaying MSA and/or MAA positivity have a worse or a better outcome than idiopathic NSIP. All patients affected by idiopathic NSIP were enrolled. MSA and MAA were detected using EUROLINE Autoimmune Inflammatory Myopathies 20 Ag (Euroimmun Lubeck, Germany), line immunoassay. A total of 16 patients (mean age 72 ± 6.1 years old) were enrolled. Six out of 16 patients (37.5%) had significant MSA and/or MAA positivity: one displayed positivity of anti-PL-7 (+ +), one of anti-Zo (+ +), anti-TIF1γ (+ + +) and anti-Pm-Scl 75 (+ + +), one of anti-Ro52 (+ +), one of anti-Mi2β (+ + +), one of anti-Pm-Scl 75 (+ + +) and the latter of both anti-EJ (+ + +) and anti-Ro52 (+ + +).Two out of 7 seropositive patients showed a significant impairment of FVC (relative risk 4.8, 95% CI 0.78-29.5; p = 0.0350). Accordingly, among the 5 patients that started antifibrotic treatment during the observation time, 4 were seronegative. Our findings highlighted a potential autoimmune or inflammatory in idiopathic NSIP patients and also in those without significant rheumatological symptoms. A more accurate diagnostic assessment may ameliorate diagnostic accuracy as well as may provide new therapeutic strategy (antifibrotic + immunosuppressive). A cautious assessment of NSIP patients with a progressive and non-responsive to glucocorticoids disease course should therefore include an autoimmunity panel comprising MSA and MAA.

Serum bilirubin levels in primary Sjögren's syndrome: an association with interstitial lung disease

OBJECTIVE

We aimed to assess the association between serum bilirubin levels and interstitial lung disease (ILD) in patients with Primary Sjögren's syndrome (pSS).

MATERIALS AND METHODS

The retrospectively analysis included 89 consecutive patients with pSS, we collected the clinical materials of pSS patients from the electronic medical records, and all pSS patients were divide into pSS with ILD group and pSS without ILD group.

RESULTS

Serum bilirubin levels were significantly lower in pSS patients with ILD than those without ILD (p = 0.010). Serum bilirubin levels showed a significant negative correlation with erythrocyte sedimentation rate (ESR) (r = -0.321, p = 0.002) in patients with pSS. A multivariable logistic regression analysis confirmed that serum bilirubin presented an independent association with ILD in patients with pSS (OR = 0.841, 95%CI:0.728-0.972, p = 0.019).

CONCLUSION

Serum bilirubin is independently associated with ILD and therefore may be a promising marker of ILD in patients with pSS.

Anti-Cytosolic 5'-Nucleotidase 1A in the Diagnosis of Patients with Suspected Idiopathic Inflammatory Myopathies: An Italian Real-Life, Single-Centre Retrospective Study

BACKGROUND

Anti-cytosolic 5'-nucleotidase 1A (anti-cN1A) antibodies were proposed as a biomarker for the diagnosis of inclusion body myositis (IBM), but conflicting specificity and sensitivity evidence limits its use. Our study aimed to assess the diagnostic accuracy of anti-cN1A in a cohort of patients who underwent a myositis line immunoassay for suspected idiopathic inflammatory myopathies (IIM). We also assessed the agreement between two testing procedures: line immunoassay (LIA) and enzyme-linked immunoassay (ELISA).

MATERIALS AND METHODS

We collected retrospective clinical and serological data for 340 patients who underwent a myositis antibody assay using LIA (EUROLINE Autoimmune Inflammatory Myopathies 16 Ag et cN-1A (IgG) line immunoassay) and verification with an anti-cN1A antibody assay using ELISA (IgG) (Euroimmun Lubeck, Germany).

RESULTS

The serum samples of 20 (5.88%) patients (15 females, 5 males, mean age 58.76 ± 18.31) tested positive for anti-cN1A using LIA, but only two out of twenty were diagnosed with IBM. Seventeen out of twenty tested positive for anti-cN1A using ELISA (median IQR, 2.9 (1.9-4.18)).

CONCLUSIONS

Our study suggests excellent concordance between LIA and ELISA for detecting anti-cN1A antibodies. LIA may be a rapid and useful adjunct, and it could even replace ELISA for cN1A assay. However, the high prevalence of diseases other than IBM in our cohort of anti-cN1A-positive patients did not allow us to consider anti-cN1A antibodies as a specific biomarker for IBM.

Anti-Ro52/Anti-nuclear Matrix Protein 2 Positive Clinically Amyopathic Dermatomyositis Presented Only With Interstitial Lung Disease

This report contemplates a unique case of clinically amyopathic dermatomyositis (CADM) that presented as interstitial lung disease. The patient was a 55-year-old woman who showed up with progressive exercise intolerance and a dry cough without muscular or dermatological clinical manifestations. Diagnostic workup and imaging revealed the presence of interstitial lung disease, and further evaluation led to a positive autoimmune panel for anti-nuclear matrix protein 2 (anti-NXP2) and anti-Ro52 antibodies, establishing the diagnosis of anti-NXP2 plus anti-Ro52 antibodies-positive amyopathic idiopathic inflammatory dermatomyositis. The patient was started on intravenous corticosteroids. She showed improvement on her chest X-ray (CXR) and was then switched to oral corticosteroids. After six months of steroid treatment, corticosteroids were stopped, and the patient was re-evaluated one month later disease relapse.

Myositis interstitial lung disease and autoantibodies

The aim of this review is to examine and evaluate published literature associated with idiopathic inflammatory myopathies (IIM) and interstitial lung disease (ILD) based on myositis specific autoantibodies (MSA) and the potential clinical significance of each autoantibody subtype for the practicing clinician. The review is a comprehensive search of literature published in PubMed from the year 2005 and onward coinciding with the surge in the discovery of new MSAs. Additionally, we comment on recommended multidisciplinary longitudinal care practices for patients with IIM-ILD with regard to imaging and other testing. Treatment is not covered in this review.

Diagnosis and treatment of interstitial lung disease related to systemic autoimmune myopathies: a narrative review

Systemic autoimmune myopathies (SAMs) are rare diseases that lead to muscle inflammation and may be associated with a variety of systemic manifestations. Although there is great heterogeneity in the spectrum of extra-muscular involvement in SAMs, interstitial lung disease (ILD) is the most frequent lung manifestation. SAM-related ILD (SAM-ILD) presents significant variations according to geographic location and temporal trends and is associated with increased morbidity and mortality. Several myositis autoantibodies have been discovered over the last decades, including antibodies targeting aminoacyl-tRNA synthetase enzymes, which are associated with a variable risk of developing ILD and a myriad of other clinical features. In this review, the most relevant topics regarding clinical manifestations, risk factors, diagnostic tests, autoantibodies, treatment, and prognosis of SAM-ILD are highlighted. We searched PubMed for relevant articles published in English, Portuguese, or Spanish from January 2002 to September 2022. The most common SAM-ILD patterns are nonspecific interstitial pneumonia and organizing pneumonia. The combination of clinical, functional, laboratory, and tomographic features is usually sufficient for diagnostic confirmation, without the need for additional invasive methods. Glucocorticoids remain the first-line treatment for SAM-ILD, although other traditional immunosuppressants, such as azathioprine, mycophenolate, and cyclophosphamide have demonstrated some efficacy and, therefore, have an important role as steroid-sparing agents.

Role of CD14+ monocyte-derived oxidised mitochondrial DNA in the inflammatory interferon type 1 signature in juvenile dermatomyositis

OBJECTIVES

To define the host mechanisms contributing to the pathological interferon (IFN) type 1 signature in Juvenile dermatomyositis (JDM).

METHODS

RNA-sequencing was performed on CD4+, CD8+, CD14+ and CD19+ cells sorted from pretreatment and on-treatment JDM (pretreatment n=10, on-treatment n=11) and age/sex-matched child healthy-control (CHC n=4) peripheral blood mononuclear cell (PBMC). Mitochondrial morphology and superoxide were assessed by fluorescence microscopy, cellular metabolism by 13C glucose uptake assays, and oxidised mitochondrial DNA (oxmtDNA) content by dot-blot. Healthy-control PBMC and JDM pretreatment PBMC were cultured with IFN-α, oxmtDNA, cGAS-inhibitor, TLR-9 antagonist and/or n-acetyl cysteine (NAC). IFN-stimulated gene (ISGs) expression was measured by qPCR. Total numbers of patient and controls for functional experiments, JDM n=82, total CHC n=35.

RESULTS

Dysregulated mitochondrial-associated gene expression correlated with increased ISG expression in JDM CD14+ monocytes. Altered mitochondrial-associated gene expression was paralleled by altered mitochondrial biology, including 'megamitochondria', cellular metabolism and a decrease in gene expression of superoxide dismutase (SOD)1. This was associated with enhanced production of oxidised mitochondrial (oxmt)DNA. OxmtDNA induced ISG expression in healthy PBMC, which was blocked by targeting oxidative stress and intracellular nucleic acid sensing pathways. Complementary experiments showed that, under in vitro experimental conditions, targeting these pathways via the antioxidant drug NAC, TLR9 antagonist and to a lesser extent cGAS-inhibitor, suppressed ISG expression in pretreatment JDM PBMC.

CONCLUSIONS

These results describe a novel pathway where altered mitochondrial biology in JDM CD14+ monocytes lead to oxmtDNA production and stimulates ISG expression. Targeting this pathway has therapeutical potential in JDM and other IFN type 1-driven autoimmune diseases.

Spontaneous Pneumomediastinum and Subcutaneous Emphysema in Dermatomyositis: A Case Series and Literature Review

Background

Spontaneous pneumomediastinum and subcutaneous emphysema are rare and serious complications of dermatomyositis (DM).

Case Presentation

Our article presents two clinically heterogeneous cases of DM who developed pneumomediastinum and subcutaneous emphysema. The first was a 24-year-old lady with a recently diagnosed DM. She developed rapidly progressive pneumonia, interstitial lung disease (ILD), pneumomediastinum, subcutaneous emphysema, and acute respiratory distress syndrome (ARDS). She died despite treatment with steroids and immunosuppressants (methotrexate and mycophenolate mofetil (MMF)). The second was a 30-year-old man diagnosed with amyopathic DM. He developed pneumomediastinum prior to ILD, which worsened over time, and subcutaneous emphysema evolved. However, he recovered completely after corticosteroid, MMF, and rituximab.

Conclusion

Spontaneous pneumomediastinum and subcutaneous emphysema may complicate DM. Corticosteroids, immunosuppressants, and respiratory support are the mainstay of management for these conditions. Though they were reported to carry a poor prognostic value, the course and outcome are highly variable among the cases.

Clinical Outcomes With and Without Plasma Exchange in the Treatment of Rapidly Progressive Interstitial Lung Disease Associated With Idiopathic Inflammatory Myopathy

BACKGROUND/OBJECTIVE

A subset of patients with idiopathic inflammatory myopathy (IIM) develops highly fatal, rapidly progressive interstitial lung disease (RP-ILD). Treatment strategies consist of glucocorticoid and adjunctive immunosuppressive therapies. Plasma exchange (PE) is an alternative therapy, but its benefit is unclear. In this study, we aimed to determine whether PE benefited outcomes for patients with RP-ILD.

METHODS

In this medical records review study, we compared baseline characteristics and clinical outcomes for 2 groups of patients with IIM-related RP-ILD: those who received and did not receive PE.

RESULTS

Our cohort consisted of 15 patients, 9 of whom received PE. Baseline demographic characteristics and severity of lung, skin, and musculoskeletal disease between the 2 groups of patients were not significantly different. Five patients required mechanical ventilation (2, PE; 3, no PE). Plasma exchange was generally a third-line adjunctive treatment option. The PE group had a longer median (interquartile range) hospitalization (27.0 [23.0-36.0] days) than the non-PE group (12.0 [8.0-14.0] days) ( p = 0.02). There was a potential benefit in 30-day mortality improvement in those receiving PE (0% vs 33%, p = 0.14), with a statistically significant improvement in 2 important composite end points including 30-day mortality or need for lung transplant (0% vs 50%, p = 0.04) and 1-year mortality or need for lung transplant or hospital readmission for RP-ILD in those receiving PE (22% vs 83%, p = 0.04).

CONCLUSIONS

Plasma exchange may be an underutilized, safe salvage therapy for patients with IIM-related RP-ILD when other immunosuppressive therapies fail.

Anti-synthetase syndrome associated interstitial lung disease after combination dual immune checkpoint inhibition

Immune checkpoint inhibitors (ICIs) unleash potent anti-tumour responses but with frequent off-target immune-mediated adverse events (irAE). ICIs can induce a spectrum of rheumatologic manifestations including inflammatory arthritis, Sjögren's syndrome, scleroderma and systemic lupus erythematosus. Here, we describe a case of antisynthetase syndrome associated interstitial lung disease (ILD) following dual Programmed Cell Death 1 and Cytotoxic T Lymphocyte-Associated Protein 4 checkpoint inhibition in a patient with metastatic melanoma. Initial treatment course was complicated by a number of irAEs including pneumonitis, colitis and thyroiditis. Suspicion of an underlying systemic rheumatic disease was heightened by the severe, relapsing and fibrosing nature of the interstitial pneumonitis. A diagnosis of amyopathic antisynthetase syndrome was made upon detection of circulating aminoacyl-tRNA synthetase (anti-EJ) autoantibodies. Intensification of induction immunosuppression followed by maintenance mycophenolate, prednisone and monthly intravenous immunoglobulin achieved long-term disease control. Detection of de novo ICI-induced inflammatory myositis ILD requires a high index of suspicion and carries important prognostic and treatment implications.

The prognostic role of C-reactive protein to albumin ratio and anti-MDA5 antibody-positive in idiopathic inflammatory myopathy: a retrospective study

This cohort study aimed to identify the characteristics and risk factors of adult idiopathic inflammatory myopathy-associated interstitial lung disease (IIM-ILD) and further explore the prognostic factors of IIM-ILD. We extracted data regarding 539 patients with laboratory-confirmed idiopathic inflammatory myopathy (IIM) with or without interstitial lung disease (ILD) from the Second Xiangya Hospital of Central South University between January 2016 and December 2021. The regression analysis was conducted to identify the possible risk factors for ILD as well as mortality. Of 539 IIM patients, 343 (64.6%) were diagnosed with IIM-ILD. The median (IQR) baseline neutrophil-to-lymphocyte ratio (NLR), C-reactive protein to albumin ratio (CAR) and ferritin were 4.1371 (2.6994-6.8143), 0.1685 (0.0641-0.5456) and 393.6 (210.6-532.2), respectively. Risk factors associated with IIM-ILD were older age (p = 0.002), arthralgia (p = 0.014), lung infection (p = 0.027), hemoglobin (p = 0.022), high CAR (p = 0.014), anti-aminoacyl-tRNA synthetase (anti-ARS) antibody-positive (p < 0.001), and anti-MDA5 antibody-positive (p < 0.001). The IIM-ILD patients whose age at diagnosis of disease ≥ 59.5 (HR = 2.673, 95% CI 1.588-4.499, p < 0.001), NLR ≥ 6.6109 (HR = 2.004, 95% CI 1.193-3.368, p = 0.009), CAR ≥ 0.2506 (HR = 1.864, 95% CI 1.041-3.339, p = 0.036), ferritin ≥ 397.68 (HR = 2.451, 95% CI 1.245-4.827, p = 0.009) and anti-MDA5 antibody-positive (HR = 1.928, 95% CI 1.123-3.309, p = 0.017) had a higher mortality rate. High CAR and anti-MDA5 antibody-positive are more likely to be associated with a high mortality rate of IIM-ILD, which can be used as serum biomarkers, especially the CAR, a simple, objective tool to assess the prognosis of IIM.

Accuracy of power Doppler ultrasonography in the diagnosis and monitoring of idiopathic inflammatory myopathies

OBJECTIVES

No clear-cut guidelines exist for the use of imaging procedures for the diagnosis of idiopathic inflammatory myopathies (IIM). The aim of the present study was to assess the diagnostic accuracy of power Doppler ultrasonography (PDUS) score in IIM patients compared with a control group and its usefulness during follow-up.

METHODS

All patients evaluated in the Vasculitis and Myositis Clinic, Rheumatology Unit, University of Siena were prospectively collected. All patients underwent US examination of both thighs in axial and longitudinal scans, which were also performed twice (T1) or three times (T2).

RESULTS

Forty-five patients with IIM (median [interquartile range] age 55 [45-66] years; 35 female) were enrolled. Receiver operating characteristic curves distinguished patients and controls based on ∑power Doppler (PD), ∑oedema, ∑atrophy and CRP. The best cut-off value for ∑PD was 0.5, ∑oedema 1.5, ∑atrophy 0.5 and CRP 0.22 mg/dl. In a logistic regression analysis, the variables that most influenced diagnosis of IIM were ∑PD and ∑oedema (P = 0.017 and P = 0.013, respectively). ∑Oedema was lower at T1 (P = 0.0108) and T2 (P = 0.0012) than at T0. Likewise, ∑PD was lower at T1 (P = 0.0294) and T2 (P = 0.0420) than at T0. Physician global assessment was lower at T1 (P = 0.0349) and T2 (P = 0.0035) than at baseline.

CONCLUSION

Our findings show that PDUS is a reliable diagnostic tool in the differential diagnosis between inflammatory and non-inflammatory myopathies. Moreover, PDUS can be employed also during the follow-up of patients with IIM. A reduction in disease activity, measured by physician global assessment, led to a concomitant decrease in both oedema and PD, which was directly correlated with their rate of change. This underlines the close link between clinical assessment and PDUS findings, not only at diagnosis but also during monitoring.

Autoimmune Pulmonary Alveolar Proteinosis during the Treatment of Idiopathic Inflammatory Myopathy

Approximately 50% of idiopathic inflammatory myopathies (IIMs) are associated with interstitial lung disease (ILD). Typically, IIM-ILD manifests as nonspecific interstitial pneumonia. We herein report a rare case of a 78-year-old man with autoimmune pulmonary alveolar proteinosis (PAP) that developed during IIM treatment. The diagnosis of autoimmune PAP was based on detecting anti-granulocyte-macrophage colony-stimulating factor antibodies. We postulated that PAP may have been induced by IIM treatment with prednisolone. Our case suggests that the possibility of autoimmune PAP should be considered in patients with lung lesions during the clinical course of IIM.

Human epididymis protein 4 as a clinical biomarker in identifying interstitial lung disease in patients with idiopathic inflammatory myopathies

OBJECTIVE

Human epididymis protein 4 (HE4) can differentiate interstitial lung disease from patients with some rheumatic diseases. However, the clinical utility of HE4 in idiopathic inflammatory myopathies (IIM) remains unclear.

METHODS

80 IIM patients and 91 age and gender-matched healthy controls (HCs) were recruited. Clinical and laboratory data were recorded at baseline and 12 weeks. HE4 was tested by the method of electrochemical luminescence.

RESULTS

Compared to HCs, the levels of HE4 significantly elevated in IIM patients. Patients with elevated HE4 had a higher interstitial lung disease (ILD) prevalence. Among patients with ILD, histological patterns of organizing pneumonia had higher HE4 levels than non-specific interstitial pneumonia. Further, there was a positive correlation between HE4 and the semi-quantitative CT grade (r = 0.778, p < 0.001) and a negative relation between HE4 and the percentage of forced vital capacity (p < 0.001) and diffusing capacity of the lung for carbon monoxide (DLco) (p = 0.001). An optimal cut-off value of HE4 (79.6 pmol/L) for distinguishing IIM-ILD was analyzed by ROC analysis with an AUC of 0.733 (p = 0.002). Regression analysis revealed that elevated HE4 independently identified IIM-related ILD (OR 34.8, 95 %CI, 3.58-338.14, p = 0.002). With the improvement after treatment, serum HE4 levels were significantly decreased (p = 0.006), accompanied by improved DLco% (p = 0.012).

CONCLUSIONS

Serum HE4 was significantly elevated in patients with IIM and may be utilized as a serum biomarker to evaluate the disease severity and prognosis of IIM-related ILD.

Clinical features and outcomes of patients with myositis associated-interstitial lung disease

Introduction

Myositis associated interstitial lung disease (ILD) seems to be an under-recognized entity.

Methods

In this multicenter, retrospective study, we recorded between 9/12/2019 and 30/9/2021 consecutive patients who presented in five different ILD centers from two European countries (Greece, France) and received a multidisciplinary diagnosis of myositis associated-ILD. The primary outcome was all-cause mortality over 1 year in specific subgroups of patients. Secondary outcomes included comparison of disease characteristics between patients diagnosed with the amyopathic subtype and patients with evidence of myopathy at diagnosis.

Results

We identified 75 patients with myositis associated-ILD. Median age (95% CI) at the time of diagnosis was 64.0 (61.0-65.0) years. Antinuclear antibody testing was positive in 40% of the cohort (n = 30/75). Myopathy onset occurred first in 40.0% of cases (n = 30), ILD without evidence of myopathy occurred in 29 patients (38.7%), while 16 patients (21.3%) were diagnosed concomitantly with ILD and myopathy. The commonest radiographic pattern was cellular non-specific interstitial pneumonia (NSIP) and was observed in 29 patients (38.7%). The radiographic pattern of organizing pneumonia was significantly more common in patients diagnosed with the amyopathic subtype compared to patients that presented with myopathy [24.1% (n = 7/29) vs. 6.5% (n = 3/46), p = 0.03]. One year survival was 86.7% in the overall population. Kaplan-Meier analysis demonstrated significantly higher all-cause 1-year mortality in patients with the amyopathic subtype compared to patients with evidence of myopathy [H R 4.24 (95% CI: 1.16-15.54), p = 0.03]. Patients diagnosed following hospitalization due to acute respiratory failure experienced increased risk of 1-year all-cause mortality compared to patients diagnosed in outpatient setting [HR 6.70 (95% CI: 1.19-37.81), p = 0.03]. Finally, patients with positive anti-MDA5 presented with higher 1-year all-cause mortality compared to anti-MDA5 negative patients [HR 28.37 (95% CI: 5.13-157.01), p = 0.0001].

Conclusion

Specific ILD radiographic patterns such as NSIP and organizing pneumonia may herald underlying inflammatory myopathies. Hospitalized patients presenting with bilateral organizing pneumonia refractory to antibiotics should be meticulously evaluated for myositis associated-ILD even if there is no overt muscular involvement. Incorporation of ILD radiological patterns in the diagnostic criteria of inflammatory myopathies may lead to timely therapeutic interventions and positively impact patients' survival.

Validation of methods to identify people with idiopathic inflammatory myopathies using hospital episode statistics

OBJECTIVE

Hospital episode statistics (HES) are routinely recorded at every hospital admission within the National Health Service (NHS) in England. This study validates diagnostic ICD-10 codes within HES as a method of identifying cases of idiopathic inflammatory myopathies (IIMs).

METHODS

All inpatient admissions at one NHS Trust between 2010 and 2020 with relevant diagnostic ICD-10 codes were extracted from HES. Hospital databases were used to identify all outpatients with IIM, and electronic care records were reviewed to confirm coding accuracy. Total hospital admissions were calculated from NHS Digital reports. The sensitivity and specificity of each code and code combinations were calculated to develop an optimal algorithm. The optimal algorithm was tested in a sample of admissions at another NHS Trust.

RESULTS

Of the 672 individuals identified by HES, 510 were confirmed to have IIM. Overall, the positive predictive value (PPV) was 76% and sensitivity 89%. Combination algorithms achieved PPVs between 89 and 94%. HES can also predict the presence of IIM-associated interstitial lung disease (ILD) with a PPV of 79% and sensitivity of 71%. The optimal algorithm excluded children (except JDM code M33.0), combined M33.0, M33.1, M33.9, M36.0, G72.4, M60.8 and M33.2, and included M60.9 only if it occurred alongside an ILD code (J84.1, J84.9 or J99.1). This produced a PPV of 88.9% and sensitivity of 84.2%. Retesting this algorithm at another NHS Trust confirmed a high PPV (94.4%).

CONCLUSION

IIM ICD-10 code combinations in HES have high PPVs and sensitivities. Algorithms tested in this study could be applied across all NHS Trusts to enable robust and cost-effective whole-population research into the epidemiology of IIM.

Interstitial disease associated with connective tissue disease and vasculitis

Systemic autoimmune diseases comprise a complex, heterogeneous group of entities. Noteworthy among the pulmonary complications of these entities is interstitial involvement, which manifests with the same radiopathologic patterns as in idiopathic interstitial pneumonia. High-resolution computed tomography is the gold-standard imaging technique; it enables us to identify and classify the disease and to determine its extent, providing useful information about the prognosis. In this group of processes, the most common pattern of presentation is nonspecific interstitial pneumonia. It is essential for radiologists to work together in collaboration with other specialists to reach the correct diagnosis and enable appropriate, integrated treatment.

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.

New-onset dermatomyositis following COVID-19: A case report

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Most of the infected individuals have recovered without complications, but a few patients develop multiple organ involvements. Previous reports suggest an association between COVID-19 and various inflammatory myopathies, in addition to autoimmune diseases. COVID-19 has been known to exacerbate preexisting autoimmune diseases and trigger various autoantibodies and autoimmune disease occurrence. Here we report a case of complicated COVID-19 with anti-synthetase autoantibodies (ASSs) presenting with skin rash, muscle weakness, and interstitial lung disease (ILD) and subsequently diagnosed with dermatomyositis (DM). A 47-year-old Japanese male patient without any previous history of illness, including autoimmune diseases, presented with a high fever, sore throat, and cough. Oropharyngeal swab for SARS-Cov-2 polymerase chain reaction tested positive. He was isolated at home and did not require hospitalization. However, his respiratory symptoms continued, and he was treated with prednisolone (20 mg/day) for 14 days due to the newly developing interstitial shadows over the lower lobes of both lungs. These pulmonary manifestations remitted within a week. He presented with face edema and myalgia 4 weeks later when he was off corticosteroids. Subsequently, he presented with face erythema, V-neck skin rash, low-grade fever, and exertional dyspnea. High-resolution computed tomography of the chest showed ILD. Biochemical analysis revealed creatine kinase and aldolase elevations, in addition to transaminases. Anti-aminoacyl tRNA synthetase (ARS) was detected using an enzyme-linked immunosorbent assay (170.9 U/mL) (MESACUP™ (Medical & Biological Laboratories, Japan), and the tRNA component was identified as anti-PL-7 and anti-Ro-52 antibodies using an immunoblot assay [EUROLINE Myositis Antigens Profile 3 (IgG), Euroimmun, Lübeck,Germany]. The patient was diagnosed with DM, especially anti- synthase antibody syndrome based on the presence of myositis-specific antibodies, clinical features, and pathological findings. The present case suggests that COVID-19 may have contributed to the production of anti-synthetase antibodies (ASAs) and the development of de novo DM. Our case highlights the importance of the assessment of patients who present with inflammatory myopathy post-COVID-19 and appropriate diagnostic work-up, including ASAs, against the clinical features that mimic DM after post-COVID-19.

Promising Neutrophil-Associated Biomarkers in Lung Diseases of Patients with Antisynthetase Syndrome and Dermatomyositis

Objectives

Antisynthetase syndrome (ASS) and dermatomyositis (DM) are serious autoimmune diseases, with lungs being the most frequently involved organ and sometimes fatal. This study is aimed at clarifying the role of neutrophil-associated biological markers in suggesting ASS and DM-associated respiratory infections and interstitial lung diseases.

Methods

We carried out a retrospective review of the medical records of 46 cases of ASS and DM diagnosed at the Second Hospital of Zhejiang University College of Medicine, between January 2017 and December 2020. Serum myeloperoxidase (MPO), neutrophil elastase (NE), α1 anti-trypsin (AAT), and interleukin-6 (IL-6) were also detected.

Results

Gottron's sign is characteristic of dermatomyositis, while polyarthritis is more characteristic of ASS. Pulmonary function is worse in ASS than in DM patients. Patients with ASS and DM had abnormal lymphocyte and neutrophil counts compared to healthy subjects, but not in relation to lung function and rapid progression of interstitial lung disease (RP-ILD). Elevated serum NE, MPO, and IL-6 levels are suggestive of respiratory infections, whereas decreased circulating IL-6 is predictive of RP-ILD.

Conclusion

Our study identified the neutrophil-associated biomarkers MPO, NE, and IL-6 as promising indicators with different suggestive roles in respiratory infections and interstitial lung diseases in patients with ASS and DM.

Interstitial lung diseases

Over 200 interstitial lung diseases, from ultra rare to relatively common, are recognised. Most interstitial lung diseases are characterised by inflammation or fibrosis within the interstitial space, the primary consequence of which is impaired gas exchange, resulting in breathlessness, diminished exercise tolerance, and decreased quality of life. Outcomes vary considerably for each of the different interstitial lung diseases. In some conditions, spontaneous reversibility or stabilisation can occur, but unfortunately in many people with interstitial lung disease, especially in those manifesting progressive pulmonary fibrosis, respiratory failure and death are a sad reality. Over the past 3 years, the field of interstitial lung disease has had important advances, with the approval of drugs to treat systemic sclerosis-associated interstitial lung disease, interstitial lung disease-associated pulmonary hypertension, and different forms of progressive pulmonary fibrosis. This Seminar provides an update on epidemiology, pathogenesis, presentation, diagnosis, disease course, and management of the interstitial lung diseases that are most frequently encountered in clinical practice. Furthermore, we describe how developments have led to a shift in the classification and treatment of interstitial lung diseases that exhibit progressive pulmonary fibrosis and summarise the latest practice-changing guidelines. We conclude with an outline of controversies, uncertainties, and future directions.

Anti-MDA5 and anti-SSA/Ro52 antibodies double-positive dermatomyositis overlapping with rheumatoid arthritis-associated interstitial lung disease: A case report

Dermatomyositis (DM) is a poorly prognostic autoimmune disease the pathogenesis of which is multifactorial and not clearly defined. DM may be influenced by genes, environment, and immunity. The typical manifestations of DM are Gottron rash, heliotrope rash, rash on the shoulders and buttocks, erythema around fingernails, excessive keratosis of the epidermis, mechanic's hands, and interstitial lung disease (ILD), among others. Anti-melanoma differentiation-associated 5 gene (MDA5) antibody has been strongly associated with DM. Furthermore, anti-SSA/Ro52 antibody has been reportedly associated with DM. A 49-year-old woman presented with cough, expectoration, and dyspnea. Relevant examinations revealed elevated levels of muscle enzyme, double-positive anti-MDA5 and anti-SSA/Ro52 antibodies, positive rheumatoid factor, and a high titer of anti-citrullinated protein antibody. DM overlapping rheumatoid arthritis with ILD was confirmed. We suggest the use of glucocorticoids combined with immunosuppressant therapy, supplemented with gastric and liver protection, and recommend the use of intravenous immunoglobulins and rituximab.

Characterisation of Disease Patterns of Dermatomyositis with Different Initial Manifestations

Purpose

To determine the characteristics and prognoses of dermatomyositis (DM) by comparing the difference in initial symptoms.

Patients and Methods

A retrospective analysis was performed on the patients diagnosed with DM from 1 January 2019 to 1 January 2021. Based on the firstly presented symptoms, patients were divided into five groups, namely rash group, muscle weakness group, arthritis group, respiratory symptom group and atypical symptom group. Clinical and laboratory data were recorded. All patients were followed up until 31 May 2021.

Results

In total 136 DM patients, rash (40%) was the most common initial symptom, followed by respiratory symptoms (22%), arthritis (20%), muscle weakness (10%) and atypical symptoms (8%). Rash group and atypical group had a higher positive rate of anti-TIF1γ antibodies than arthritis group and respiratory symptom group (P < 0.05). Respiratory symptom and arthritis groups had a higher positive rate of anti-Ro52 antibodies than rash and muscle weakness groups (P < 0.05). Respiratory group had a higher incidence of ILD than rash and atypical groups. The FVC and DLCO in respiratory group were significantly lower than rash group, arthritis group and atypical group (P < 0.05). The survival rate of rash group was significantly higher than muscle weakness group and arthritis group (P < 0.05).

Conclusion

DM patients with different initial manifestations had different myositis antibodies and prognoses.

Enhanced tryptophan-kynurenine metabolism via indoleamine 2,3-dioxygenase 1 induction in dermatomyositis

Objectives

Extrahepatic tryptophan (Trp)-kynurenine (Kyn) metabolism via indoleamine 2,3-dioxygenase 1 (IDO1) induction was found to be associated with intrinsic immune regulation. However, the Trp-Kyn metabolism–associated immune regulation in dermatomyositis (DM) remains unknown. Therefore, we aimed to investigate the clinical relevance of the Trp-Kyn metabolism via IDO1 induction in DM.

Methods

Liquid chromatography-mass spectrometry (HPLC–MS) was used to examine the serum Kyn and Trp concentrations in DM. In addition, we used X-tile software to determine the optimal cutoff value of the Kyn/Trp ratio, a surrogate marker for Trp-Kyn metabolism. Spearman analysis was performed to evaluate the association of Trp-Kyn metabolism with muscle enzymes and inflammatory markers.

Results

DM patients had significantly higher serum Kyn/Trp ratio (× 10⁻³) when compared with the healthy controls. The serum Kyn/Trp ratio was positively correlated with the levels of muscle enzymes and inflammatory markers. In addition, the serum Kyn/Trp ratio significantly decreased (36.89 (26.00–54.00) vs. 25.00 (18.00–37.00), P = 0.0006) after treatment. DM patients with high serum Kyn/Trp ratio had a significantly higher percentage of muscle weakness symptoms (62.5% vs. 20.0%, P = 0.019) and higher levels of LDH (316.0 (236.0–467.0) vs. 198.0 (144.0–256.0), P = 0.004) and AST (56.5 (35.0–92.2) vs. 23.0 (20.0–36.0), P = 0.002)) than those with low serum Kyn/Trp ratio. Multiple Cox regression analyses identified ln(Kyn/Trp) (HR 4.874, 95% CI 1.105–21.499, P = 0.036) as an independent prognostic predictor of mortality in DM.

Conclusions

DM patients with enhanced Trp-Kyn metabolism at disease onset are characterized by more severe disease status and poor prognosis. Intrinsic immune regulation function via enhanced Trp-Kyn metabolism by IDO1 induction may be a potential therapeutic target in DM.

Key Points • HPLC–MS identified increased serum Kyn/Trp ratio in DM patients, which positively correlated with levels of muscle enzymes and inflammatory markers and was downregulated upon treatment. • Cox regression analyses identified ln(Kyn/Trp) as an independent prognostic predictor of mortality in DM. • Monitoring intrinsic immune regulation function should be considered a potential therapeutic target in DM patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10067-022-06263-3.

Advances in the management of idiopathic pulmonary fibrosis and progressive pulmonary fibrosis

Similarly to idiopathic pulmonary fibrosis (IPF), other interstitial lung diseases can develop progressive pulmonary fibrosis (PPF) characterized by declining lung function, a poor response to immunomodulatory therapies, and early mortality. The pathophysiology of disordered lung repair involves common downstream pathways that lead to pulmonary fibrosis in both IPF and PPF. The antifibrotic drugs, such as nintedanib, are indicated for the treatment of IPF and PPF, and new therapies are being evaluated in clinical trials. Clinical, radiographic, and molecular biomarkers are needed to identify patients with PPF and subgroups of patients likely to respond to specific therapies. This article reviews the evidence supporting the use of specific therapies in patients with IPF and PPF, discusses agents being considered in clinical trials, and considers potential biomarkers based on disease pathogenesis that might be used to provide a personalized approach to care.

Clinical experience in anti-synthetase syndrome: a monocentric retrospective analytical study

OBJECTIVES: Anti-synthetase syndrome (ASS) is a rare autoimmune disorder combining autoantibodies and specific clinical manifestations. One of the particularities of ASS is the pleiomorphic radiological presentation seen at the initial work-up. Evaluating treatment response can also be challenging and requires specific clinical, functional, biological and radiological monitoring. For these reasons, it is fundamental to identify specific radiological and clinical features of ASS for improved diagnosis and therapeutic approaches.METHODS: We retrospectively studied all patients suffering from ASS in the CHU of Liège from 2008 to 2019. We analysed the clinical features, pulmonary function tests (PFTs), computed tomography (CT), and longitudinal evolution with regard to patient treatment.RESULTS: In the whole cohort of 30 patients, we identified 19 with anti-JO1 antibodies, 5 with anti-PL12 antibodies and 6 with anti-PL7 antibodies. The sex ratio was slightly in favour of males. Interestingly, PL-12 syndrome was more likely to be present in younger patients than those associated with other antibodies. Overall, 77% of the overall cohort exhibited specific pulmonary involvement without any significant difference with regard to the severity assessed by PFT at diagnosis. In contrast, the radiological presentation was pleomorphic for anti-JO1 syndrome, and anti-PL12 syndrome exhibited mainly ground-glass opacities (GGOs) and reticular abnormalities, while those with anti-PL7 antibodies showed reticulations and bronchiectasis. Longitudinal CT analysis mainly showed a reduction in consolidations and GGOs with specific therapies.CONCLUSION: In our single-centre retrospective study, we found different profiles for different autoantibodies according to age and radiological appearance.

Lung function trajectory in progressive fibrosing interstitial lung disease

BACKGROUND

Proposed criteria for progressive fibrosing interstitial lung disease (PF-ILD) have been linked to increased mortality risk, but lung function trajectory after satisfying individual criteria remains unknown. Because survival is rarely employed as the primary end-point in therapeutic trials, identifying PF-ILD criteria that best predict subsequent change in forced vital capacity (FVC) could improve clinical trial design.

METHODS

A retrospective, multicentre longitudinal cohort analysis was performed in consecutive patients with fibrotic connective tissue disease-associated ILD (CTD-ILD), chronic hypersensitivity pneumonitis and idiopathic interstitial pneumonia at three US centres (test cohort) and one UK centre (validation cohort). 1-year change in FVC after satisfying proposed PF-ILD criteria was estimated using joint modelling. Subgroup analyses were performed to determine whether results varied across key subgroups.

RESULTS

1227 patients were included, with CTD-ILD predominating. Six out of nine PF-ILD criteria were associated with differential 1-year change in FVC, with radiological progression of fibrosis, alone and in combination with other features, associated with the largest subsequent decline in FVC. Findings varied significantly by ILD subtype, with CTD-ILD demonstrating little change in FVC after satisfying most PF-ILD criteria, while other ILDs showed significantly larger changes. Findings did not vary after stratification by radiological pattern or exposure to immunosuppressant therapy. Near-term change in FVC after satisfying proposed PF-ILD criteria was heterogeneous depending on the criterion assessed and was strongly influenced by ILD subtype.

CONCLUSIONS

These findings may inform future clinical trial design and suggest ILD subtype should be taken into consideration when applying PF-ILD criteria.

Expression of Inflammatory Markers in the Muscles of Patients with Idiopathic Inflammatory Myopathy According to the Presence of Interstitial Lung Disease

BACKGROUND

Several studies have identified factors associated with the development of interstitial lung disease (ILD) in patients with idiopathic inflammatory myopathies (IIMs). However, few have assessed the association between ILD and muscle biopsy findings, including inflammatory marker expressions analyzed using immunohistochemistry (IHC).

METHODS

Muscle biopsies from patients who were newly diagnosed with IIMs between 2000 and 2017 were reviewed. ILD was diagnosed based on chest computed tomography findings at the time of diagnosis of IIMs. IHC staining was performed for CD3, CD4, CD8, CD20, CD68, CD163, MX1, MHC class I, and HLA-DR. The factors associated with the presence of ILD were evaluated by logistic regression analysis.

RESULTS

Of the 129 patients with IIM, 49 (38%) had ILD. In the muscle biopsy findings, CD4 expression, MX1 expression on immune cells, and expression of MHC class I and HLA-DR on myofibers were more common in patients with ILD than those without. In the logistic regression analysis, the HLA-DR expression on myofibers was significantly associated with the risk of ILD (OR, 2.39; 95% CI, 1.24-4.90, p = 0.012) after adjusting for pathologic findings, clinical features, and autoantibodies.

CONCLUSION

The expression of HLA-DR on myofibers was associated with the presence of ILD in patients with IIM.

Resistin Expression Is Associated With Interstitial Lung Disease in Dermatomyositis

Objective

In the current study, we aimed to assess resistin mRNA levels in the peripheral blood mononuclear cells (PBMCs) of dermatomyositis patients with interstitial lung disease (DM-ILD) and their correlation with disease activity.

Methods

We detected resistin mRNA levels in the PBMCs of 37 DM-ILD, 8 DM patients without ILD, and 19 healthy control (HC) subjects by performing quantitative reverse transcription real-time polymerase chain reaction analysis. Associations between resistin expression levels and major clinical manifestations, laboratory examinations, and disease activity were also analyzed. In addition, resistin expression in lung specimens from patients with DM-ILD was examined via immunohistochemistry and immunofluorescence.

Results

Resistin mRNA levels in PBMCs were significantly higher in DM-ILD than that in DM patients without ILD and HCs (p = 0.043, 0.014, respectively). Among these DM-ILD patients, the resistin levels were significantly elevated in those with rapidly progressive ILD than in those with chronic ILD (p = 0.012). The resistin mRNA levels in DM-ILD positively correlated with serum alanine aminotransferase (r = 0.476, p = 0.003), aspartate aminotransferase (r = 0.488, p = 0.002), lactate dehydrogenase (r = 0.397, p = 0.014), C-reactive protein (r = 0.423, p = 0.008), ferritin (r = 0.468, p = 0.003), carcinoembryonic antigen (r = 0.416, p = 0.011), carbohydrate antigen 125 (r = 0.332, p = 0.047), interleukin-18 (r = 0.600, p < 0.001), and lung visual analog scale values (r = 0.326, p = 0.048), but negatively correlated with the diffusing capacity of carbon monoxide (DLco)% (r = −0.447, p = 0.041). Immunohistochemical analysis of resistin showed its elevated expression in the macrophages, alveolar epithelial cells, and weak fibrotic lesions from patients with DM-ILD. Immunofluorescence staining confirmed CD68+ macrophages co-express resistin.

Conclusions

Resistin levels were increased in patients with DM-ILD and associated with disease activity and ILD severity. Therefore, resistin may participate in the pathogenesis of DM-ILD and may act as a useful biomarker.

Single-Cell Transcriptomics Reveals Peripheral Immune Responses in Anti-Synthetase Syndrome-Associated Interstitial Lung Disease

OBJECTIVE

Interstitial lung diseases (ILDs) secondary to anti-synthetase syndrome (ASS) greatly influence the prognoses of patients with ASS. Here we aimed to investigate the peripheral immune responses to understand the pathogenesis of this condition.

METHODS

We performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) from 5 patients with ASS-ILD and 3 healthy donors (HDs). Flow cytometry of PBMCs was performed to replenish the results of scRNA-seq.

RESULTS

We used scRNA-seq to depict a high-resolution visualization of cellular landscape in PBMCs from patients with ASS-ILD. Patients showed upregulated interferon responses among NK cells, monocytes, T cells, and B cells. And the ratio of effector memory CD8 T cells to naïve CD8 T cells was significantly higher in patients than that in HDs. Additionally, Th1, Th2, and Th17 cell differentiation signaling pathways were enriched in T cells. Flow cytometry analyses showed increased proportions of Th17 cells and Th2 cells, and decreased proportion of Th1 cells in patients with ASS-ILD when compared with HDs, evaluated by the expression patterns of chemokine receptors.

CONCLUSIONS

The scRNA-seq data analyses reveal that ASS-ILD is characterized by upregulated interferon responses, altered CD8 T cell homeostasis, and involvement of differentiation signaling pathways of CD4 T cells. The flow cytometry analyses show that the proportions of Th17 cells and Th2 cells are increased and the proportion of Th1 cells is decreased in patients with ASS-ILD. These findings may provide foundations of novel therapeutic targets for patients with this condition.

Defining anti-synthetase syndrome: a systematic literature review

OBJECTIVES

Anti-synthetase syndrome (ASSD) is a heterogeneous autoimmune disease characterised by multi-system involvement with a wide variety of manifestations. Validated classification criteria are necessary to improve recognition and prevent misclassification, especially given the lack of reliable and standardised autoantibody testing. We systematically reviewed the literature to analyse proposed ASSD criteria, characteristics, and diagnostic performance.

METHODS

We searched PubMed and Embase databases (01/01/1984 to 06/11/2018) and the ACR and EULAR meeting abstracts (2017-2018). Sensitivities, specificities, positive, negative likelihood ratios and risk of bias were calculated for ASSD criteria and key variables reported in the literature. We performed meta-analysis when appropriate.

RESULTS

We retrieved 4,358 studies. We found 85 proposed ASSD criteria from a total of 82 studies. All but one study included anti-synthetase autoantibody (ARS) positivity in the ASSD criteria. Most studies required only one ASSD feature plus anti-ARS to define ASSD (n=64, 78%), whereas 16 studies required more than one ASSD variable plus anti-ARS. The only criteria not including anti-ARS positivity required 5 ASSD clinical features. We found limited data and wide variability in the diagnostic performance of each variable and definition proposed in the literature. Given these limitations we only meta-analysed the performance of individual muscle biopsy and clinical variables in diagnosing ASSD, which performed poorly.

CONCLUSIONS

The current ASSD criteria include a variety of serological, clinical, and histological features with wide variability amongst proposed definitions and the performance of these definitions has not been tested. This systematic literature review suggests the need for additional data and consensus-driven classification criteria for ASSD.