Prognosis of adult idiopathic inflammatory myopathy-associated interstitial lung disease: a retrospective study of 679 adult cases

Human epididymis secretory protein 4 in idiopathic inflammatory myopathy-associated interstitial lung disease

OBJECTIVE

The current study assessed the level of serum HE4 in patients with IIM to evaluate its feasibility in diagnosing IIM-ILD, as well as determined the association between HE4 and demographic, clinical, and laboratory characteristics of IIM patients.

METHODS

Sera and clinical data were collected from 139 patients with IIMs and 135 healthy controls. We compared the clinical parameters between the high and low HE4 groups, and the relationship between HE4 levels and clinical parameters was determined. Moreover, the expression of HE4 in the lung tissue was accessed.

RESULTS

HE4 level was significantly higher in the serum of IIM patients than in the controls (median 69.3 versus 33.5 μg/L, P < 0.001). Patients in the high HE4 group had higher ferritin (median 559 versus 83.7 μg/L, P = 0.006), frequencies of ILD(94.4% versus 56.1%, P < 0.001) and anti-Jo-1 autoantibodies (25.5% versus 5.7%, P = 0.018) compared with the low HE4 group. The immunohistochemical staining of HE4 in lung tissues was positive in IIM-ILD and negative in controls.

CONCLUSION

Our findings suggested that serum HE4 might be a clinically useful biomarker for IIM-ILD. Key Points • Patients with IIMs, particularly those with IIM-ILD, had high serum levels of HE4. • Patients with high HE4 levels demonstrated a high prevalence of anti-Jo-1 autoantibodies. • Patients with IIM-ILD showed significant expression of HE4 within the lung tissue.

Clinical characteristics and prognosis of amyopathic dermatomyositis patients with interstitial lung disease: insights from a retrospective cohort

INTRODUCTION

The diagnosis of amyopathic dermatomyositis with interstitial lung disease (ADM-ILD) is challenging due to the lack of typical skin features and overlapping syndromes. We aimed to determine the characteristics and prognosis of patients with ADM-ILD to further guide their clinical management.

METHODS

A retrospective cohort study comprising 190 Chinese patients diagnosed with interstitial lung disease (ILD) was conducted. Patients were stratified into four groups using the Sontheimer criteria and predominant high-resolution computed tomography (HRCT) patterns. Demographic features, clinical presentation, laboratory parameters, duration of ILD, and follow-up data were analysed.

RESULTS

There were significant differences in the clinical parameters among the 190 patients with ILD in the amyopathic dermatomyositis (ADM, n = 69) and control (n = 121) groups. The ADM with nonspecific interstitial pneumonia (NSIP) group (n = 46) presented increased haemoglobin (125.93 ± 12.91 g/L, p = 0.005), creatine kinase-MB (15.19 ± 8.58 U/L, p < 0.001), and partial pressure of oxygen (93.08 ± 26.20 mmHg, p = 0.003) levels and decreased β2-microglobulin (2.61 ± 1.21 mg/L, p = 0.039) levels compared to the control-NSIP group (n = 92). The ADM with organizing pneumonia (OP) group (n = 23) had a greater percentage of females (7/16, p = 0.023) and higher alanine aminotransferase (30.30 ± 20.67 U/L, p = 0.039) and aspartate aminotransferase (53.35 ± 65.86 U/L, p = 0.003) levels than the control-OP group (n = 29). Both the ADM-NSIP and OP groups presented elevated lactate dehydrogenase (LDH) levels (290.61 ± 86.49 U/L, p = 0.009; 317.35 ± 181.32 U/L, p = 0.003, respectively) and increased anti-nuclear antibody (ANA) positivity rates (82.61%, p = 0.01; 73.91%, p < 0.001, respectively). Notably, 81.26% of patients with ADM-NSIP/OP had LDH levels above normal. The serum LDH levels could be used to distinguish patients with ADM-NSIP/OP (sensitivity: 73.91%, specificity: 82.64%). Survival was shorter among patients with ADM-OP than among control patients (p = 0.002). Cox multivariate analysis revealed that age (p = 0.002), smoking status (p = 0.011), anti-melanoma differentiation-associated gene 5 (MDA5) antibody (p = 0.017), and white blood cell count (p = 0.004) were independent predictors of shorter survival.

CONCLUSIONS

Elevated serum LDH levels in patients predominantly presenting with NSIP or OP patterns may indicate the presence of ADM-ILD. The identified prognostic factors underscore the importance of early detection and personalized management strategies for optimizing outcomes in patients with ADM-ILD.

Idiopathic Inflammatory Myopathies-Associated Interstitial Lung Disease in Adults

Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of autoimmune diseases characterized by muscle involvement and various extramuscular manifestations. Interstitial lung disease (ILD) is one of the most common extramuscular manifestations of IIM and is associated with significant mortality and morbidity. The clinical phenotypes, treatment responses, and prognosis of IIM-ILD are significantly related to myositis-specific antibody (MSA) profiles, with some racial differences. The features associated with MSA in IIM-ILD could also be relevant to cases of ILD where MSA is present but does not meet the criteria for IIM. The anti-melanoma differentiation-associated gene 5 antibody is highly associated with rapidly progressive ILD (RP-ILD), especially in Asian populations, and with characteristic cutaneous manifestations, such as skin ulcers. Radiologically, ground-glass opacities, consolidations, and nonsegmental linear opacities were more predominant than reticular opacities and honeycombing. While the mortality rate is still around 30%, the prognosis can be improved with early intensive therapy with corticosteroids and multiple immunosuppressants. In contrast, anti-aminoacyl-tRNA synthetase (ARS) antibodies are associated with chronic ILD, although RP-ILD is also common. Patients with anti-ARS antibodies often show lung-predominant presentations, with subtle muscle and skin involvement. Radiologically, reticular opacities, with or without consolidation, are predominant and may progress to honeycombing over time. Combination therapy with corticosteroids and a single immunosuppressant is recommended to prevent relapses, which often lead to a decline in lung function and fatal long-term outcomes. Significant advances in immunology and genetics holds promise for fostering more personalized approaches to managing IIMILD.

A retrospective study for clinical characteristics of 293 patients with dermatomyositis

This retrospective study aimed to investigate differences in clinical characteristics between different antibody phenotypes in patients with dermatomyositis (DM). Two hundred and ninety-three patients with DM were included in this study from September 2018 to September 2023. We collected basic clinical data from the patients, using statistical methods to analyze the clinical characteristics, and used survival analysis and COX regression to assess the prognosis of the patients. In the 293 patients, the antibody distribution was as follows: antibody negative (50, 20.3%), anti-melanoma differentiation-associated gene 5 (MDA5) antibody (104, 42.3%), anti-transcription intermediary factor γ (TIF-γ) antibody (41, 16.7%), anti-complex nucleosome remodeling histone deacetylase (Mi2) antibody (28, 11.4%), anti-nuclear matrix protein 2 (NXP2) antibody (19, 7.7%), anti-small ubiquitin-like modifier activating enzyme (SAE) antibody (4, 1.6%). Interstitial pneumonia (P < .001), lung infection (P < .001), respiratory symptoms (P < .001), arthralgia (P < .001), and fever (P < .001) were more likely to be seen in patients with anti-MDA5 antibody. Malignancy (P < .001) and V-sign (P = .017) were more likely to occur in anti-TIF1-γ antibody positive patients. Anti-NXP2 antibody-positive patients showed more symptoms of muscle involvement, such as myasthenia (P = .002), myalgia (P = .003) and dysphagia (P = .001). In the analysis of prognosis, age at onset (hazard ratio = 1.096, 95% CI: 1.064-1.129, P < .001), fever (hazard ratio = 2.449, 95% CI: 1.183-5.066, P = .016), γ-glutamyl transferase level (hazard ratio = 1.005, 95% CI: 1.002-1.008, P < .001), eosinophil level (hazard ratio = 0.000, 95% CI: 0.000-0.324, P = .024), and complement 3 (C3) level (hazard ratio = 0.115, 95% CI: 0.023-0.575, P = .008) had a statistically significant effect on survival time. The clinical features of DM are associated with myositis-specific antibodies. At the same time, advanced age, fever, elevated γ-glutamyl transferase levels, and reduced C3 and eosinophil levels may be associated with poor prognosis in patients with DM. These data may provide useful information for clinical management of patients with DM.

Antibody predictors of mortality and lung function trends in myositis spectrum interstitial lung disease

OBJECTIVES

The impact of autoantibody profiles on the prognosis for idiopathic inflammatory myositis-associated interstitial lung disease (IIM-ILD) and myositis spectrum ILD with myositis-specific antibodies (MSAs) remains unclear. This retrospective cohort study examined whether serological profiles were associated with mortality or longitudinal lung function change.

METHODS

The baseline clinical/demographic characteristics and follow-up lung function data of consecutive adult patients with IIM-ILD or interstitial pneumonia with autoimmune features (IPAF) positive for MSAs (IPAF-MSA) were extracted from three hospitals. Univariate and multivariate Cox proportional hazards analyses were used to compare mortality between groups of patients with different autoantibodies. Regression models were used to analyse their lung function trends.

RESULTS

Of the 430 included patients, 81% met the IIM criteria, and the remaining 19% were diagnosed with IPAF-MSA. On univariate analysis, the risk factors associated with mortality included higher age, Charlson Comorbidity Index, and CRP; and lower BMI, baseline TLCO% and FEV1%. Compared with anti-MDA5 negativity, anti-MDA5 positivity (MDA5+) was associated with higher mortality in the first 3 months [hazard ratio (HR) 65.2, 95% CI 14.1, 302.0], while no significant difference was seen thereafter (HR 0.55, 95% CI 0.14, 2.28). On multivariate analysis, combined anti-synthetase antibodies were associated with a reduced risk of mortality (HR 0.63), although individually, mortality was reduced in patients with anti-Jo1+ (HR 0.61, 95% CI 0.4-0.87) and increased in patients with anti-PL7+ (HR 2.07, 95% CI 1.44-2.99). Anti-MDA5+ was associated with slow improvement in %FVC over the first 3 years, while anti-PL7+ was linked with a slow decline from 12 months onwards.

CONCLUSION

Among the autoantibody profiles in myositis spectrum disorders, anti-MDA5+ and anti-PL7+ conferred higher mortality risks in patients with IIM-ILD. Survivors of an early peak of mortality in anti-MDA5+ disease appeared to have a favourable prognosis.

An Observational Study on the Clinical Characteristics and Prognosis of Patients With Interstitial Lung Disease Secondary to Dermatomyositis and Antisynthetase Syndrome

Objective: Identify the clinical characteristics and prognostic factors in patients with idiopathic inflammatory myopathy (IIM) combined with interstitial lung disease (ILD). Methods: IIM-ILD patients who were hospitalized at Guangxi Medical University from January 2017 to December 2022 were retrospectively analyzed and classified as having dermatomyositis (DM)-ILD or -ILD. Clinical and laboratory results were analyzed. Results: There were 39 males and 111 females, the mean age of disease onset was 50.4 ± 12.3 years, and the median disease duration was 3 months (range: 1-6). Ninety-seven patients had DM-ILD, and 53 had ASS-ILD. The DM-ILD group had 72% positivity for the anti-MDA5 antibody and 5.2% positivity for the anti-Mi-2 antibody; the ASS-ILD group had 67.9% positivity for the anti-Jo-1 antibody and 17% positivity for the anti-EJ antibody. Muscle symptoms, skin ulcers, rash, rapidly progressing interstitial lung disease (RP-ILD), and elevated levels of serum carcinoembryonic antigen were more common in DM-ILD patients (all p < 0.05). However, pericardial effusion and pleural effusion, elevated creatinine kinase, and elevated C-reactive protein were more common in ASS-ILD patients. After a median follow-up of 15.5 months, there were more deaths in the DM-ILD group (42.3% vs. 13.2%, p < 0.001). Multivariate Cox regression analysis showed that RP-ILD, dyspnea, and the usual interstitial pneumonia type of ILD had negative associations with overall survival (OS), and arthralgia had a positive association with OS (all p < 0.05). Conclusion: DM-ILD patients were more prone to secondary RP-ILD and skin ulcers, had milder symptoms of myositis and less severe serositis, and had lower survival rates than the ASS-ILD patients. RP-ILD, dyspnea, and the usual interstitial pneumonia type of ILD had adverse effects on prognosis, but arthralgia was a protective factor.

Progressive pulmonary fibrosis in myositis-specific antibody-positive interstitial pneumonia: a retrospective cohort study

Objectives

Idiopathic inflammatory myopathy (IIM) frequently coexists with interstitial pneumonia (IP) and is commonly the initial or sole manifestation accompanied by positive myositis-specific autoantibodies (MSAs), even in the absence of meeting diagnostic criteria. This study aims to evaluate the proportion of progressive pulmonary fibrosis (PPF) and identify potential predictors influencing the progression of pulmonary fibrosis in patients with MSA-IP.

Methods

This descriptive study employed a retrospective cohort design, enrolling patients diagnosed with interstitial pneumonia and positive MSAs at Beijing Chao-Yang Hospital in a sequential manner. Clinical data were systematically collected from the patients' medical records during regular follow-up visits conducted every 3 to 6 months. Cox regression analysis was utilized to identify independent predictors of PPF in patients with positive MSAs and interstitial pneumonia.

Results

A total of 307 patients were included in the study, with 30.6% of them developing PPF during a median follow-up period of 22 months. Kaplan-Meier survival curves demonstrated a significantly lower survival in the PPF patients compared to the non-PPF patients (median 11.6 months vs. 31 months, p = 0.000). An acute/subacute onset of interstitial pneumonia (HR 3.231, 95%CI 1.936-5.392, p = 0.000), lower diffusing capacity of the lungs for carbon monoxide (DLCO) % predicted (HR 6.435, 95%CI 4.072-10.017, p = 0.001), and the presence of diffuse alveolar damage (DAD) on high-resolution computed tomography (HRCT) (HR 8.679, 95%CI 1.974-38.157, p = 0.004) emerged as independent predictors of PPF. Notably, the implementation of triple therapy comprising glucocorticoids, immunosuppressants, and antifibrotic drugs was associated with a reduced risk of developing PPF (HR 0.322, 95%CI 0.115-0.899, p = 0.031).

Conclusion

Approximately 30.6% of patients with MSA-IP may develop PPF within the follow-up period. Patients presenting with an acute/subacute onset of interstitial pneumonia, lower predicted DLCO SB% and evidence of DAD on HRCT are more susceptible to developing PPF. Conversely, the administration of triple therapy appears to serve as a protective factor against the development of PPF in patients with MSA-IP.

[18F]FDG-PET/CT in Idiopathic Inflammatory Myopathies: Retrospective Data from a Belgian Cohort

[¹⁸F]FDG-PET/CT is a useful tool for diagnosis and cancer detection in idiopathic inflammatory myopathies (IIMs), especially polymyositis (PM) and dermatomyositis (DM). Data deriving from Europe are lacking. We describe [¹⁸F]FDG-PET/CT results in a Belgian cohort with IIMs, focusing on patients with PM and DM. All of the cases of IIMs admitted between December 2010 and January 2023 to the Cliniques Universitaires Saint-Luc (Belgium) were retrospectively reviewed. In total, 44 patients were identified with suspected IIMs; among them, 29 were retained for final analysis. The mean age of the retained patients was 48.7 years; 19 patients were female (65.5%). Twenty-two patients had DM and seven had PM. The mean serum creatinine kinase (CK) and the mean CRP levels were 3125 UI/L and 30.3 mg/L, respectively. [¹⁸F]FDG-PET/CT imaging was performed for 27 patients, detecting interstitial lung diseases (ILDs) in 7 patients (25.9%), cancer in 3 patients (11.1%), and abnormal muscle FDG uptake compatible with myositis in 13 patients (48.1%). All of the patients who were detected to have ILDs via PET/CT imaging were confirmed using a low-dose lung CT scan. Among the patients who were detected to have abnormal muscle FDG uptake via PET/CT scans (13/28), the EMG was positive in 12 patients (p = 0.004), while the MRI was positive in 8 patients (p = 0.02). We further observed that there was a significantly higher level of CK in the group with abnormal muscle FDG uptake (p = 0.008). Our study showed that PET/CT is useful for detecting cancer and ILDs. We showed that the detection of abnormal muscle uptake via PET/CT was in accordance with EMG and MRI results, as well as with the mean CK value, and that the presence of dyspnea was significantly associated with the presence of ILDs detected via PET/CT imaging (p = 0.002).

The Efficacy and Safety of Rituximab in Patients with Idiopathic Inflammatory Myopathy-Associated Interstitial Lung Disease: Case Series

Idiopathic inflammatory myopathy (IIM)-associated interstitial lung disease (ILD) is often rapidly progressive with a poor prognosis; however, no standard therapeutic regimen has been identified. This study aimed to investigate the efficacy and safety of rituximab in IIM-ILD patients. Five patients who had been administered rituximab for IIM-ILD at least once between August 2016 and November 2021 were included. Lung function decline was compared one year before and after rituximab. Disease progression, defined as a greater than 10% relative decline in forced vital capacity (FVC) compared to the baseline, was also compared before and after treatment. Adverse events were recorded for safety analysis. Five IIM-ILD patients received eight cycles. FVC-predicted values significantly decreased from 6 months before rituximab administration to those at the baseline (54.1% predicted (pre-6 months) vs. 48.5% predicted (baseline), p = 0.043); however, the FVC decline stabilized after rituximab. The rate of disease progression before rituximab showed a tendency to decrease after rituximab (75% (before) vs. 12.5% (6 months after, p = 0.059) vs. 14.3% (12 months after, p = 0.102)). Three adverse events developed, but none resulted in death. Rituximab can stabilize lung function decline with tolerable safety in Korean IIM patients with refractory ILD.

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.

Clinical and HRCT features of amyopathic dermatomyositis associated with interstitial lung disease: A retrospective study of 128 patients with connective tissue disease-related interstitial lung disease

BACKGROUND

This study retrospectively analyzed the laboratory data and chest images of patients with amyopathic dermatomyositis associated with interstitial lung disease (ADM-ILD) and patients with other connective tissue disease-related ILDs (CTD-ILDs) to find a characteristic index for the early recognition of ADM-ILD and help clinicians consider the possibility of ADM-ILD as soon as possible.

METHODS

In our cohort study, the records of 128 Chinese patients with CTD-ILD, including 33 ADM-ILD patients, 37 rheumatoid arthritis (RA)-ILD patients, 33 primary Sjogren's syndrome (pSS)-ILD patients, 14 systemic sclerosis (SSc)-ILD patients and 11 systemic lupus erythematosus (SLE)-ILD patients. The patients' clinical features, laboratory parameters, and chest HRCT findings were analyzed.

RESULTS

ADM-ILD patients generally had significantly higher LDH (333.52±160.21 U/L), AST (66.21±83.66 U/L), and CK-MB (18.23±8.28 U/L) levels than other CTD-ILD patients. A total of 90.91% (30/33) of ADM-ILD patients had elevated LDH. Patients with ADM-ILD were more prone to organizing pneumonia radiologic patterns on chest HRCT scans than patients with other CTD-ILDs (χ²=37.39, p < 0.001) and were found in 18 of 33 ADM-ILD patients. Anti-MDA5 (45.45%) was the most commonly detected autoantibody in ADM-ILD patients, followed by anti-PL-7 (21.21%), anti-Jo-1 (12.12%), and anti-PL-12 (9.09%), and levels of ALT (96.93±119.79 vs. 17.50±6.218 U/L), AST (113.00±106.13 vs. 23.56±6.91 U/L), LDH (415.00±198.51 vs. 261.94±67.75 U/L) and CK-MB (22.57±5.91 vs. 14.61±8.36 U/L) were significantly higher in anti-MDA5-positive patients, but these patients had significantly lower WBC counts (4.82±2.61 vs. 7.14±3.00 × 10⁹/L), lymphocyte counts (0.72±0.20 vs. 1.23±0.53 × 10⁹/L), and ALB levels (31.90±4.76 vs. 35.49±4.71 g/L).

CONCLUSIONS

ADM-ILD patients have higher serum LDH, AST and CK-MB levels, especially serum LDH levels, and are more prone to organizing pneumonia radiologic patterns on chest HRCT scans than other CTD-ILD patients. A high level of serum LDH with ILD may be a useful characteristic index for recognizing ADM-ILD.

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.

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.

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.

Idiopathic inflammatory myopathies: CT characteristics of interstitial lung disease and their association(s) with myositis-specific autoantibodies

OBJECTIVES

Interstitial lung disease (ILD), one of the most common extramuscular manifestations of idiopathic inflammatory myopathies (IIMs), carries a poor prognosis. Myositis-specific autoantibody (MSA)-positivity is a key finding for IIM diagnosis. We aimed to identify IIM-associated lung patterns, evaluate potential CT-ILD finding-MSA relationships, and assess intra- and interobserver reproducibility in a large IIM population.

METHODS

All consecutive IIM patients (2003-2019) were included. Two chest radiologists retrospectively assessed all chest CT scans. Multiple correspondence and hierarchical cluster analyses of CT findings identified and characterized ILD-patient subgroups. Classification and regression-tree analyses highlighted CT-scan variables predicting three patterns. Three independent radiologists read CT scans twice to assign patients according to CT-ILD-pattern clusters.

RESULTS

Among 257 IIM patients, 94 (36.6%) had ILDs; 87 (93%) of them were MSA-positive. ILD-IIM distribution was 54 (57%) ASyS, 21 (22%) DM, 15 (16%) IMNM, and 4 (4%) IBM. Cluster analysis identified three ILD-patient subgroups. Consolidation characterized cluster 1, with significantly (p < 0.05) more frequent anti-MDA5-autoantibody-positivity. Significantly more cluster-2 patients had a reticular pattern, without cysts and with few consolidations. All cluster-3 patients had cysts and anti-PL12 autoantibodies. Clusters 2 and 3 included significantly more ASyS patients. Intraobserver concordances to classify patients into those three clusters were good-to-excellent (Cohen κ 0.64-0.81), with good interobserver reliability (Fleiss's κ 0.56).

CONCLUSION

Despite the observed IIM heterogeneity, CT-scan criteria enabled ILD assignment to the three clusters, which were associated with MSAs. Radiologist identification of those clusters could facilitate diagnostic screening and therapeutics. Interstitial lung disease in patients with idiopathic inflammatory myopathy could be classified into three clusters according to CT-scan criteria, and these clusters were significantly associated with myositis-specific autoantibodies.

KEY POINTS

• Cluster analysis discerned three homogeneous groups of interstitial lung disease (ILD) for which cysts, consolidations, and reticular pattern were discriminatory, and associated with myositis-specific autoantibodies. • Like muscle- and extramuscular-specific phenotypes, myositis-specific autoantibodies are also associated with specific ILD patterns in patients with idiopathic inflammatory myopathies.

Respiratory symptoms as initial manifestations of interstitial lung disease in clinically amyopathic juvenile dermatomyositis: a case report with literature review

Background

Clinically amyopathic juvenile dermatomyositis (CAJDM) is a clinical subgroup of juvenile dermatomyositis (JDM), characterized by JDM rashes with little or no clinically evident muscle weakness. Interstitial lung disease (ILD) is an uncommon but potentially fatal complication of juvenile dermatomyositis (JDM). While adults with dermatomyositis-associated ILD usually present respiratory symptoms before or at the same time as skin muscle manifestations, only a few studies have covered the onset of respiratory symptoms of ILD in JDM patients, especially CAJDM. There is currently no clear effective treatment regime or any prognostic factors for CAJDM-associated ILD.

Case presentation

Here, we report the first case of a CAJDM patient who presented with respiratory symptoms as the initial manifestation. A 10-year-old male patient presented to the hospital with a complaint of progressive cough and chest pain. Violaceous macule and papules appeared a few days later and he was positive for anti-Ro-52 antibodies. Imaging showed diffuse interstitial infiltration in both lungs and lung function tests showed restrictive and obstructive ventilatory dysfunction. Muscular abnormalities were excluded by thigh magnetic resonance imaging (MRI) and electromyography. Skin biopsy showed pathognomonic findings consistent with DM. Lung biopsy indicated chronic inflammation of the mucosa. This patient was finally diagnosed with CAJDM complicated by ILD and prescribed methylprednisolone, immunoglobulin, prednisolone and mycophenolate mofetil (MMF) for treatment. The patient’s cutaneous and respiratory manifestations were largely improved. We retrospectively reviewed this and another six cases with CAJDM-associated ILD reported previously to better understand its clinical characteristics and effective management.

Conclusions

Initial respiratory symptoms with rapid progression in patients presenting Gottron papules should be considered manifestations of CAJDM-associated ILD. We also found a combination of corticosteroids, IVIG and MMF to be an effective method of arresting the progress of CAJDM-associated ILD and improving the prognosis of the patients.

The lungs were on fire: a pilot study of 18F-FDG PET/CT in idiopathic-inflammatory-myopathy-related interstitial lung disease

Background

Interstitial lung disease (ILD) and its rapid progression (RP) are the main contributors to unfavourable outcomes of patients with idiopathic inflammatory myopathy (IIM). This study aimed to identify the clinical value of PET/CT scans in IIM-ILD patients and to construct a predictive model for RP-ILD.

Methods

Adult IIM-ILD patients who were hospitalized at four divisions of the First Affiliated Hospital, Zhejiang University School of Medicine (FAHZJU), from 1 January 2017 to 31 December 2020 were reviewed. PET/CT scans and other characteristics of patients who met the inclusion and exclusion criteria were collected and analysed.

Results

A total of 61 IIM-ILD patients were enrolled in this study. Twenty-one patients (34.4%) developed RP-ILD, and 24 patients (39.3%) died during follow-up. After false discovery rate (FDR) correction, the percent-predicted diffusing capacity of the lung for carbon monoxide (DLCO%, P = 0.014), bilateral lung mean standard uptake value (SUVmean, P = 0.014) and abnormal mediastinal lymph node (P = 0.045) were significantly different between the RP-ILD and non-RP-ILD groups. The subsequent univariate and multivariate logistic regression analyses verified our findings. A “DLM” model was established by including the above three values to predict RP-ILD with a cut-off value of ≥ 2 and an area under the curve (AUC) of 0.905. Higher bilateral lung SUVmean (P = 0.019) and spleen SUVmean (P = 0.011) were observed in IIM-ILD patients who died within 3 months, and a moderate correlation was recognized between the two values.

Conclusions

Elevated bilateral lung SUVmean, abnormal mediastinal lymph nodes and decreased DLCO% were significantly associated with RP-ILD in IIM-ILD patients. The “DLM” model was valuable in predicting RP-ILD and requires further validation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02578-9.

Myositis specific antibodies are associated with isolated anti-Ro-52 associated interstitial lung disease

OBJECTIVES

Anti-Ro-52 antibody positivity might be associated with the presence of interstitial lung disease (ILD) among patients with autoimmune features. However, the clinical significance of isolated anti-Ro-52 positivity (i.e., the presence of anti-Ro52 antibodies but the absence of anti-Ro60 antibodies; anti-Ro52+-Ro60-) in patients with ILD is not clear.

METHODS

This is a prospective and observational study of Chinese ILD patients with isolated anti-Ro-52 positivity. According to their myositis-specific antibody (MSA) status, patients were split into groups, and their clinical and radiological features were compared.

RESULTS

Of the 158 enrolled patients with ILD and isolated anti-Ro-52 positivity (isolated anti-Ro-52-ILD), there were 130 patients with a positive MSA status and 28 patients with a negative MSA status. Anti-synthetase antibodies (ASAs) were found in 61.5% of patients with MSA+ ILD, and anti-melanoma differentiated-associated protein 5 (MDA-5) antibodies were found in the remaining 38.5% of patients. The anti-nuclear antibody (ANA) pattern was associated with ASA and anti-MDA-5 positivity (χ2=70.7, P < 0.001; Cramer's value 0.47, P < 0.001): ANA negativity was associated with anti-MDA-5 positivity, and cytoplasmic ANA positivity was associated with ASA positivity. There were statistically significant differences in the high-resolution CT patterns between patients with isolated anti-Ro-52 positivity with different MSA statuses (χ2=29.8, P < 0.001; Cramer's value 0.31, P < 0.001): OP pattern was more common in patients with anti-MDA-5 antibodies than in those without anti-MDA-5 antibodies.

CONCLUSIONS

Patients with isolated anti-Ro-52-ILD showed high positivity of MSA. Isolated anti-Ro-52 positivity with cytoplasmic ANA positivity was strongly associated with ASA+-ILD, while ANA negativity was associated with anti-MDA-5+-ILD.

Analysis of risk factors of interstitial lung disease and mortality rates in Chinese patients with idiopathic inflammatory myopathy

Aim

To investigate the risk factors for interstitial lung disease (ILD) and prognosis in patients with idiopathic inflammatory myopathy (IIM).

Methods

A retrospective longitudinal study was performed in patients diagnosed with IIM between January 2012 and December 2018.

Results

The study cohort included 91 men and 195 women who were classified as having dermatomyositis (DM, n = 183), polymyositis (PM, n = 77), or clinical amyopathic DM (CADM, n = 26). ILD was identified in 46.5% (n = 133) of patients with IIM. The independent risk factors for ILD were age at disease onset, presence of anti‐Ro‐52 antibody, Gottron's papules, elevated serum immunoglobulin M levels and hypoalbuminemia. Older age at disease onset, ILD, malignancy, and increased serum aspartate aminotransferase and neutrophil‐to‐lymphocyte ratio (NLR) were identified as the independent predictors for mortality, whereas elevated serum albumin level was associated with a better prognosis. A total of 73 deaths (25.5%) occurred after a median follow‐up time of 33 months. Infection (49.3%) was the leading cause of death. In the overall cohort, the 1‐year, 5‐year and cumulative survival rates were 83.2%, 74.2% and 69.4%, respectively. The receiver operating characteristic curve indicated that the optimal cut‐off value of NLR for predicting death in IIM was 6.11.

Conclusion

IIM patients have a poor prognosis with substantial mortality, especially in patients who have older age at onset, ILD, malignancy and higher NLR. Close monitoring and aggressive therapies are required in patients having poor predictive factors.