Myositis-specific autoantibodies in dermatomyositis/polymyositis with interstitial lung disease

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

OBJECTIVES

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

DESIGN

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

DATA SOURCES

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

ELIGIBILITY CRITERIA

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

DATA EXTRACTION AND SYNTHESIS

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

RESULTS

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

CONCLUSION

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

PROSPERO REGISTRATION NUMBER

CRD42022381447.

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.

Imaging of Lung Disease Associated with Connective Tissue Disease

There is a well-known association between the connective tissue disorders (CTDs) and lung disease. In addition to interstitial lung disease, the CTDs may affect the air spaces and pulmonary vasculature. Imaging tests are important not only in diagnosis but also in management of these complex disorders. In the present review, key aspects of the imaging of CTD-reated diseases are discussed.

Prediction model for the pretreatment evaluation of mortality risk in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis with interstitial lung disease

Background

Anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis with interstitial lung disease (anti-MDA5 DM-ILD) is a disease with high mortality. We sought to develop an effective and convenient prediction tool to estimate mortality risk in patients with anti-MDA5 DM-ILD and inform clinical decision-making early.

Methods

This prognostic study included Asian patients with anti-MDA5 DM-ILD hospitalized at the Nanjing Drum Hospital from December 2016 to December 2020. Candidate laboratory indicators were retrospectively collected. Patients hospitalized from 2016 to 2018 were used as the discovery cohort and applied to identify the optimal predictive features using a least absolute shrinkage and selection operator (LASSO) logistic regression model. A risk score was determined based on these features and used to construct the mortality risk prediction model in combination with clinical characteristics. Results were verified in a temporal validation comprising patients treated between 2019 and 2020. The primary outcome was mortality risk within one year. The secondary outcome was overall survival. The prediction model’s performance was assessed in terms of discrimination, calibration, and clinical usefulness.

Results

This study included 127 patients, (72 men [56.7%]; median age, 54 years [interquartile range, 48-63 years], split into discovery (n = 87, 70%) and temporal validation (n=37, 30%) cohorts. Five optimal features were selected by LASSO logistic regression in the discovery cohort (n = 87) and used to construct a risk score, including lymphocyte counts, CD3+CD4+ T-cell counts, cytokeratin 19 fragment (CYFRA21-1), oxygenation index, and anti-Ro52 antibody. The retained predictive variables in the final prediction model were age, Heliotrope, fever, and risk score, and the most predictive factor was the risk score. The prediction model showed good discrimination (AUC: 0.915, 95% CI: 0.846–0.957), good calibration (Hosmer–Lemeshow test, P = 0.506; Brier score, 0.12), and fair clinical usefulness in the discovery cohort. The results were verified among patients in the temporal validation cohort (n = 38). We successfully divided patients into three risk groups with very different mortality rates according to the predictive score in both the discovery and validation cohorts (Cochran-Armitage test for trend, P < 0.001).

Conclusions

We developed and validated a mortality risk prediction tool with good discrimination and calibration for Asian patients with anti-MDA5 DM-ILD. This tool can offer individualized mortality risk estimation and inform clinical decision-making.

Clinical Heterogeneity of Patients With Antinuclear Matrix Protein 2 Antibody-Positive Myositis: A Retrospective Cohort Study in China

OBJECTIVE

Heterogeneity exists among patients with myositis who have antinuclear matrix protein 2 (anti-NXP2) antibodies, although they usually present with severe muscle weakness. This study aimed to investigate the differences in phenotypes and prognoses among adult patients with myositis who have anti-NXP2 antibodies.

METHODS

Adult patients with myositis who have anti-NXP2 antibodies were enrolled from January 2010 to December 2019. Their clinical features and laboratory data were recorded retrospectively. We followed up on their survival status until June 30, 2020. A hierarchical cluster analysis, Kaplan-Meier curves, and classification and regression trees were used to analyze the data.

RESULTS

A total of 70 adult patients with myositis who have anti-NXP2 antibodies were enrolled. All patients experienced muscle weakness. A total of 11 patients did not present with rashes during disease progression, and 43 patients developed dysphagia. In total, 21 patients had interstitial lung disease (ILD), whereas no patients had rapidly progressive ILD. Hierarchical cluster analysis identified 2 clusters. Patients in cluster 1 were younger at disease onset, had a higher incidence of subcutaneous calcification, and had a lower incidence of V sign and shawl sign. Patients in cluster 2 had a higher frequency of ILD, accompanied by lower levels of lymphocytes and higher levels of serum ferritin. Moreover, patients in cluster 2 had worse prognoses.

CONCLUSION

Patients with myositis who have anti-NXP2 antibodies may present with different phenotypes that are characterized by unique features and prognoses.

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.

Detection of multiple myositis-specific autoantibodies in unique patients with idiopathic inflammatory myopathy: A single centre-experience and literature review: Systematic review

INTRODUCTION

Myositis-specific autoantibodies (MSAs) are thought to be mutually exclusive in patients with idiopathic inflammatory myopathies (IIM) based on studies with immunoprecipitation-based (IP) detection methods. Recently, detection of multiple MSAs in unique patients is increasingly reported, but the extent of this phenomenon remains unclear.

METHODS

At our centre, we reviewed results from two line immunoassays and one dot immunoassay in 145 IIM patients and 240 controls for the presence of multiple MSAs. Pubmed and Embase were systematically searched for articles mentioning detection of multiple MSAs in IIM patients, published until February 2019. We assessed the frequency, detection method, the precise combinations and clinical phenotypes of participants with multiple MSAs.

RESULTS

At our centre, detection of multiple MSAs occurred in 3.4-8.3% of patients with IIM, depending on the assay. However, no cases with full concordance across all three assays were identified. Forty-four articles reported detection of multiple MSAs, representing a total of 133 cases, including four patients with a connective tissue disease other than IIM and two healthy controls. In 101 cases all MSAs were detected using only one detection method: 40 cases with IP-based methods (most frequently used technique) and 61 cases with other assay types. In most cases the phenotype of patients with multiple MSAs matched the predicted presentation associated with one MSA and in few cases the phenotype matched with both MSAs.

CONCLUSION

Detection of multiple MSAs in unique IIM patients is less rare than commonly accepted. Specificity issues of the commercially available multiplex immunoassays may, at least partly, explain the higher frequency compared to IP-based methods. 'True multiple MSA-positive' patients may exist, though they are most likely rare.

Risk factors of interstitial lung diseases in clinically amyopathic dermatomyositis

Background

Clinically amyopathic dermatomyositis (CADM) is a unique sub-type of idiopathic inflammatory myopathies with a high prevalence of interstitial lung disease (ILD). Poor prognosis of the patients was strongly associated with rapid progressive ILD. The aim of this study was to identify risk factors for prediction of different types of ILD in CADM.

Methods

In this study, data of 108 inpatients with CADM were collected, including 87 with ILD. The baseline clinical data and laboratory parameters, including myositis-specific and associated antibodies and tumor-associated antigens were analyzed to identify risk factors for acute or subacute interstitial pneumonitis (A/SIP) and chronic interstitial pneumonitis (CIP).

Results

In 87 patients with CADM-ILD, 39 (36.1%) were A/SIP, and 48 (44.4%) were CIP. There were 22 (20.4%) patients with asymptomatic ILD who were detected by routine high resolution computed tomography. Cytokeratin-19 fragment (CYFRA21-1) was significantly higher in CADM-ILD than that in CADM patients without ILD; carcinoembryonic antigen and neuron-specific enolase were significantly elevated in A/SIP than that in CIP. Patients with A/SIP had a higher positive rate of anti-melanoma differentiation-associated gene 5 (MDA5), while patients with CIP had a higher positive rate of anti PL-12 and anti-Ro-52. Logistic regression analysis indicated that elevation of CYFRA21-1 was a risk factor for ILD, higher titer of anti-MDA5 indicated increased likelihood for A/SIP, and higher titer of anti-Ro-52 was also clearly associated with CIP.

Conclusions

This study indicated that the prevalence of ILD was high in CADM. Asymptomatic ILD has been previously underestimated. Anti-MDA5 was a risk factor for the presence of A/SIP, and CYFRA21-1 was a risk factor for ILD.

The significance of myositis autoantibodies in idiopathic inflammatory myopathy concomitant with interstitial lung disease

AIM

This study identified factors associated with interstitial lung disease (ILD) in patients with idiopathic inflammatory myopathy (IIM) based on the latest classification and recent advances in autoantibody serology.

METHODS

We retrospectively analyzed data of 173 patients who underwent complete myositis autoantibody serology examination in a medical center in Taiwan from July 2018 to February 2020. After exclusion of patients who did not receive a final diagnosis of IIM, clinical features, serology data, concomitant diseases, treatment, presence of respiratory failure, and mortality rate of the remaining 97 patients were analyzed.

RESULTS

Of IIM patients in our cohort, 47.4% had ILD. ILD was significantly associated with subtypes of IIM, older age of onset, presence of mechanic's hand, and presence of anti-Jo-1 and anti-Ro52 antibodies. Among five IIM subtypes, overlap myositis (OM) and dermatomyositis (DM) were significantly associated with a higher prevalence rate of ILD (67.5% in OM and 53.3% in DM). Among patients with OM, the presence of anti-Jo-1 (100%), anti-PL-7 (100%), and anti-EJ antibodies (77.8%) was most significantly associated with ILD.

CONCLUSION

The latest classification of IIM, older age of onset, presence of mechanic's hand, and presence of anti-Jo-1 and anti-Ro52 antibodies were significantly associated with ILD. Among five IIM subtypes, OM and DM had higher prevalence rate of ILD. Among OM patients, the presence of anti-Jo-1, anti-EJ, and anti-PL-7 antibodies was significantly associated with ILD. The study results may help physicians to timely screen and monitor pulmonary function in high-risk groups.

COVID-19 or clinical amyopathic dermatomyositis associated rapidly progressive interstitial lung disease? A case report

Background

Coronavirus disease 2019 (COVID-19) has reach pandemic proportions globally. For patients with symptoms of fever and cough accompanied by rapid lung damage progression, COVID-19 needs to be distinguished from interstitial lung disease (ILD) attributed to connective tissue disease (CTD), especially dermatomyositis (DM)/clinical amyopathic dermatomyositis (CADM) associated rapidly progressive interstitial lung disease (RP-ILD).

Case presentation

We report a case of a woman observed with fever, cough, and rapid lung damage during the epidemic. The patient had a suspicious epidemiological history, and her chest CT scans showed lung damage similar to that caused by COVID-19, but anti-Ro52 antibody was strongly positive. She was diagnosed with CADM associated RP-ILD and died 1 month later.

Conclusions

During the COVID-19 epidemic, it is critical to carefully assess patients with CTD related ILD, especially RP-ILD associated with CADM. Repeated nucleic acid tests for COVID-19 are necessary to achieve accurate case diagnosis. High-resolution CT (HRCT) of the chest is presently deemed an inefficient technique to distinguishing between COVID-19 and CADM associated RP-ILD. The characteristic rashes of dermatomyositis require careful observation and can often provide diagnostic clues. For patients with CADM, a high titers of anti-Ro52 antibody may be related to the pathogenesis of RP-ILD, suggesting a poor prognosis.

Line blot immunoassays in idiopathic inflammatory myopathies: retrospective review of diagnostic accuracy and factors predicting true positive results

Background

Line blot immunoassays (LIA) for myositis-specific (MSA) and myositis-associated (MAA) autoantibodies have become commercially available. In the largest study of this kind, we evaluated the clinical performance of a widely used LIA for MSAs and MAAs.

Methods

Adults tested for MSA/MAA by LIA at a tertiary myositis centre (January 2016–July 2018) were identified. According to expert-defined diagnoses, true and false positive rates were calculated for strongly and weakly positive autoantibody results within three cohorts: idiopathic inflammatory myopathy (IIM), connective tissue disease (CTD) without myositis, and non-CTD/IIM. Factors associated with true positivity were determined.

Results

We analysed 342 cases. 67 (19.6%) had IIM, in whom 71 autoantibodies were detected (50 strong positives [70.4%], 21 weak positives [29.6%]). Of the strong positives, 48/50 (96.0%; 19 MSAs, 29 MAAs) were deemed true positives. Of the weak positives, 15/21 (71.4%; 3 MSAs, 12 MAAs) were deemed true positives.

In CTD without myositis cases (n = 120), 31/61 (51.0%; 5 MSAs, 26 MAAs) autoantibodies were strongly positive, with 24/31 (77.4%; 0 MSAs, 24 MAAs) true positives. 30/61 (49.2%; 13 MSAs, 17 MAAs) were weakly positive, with 16/30 (53.3%; 0 MSAs, 16 MAAs) true positives. In non-CTD/IIM cases (n = 155), all 24 MSAs and 22 MAAs were false positives; these results included 17 (37.0%; 7 MSAs, 10 MAAs) strong positives.

Individual autoantibody specificities were > 98.2 and > 97.5% for weakly and strongly positive results, respectively. True positivity was associated with high pre-test for IIM (odds ratio 50.8, 95% CI 13.7–189.2, p < 0.001) and strong positive (versus weak positive) results (4.4, 2.3–8.3, p < 0.001).

Conclusions

We demonstrated the high specificity of a myositis LIA in a clinical setting. However, a significant burden of false positive results was evident in those with a low pre-test likelihood of IIM and for weakly positive autoantibodies.

Assessment of diagnostic utility, clinical phenotypic associations, and prognostic significance of anti-NXP2 autoantibody in patients with idiopathic inflammatory myopathies: a systematic review and meta-analysis

The objectives of this study are to analyze the association between anti-nuclear matrix protein 2 (NXP2) autoantibody and idiopathic inflammatory myopathies (IIMs) and to assess the diagnostic and prognostic relevance of anti-NXP2 autoantibody in patients with IIMs. A systematic search was performed in PubMed, Web of Science, EMBASE, the Cochrane Library, and Scopus to identify studies published as of February 29, 2020. Data was analyzed using Stata 12.0 and Meta-DiSc 1.4. Twenty-eight studies (4764 patients with IIMs and 1981 controls) were included in the meta-analysis. Anti-NXP2 autoantibody showed a significant association with IIMs (odds ratio (OR) = 26.36, 95% confidence interval (CI): 12.05-57.67, P < 0.001), especially juvenile IIMs (OR = 62.48, 95% CI: 16.97-229.98, P < 0.001). The pooled sensitivity, specificity, and area under the curve were 0.19 (95% CI = 0.16-0.21), 1.00 (95% CI = 1.00-1.00), and 0.95 for patients with juvenile IIMs versus controls. Anti-NXP2 autoantibody was associated with an increased risk of developing five characteristics (edema, muscle weakness, myalgia/myodynia, dysphagia, and calcinosis) and reduced risk of interstitial lung disease (ILD) (P < 0.001). Anti-NXP2 autoantibody showed no association with increased risk of death in IIMs (P = 0.463). These findings suggest that anti-NXP2 autoantibody is specially related to IIMs and is related to edema, muscle weakness, myalgia/myodynia, dysphagia, calcinosis, and ILD in patients with IIMs. However, there is no evidence to suggest that the presence of anti-NXP2 autoantibody confers a poor prognosis with respect to overall survival. Key Points • This study summarized the diagnostic and prognostic accuracies of anti-NXP2 autoantibody for patients with IIMs. Anti-NXP2 autoantibody is related to edema, muscle weakness, myalgia/myodynia, dysphagia, calcinosis, and ILD in patients with IIMs.

Serum levels of interleukins and S100A8/A9 correlate with clinical severity in patients with dermatomyositis-associated interstitial lung disease

Background

Dermatomyositis (DM) is a systemic autoimmune inflammatory disorder that affects primarily skin, muscle and lung, frequently associated with interstitial lung disease (ILD). The objective of this study is to investigate the association between serum cytokines and clinical severity in patients with DM-ILD.

Methods

Serum samples of 30 healthy controls, 14 DM patients without ILD and 40 DM patients with ILD were collected. Serum S100A8/A9 levels were analyzed by enzyme-linked immunosorbent assay (ELISA) and levels of interleukins were measured by cytometric beads array (CBA). Then we performed multivariate logistic regression analysis to determine factors independently associated with ILD development.

Results

Serum IL-4, IL-6 and S100A8/A9 levels were significantly higher in DM patients with ILD than those in healthy controls (p = 0.0013, 0.0017 and < 0.0001, respectively). Serum IL-10 level of patients was dramatically lower than that in controls (p = 0.0001). In DM patients, the levels were significantly higher in patients with A/SIP than in those with CIP (p = 0.0046, 0.0339 and 0.0133) or without ILD (p = 0.0165, 0.0370 and < 0.0001). IL-4 (r = 0.1171, p = 0.0040), IL-6 (r = 0.1174, p = 0.0040) and IL-10 (r = − 0.1829, p = 0.0003) were significantly correlated with S100A8/A9 in DM-ILD patients. S100A8/A9 was significantly correlated with high-resolution computed tomography (HRCT) (r = 0.1642, p = 0.0157) and lung function (DLCO%: r = − 0.2066, p = 0.0061, FVC%: r = − 0.2156, p = 0.0050). Moreover, logistic regression analysis revealed that S100A8/A9 levels were independently associated with ILD development in DM patients (p = 0.004).

Conclusions

Serum level of S100A8/A9 may be a valuable predictor for assessing the clinical severity of DM-ILD patients. Serum IL-4, IL-6 and IL-10 levels were highly correlated with S100A8/A9, so these cytokines may play a synergistic effect on the progression of DM-ILD.

Insights into pathogenesis and clinical implications in myositis-associated interstitial lung diseases

PURPOSE OF REVIEW

Interstitial lung diseases (ILDs) have been reported to be associated with myositis (including polymyositis and dermatomyositis). These myositis-associated ILDs carry significant morbidity and mortality. This review summarizes recent findings on myositis-associated ILD with a focus on pathogenesis and emerging treatment.

RECENT FINDINGS

Recent advances in genetics have revealed 22 myositis-associated genome-wide loci, which were significantly enriched in regulatory regions in immune cells. An analysis of such disease-associated loci elucidated potential drug targets (e.g., TYK2 targeted by tofacitinib). In another study, an intronic variant in WDFY4 in association with clinically amyopathic dermatomyositis (CADM) had an effect for higher expression of a truncated WDFY4 isoform. Truncated WDFY4 markedly enhanced the MDA5-mediated NF-κB activation and cell apoptosis, indicating the dysregulated WDFY4-MDA5 pathway as a novel pathogenesis of CADM. As a novel strategy, tofacitinib treatment showed a promising improvement in survival and clinical features of CADM-associated ILD.

SUMMARY

The genetic differences in the myositis-susceptible loci may explain the heterogeneous phenotypes and treatment responses in myositis-associated ILD. The understanding of pathogenesis with the genetic background as well as autoantibodies will enable the practice of personalized treatment in the management of the disease.

Interstitial Lung Disease in Polymyositis and Dermatomyositis

The idiopathic inflammatory myopathies (IIMs), including polymyositis (PM) and dermatomyositis (DM), are autoimmune connective tissue diseases with variable degrees of muscle inflammation and systemic involvement. Interstitial lung disease (ILD) is a common complication of the IIMs and is associated with increased mortality. Many patients with PM/DM have myositis-specific and myositis-associated antibodies (MSA/MAAs) that result in distinct clinical phenotypes. Among these MSAs, anti-aminoacyl-tRNA antibodies and anti-melanoma differentiation factor 5 antibodies have high rates of ILD. Corticosteroids are the mainstay of treatment, although the addition of other immunosuppressive therapy is typically necessary to achieve disease control.

Juvenile dermatomyositis: advances in clinical presentation, myositis-specific antibodies and treatment

BACKGROUND

Juvenile dermatomyositis (JDM) is a chronic autoimmune disease characteristic by inflammation of small vessels within the skin, muscle and vital organs. But the clinical features and treatment of JDM have not been fully clarified.

DATA SOURCES

Databases underwent through PubMed for articles about the clinical features, myositis-specific antibodies of JDM and its treatment, and we selected publications written in English which were relevant to the topic of this review.

RESULTS

Clinical features and myositis-specific antibodies may predict the severity and prognosis of disease. Although the mortality rate has been lower with traditional treatments, such as corticosteroid, intravenous immunoglobulin, and disease-modifying anti-rheumatic drugs such as methotrexate, their usages are variable. Novel biological therapies seem to be effective for refractory JDM patients, but more clinical trials are necessary.

CONCLUSIONS

JDM is a sever disease of childhood. We need to better understand recent advances of JDM in the context of clinical features including skin manifestations, muscle weakness and organ damage, myositis-specific antibodies and their associated outcomes and the treatment of disease.

Serum S100A12 levels are correlated with clinical severity in patients with dermatomyositis-associated interstitial lung disease

Objective

S100A12 is an emerging inflammatory disease biomarker. Interstitial lung disease (ILD) is a common, severe complication of dermatomyositis (DM). This study was performed to investigate the association between S100A12 and disease activity and prognosis in patients with DM-associated ILD (i.e., DM-ILD).

Methods

Serum S100A12 levels were measured using enzyme-linked immunosorbent assays in patients with stable DM-ILD, patients with acute exacerbation of DM-ILD (AE DM-ILD), and healthy controls (HCs). The relationships of serum S100A12 levels with C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ferritin, high-resolution computed tomography (HRCT) scores, and pulmonary functions were evaluated by multiple unpaired t-tests and Pearson correlation.

Results

Serum S100A12 levels were higher in patients with stable DM-ILD and those with AE DM-ILD than in HCs. Serum S100A12 levels in patients with stable DM-ILD and those with AE DM-ILD were positively correlated with CRP, ESR, and ferritin. S100A12 levels were positively correlated with HRCT scores in patients with stable DM-ILD and those with AE DM-ILD, while they were negatively correlated with predicted percentages of forced vital capacity and predicted percentages of carbon monoxide diffusing capacity in those patients.

Conclusion

Our findings demonstrate the usefulness of serum S100A12 levels for assessing clinical severity and prognosis of DM-ILD.

Autoantibodies in Myositis. How to Achieve a Comprehensive Strategy for Serological Testing

Myopathies are a rare type of acquired, chronic autoimmune diseases of the skeletal muscles and affect both children and adults. The hallmark symptoms of idiopathic inflammatory myopathies (IIM) are muscle inflammation, proximal muscle weakness and disability, arthritis, cutaneous rashes, calcinosis, ulceration, malignancy and interstitial lung disease (ILD). Subforms of IIM include polymyositis, dermatomyositis, cancer-related myositis and sporadic inclusion body myositis. Autoantibodies function as biomarkers for diagnosis of IIM and can be used to delimit clinically distinguishable IIM subforms. To maximise the diagnostic information it is essential to perform comprehensive multiparametric serological testing including both screening and confirmation tests.

Dermatomyositis: Diagnosis and treatment

The second article in this continuing medical education series reviews the initial evaluation of patients with suspected dermatomyositis (DM), the relevant work-up for malignancy and interstitial lung disease once a diagnosis of DM is made, and treatment recommendations for patients with DM based on disease severity, the presence of systemic symptoms, and myositis-specific antibody (MSA) profiles. This review emphasizes the emerging role of MSAs in the diagnosis of DM and highlights how MSAs can be used to guide the appropriate work-up for malignancy and interstitial lung disease. The treatment approach proposed by this continuing medical education series discusses both established and novel therapies for DM and highlights the importance of considering lesion type, degree of muscle involvement, presence of systemic symptoms, presence of MSAs, and patient age when determining the best treatment approach for a patient with DM.