239th ENMC International Workshop: Classification of dermatomyositis, Amsterdam, the Netherlands, 14-16 December 2018

Effectiveness and safety of anti-CD20 monoclonal antibodies versus csDMARDs in anti-Jo-1 antisynthetase syndrome: A retrospective cohort study

OBJECTIVES

Anti-Jo-1 antisynthetase syndrome (Jo1+ASyS) is the most common form of idiopathic inflammatory myopathy with high relapse rates and limited treatment options beyond csDMARDs, which frequently fail to achieve adequate disease control. This study aimed to evaluate the efficacy and safety of anti-CD20 monoclonal antibodies (CD20mAbs) compared to conventional synthetic(cs) DMARDs in patients with Jo1+ASyS.

METHODS

A single-center retrospective cohort of patients with Jo1+ASyS were collected at RenJi Hospital in China (2007-2023). A prevalent new-user design with time-based propensity scores, applied without replacement, was used to match CD20mAb and csDMARD users. The primary outcome was the percentage of patients reaching Low Disease Activity (5-item LDA), as defined by the absence of active arthritis, myositis, ILD, fever, and prednisone dosage ≤7.5 mg/day.

RESULTS

A total of 166 eligible treatment regimens, including CD20mAbs and csDMARDs, were extracted from 128 Jo1+ASyS patients with a median follow-up period of 5 years. Utilizing propensity score, 49 pairs of individual prescriptions for CD20mAbs and csDMARDs users were matched. The group treated with CD20mAbs exhibited a significantly higher rate of achieving LDA compared to those treated with csDMARDs (46.9 % vs. 22.4 %, p = 0.011). No significant differences in exposure-adjusted incidence rate were detected between the two treatment modalities (CD20mAbs vs. csDMARDs = 7.911 vs. 6.479 per 100 patient-yr, RR = 1.22; 95 % CI: 0.64, 2.36), with respect to major infections. Sensitivity analyses further confirmed the robustness of the superior effectiveness of the CD20mAbs compared to the csDMARDs.

CONCLUSION

CD20mAbs exhibited remarkable treatment efficacy and acceptable safety in patients with Jo1+ASyS. Cumulative evidence, including ours suggested that CD20mAbs should be considered as a first-line option for Jo1+ASyS.

External validation of the 2017 EULAR/ACR classification criteria for idiopathic inflammatory myopathies in anti-MDA5 antibody-positive interstitial lung disease patients: A multicenter retrospective cohort study in China

The aim of this study was to assess the 2017 EULAR/ACR classification criteria performance for determining idiopathic inflammatory myopathies (IIMs) in a cohort of patients with anti-MDA5 antibody-positive IIM-related interstitial lung disease (anti-MDA5+IIM-ILD). The outcomes of patients, who did not meet the EULAR/ACR criteria, and who had interstitial pneumonia and exhibited an autoimmune phenotype associated with anti-MDA5 positivity were also investigated.

METHODS

This retrospective study recruited adult patients from four hospitals in China who were diagnosed with anti-MDA5 antibody-positive IIM-related interstitial lung disease. Data on disease manifestations, laboratory findings, and imaging findings were collected through electronic medical records. The performance and consistency of the 2017 EULAR/ACR classification criteria were compared with those of the Bohan/Peter criteria combined with Sontheimer's CADM criteria. Additionally, this study evaluated the performance of incorporating anti-MDA5 antibodies into the EULAR/ACR criteria and explored the criteria proposed by Casal-Domingez based on myositis-specific antibodies (MSAs). Finally, clinical characteristics and prognoses were compared between patients with MDA5+IIM-ILD who met the EULAR/ACR criteria and those who did not meet the EULAR/ACR criteria.

RESULTS

A total of 250 patients with anti-MDA5-related IIM-ILD, including those with dermatomyositis (DM, 23.6 %) and clinically amyopathic dermatomyositis (CADM, 76.4 %), were recruited. Of these, 175 (70 %) and 64 (25.7 %) patients met the EULAR/ACR and Bohan/Peter criteria, respectively. According to Sontheimer's CADM criteria, 60.4 % of patients could be classified according to the Bohan and Peter criteria. Thirty percent of the anti-MDA5 antibody-positive patients did not meet the EULAR/ACR criteria but met the IPAF criteria. The sensitivity of the EULAR/ACR criteria increased to 99.2 % when anti-JO-1 antibodies were replaced with anti-MDA5 antibodies. In this cohort, a sensitivity of 100 % was obtained using the Casal-Domingez criteria. There were no significant differences in clinical characteristics or prognoses between MDA5+IIM-ILD patients who met the EULAR/ACR criteria, those who did not meet the criteria, and those who met the IPAF criteria.

CONCLUSION

Approximately 30 % of clinically diagnosed anti-MDA5 antibody-positive IIM-ILD patients cannot be classified according to the EULAR/ACR criteria, suggesting that such patients should be managed as IIM-ILD patients. Modifying the existing criteria by including other MSAs, such as anti-MDA5 antibodies, as one of the scoring criteria is recommended. Future IIM guidelines should consider incorporating ILD into the diagnostic criteria.

Tofacitinib treatment for active dermatomyositis and anti-synthetase syndrome: a prospective cohort pilot study

OBJECTIVES

The objective of this study was to evaluate the efficacy and safety of tofacitinib in the treatment of active dermatomyositis (DM) and anti-synthetase syndrome (ASS).

METHODS

Tofacitinib was administered at a dose of 5 mg twice daily to patients who exhibited inadequate response to conventional treatments. The primary end point was the reduction in T follicular helper (Tfh) cells at week 24. Key secondary end points included clinical scores. Moreover, we analysed the immunological profiles and conducted RNA sequencing (RNAseq) on peripheral blood samples from four patients.

RESULTS

A total of 26 patients were enrolled, with 21 completing the study. Both DM and ASS patients demonstrated significant improvements in disease activity. Among these patients, the percentage of Tfh cells in peripheral blood decreased in 81.0% (17/21) of them (P = 0.003). Significant reductions in Th17 cells were observed in vivo in the peripheral blood mononuclear cells (PBMCs) of these patients (P = 0.017). In vitro, Tfh cells (2.88 ± 1.13 vs 2.28 ± 0.92, P< 0.001), Th17 cells (1.42 ± 0.92 vs 1.01 ± 0.74, P = 0.016), Treg cells (2.06 ± 1.26 vs 0.98 ± 0.65, P = 0.019) and Tfh17 cells (33.38 ± 15.14 vs 30.28 ± 4.89, P = 0.014) were inhibited. RNAseq analysis revealed significant downregulation of genes associated with the 'herpes simplex virus 1 infection' and 'IL-17 signalling' pathway. Myositis Disease Activity Assessment Tool (MDAAT) scores improved in 21 out of 24 patients. Fifteen (62.5%) patients met the criteria for International Myositis Assessment and Clinical Studies (IMACS) definition of improvement (DOI). Importantly, no severe adverse events necessitated treatment discontinuation.

CONCLUSION

Tofacitinib demonstrated significant immunologic and clinical effectiveness in DM and ASS patients, reducing key immune cell populations and downregulating immune activation pathways.

Shared and Distinctive Inflammation-Related Protein Profiling in Idiopathic Inflammatory Myopathy with/without Anti-MDA5 Autoantibodies

Purpose

Due to the heterogeneous nature of the diseases, treatment efficacy and prognosis vary for idiopathic inflammatory myopathy (IIM) patients with different myositis specific autoantibodies (MSAs). This study aimed to investigate the inflammation-related protein profiling of IIM patients with different MSAs. In addition, the shared and distinctive inflammation-related protein profiling in IIM with/without anti-MDA5 autoantibodies.

Methods

Seventy-seven patients with IIM of different MSAs and 53 gender/age matched healthy controls (HCs) were enrolled in this study. Ninety-two inflammation-related proteins were detected by Olink proteomics. We identified differentially expressed proteins (DEPs), and performed gene set enrichment analysis and KEGG pathway analysis. In addition, correlation between DEPs and serological parameters were performed. The least absolute shrinkage and selection operator (Lasso) regression algorithm of machine learning was used to screen biomarkers related to anti-MDA5+ DM.

Results

Compared with HCs, 36 inflammation-related proteins were identified as DEPs. The top 10 DEPs were CXCL10, CXCL11, CXCL9, CXCL8, S100A12, IL-6, CCL2, CCL8, IL-10 and CCL3. The inflammation-related proteins and cytokine-cytokine receptor interaction pathway were more strikingly expressed in patients with anti-MDA5+ DM patients than in anti-MDA5- IIM patients. In addition, multiple DEPs correlated with serum ferritin, KL-6, muscle enzymes. For the first time, we established that a multi-factor panel comprising CX3CL1, IL-17C, IL-18R1, CCL20, and TNF (AUC = 0.824) serves as a highly efficient diagnostic biomarker for anti-MDA5+ DM.

Conclusion

Plasma profiling revealed that inflammation and inflammatory pathways were extremely elevated in patients with IIM, especially in patients with anti-MDA5 autoantibodies. The shared and distinctive inflammation-related protein signature was demonstrated in patients with/without anti-MDA5 autoantibodies. The expression of CX3CL1 was significantly higher in anti-MDA5+ DM than in patients without anti-MDA5 autoantibodies. In addition, CX3CL1 correlated with ESR, serum ferritin, CK enzymes and disease activity, indicating that CX3CL1 participated in inflammation status of anti-MDA5+ DM.

Long-term outcomes of idiopathic inflammatory myopathies: a large-scale longitudinal cohort study

OBJECTIVES

To investigate mortality, patient-reported outcomes (PROs), and drug-free remission (DFR) in a large well-characterised cohort of idiopathic inflammatory myopathies (IIMs).

METHODS

This study retrospectively enrolled 1854 patients with IIMs. Follow-up lasted up to 20 years. Mortality was analysed using the standardised mortality ratio (SMR) and Kaplan-Meier survival analysis. PROs and DFR rates were examined in the survivors at the end of follow-up.

RESULTS

Of 1854 patients, 348 (18.8 %) died during follow-up, with an overall SMR of 6.82 (95 % confidence interval [CI] 6.11-7.54). Subgroup analysis revealed the highest SMRs in dermatomyositis (DM), followed by antisynthetase syndrome (ASS), and immune-mediated necrotising myopathy, while SMRs in patients with polymyositis indicated no significant mortality difference from general population. Patients with anti-MDA5-positive DM exhibited higher SMRs than those with other IIM serotypes. Respiratory failure was the leading cause of death among patients with IIMs. Patients with DM had the lowest survival rates within the initial nine years of disease duration, whereas patients with ASS exhibited significantly reduced survival after nine years. At the end of follow-up, 17.1 % of patients achieved DFR (cumulative 3-, 5-, and 10-year DFR rates of 6.1 %, 14.9 %, and 29.3 %, respectively). Patients with DM presented with better PROs and higher DFR rates than those with other IIM subtypes.

CONCLUSIONS

Our data indicated increased mortality in patients with IIM compared with the general population and provided an important foundational understanding of IIMs. These findings emphasise the heterogeneity in the long-term outcomes across IIM subtypes, DM's acute nature, and ASS's progressive course.

Effectiveness and safety of tofacitinib versus calcineurin inhibitor in interstitial lung disease secondary to anti-MDA5-positive dermatomyositis: a multicentre cohort study

OBJECTIVE

To compare the effectiveness and safety of tofacitinib versus calcineurin inhibitor (CNI) as initial immunosuppressive regimen for anti-melanoma differentiation-associated gene 5-positive dermatomyositis with interstitial lung disease (MDA5+DM-ILD).

METHODS

Adult Chinese patients with newly diagnosed MDA5+DM-ILD (ILD course <3 months) from five tertiary referral centres between April 2014 and January 2023 were included in this retrospective cohort study. The primary effectiveness end-point was lung transplantation-free survival within 1 year. Propensity score-based inverse probability of treatment weighting (IPTW) was applied for adjustment in this real-world study.

RESULTS

In the eligible cohort, a total of 94 (32.4%) and 105 (46.7%) patients died or underwent lung transplantation within 1 year in the tofacitinib group (n=290) and the CNI group (n=225), respectively. After adjustment by IPTW, patients' lung transplantation-free survival rate within 1 year was significantly higher in the tofacitinib group compared to the CNI group (log-rank p=0.013). Multivariable Cox analysis performed in the IPTW dataset revealed that the hazard ratio of tofacitinib versus CNI for 1-year survival was 0.72 (95% CI 0.56-0.94; p=0.013). The adjusted difference of survival rate was 9.3% (95% CI 2.8-15.8%). Alternative analytic strategies yielded consistent results in sensitivity analyses. Patients aged <60 years, without rapidly progressive ILD, or with baseline arterial oxygen tension/inspiratory oxygen fraction ≥300 mmHg might benefit more from tofacitinib. Opportunistic infection was the major treatment-related serious adverse event, with generally comparable incidence (42.4% versus 45.3%).

CONCLUSION

In this large multicentre cohort study, tofacitinib showed significantly more benefits for 1-year lung transplantation-free survival than calcineurin inhibitors in MDA5+DM-ILD.

Prognostic factors for patients with cancer-associated dermatomyositis: a retrospective, multicentre cohort study of 73 patients

OBJECTIVES

To investigate factors associated with DM complete clinical response and overall survival with a focus on the use of immunosuppressive therapies in patients with cancer-associated DM.

METHODS

We performed a multicentre, retrospective cohort study. Multivariable survival analyses used a Cox model with time-dependent covariates and adjustments with inverse probability censoring weighting.

RESULTS

We included 73 patients with cancer-associated DM. Median follow-up was 3.92 years. Overall, 40 (54.8%) patients achieved cancer remission, with DM complete clinical response in 28/40 (70.0%). DM complete clinical response was associated with cancer remission (hazard ratio [HR] 2.46, 95% CI [1.13-5.32]) and younger age (HR 0.68, 95% CI [0.49-0.95]). Risk of mortality was associated with sustained cancer activity (HR 12.93, 95% CI [2.42-69.25]), male sex (HR 2.82, 95% CI [1.19-6.70]), and older age (HR 1.86, 95% CI [1.26-2.79]) but not sustained DM activity (HR 0.40, 95% CI [0.13-1.26]). Oral corticosteroid use was a protective factor only on univariate analysis (HR 0.18, 95% CI [0.08-0.42]).

CONCLUSION

This study provides strong evidence of a significant association between the evolutions of DM and cancer, both in terms of overall survival and DM complete clinical response. Immunosuppressive treatments for DM were not significantly associated with mortality.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04637672.

Transposon expression and repression in skeletal muscle

Transposons and their derivatives make up a major proportion of the human genome, but they are not just relics of ancient genomes. They can still be expressed, potentially affecting the transcription of adjacent genes, and can sometimes even contribute to their coding sequence. Active transposons can integrate into new sites in the genome, potentially modifying the expression of nearby loci and leading to genetic disorders. In this review, we highlight work exploring the expression of transposons in skeletal muscles and transcriptional regulation by the KRAB-ZFP/KAP1/SETDB1 complex. We next focus on specific cases of transposon insertion causing phenotypic variation and distinct muscular dystrophies, as well as the implication of transposon expression in immune myopathies. Finally, we discuss the dysregulation of transposons in facioscapulohumeral dystrophy and aging.

Prevalence of Elevated CK Levels, Myositis-Specific and Myositis-Associated Antibodies, Myositis, and Other Neuromuscular Diseases in Myasthenia Gravis Patients-Experience from an Eastern European Tertiary Center

Background: Myasthenia gravis (MG) and idiopathic inflammatory myopathy (IIM) are autoimmune diseases that affect the musculoskeletal system. The association of the two diseases is rare. Their management is different, so it is important to recognize the concomitant presentation. Methods: In this cross-sectional study, we study the presence of CK elevation, myositis-specific and myositis-associated antibodies (MSA/MAA), and vitamin D levels in a cohort of 101 MG patients. Electromyography, limb magnetic resonance imaging (MRI), and, in some cases, muscle biopsy were performed when IIM was suspected. We reviewed the patients' medical records to access the results of these tests if they had been performed previously. Results: CK elevation was detected in 10 patients (9.9%). We identified one case of anti-Jo-1 antibody-positive polymyositis and two cases of possible myositis. MSA/MAA antibodies were not found in the patients with high CK levels, except for the one with anti-Jo-1-positive IIM. One patient with elevated CK levels had an overlapping muscular dystrophy. MSA/MAA antibodies were detected in 19 patients (18.8%). A total of 37% had high-titer antibodies and concomitant systemic autoimmune diseases, while 63% had low-titer antibodies, most of whom had no systemic autoimmune disease. Low serum vitamin D levels were found in 67.3% of patients. Comparison of myasthenia gravis composite (MGC) scores between patients with low and normal vitamin D levels did not show a statistically significant difference. Conclusions: Our results may raise awareness among neuromuscular specialists caring for MG patients of the possibility of associated myositis or other neuromuscular diseases and the need to assess vitamin D levels. Although deficiency was frequent, its impact on MG severity remains unclear, necessitating further investigation into its immunological relevance.

Idiopathic Inflammatory Myopathies: Recent Evidence Linking Pathogenesis and Clinical Features

Idiopathic inflammatory myopathies are rare and complex representatives of systemic connective tissue diseases. Described initially as only two entities, recent advances in molecular and imaging techniques now divide them into many subtypes, each with unique pathogenesis and clinical phenotypes. Dermatomyositis and its juvenile form are the most prevalent subtypes and are characterized by systemic vasculopathy and humoral autoimmunity. Genetic predisposition and environmental triggers initiate immune tolerance breakdown, leading to autoantibody production, complement activation, and tissue damage. Anti-synthetase syndrome primarily affects the lungs, where immune responses to aminoacyl-RNA synthetases drive vasculopathy, lung inflammation, and fibrosis. Immune-mediated necrotizing myopathies are muscle-specific, with autoantibodies inducing fiber necrosis and atrophy. Lastly, sporadic inclusion body myositis is a slowly progressive myopathy in which dysfunctional protein handling and autophagy are more important pathogenic elements than muscle inflammation itself. The expanding body of basic science evidence can be overwhelming, making it challenging to connect pathogenic mechanisms to clinical manifestations. This review aims to address this challenge by presenting recent insights into myositis pathogenesis from a practical perspective, reinforcing the links between basic science and clinical semiology.

Modulating IL-21-driven B cell responses in idiopathic inflammatory myopathies via inhibition of the JAK/STAT pathway

BACKGROUND

Idiopathic inflammatory myopathies (IIM) are autoimmune disorders characterized by muscle inflammation and autoreactive B cell responses. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway is essential for B cell functions, making it a promising therapeutic target. This study explores the potential of tofacitinib, a JAK1/JAK3 inhibitor, to modulate B cell activity in IIM.

METHODS

Peripheral B cell populations from dermatomyositis (DM), anti-synthetase syndrome (ASyS) and overlap myositis (OM) patients were analyzed by flow cytometry. Peripheral blood mononuclear cells (PBMC) or sorted memory B cells were cultured with tofacitinib and stimulated with combinations of CD40, IL-21, IL-2, BAFF and CpG. B cell proliferation, differentiation and (auto)antibody, cytokine/chemokine production were assessed by flow cytometry, Luminex, and ELISA/ELiA assays.

RESULTS

The IIM peripheral B cell compartment had elevated transitional and naive B cells, with reduced Bmem frequencies compared to healthy donors. Tofacitinib significantly inhibited CD40/IL-21-induced B cell proliferation, plasmablast formation and function in PBMC and B cell-only cultures across all IIM subgroups, predominantly affecting the IL-21-induced differentiation and antibody production. Remarkably, tofacitinib reduced the levels of anti-Jo1 autoantibodies, as well as of CXCL10 and CXCL13 in ASyS memory B cell cultures.

CONCLUSIONS

These findings highlight the B cell involvement in IIM, evidenced by altered peripheral B cell composition in active disease and the effective inhibition of essential B cell responses, including proliferation, differentiation, and (auto)antibody production, by tofacitinib in vitro. This positions the JAK/STAT pathway as a promising new therapeutic target to modulate B cell activity in IIM.

Refractory cutaneous ulcers in anti-MDA5 dermatomyositis were not associated with rapidly progressive interstitial lung disease, and responded to tadalafil

OBJECTIVES

The purpose of this study was to analyze the characteristics of an ulcerative rash in dermatomyositis (DM) patients with anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody and to assess the efficacy of tadalafil in the management of refractory cutaneous ulcers.

METHODS

Medical records of DM patients with anti-MDA5 antibody were reviewed. Skin rash data, radiologic characteristic and serum markers were collected. Patients with refractory cutaneous ulcers treated with tadalafil were reviewed retrospectively.

RESULTS

Eighty-two consecutive cases with anti-MDA5-antibody positive DM (anti-MDA5 DM) were identified, including 62 (75.6 %) female patients. Approximately 95.0 % of the patients had interstitial lung disease (ILD) and 45.1 % had rapidly progressive ILD (RP-ILD). All patients (100 %) had typical skin rashes, such as Gottron's sign (87.8 %), heliotrope sign (69.5 %), and the holster sign (24.4 %). Twenty-six patients (31.7 %) had cutaneous ulcers. Univariate analysis showed that ulcer patients were prone to Gottron's sign (p = 0.026), perlungual erythematosus (p = 0.007), and arthritis (p = 0.031), while shortness of breath after exercise (p = 0.027) and RP-ILD (p = 0.024) are more likely to appear in patients with non-skin ulcers. Among the anti-MDA5 DM patients with skin ulcers, 10 (38.5 %) were refractory cutaneous ulcers, including five male patients. After tadalafil was added, eight (80 %) patients showed improvement in the physician global assessment (PGA), Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) score and the patient's pain score using the visual analog score (p-VAS), within one to two months. In addition, the refractory cutaneous ulcers of five patients completely resolved after treatment.

CONCLUSIONS

This study found that ulcerative rash in anti-MDA5 DM may not be associated with RP-ILD. The results also suggest that tadalafil may be a useful therapy for refractory cutaneous ulcers.

The role of multicriteria decision analysis in the development of candidate classification criteria for antisynthetase syndrome: analysis from the CLASS project

OBJECTIVES

To develop and evaluate the performance of multicriteria decision analysis (MCDA)-driven candidate classification criteria for antisynthetase syndrome (ASSD).

METHODS

A list of variables associated with ASSD was developed using a systematic literature review and then refined into an ASSD key domains and variables list by myositis and interstitial lung disease (ILD) experts. This list was used to create preferences surveys in which experts were presented with pairwise comparisons of clinical vignettes and asked to select the case that was more likely to represent ASSD. Experts' answers were analysed using the Potentially All Pairwise RanKings of all possible Alternatives method to determine the weights of the key variables to formulate the MCDA-based classification criteria. Clinical vignettes scored by the experts as consensus cases or controls and real-world data collected in participating centres were used to test the performance of candidate classification criteria using receiver operating characteristic curves and diagnostic accuracy metrics.

RESULTS

Positivity for antisynthetase antibodies had the highest weight for ASSD classification. The highest-ranked clinical manifestation was ILD, followed by myositis, mechanic's hands, joint involvement, inflammatory rashes, Raynaud phenomenon, fever, and pulmonary hypertension. The candidate classification criteria achieved high areas under the curve when applied to the consensus cases and controls and real-world patient data. Sensitivities, specificities, and positive and negative predictive values were >80%.

CONCLUSIONS

The MCDA-driven candidate classification criteria were consistent with published ASSD literature and yielded high accuracy and validity.

Anti-FHL1 autoantibodies in adult patients with myositis: a longitudinal follow-up analysis

OBJECTIVES

To determine prevalence and clinical associations of anti-Four-and-a-half-LIM-domain 1 (FHL1) autoantibodies in patients with idiopathic inflammatory myopathies (IIM) and to evaluate autoantibody levels over time.

METHODS

Sera at the time of diagnosis from patients with IIM (n = 449), autoimmune disease controls (DC, n = 130), neuromuscular diseases (NMDs, n = 16) and healthy controls (HC, n = 100) were analysed for anti-FHL1 autoantibodies by enzyme-linked immunosorbent assay (ELISA). Patients with IIM FHL1+ and FHL1- were included in a longitudinal analysis. Serum levels were correlated to disease activity.

RESULTS

Autoantibodies to FHL1 were more frequent in patients with IIM (122/449, 27%) compared with DC (autoimmune DC and NMD, 13/146, 9%, P < 0.001) and HC (3/100.3%, P < 0.001). Anti-FHL1 levels were higher in IIM [median (IQR)=0.62 (0.15-1.04)] in comparison with DC [0.22 (0.08-0.58)], HC [0.35 (0.23-0.47)] and NMD [0.48 (0.36-0.80)] P < 0.001. Anti-FHL1+ patients with IIM were younger at the time of diagnosis compared with the anti-FHL1- group (P = 0.05) and were seronegative for other autoantibodies in 25%.In the first follow-up, anti-FHL1+ sample 20/33 (60%) positive at baseline had turned negative for anti-FHL1 autoantibodies. Anti-FHL1 autoantibodies rarely appeared after initiating treatment. Anti-FHL1 autoantibody levels correlated with CK (r = 0.62, P= 0.01), disease activity measured using the Myositis Disease Activity Assessment Tool (MYOACT) (n = 14, P = 0.004) and inversely with Manual Muscle Test-8 (r = -0.59, P = 0.02) at baseline.

CONCLUSION

Anti-FHL1 autoantibodies were present in 27% of patients with IIM; of these, 25% were negative for other autoantibodies. Other autoimmune diseases had lower frequencies and levels. Anti-FHL1 levels often decreased with immunosuppressive treatment, correlated with disease activity measures at diagnosis and rarely appeared after start of treatment.

A nomogram for the prediction of co-infection in MDA5 dermatomyositis: A rapid clinical assessment model

BACKGROUND

Patients with anti-melanoma differentiation-associated gene 5-positive dermatomyositis (MDA5 DM) are prone to infections, but there is a lack of rapid methods to assess infection risk, which greatly affects patient prognosis. This study aims to analyze the clinical features of MDA5 DM patients systematically and develop a predictive model for infections.

METHODS

Retrospective analysis was performed on clinical data from 118 hospitalized patients with MDA5 DM. According to the results of pathogen detection and clinical manifestations, the patients were divided into infected group and non-infected group. LASSO analysis and multivariate logistic regression were used to establish the prediction model of infection in MAD5 DM patients. The resulting model was visualized using a Nomogram. We used methods such as Receiver Operating Characteristic (ROC) curve analysis, Area Under the Curve (AUC) calculation to evaluate the model.

RESULT

The Cough, interstitial lung disease, moist rales, positive anti-RO-52, carcinoembryonic antigen, triglyceride, hydroxybutyrate dehydrogenase and erythrocyte sedimentation rate were significantly associated with infection risk in MDA5 DM patients. A prediction model was developed using these eight risk factors, achieving an AUC of 0.851 in determining co-infection status. Further analysis based on infection site and pathogen classification demonstrated strong discrimination performance of the model in identifying pulmonary infection (AUC: 0.844) and fungal infection (AUC: 0.822).

CONCLUSION

This study aimed to develop a clinical prediction model and visualize it using Nomogram to assess the risk of infection in MDA5 DM. The model provides an effective tool for determining infection status in patients and serves as a reference for formulating clinical medication regimens.

What is in the Myopathy Literature?

ABSTRACT

This update begins with the incidence and features of statin-associated muscle symptoms, which may often be misattributed. Articles on potential muscle mitochondria dysfunction from statins follow, along with recommendations for possibly avoiding statins in some patients with genetic myopathies. Next, autoimmune myopathies, including immune-mediated necrotizing myopathy, myositis with antimitochondrial antibodies, and overlap myositis with lupus, as well as the role of myxovirus protein A identification in muscle specimens, are addressed. The next section includes reports on the significance of elevated serum aldolase with normal creatine kinase and recommended approaches to evaluate a patient with rhabdomyolysis. A cluster of reports on muscle imaging, particularly using ultrasound and magnetic resonance imaging, are covered. They include studies of inherited and inflammatory myopathies and neck extensor myopathy on topics such as imaging features, patterns of involvement, diagnostic utility, and correlation with histopathology. Last, there are discussions on mexiletine versus lamotrigine for nondystrophic myotonias and the treatment of fatty acid oxidation disorders in adults.

Longitudinal study of patients with anti-SAE antibody-positive dermatomyositis: a multicenter cohort study in China

OBJECTIVES

To describe the longitudinal study and long-term prognosis of a multicentre large inception cohort of patients with anti-SAE positive DM.

METHODS

We retrospectively recruited patients with anti-SAE+DM in four tertiary referral centres from China between March 2005 and December 2022. Long-term survival analysis was performed on the enrolled patients. The Myositis Damage Index and Cutaneous Disease Area and Severity Index were used to evaluate the degree of different organ damage and the extent of skin rashes. Longitudinal CT patterns were analysed. Phenotypes were characterized using unsupervised cluster analysis.

RESULTS

All-cause death occurred in 10.5% (4/38) of all patients, in which three patients succumbed to malignancies at 13, 18 and 36 months. Most patients had favourable long-term outcomes, 35.3% of them were in drug-free remission. Skin rashes showed significant improvement evaluated by Cutaneous Disease Area and Severity Index with time. However, damage to different systems was observed in 70.6% of the surviving patients using the Myositis Damage Index, which mainly consisted of skin damage, accounting for 47.1%. Nine patients with anti-SAE+DM-associated interstitial lung disease underwent repeat CT showed marked radiological improvement at 6 months or being stable after 12 months. In further, different characteristics and outcomes were also showed in three clusters identified by unsupervised analysis.

CONCLUSIONS

Anti-SAE+DM is characterized with a lower mortality rate and the development of malignancies being the primary cause of death. Patients who survived showed notable cutaneous damage, while the interstitial lung disease tends to stabilize. Clusters identified with unsupervised analysis could assist physicians in identifying a higher risk of mortality.

Anti-mitochondrial M2 antibody-positive myositis may be an independent subtype of autoimmune myositis

It is still unknown whether anti-mitochondrial M2 antibody (AM2A)-positive myositis is an independent subtype of autoimmune myositis (AIM). As such, the aim of this study is to better characterize the clinicopathological features in a large cohort of patients. This study utilized the muscle biopsy samples from AM2A-positive patients, which were sent to the National Center of Neurology and Psychiatry for diagnostic purposes from January 2008 to December 2020. The clinicopathologic information of 201 patients were compared with those who were diagnosed with immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome, or dermatomyositis. AM2A-positive patients had the longest pre-biopsy disease duration (PBDD) at 48.7 ± 63.0 months and the highest frequency of arrhythmia of 51.1%. Necrotic and/or regenerating fibers were seen in 93.5% and membrane attack complex sarcolemmal deposits were noted in 43.3%, similar to IMNM. Furthermore, AM2A-positive patients with shorter PBDD showed more CD8-positive lymphocyte infiltrates. Clinically, shorter PBDD was associated with higher serum creatine kinase levels, whereas longer PBDD was associated with a higher frequency of arrhythmia. Principal component analysis separated disease groups with high weight of muscle pathology components on two-dimensional plotting, although AM2A-positive myositis and IMNM partly overlapped. On logistic regression model analysis, we obtained high sensitivity (0.846) and specificity (0.842) for distinguishing them using clinical and pathological variables. This largest cohort study suggests that AM2A-positive myositis may be an independent subtype of AIM characterized by a chronic myositis with IMNM-like pathology, along with a high prevalence of cardiac involvement and respiratory muscle weakness.

Ultrasensitive interferons quantification reveals different cytokine profile secretion in inflammatory myopathies and can serve as biomarkers of activity in dermatomyositis

Objective

The objective of this study was to evaluate the presence of different types of interferon in idiopathic inflammatory myopathies (IIM) and their subgroups using ultrasensitive cytokine detection techniques (SIMOA) and to assess their potential as activity biomarkers.

Methods

Disease activity was measured at the time of serum collection and assessed by manual muscle testing eight (MMT8 score 0-150), muscle enzymes to calculate the Physician Global Assessment (PGA) (0-10). Patients were classified as active if PGA>5.Serum IFN-α and IFN-γ levels was measured using the single molecule array (SIMOA) technique. Serum IFN-β level was measured by Elisa. Correlation between IFN levels and disease activity were performed.

Results

We included 242 IIM patients and found a good correlation between type I Interferon (IFN) and dermatomyositis disease activity. IFN-α and IFN-β was highly correlated with disease activity (r=0.76 and r=0,58). To evaluate whether the different types of Interferons could serve as biomarkers of activity, we generated ROC curves. Patients with active DM had a higher median IFN-α level (0.49 pg/ml [0.1-3.7]) compared with non-active patients (0.03 pg/ml [0.01-0.07] p<0.05). The area under the curve was 0.90 IC95 (0.76-0.97) p<0.05. Furthermore, Myositis-specific antibodies appear to be associated with a different secretion profile; patients with anti-MDA 5 antibodies had higher level of IFN-α than most other antibodies (6.58 vs 0.14 p<0.005). NXP2 had higher IFN-β level than patients with Tif1γ antibodies.

Conclusion

Serum IFN-α level measured by SIMOA is a reliable biomarker of DM activity. Myositis-specific antibodies appear to be associated with a different secretion profile. This data needs to be confirmed in order to select the good therapeutics strategies in DM.

Clinical Features and Prognosis of Double-Positive Anti-MDA5 and Anti-CCP Antibodies in Dermatomyositis: A Retrospective Study

Objective

To investigate the clinical features and prognosis of anti-melanoma differentiation-related gene 5 (MDA5) antibody and anti-cyclic citrullinated peptide (CCP) antibody double-positive dermatomyositis (DM) (MDA5+/CCP+ DM).

Methods

A retrospective analysis of 264 consecutive cases of MDA5+ DM hospitalized from March 2018 to March 2022, and patients with anti-CCP antibodies were screened out. Patients from MDA5+/CCP- served as the control. Propensity score matching was used to compare the clinical features, as well as the treatment and survival outcomes between the two groups.

Results

A total of 18 patients (6.8%) with MDA5+/CCP+ DM were identified. Gottron's sign in 17 cases (94.4%), Heliotrope rash in 14 cases (77.8%), and skin ulcer in 5 cases (27.8%). Arthritis occurred in 10 cases (55.6%) and presented as the initial symptom in 6 cases (33.3%). Only 8 (44.4%) of the patients met the criteria for rheumatoid arthritis (RA). Interstitial lung disease (ILD) was diagnosed in 17 cases (94.4%), with non-specific interstitial pneumonia (NSIP) and organizing pneumonia (OP) combined with NSIP being the most predominant, as they presented in 6 cases (33.3%) each. Two of the ILD cases (11.1%) developed into rapidly progressive ILD (RP-ILD). Arthritis (55.6% vs 15.3%, p = 0.001) and malignancy (22.2% vs 0%, p < 0.001) were significantly more common in the MDA5+/CCP+ group compared to the MDA5+/CCP- group. The clinical manifestations of MDA5+/CCP+ DM with or without anti-Ro-52 antibody were not significantly different from those of the ILD type. During the follow-up period, there was no significant difference in survival between the two groups.

Conclusion

More than half of the patients with MDA5+/CCP+ DM may present with arthritis as one of the initial symptoms. They may also have an increased risk of malignancy. For MDA5+ DM patients with positive anti-CCP antibodies, thorough screening for tumors is crucial to guide treatment and improve prognosis.

Mortality Risk Prediction in Patients With Antimelanoma Differentiation-Associated, Gene 5 Antibody-Positive, Dermatomyositis-Associated Interstitial Lung Disease: Algorithm Development and Validation

BACKGROUND

Patients with antimelanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated interstitial lung disease (anti-MDA5+DM-ILD) are susceptible to rapidly progressive interstitial lung disease (RP-ILD) and have a high risk of mortality. There is an urgent need for a reliable prediction model, accessible via an easy-to-use web-based tool, to evaluate the risk of death.

OBJECTIVE

This study aimed to develop and validate a risk prediction model of 3-month mortality using machine learning (ML) in a large multicenter cohort of patients with anti-MDA5+DM-ILD in China.

METHODS

In total, 609 consecutive patients with anti-MDA5+DM-ILD were retrospectively enrolled from 6 hospitals across China. Patient demographics and laboratory and clinical parameters were collected on admission. The primary endpoint was 3-month mortality due to all causes. Six ML algorithms (Extreme Gradient Boosting [XGBoost], logistic regression (LR), Light Gradient Boosting Machine [LightGBM], random forest [RF], support vector machine [SVM], and k-nearest neighbor [KNN]) were applied to construct and evaluate the model.

RESULTS

After applying inclusion and exclusion criteria, 509 (83.6%) of the 609 patients were included in our study, divided into a training cohort (n=203, 39.9%), an internal validation cohort (n=51, 10%), and 2 external validation cohorts (n=92, 18.1%, and n=163, 32%). ML identified 8 important variables as critical for model construction: RP-ILD, erythrocyte sedimentation rate (ESR), serum albumin (ALB) level, age, C-reactive protein (CRP) level, aspartate aminotransferase (AST) level, lactate dehydrogenase (LDH) level, and the neutrophil-to-lymphocyte ratio (NLR). LR was chosen as the best algorithm for model construction, and the model demonstrated excellent performance, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.866, a sensitivity of 84.8%, and a specificity of 84.4% on the validation data set and an AUC of 0.90, a sensitivity of 85.0%, and a specificity of 83.9% on the training data set. Calibration curves and decision curve analysis (DCA) confirmed the model's accuracy and clinical applicability. Moreover, the model showed strong predictive performance in the external validation cohorts (cohort 1: AUC=0.836, 95% CI 0.754-0.916; cohort 2: AUC=0.915, 95% CI 0.871-0.959), indicating good generalizability. This model was integrated into a web-based tool to predict the 3-month mortality for patients with anti-MDA5+DM-ILD.

CONCLUSIONS

We successfully developed a robust clinical prediction model and an accompanying web tool to estimate the 3-month mortality risk for patients with anti-MDA5+DM-ILD.

Peripheral Blood Lymphocyte Subsets and Heterogeneity of B Cell Subsets in Patients of Idiopathic Inflammatory Myositis with Different Myositis-specific Autoantibodies

Idiopathic inflammatory myopathies (IIM) are a group of myopathies that present with muscle weakness and multiple extra-muscular manifestations, in which lymphocytes play central roles in myositis pathogenesis. This study aimed to explore the clinical characteristics of lymphocyte subsets, especially B cell subsets, in patients with IIM. Our study included 176 patients with active IIM and 210 gender/age-matched healthy controls (HCs). Compared to HCs, patients have reduced counts of T cells, B cells, and natural killer cells. In addition, B cell subsets from 153 patients with IIM and 92 HCs were characterized. Patients had a lower percentage of memory B cells and translational memory B cells, while those patients were with an elevated percentage of CD19+ B cells, plasmablast and naïve B cells compared with HCs. Moreover, to further explore the heterogeneity of B cells in IIM, patients were categorized into three clusters based on clustering analysis. Cluster 1 was dominated by CD19+ B cells, Bregs and naïve B cells, cluster 3 was dominated by memory B cells and plasmablast, and cluster 2 had the highest proportion of translational memory B cells. Notably, patients in cluster 1 presented with higher CK levels, indicating muscle damage, whereas patients in cluster 3 showed a higher incidence of chest tightness. Our study indicated that lymphopenia is a common manifestation in patients with IIM. B cell subsets are abnormally expressed and showed high heterogeneity in patients with IIM. The patients with IIM were divided into three different clusters with different percentages of chest tightness and distinct CK levels.

Neutrophil-to-lymphocyte ratio and short-term mortality in patients having anti-MDA5-positive dermatomyositis with interstitial lung disease: a retrospective study

BACKGROUND

In this study, we aimed to explore the association between baseline and early changes in the neutrophil-to-lymphocyte ratio (NLR) and the 30-day mortality rate in patients having anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis with interstitial lung disease (DM-ILD).

METHODS

Overall, 263 patients with anti-MDA5 DM-ILD from four centers in China were analyzed. Multivariate logistic regression analysis was used to evaluate the impact of baseline NLR on the 30-day mortality rate in patients with anti-MDA5-positive DM-ILD. Furthermore, a generalized additive mixed model (GAMM) was applied to compare the NLR variations over time between 30-day survival group and non-survival group.

RESULTS

Two hundred sixty-three patients with anti-MDA5-positive DM-ILD were divided into different groups based on their NLR and whether they survived or not within 30 days. The multivariate logistic regression analysis, accounting for confounding factors, identified an elevated baseline NLR as a prognostic indicator for 30-day mortality in patients with anti-MDA5-positive DM-ILD (hazard ratio 2.68, 95% confidence interval [CI] 1.18,6.00, P = 0.019). Furthermore, the GAMM results indicated that the NLR gradually increased more in the non-survival group compared with the survival group within 14 days of admission, with a daily average increase of 1.03 (β = 1.03; 95% CI, 0.75-1.31; P < 0.001).

CONCLUSIONS

We found that an elevated baseline NLR and its progressive increase are associated with 30-day mortality in patients with anti-MDA5-positive DM-ILD.

Applicability of a serodiagnostic line blot for idiopathic inflammatory myopathy: the muscle biopsy is not all

Introduction

Differential diagnosis of rare idiopathic inflammatory myopathies (IIM) is mainly based on clinical aspects, muscle biopsy analysis, and auxiliary assays that determine myositis-specific and associated autoantibodies (MSA and MAA). While MSAs are considered specific for their respective IIM subclass, MAAs can be present in more than one subclass and in other conditions. This study compares results of a multispecific line blot assay with the final diagnosis of IIM patients based on clinical features and muscle biopsy to draw conclusions for the test's applicability in the diagnostic workflow.

Methods

Samples from patients (n = 50) diagnosed with various forms of IIM, including patients (n = 5) with other myopathies, were analyzed using the EUROLINE Autoimmune Inflammatory Myopathies 16 Ag (IgG), an anti-HMGCR (IgG) line blot, and the Anti-cN-1A ELISA (IgG, all EUROIMMUN).

Results

MSA and MAA were detected in 74.0% (37/50) of sera and were concordant with the final diagnosis in 64.8% (24/37), discordant in 16.2% (6/37) and not evaluable in 18.9% (7/37) of cases. In 100% (5/5) of patients with other myopathies, no MSA was found. MSA/MAA-co-positivity was observed in 18.0% (9/50) of patients. In 30.0% (15/50) of cases, the muscle biopsy analysis was essential to establish the final diagnosis.

Conclusion

The agreement between serodiagnostic results and final diagnosis highlights the applicability of the EUROIMMUN myositis-related diagnostic test as first line diagnostic tool in the IIM diagnosis workflow and suggests morphological analysis in cases of inconclusive or negative serology. However, results of diagnostic assays shall always be interpreted in combination with clinical features.

Prevalence and risk surveillance of anti-mitochondrial antibody-positive myositis: Outcomes of a nationwide survey

BACKGROUND

Anti-mitochondrial antibody (AMA)-positive myositis is a chronic disease characterized by skeletal muscle atrophy and is associated with cardiac complications and restrictive ventilatory impairment. This study aimed to determine the prevalence, rate of organ complications, and prognostic risk factors of AMA-positive myositis.

METHODS

We conducted a cross-sectional study using a nationwide questionnaire from 2011 to 2021, enrolling participants from neurology departments at 811 facilities certified by the Japanese Society of Neurology.

RESULTS

A total of 380 patients were identified, with a prevalence rate of 0.3 per 100,000 persons. The frequencies of cardiac complications and restrictive ventilatory impairment were 53 and 33 %, respectively; whereas, those of cardiac device and respirator introduction were 32 and 22 %, respectively. The frequencies of recurrence, subacute exacerbation, no muscle strength improvement, cardiac device introduction, respirator introduction, and death were 29, 25, 54, 32, 22, and 12 %, respectively. According to univariate analysis, abnormal echocardiograms (odds ratio [OR], 5.43), restrictive ventilatory impairment (OR, 3.70), and inflammatory changes revealed by muscle biopsy (OR, 0.34) were associated with subacute exacerbations, whereas abnormal echocardiograms (OR, 8.00) and durations from onset to admission and diagnosis (OR, 2.99) were associated with cardiac device introduction. Multivariable analysis showed that restrictive ventilatory impairment was associated with recurrence (adjusted OR, 3.01), adjusted for the duration from onset to admission and diagnosis, and with subacute exacerbations (adjusted OR, 3.86), adjusted for abnormal echocardiograms and inflammatory changes.

CONCLUSIONS

AMA-positive myositis is characterized by severe and urgent organ complications, and anticipatory management is critical for management of this disease.

Validation of the 2018 (New) ENMC Classification Criteria for Dermatomyositis in Chinese Patients with Idiopathic Inflammatory Myopathies

OBJECTIVES

To validate the 2018 European Neuromuscular Centre classification (ENMC) criteria, compare its performance to the 1975 Bohan & Peter (B&P) and 2017 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) criteria for dermatomyositis (DM), and describe characteristics of different myositis-specific autoantibody (MSA)-positive patients defined by the ENMC-DM criteria.

METHODS

Medical records and data on MSAs and muscle biopsies were retrospectively obtained from 1370 Chinese patients with idiopathic inflammatory myopathy (IIM) between 2008 and 2020. Patients were diagnosed with DM by at least two rheumatologists and classified according to the ENMC-DM, EULAR/ACR, and B&P criteria.

RESULTS

Of the 1370 patients, 857, 671, 693, and 913 were diagnosed with DM using the specialists' gold standard, ENMC-DM, EULAR/ACR, and B&P criteria, respectively. Significant between-group differences were observed in the clinical symptoms, serum creatine kinase levels, and MSAs (P < 0.05). Based on muscle biopsy data, the B&P criteria had the highest sensitivity (94%) but lowest specificity (65%). Without muscle biopsy data, the ENMC-DM criteria had the highest specificity (92%) but lowest sensitivity (61%). The sensitivity and specificity of the EULAR/ACR criteria were intermediate (72% and 86%, respectively) regardless of muscle biopsy data availability. With MSA data, the sensitivity and specificity of the ENMC-DM criteria were 73% and 91% and increased to 76% and 97%, respectively, with both muscle biopsy and MSA data.

CONCLUSIONS

The ENMC-DM criteria had higher specificity than the other criteria, especially in the absence of muscle biopsy data. Sensitivity and specificity improved when both muscle biopsy and MSA data were available. Key Points • Idiopathic inflammatory myopathy presents diagnostic challenges due to its variable features and dermatomyositis has distinct subtypes based on myositis-specific autoantibodies (MSAs) with unique clinical phenotypes. • This study validates the ENMC-DM criteria in Chinese patients and provides a comprehensive comparison with the B&P and EULAR/ACR criteria. • It demonstrates that the new ENMC-DM criteria exhibit higher specificity, especially noteworthy in cases without muscle biopsy, and the study further highlights the improved sensitivity and specificity when combining muscle biopsy and MSAs, offering a refined approach for accurate DM classification.

Contribution of major histocompatibility complex class II immunostaining in distinguishing idiopathic inflammatory myopathy subgroups: A histopathological cohort study

Idiopathic inflammatory myopathies (IIM) are rare, acquired muscle diseases; their diagnosis of is based on clinical, serological, and histological criteria. MHC-I-positive immunostaining, although non-specific, is used as a marker for IIM diagnosis; however, the significance of major histocompatibility complex (MHC)-II immunostaining in IIM remains debated. We investigated patterns of MHC-II immunostaining in myofibers and capillaries in muscle biopsies from 103 patients with dermatomyositis ([DM], n = 31), inclusion body myositis ([IBM], n = 24), anti-synthetase syndrome ([ASyS], n = 10), immune-mediated necrotizing myopathy ([IMNM], n = 18), or overlap myositis ([OM], n = 20). MHC-II immunostaining of myofibers was abnormal in 63/103 of patients (61%) but the patterns differed according to the IIM subgroup. They were diffuse in IBM (96%), negative in IMNM (83%), perifascicular in ASyS (70%), negative (61%) or perifascicular (32%) in DM, and either clustered (40%), perifascicular (30%), or diffuse heterogeneous (15%) in OM. Capillary MHC-II immunostaining also identified quantitative (capillary dropout, n = 47/88, 53%) and qualitative abnormalities, that is, architectural abnormalities, including dilated and leaky capillaries, (n = 79/98, 81%) in all IIM subgroups. Thus, MHC-II myofiber expression patterns allow distinguishing among IIM subgroups. We suggest the addition of MHC-II immunostaining to routine histological panels for IIM diagnosis.

Pneumocystis jirovecii pneumonia increases the 3-months mortality of anti-MDA5-antibody-positive dermatomyositis patients

Background

Anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (anti-MDA5+DM) patients are associated with considerable mortality, and opportunistic infections including Pneumocystis jirovecii pneumonia (PJP)is the main cause. This study was to identify clinical characteristics, risk factors, and prognostic factors of PJP diagnosed by bronchoalveolar lavage fluid (BALF) metagenomic next-generation sequencing (mNGS) in anti-MDA5+ DM patients.

Methods

In this retrospective observational study, all patients admitted with suspected pneumonia were detected for mNGS in BALF. The demographics, comorbidities, laboratory parameters, and treatments of the patients were compared and analyzed in both groups to identify the potential risk factors for PJP and death via Logistic regression and Cox proportional hazards regression, respectively.

Results

Overall, 92 patients were included in this study, 46(50.0%) were defined as PJP+ group, and the other 46 (50.0%) as PJP- group, and 31(67.4%) PJP occurred in the first 3 months. Increased neutrophil-lymphocyte ratio (NLR) and CRP were independent risk factors for PJP occurrence, while trimethoprim-sulfamethoxazole (TMP/SMZ) prophylaxis was an independent protective factor (all p<0.05). The three-months mortality rate was higher in the PJP+ group compared to PJP- group (43.5% vs 23.9%, p=0.047). Rapidly progressive interstitial lung disease (RPILD) was a main predictor of mortality in anti-MDA5+DM patients with PJP, whereas glucocorticoid use was a significant protective factor.

Conclusions

PJP has high prevalence and mortality in anti-MDA5+DM, while TMP/SMZ prophylaxis significantly reduces PJP risk. Mortality in PJP+ patients is primarily concentrated within the first 3 months, associated with RPILD. Early intervention with corticosteroids and prophylactic measures are crucial in reducing mortality.

Current efforts and historical perspectives on classification of idiopathic inflammatory myopathies

PURPOSE OF REVIEW

The classification of idiopathic inflammatory myopathies is challenging due to the large number of clinical, serological, histopathological and genetic findings, as well as the latest findings and developments in the field of myositis research. The latest official classification criteria are the 2017 European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) classification criteria for adult and juvenile idiopathic inflammatory myopathies, which have been extensively reviewed in recent years for their applicability, sensitivity and specificity.

RECENT FINDINGS

The sensitivity and specificity of the 2017 ACR/EULAR criteria are sometimes performing better, but usually at the same level as the previous criteria. A large number of further suggestions for amendments to the criteria have been made. In particular there is a need to revise the criteria with regard to the addition of new myositis-specific autoantibodies, newly defined subgroups (especially antisynthetase syndrome, immune medicated necrotizing myopathy and overlap myositis) and possibly the addition of further diagnostic procedures (for instance, muscle MRI or PET CT) to improve the accuracy and timeliness of the criteria.

SUMMARY

Efforts to optimize the myositis classification criteria have been extensive in recent years and a new global interdisciplinary collaboration of clinicians is currently taking place based on the previous results with the aim of revising the 2017 EULAR/ACR classification criteria.

Antimelanoma differentiation antigen 5-positive dermatomyositis: an update

PURPOSE OF REVIEW

Antimelanoma differentiation antigen 5-dermatomyositis (MDA5-DM) is a complex and serious systemic autoimmune disease that primarily affects the skin and lungs. In this review, we aimed to provide new insights into the clinical features, pathogenesis, and practical management approach for this disease.

RECENT FINDINGS

Although lung lesions are prominent in most patients with MDA5-DM, they are now recognized as heterogeneous diseases. Peripheral blood lymphocyte count can serve as a simple and reliable laboratory parameter for categorizing MDA5-DM into three subgroups: mild, medium, and severe. Recent studies have implicated viral infection, genetic factors, autoimmunity against MDA5, multiple immune cells, and interferons as significant contributors to MDA5-DM pathogenesis. In addition to traditional treatments with glucocorticoids and immunosuppressants, many new approaches, including new biologics and targeted agents, have been explored. Additionally, infection is a common complication of MDA5-DM, and prophylaxis or treatment of the infection is as important as treating the primary disease.

SUMMARY

Knowledge of clinical characteristics and pathogenesis of MDA5-DM has grown in recent years. Although many new therapeutic approaches have been explored, further studies are required to confirm their efficacy.

Anti-MDA5 autoantibodies predict clinical dynamics of dermatomyositis following SARS-CoV-2 mRNA vaccination: a retrospective statistical analysis of case reports

Since the introduction of mRNA vaccines against SARS-CoV-2, the induction of autoimmunity by mRNA vaccination has been discussed. Several cases of dermatomyositis (DM) associated with mRNA vaccination against SARS-CoV-2 infection have been reported. The question is whether there is a common pathomechanism for the induction of DM by this mRNA vaccination. The aim of this review is to analyse the sample of previously published case reports of DM following COVID-19 mRNA vaccination for common indicators of a possible immune pathomechanism.In this review, we summarised case reports of DM following mRNA vaccination against COVID-19. We considered this case report landscape as a cumulative sample (n = 32) and identified common clinical and molecular parameters in the intersection of case reports and statistically analysed the effect of these parameters on the development of DM.MDA-5 antibodies seem to play a role in the autoantibody signature after mRNA vaccination. MDA-5-positive DM is statistically more strongly associated with mRNA vaccination and interstitial lung disease/rapidly progressive interstitial lung disease (ILD/RP-ILD) than MDA-5-negative DM. MDA-5-positive DM seems not to be associated with an increased risk of malignancy, whereas MDA-5-negative DM is more strongly associated with malignancy.Our findings emphasize the potential role of innate antiviral signalling pathways in connecting DM to mRNA vaccination. MDA-5 autoantibodies appear to be predictive of a severe DM progression following mRNA vaccination. There seems to be an association between MDA-5 autoantibodies and paraneoplastic DM post-vaccination. Further studies are required to uncover the underlying mechanisms of autoimmunity triggered by mRNA vaccination.

Magnetic resonance imaging patterns revealing muscle pathology and clinical features in idiopathic inflammatory myopathies

OBJECTIVE

Idiopathic inflammatory myopathies (IIMs) are autoimmune disorders significantly impacting skeletal muscles; however, the precise correlation between muscle magnetic resonance imaging (MRI) findings, muscle pathology, disease subtypes and clinical characteristics remains uncertain. Thus, we investigated the association of muscle MRI findings in IIMs with muscle pathology and clinical features.

METHODS

New-onset IIM patients underwent proximal upper and/or lower limb muscle MRI. Patterns of muscle oedema on MRI were categorised into fascial, honeycomb, peripheral, foggy, dense, or coarse dot patterns and compared with inflammatory cell infiltration sites in corresponding muscle biopsies. The incidence of MRI patterns was examined in patient subgroups using myositis-specific antibodies (MSAs) and 2017 EULAR/ACR classification criteria. Univariate and multivariate analyses were conducted to determine the odds ratios (ORs) of MRI findings for clinical characteristics.

RESULTS

Fifty-six of 85 patients underwent muscle biopsy. Foggy, honeycomb and fascial patterns at biopsy sites correlated with inflammatory cell infiltration in the endomysium (OR 11.9, P = 0.005), perimysium (OR 6.0, P = 0.014) and fascia (OR 16.9, P < 0.001), respectively. Honeycomb and foggy patterns were characteristic of patients with anti-TIF1γ or anti-Mi2 antibodies and MSA-negative dermatomyositis, and those with anti-SRP or anti-HMGCR antibodies and MSA-negative polymyositis (PM), respectively. The honeycomb pattern positively correlated with malignancy (OR 6.87, P < 0.001) and Gottron sign (OR 8.05, P = 0.002); the foggy pattern correlated with muscle weakness (OR 11.24, P = 0.005). The dense dot pattern was associated with dysphagia (OR 6.27, P = 0.006) and malignancy (OR 8.49, P = 0.002).

CONCLUSION

Muscle MRI holds promise in predicting muscle pathology, disease subtypes and clinical manifestations of IIMs.

Updates in Dermatomyositis: Newer Treatment Options and Outcome Measures From Dermatologic Perspectives

Dermatomyositis (DM) is a rare autoimmune connective tissue disease with characteristic skin manifestations and possible muscle involvement. Recent advances in classification system to include skin-predominant subtypes, understanding underlying pathogenic mechanisms and the relationship between clinical phenotypes and myositis-specific autoantibodies have led to development of novel therapeutic options. This corresponds with efforts to develop better outcome measures to accurately catch the patients' current disease status and treatment-induced improvements. This report will review the updates in newer treatments and outcome measures of DM, specifically from a dermatologic point of view.

Sarcopenia assessed by DXA and hand-grip dynamometer: a potential marker of damage, disability and myokines imbalance in inflammatory myopathies

OBJECTIVES

To assess the ability of dual-energy X-ray absorptiometry (DXA) and hand-grip dynamometer to measure damage in inflammatory myopathies (IM).

METHODS

Forty adult IM patients with a disease duration ≥12 months, low or no disease activity for ≥6 months, were prospectively enrolled. Thirty healthy age and sex-matched volunteers were enrolled as controls. Whole-body DXA and hand-grip dynamometer were used to measure muscle mass, grip strength and diagnose sarcopenia (EWGSOP2 criteria). Relationships between the results of strength in 12 muscles, functional tests, patient-reported disability, IMACS damage score, and history of the disease were assessed. The serum levels of potential molecular actors in the damage were measured.

RESULTS

DXA and grip strength measurements took ≤20 min. Both muscle mass and grip strength were decreased in IM patients vs volunteers (-10% and -30%, respectively) with a dispersion that varied widely (interquartile range -24.3% to +7.8% and -51.3% to -18.9%, respectively). Muscle mass and grip strength were non-redundantly correlated (r up to 0.6, P = 0.0001) with strength in 14 muscles (manual muscle test and hand-held dynamometer), functions (of limbs, respiratory and deglutition muscles), patient-reported disability, damage (extension and severity in muscular and extra-muscular domains) and blood levels of several myokines. Seven IM patients (17.5%) were sarcopenic. They had the worst damage, impaired functions, disability and history of severe myopathy. Decreased irisin and osteonectin levels were associated with sarcopenia (area under the curve 0.71 and 0.80, respectively).

CONCLUSION

DXA and hand-grip dynamometer are useful tools to assess damage in IM. Irisin and osteonectin may play a role in IM damage pathogenesis.

Chinese Expert Consensus on the Diagnosis and Treatment of Adult Dermatomyositis (2022)#

Dermatomyositis, an idiopathic inflammatory myopathy, is characterized by distinctive skin manifestations, proximal muscle weakness, and multiple organ involvement and can be accompanied by malignancies. To provide a reference for dermatologists and clinicians in other relevant fields of clinical practice, experts from the Dermatology Branch of the China International Exchange and Promotion Association for Medical and Health Care and the National Clinical Research Center for Dermatologic and Immunologic Diseases developed this consensus on the diagnosis and treatment of adult dermatomyositis using Chinese and international literature and expert advice.

Clinicopathological features and treatment outcome of juvenile idiopathic inflammatory myopathies with anti-melanoma differentiation associated gene 5 antibodies: A case series study

To characterize the clinicopathological features and treatment outcomes of juvenile idiopathic inflammatory myopathies (JIIM) with anti-melanoma differentiation associated gene 5 (MDA5) antibodies in a Chinese cohort. Anti-MDA5 antibody was detected by immunodot assay and indirect immunofluorescence assay on HEK293 cells in a series of Chinese JIIM cohort between 2005 and 2022. The clinical features, histological findings, and treatment outcomes of these anti-MDA5-antibody-positive patients were summarized. Of 59 JIIM patients, 3 (5.08%) were found to be anti-MDA5-antibody-positive. The frequency of anti-MDA5 antibody did not show significant difference between adult idiopathic inflammatory myopathies and JIIM cohorts (P = .720). The disease duration in patients with anti-MDA5 antibody was 2.83 ± 1.04 months. All 3 patients had typical skin lesions including Gottron sign and heliotrope rash, while interstitial lung disease and arthritis was only found in 1 patient. All 3 patients showed normal creatine kinase levels. On muscle biopsy, diffuse major histocompatibility complex class-I expression was seen in 3 patients and myxovirus-resistance protein A expression was found in 2 patients. All patients received long-term follow-up (6.42 ± 4.01 years). They were all drug-free and showed favorable treatment outcome with prednisone and additional immunosuppressant. Our study indicates that anti-MDA5 antibodies may not be common in Chinese JIIM. Anti-MDA5-positive JIIMs are characterized by typical skin lesions of dermatomyositis, normal CK levels, and increased major histocompatibility complex class-I expression. JIIMs with anti-MDA5 generally have good response to immunotherapies.

Pathogenic mechanisms of disease in idiopathic inflammatory myopathies: autoantibodies as clues

Idiopathic inflammatory myopathies (IIMs) encompass a spectrum of autoimmune diseases characterized by muscle inflammation and systemic involvement. This review aimed to synthesize current evidence on the clinical significance and pathogenic mechanisms underlying autoantibodies associated with IIMs. Autoantibodies targeting aminoacyl-tRNA synthetases (ARS) play a pivotal role in antisynthetase syndrome (ASS), highlighting associations with interstitial lung disease (ILD) and distinctive clinical features. Anti-Mi-2 antibodies in dermatomyositis (DM) are hallmarked by characteristic cutaneous manifestations and favorable prognostic outcomes. Conversely, anti-TIF1 antibodies are correlated with DM and a higher risk of malignancies, implicating CD8+ T cells in its pathogenesis. Anti-MDA5 antibodies signify clinically amyopathic DM (CADM) with severe ILD, linked to dysregulated neutrophil extracellular trap (NET) formation. In immune-mediated necrotizing myopathies (IMNMs), anti-SRP and anti-HMGCR antibodies induce complement-mediated myopathy, typically following statin exposure. Additionally, anti-TRIM72 antibodies emerge as potential diagnostic markers in IIMs. Anti-cN1A autoantibodies are linked to inclusion body myositis (IBM) and play a decisive role in muscle protein degradation. Meanwhile, anti-FHL1 autoantibodies are associated with severe disease manifestations and muscle damage, as established in experimental models. Anti-eIF3 autoantibodies, recently identified in polymyositis (PM) patients, are rarely detected (<1%) and associated with a favorable prognosis. Elucidating these autoantibodies is anticipated to not only assist in early diagnosis and disease stratification but also inform targeted therapeutic interventions, emphasizing the intricate interplay between autoimmunity, cellular dysfunction, and clinical outcomes in IIMs.

Differentiating idiopathic inflammatory myopathies by automated morphometric analysis of MHC-1, MHC-2 and ICAM-1 in muscle tissue

AIMS

Diagnosis of idiopathic inflammatory myopathies (IIM) is based on morphological characteristics and the evaluation of disease-related proteins. However, although broadly applied, substantial bias is imposed by the respective methods, observers and individual staining approaches. We aimed to quantify the protein levels of major histocompatibility complex (MHC)-1, (MHC)-2 and intercellular adhesion molecule (ICAM)-1 using an automated morphometric method to mitigate bias.

METHODS

Double immunofluorescence staining was performed on whole muscle sections to study differences in protein expression in myofibre and endomysial vessels. We analysed all IIM subtypes including dermatomyositis (DM), anti-synthetase syndrome (ASyS), inclusion body myositis (IBM), immune-mediated-necrotising myopathy (IMNM), dysferlinopathy (DYSF), SARS-CoV-2 infection and vaccination-associated myopathy. Biopsies with neurogenic atrophy (NA) and normal morphology served as controls. Bulk RNA-Sequencing (RNA-Seq) was performed on a subset of samples.

RESULTS

Our study highlights the significance of MHC-1, MHC-2 and ICAM-1 in diagnosing IIM subtypes and reveals distinct immunological profiles. RNASeq confirmed the precision of our method and identified specific gene pathways in the disease subtypes. Notably, ASyS, DM and SARS-CoV-2-associated myopathy showed increased ICAM-1 expression in the endomysial capillaries, indicating ICAM-1-associated vascular activation in these conditions. In addition, ICAM-1 showed high discrimination between different subgroups with high sensitivity and specificity.

CONCLUSIONS

Automated morphometric analysis provides precise quantitative data on immune-associated proteins that can be integrated into our pathophysiological understanding of IIM. Further, ICAM-1 holds diagnostic value for the detection of IIM pathology.

Clinico-sero-pathological profiles and risk prediction model of idiopathic inflammatory myopathy (IIM) patients with different perifascicular changes

AIMS

To explore the clinico-sero-pathological characteristics and risk prediction model of idiopathic inflammatory myopathy (IIM) patients with different muscular perifascicular (PF) changes.

METHODS

IIM patients in our center were enrolled and the clinico-sero-pathological data were retrospectively analyzed. A decision tree model was established through machine learning.

RESULTS

There were 231 IIM patients enrolled, including 53 with perifascicular atrophy (PFA), 39 with perifascicular necrosis (PFN), and 26 with isolated perifascicular enhancement of MHC-I/MHC-II (PF-MHCn). Clinically, PFA patients exhibited skin rashes and dermatomyositis-specific antibodies (DM-MSAs, 74.5%) except for anti-Mi2. PFN patients showed the most severe muscle weakness, highest creatine kinase (CK), anti-Mi2 (56.8%), and anti-Jo-1 (24.3%) antibodies. PF-MHCn patients demonstrated negative MSAs (48.0%) and elevated CK. Histopathologically, MAC predominantly deposited on PF capillaries in PFA but on non-necrotic myofiber in PFN (43.4% and 36.8%, p < 0.001). MxA expression was least in PF-MHCn (36.0% vs. 83.0% vs. 63.2%, p < 0.001). The decision tree model could effectively predict different subgroups, especially PFA and PFN.

CONCLUSIONS

Three types of PF change of IIMs representing distinct clinico-serological characteristics and pathomechanism. Undiscovered MSAs should be explored especially in PF-MHCn patients. The three pathological features could be accurately predicted through the decision tree model.

Comparison of clinical features between patients with anti-synthetase syndrome and dermatomyositis: results from the MYONET registry

OBJECTIVES

To compare clinical characteristics, including the frequency of cutaneous, extramuscular manifestations and malignancy, between adults with anti-synthetase syndrome (ASyS) and DM.

METHODS

Using data regarding adults from the MYONET registry, a cohort of DM patients with anti-Mi2/-TIF1γ/-NXP2/-SAE/-MDA5 autoantibodies, and a cohort of ASyS patients with anti-tRNA synthetase autoantibodies (anti-Jo1/-PL7/-PL12/-OJ/-EJ/-Zo/-KS) were identified. Patients with DM sine dermatitis or with discordant dual autoantibody specificities were excluded. Sub-cohorts of patients with ASyS with or without skin involvement were defined based on presence of DM-type rashes (heliotrope rash, Gottron's papules/sign, violaceous rash, shawl sign, V-sign, erythroderma, and/or periorbital rash).

RESULTS

In total 1054 patients were included (DM, n = 405; ASyS, n = 649). In the ASyS cohort, 31% (n = 203) had DM-type skin involvement (ASyS-DMskin). A higher frequency of extramuscular manifestations, including Mechanic's hands, Raynaud's phenomenon, arthritis, interstitial lung disease and cardiac involvement differentiated ASyS-DMskin from DM (all P < 0.001), whereas higher frequency of any of four DM-type rashes-heliotrope rash (n = 248, 61% vs n = 90, 44%), violaceous rash (n = 166, 41% vs n = 57, 9%), V-sign (n = 124, 31% vs n = 28, 4%), and shawl sign (n = 133, 33% vs n = 18, 3%)-differentiated DM from ASyS-DMskin (all P < 0.005). Cancer-associated myositis (CAM) was more frequent in DM (n = 67, 17%) compared with ASyS (n = 21, 3%) and ASyS-DMskin (n = 7, 3%) cohorts (both P < 0.001).

CONCLUSION

DM-type rashes are frequent in patients with ASyS; however, distinct clinical manifestations differentiate these patients from classical DM. Skin involvement in ASyS does not necessitate increased malignancy surveillance. These findings will inform future ASyS classification criteria and patient management.

[Diagnosis of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis led by sarcoplasmic myxovirus resistance protein A expression on muscle pathology]

A 44-year-old woman with autism spectrum disorder developed bulbar symptoms and generalized muscle weakness 7 months before referral. Six months before, she was administered glucocorticoid for liver involvement. During the course, while she presented alopecia, skin ulcers, and poikiloderma, hyperCKemia was observed only twice. Due to complications including cardiac involvement and hearing loss as well, we suspected mitochondrial disease and performed a muscle biopsy. The muscle pathology showed sarcoplasmic myxovirus resistance A (MxA) expression with scattered pattern. Since anti-melanoma differentiation-associated gene 5 (MDA5) antibody was detected, we diagnosed the patient with anti-MDA5 antibody-positive dermatomyositis (DM). We reinforced immunosuppressive therapy, and her clinical symptoms and liver involvement were improved. When we diagnose a case of anti-MDA5 antibody-positive DM who is difficult to make clinical diagnosis, it may be valuable to evaluate sarcoplasmic MxA expression on muscle pathology.

Case report: A patient with brachio-cervical inflammatory myopathy was misdiagnosed as flail arm syndrome

Brachio-cervical inflammatory myopathy (BCIM) is a rare inflammatory myopathy characterized by dysphagia, bilateral upper limb atrophy, limb-girdle muscle weakness, and myositis-specific antibody (MSA) negativity. BCIM has a low incidence and is commonly associated with autoimmune diseases. We present a case report of a 55-year-old man with progressive upper limb weakness and atrophy, diagnosed with flail arm syndrome (FAS). The initial electromyography revealed extensive spontaneous muscle activity and increased duration of motor unit potentials (MUPs). During follow-up, evidence of myogenic damage was observed, as indicated by a decreased duration of MUPs in the right biceps muscle. Laboratory and genetic testing ruled out hereditary or acquired diseases. Negative serological antibodies for myasthenia gravis. Hereditary or acquired diseases were ruled out through laboratory and genetic testing. Whole-body muscle magnetic resonance imaging (MRI) showed extensive edema and fat replacement in the bilateral upper limbs, scapular, and central axis muscles, while the lower extremities were relatively mildly affected. Muscle biopsy revealed numerous foci of inflammatory cells distributed throughout the muscle bundle, with predominant CD20, CD138, and CD68 expression, accompanied by a light infiltration of CD3 and CD4 expression. The muscle weakness improved with the combination of oral prednisone (initially 60 mg/day, tapered) and methotrexate (5 mg/week) treatment.

Immunohistochemical expression in idiopathic inflammatory myopathies at a single center in Vietnam

BACKGROUND

The identification of idiopathic inflammatory myopathies (IIMs) requires a comprehensive analysis involving clinical manifestations and histological findings. This study aims to provide insights into the histopathological and immunohistochemical aspects of IIMs.

METHODS

This retrospective case series involved 56 patients diagnosed with IIMs at the Department of Pathology, University of Medicine and Pharmacy at Ho Chi Minh City, from 2019 to 2023. The histology and immunohistochemical expression of HLA-ABC, HLA-DR, C5b-9, Mx1/2/3, and p62 were detected.

RESULTS

We examined six categories of inflammatory myopathy, including immunemediated necrotizing myopathy (58.9%), dermatomyositis (DM; 23.2%), overlap myositis (8.9%), antisynthetase syndrome (5.4%), inclusion body myositis (IBM; 1.8%), and polymyositis (1.8%). The average age of the patients was 49.7 ± 16.1 years, with a female-to-male ratio of 3:1. Inflammatory cell infiltration in the endomysium was present in 62.5% of cases, perifascicular atrophy was found in 17.8%, and fiber necrosis was observed in 42 cases (75.0%). Rimmed vacuoles were present in 100% of cases in the IBM group. Immunohistochemistry showed the following positivity rates: HLA-ABC (89.2%), HLA-DR (19.6%), C5b-9 (57.1%), and Mx1/2/3 (10.7%). Mx1/2/3 expression was high in DM cases. p62 vacuole deposits were noted in the IBM case. The combination of membrane attack complex and major histocompatibility complex I helped detect IIMs in 96% of cases.

CONCLUSIONS

The diagnosis of IIMs and their subtypes should be based on clinical features and histopathological characteristics. Immunohistochemistry plays a crucial role in the diagnosis and differentiation of these subgroups.

Characterised intron retention profiles in muscle tissue of idiopathic inflammatory myopathy subtypes

OBJECTIVES

Idiopathic inflammatory myopathies (IIMs) are a group of heterogeneous autoimmune diseases. Intron retention (IR) serves as an important post-transcriptional and translational regulatory mechanism. This study aims to identify changes in IR profiles in IIM subtypes, investigating their influence on proteins and their correlations with clinical features.

METHODS

RNA sequencing and liquid chromatography-tandem mass spectrometry were performed on muscle tissues obtained from 174 patients with IIM and 19 controls, following QC procedures. GTFtools and iREAD software were used for IR identification. An analysis of differentially expressed IRs (DEIs), exons and proteins was carried out using edgeR or DEP. Functional analysis was performed with clusterProfiler, and SPIRON was used to assess splicing factors.

RESULTS

A total of 6783 IRs located in 3111 unique genes were identified in all IIM subtypes compared with controls. IIM subtype-specific DEIs were associated with the pathogenesis of respective IIM subtypes. Splicing factors YBX1 and HSPA2 exhibited the most changes in dermatomyositis and immune-mediated necrotising myopathy. Increased IR was associated with reduced protein expression. Some of the IIM-specific DEIs were correlated with clinical parameters (skin rash, MMT-8 scores and muscle enzymes) and muscle histopathological features (myofiber necrosis, regeneration and inflammation). IRs in IFIH1 and TRIM21 were strongly correlated with anti-MDA5+ antibody, while IRs in SRP14 were associated with anti-SRP+ antibody.

CONCLUSION

This study revealed distinct IRs and specific splicing factors associated with IIM subtypes, which might be contributing to the pathogenesis of IIM. We also emphasised the potential impact of IR on protein expression in IIM muscles.

The Clinical Value of the Neutrophil-to-Lymphocyte Ratio, the C-Reactive Protein-to-Albumin Ratio, the Systemic Inflammatory Index, and the Systemic Inflammatory Response Index in Patients with the Anti-Synthetase Syndrome

Objective

There are no studies examining the role of the neutrophil-to-lymphocyte ratio (NLR), the C-reactive protein-to-albumin ratio (CAR), the systemic inflammatory index (SII), and the systemic inflammatory response index (SIRI) in anti-synthetase syndrome (ASS). We aim to compare NLR, CAR, SII, and SIRI in ASS and dermatomyositis/polymyositis (DM/PM), as well as to examine potential correlations between NLR, CAR, SII, and SIRI and clinical features and laboratory parameters in ASS.

Methods

Retrospective collection of data from 111 patients with ASS and 175 patients with DM/PM. A Spearman rank correlation analysis was utilized to analyze the correlation between NLR, CAR, SII, and SIRI and inflammatory indexes. Receiver operating characteristic (ROC) curves were used to assess the diagnostic value. Univariate logistic regression analysis was performed to assess risk factors for interstitial lung disease (ILD).

Results

Compared with DM/PM, NLR, CAR, SII, and SIRI were significantly greater in ASS patients (p < 0.05). NLR, CAR, SII, and SIRI were correlated with albumin, lactic dehydrogenase (LDH), C-reactive protein (CRP), ferritin, white blood cell (WBC), platelets, and myositis disease activity assessment visual analog scales (MYOACT) score (p < 0.05). The ROC curves analysis showed that NLR, SII, and SIRI were all highly predictive of the occurrence of ASS. Comparisons based on clinical characteristics showed elevated levels of NLR, CAR, SII, and SIRI in ASS patients with ILD, fever, and infection (p < 0.05). Univariate logistic regression analysis revealed that NLR, CAR, and SII were significant risk factors for ASS-ILD (p < 0.05).

Conclusion

The levels of NLR, CAR, SII, and SIRI were higher in ASS than in DM/PM and correlated with disease activity and specific clinical features. NLR, CAR, SII, and SIRI may be an aid in differentiating ASS from DM/PM and maybe promising biomarkers for ASS.

Prevalence, Risk Factors, and Mortality of Invasive Pulmonary Aspergillosis in Patients with Anti-MDA5+ Dermatomyositis: A Retrospective Study in China

Objective

To investigate the prevalence, risk factors and prognosis of invasive pulmonary aspergillosis (IPA) in patients with anti-melanoma differentiation-associated gene 5 positive dermatomyositis (anti-MDA5+ DM).

Methods

A retrospective analysis was conducted in anti-MDA5+ DM patients diagnosed between January 2016 and March 2023. Patients with lower respiratory tract specimens were categorized into IPA+ and IPA- groups based on the presence of IPA and their clinical characteristics and prognoses then compared.

Results

Of the 415 patients diagnosed with anti-MDA5+ DM, 28 cases had IPA (prevalence rate of 6.7%) with Aspergillus fumigatus being the most common species. The patients were categorized into IPA+ (n=28) and IPA- (n=98) groups, with no significant age or gender-related differences (P>0.05). The IPA+ group had a lower lymphocyte count, particularly the CD4+ T-cell count, and reduced serum albumin and higher serum ferritin levels (P all<0.05). An elevated bronchoalveolar lavage fluid (BALF) galactomannan level was found to be the sole independent risk factor for the occurrence of IPA (adjusted OR=2.191, P=0.029) with a cut-off value of 0.585 and area under the curve of 0.779. The mortality rate in the IPA+ group was 25%. Compared to survivors, non-survivors in this group exhibited a higher incidence of rapidly progressive interstitial lung disease, lower lymphocyte counts, and increased co-infection with Pneumocystis jirovecii (P all<0.05).

Conclusion

IPA was not rare in patients with anti-MDA5+ DM, with elevated BALF galactomannan levels being an independent risk factor for IPA occurrence. Clinicians must exercise vigilance to identify patients exhibiting the aforementioned risk factors.

Liver Involvement is Associated with Higher Risk of Rapidly Progressive Interstitial Lung Disease and Mortality in Anti-Melanoma Differentiation-Associated Gene 5 Antibody- Positive Dermatomyositis

Purpose

This study aimed to assess liver involvement and investigate its correlation with rapidly progressive interstitial lung disease (RP-ILD) and mortality in anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5 positive) DM patients.

Patients and Methods

This retrospective study included 159 patients diagnosed with anti-MDA5 positive DM or anti-synthetase syndrome (ASyS). Clinical features and laboratory findings were compared between patients with anti-MDA5 positive DM and patients with ASyS. In the anti-MDA5 positive DM cohort, clinical features and laboratory findings between patients with liver involvement and without liver involvement were further compared. The effects of liver involvement on the overall survival (OS) and development of RP-ILD were also analyzed using Kaplan-Meier method and Cox regression analysis.

Results

Levels of serum aspartate aminotransferase (AST), alanine transaminase (ALT), γ-glutamyl transferase (γGT) and alkaline phosphatase (ALP) were all significantly higher in patients with anti-MDA5 positive DM than those in patients with ASyS. In our cohort of anti-MDA5 positive DM patents, 31 patients (34.4%) were complicated with liver involvement. Survival analysis revealed that serum ferritin >1030.0 ng/mL (p<0.001), ALT >103.0 U/l (p<0.001), AST >49.0 U/l (p<0.001), γGT >82.0 U/l (p<0.001), ALP >133.0 U/l (p<0.001), lactate dehydrogenase (LDH)>474.0 U/l (p<0.001), plasma albumin (ALB) <35.7 g/l (p<0.001) and direct bilirubin (DBIL) >2.80 μmol/l (p=0.002) predicted poor prognosis. The incidence of RP-ILD increased remarkably in patients with liver involvement compared to patients without liver involvement (58.1% vs 22.0%, p=0.001). Multivariate analysis revealed that elevated serum ALT level was an independent risk factor for mortality (HR 6.0, 95% CI 2.3, 16.2, p<0.001) and RP-ILD (HR 5.9, 95% CI 2.2, 15.9, p<0.001) in anti-MDA5 positive DM patents.

Conclusion

Liver involvement is common in patients with anti-MDA5 positive DM. Elevated serum ALT level was an independent risk factor for RP-ILD and mortality in patients with anti-MDA5 positive DM.

Myxovirus resistance protein A (MxA) expression in myositides: Sarcoplasmic expression is common in both dermatomyositis and lupus myositis

INTRODUCTION/AIMS

Myxovirus resistance protein A (MxA) is a type I interferon (IFN1) pathway activation marker and MxA sarcoplasmic expression is currently recognized as a highly specific marker for dermatomyositis (DM). However, we have frequently observed endothelial tubuloreticular inclusions (TRI), another surrogate IFN1 activation marker, in a variety of overlap myositides. The aim of this study was to examine MxA expression in those myositides.

METHODS

We retrospectively performed MxA immunostaining on a wide range of myositides.

RESULTS

MxA sarcoplasmic expression was present in DM (94.4%, 17/18), active lupus myositis (LM, 80%,16/20), inactive LM (36%, 4/11), antisynthetase syndrome (ASyS, 20%, 2/10), systemic sclerosis (13%, 2/15), Sjogren's syndrome (7.7%, 1/13), and human immunodeficiency virus (HIV) myositis (5.6%, 1/18) and was absent in immune-mediated necrotizing myopathy (IMNM, 0/16) and hydroxychloroquine myopathy (0/5). The sensitivity and specificity of MxA sarcoplasmic expression for LM and DM combined compared with all other myositides were 84.6% (95% CI: 69.5-94.1) and 92.1 (95% CI: 83.6-97.0), respectively, and superior to TRIs. MxA capillary expression was nonspecific. Histologically, 35% of LM cases demonstrated a unique panfascicular necrotizing myopathy pattern. The remainder of the LM cases had significant morphological overlap with DM/ASyS (20%), IMNM (20%), or polymyositis (15%).

DISCUSSION

MxA sarcoplasmic expression is highly prevalent in LM and DM and is a useful marker in differentiating DM and LM from other myositides. LM can manifest in various pathology patterns that need to be differentiated from DM, IMNM, ASyS, and polymyositis.