Polymyositis and dermatomyositis (first of two parts)

Severe interstitial lung disease risk prediction in anti-melanoma differentiation-associated protein 5 positive dermatomyositis: the STRAD-Ro52 model

OBJECTIVE

Anti-melanoma differentiation-associated gene 5-positive dermatomyositis-associated interstitial lung disease (MDA5+DM-ILD) often leads to acute respiratory failure and endangers lives. This study quantitatively analysed chest high-resolution computed tomography (HRCT) images to assess MDA5+DM-ILD and establish a risk prediction model for severe ILD within six months.

METHODS

We developed a 'Standardized Threshold Ratio Analysis & Distribution' (STRAD) to analyse lung HRCT images. In this retrospective study, 51 patients with MDA5+DM-ILD were included and divided into severe-ILD and non-severe-ILD groups based on the occurrence of acute respiratory failure within six months post-diagnosis of MDA5+DM. The STRAD parameters, clinical indicators and treatments were compared between the two groups. Least absolute shrinkage and selection operator (LASSO) regression was used to select the optimal STRAD parameters. Multivariate analysis selected clinical factors to be further combined with STRAD to enhance the predictive performance of the final model (STRAD-Ro52 model).

RESULTS

Significant differences were observed between the two groups in STRAD parameters, anti-Ro52 antibody titers, presence of anti-Ro52 antibodies, age, ESR, ALB, Pa/FiO2, IgM and IL-4 levels. The STRAD parameters were significantly correlated with demographic, inflammatory, organ function and immunological indicators. Lasso logistic regression analysis identified the -699 to -650 HU lung tissue proportion (%V7) as the optimal parameter for predicting severe ILD and S6·%V7, and the distribution of %V7 in the mid lungs was the optimal space parameter. Multifactorial regression of clinical indicators showed that the presence of anti-Ro52 antibodies was an independent risk factor for severe ILD, leading to the establishment of the STRAD-Ro52 model.

CONCLUSIONS

The STRAD-Ro52 model assists in identifying MDA5+DM patients at risk of developing severe ILD within six months, further optimizing precise disease management and clinical research design.

An update on the pathogenesis of idiopathic inflammatory myopathies

PURPOSE OF REVIEW

As the question of the pathogenesis of inflammatory myopathies remains unanswered, there has been a significant effort in recent years to investigate various components of the innate and adaptive immune systems, with evidence pointing that they work together to initiate and propagate the autoimmune response. This review aims to explore recent advancements in understanding the mechanisms underlying myopathies.

RECENT FINDINGS

Recent research has concentrated on uncovering potential triggers, examining the role of immune cells, both lymphocytes and myeloids, and investigating the contribution of inflammatory mediators to the autoimmune response in inflammatory myopathies. Unsuccessful clinical trials helped reshape established hypotheses about pathogenesis, while genetic mutations offered clues to the disease's root causes. The pathogenic role of autoantibodies is being reconsidered based on transcriptional data. Repurposing existing medications to combat muscle fiber dysfunction is also emerging as a potential therapeutic approach.

SUMMARY

Our understanding of inflammatory myopathies has evolved significantly as our understanding of the disease has grown. Even though breakthroughs have been documented on the underlying mechanisms of myopathies, important questions remain unanswered.

Analysis of clinical features and risk factors of pulmonary hypertension associated with interstitial lung disease

Pulmonary hypertension (PH) can significantly impact the prognosis of interstitial lung disease (ILD). There are limited studies on the clinical characteristics and risk factors of PH associated with ILD (PH-ILD). The present study aimed to analyze the clinical characteristics of patients with PH-ILD and explore the correlation and predictive value of the easily obtainable indicators with respect to the severity of PH in patients with ILD. The results indicated that the red blood cell distribution width (RDW) and mean platelet volume (MPV) of patients with ILD with the moderate-to-severe PH (Ms-PH) were significantly higher compared with those of patients with ILD without PH and those with Mild-PH (P<0.05). Age, RDW, MPV and immunoglobulin G levels were emerged as independent risk factors for Ms-PH in patients with ILD. Receiver operating characteristic curve analysis demonstrated that the combination of RDW and MPV enhances the diagnostic efficiency for Ms-PH in patients with ILD. Consequently, the present study demonstrated that RDW and MPV are predictive factors for Ms-PH in patients with ILD.

Comparison of rituximab efficacy in treatment-naïve and refractory inflammatory myopathies: experiences from a tertiary care centre

OBJECTIVES

To determine whether rituximab (RTX) is effective in 'treatment-naïve' idiopathic inflammatory myopathies (IIM), and whether there could be differential treatment responses between 'treatment-naïve' and treatment 'refractory' IIM.

METHODS

Data were obtained from a prospectively maintained database comprising patients with IIM treated with RTX. Patient details were obtained at baseline, 3- and 6-months intervals, and at subsequent follow-up visits. Treatment response was categorized as improved, worsening or stable based on Manual Muscle Testing 8 (MMT8) scores, patient global and physician global improvement for skin and joint symptoms improvement, and spirometry at 6 months. The time to clinical improvement and remission were noted and survival analysis curves were constructed.

RESULTS

Sixty patients with IIM (including 18 with anti-signal recognition particle myopathy) were included, of whom 33 who received RTX were treatment naïve. The remaining 27 were started on RTX for refractory myopathy. The mean age was 39 years (s.d. 12.58) in the 'treatment-naïve' group and 43 years (s.d. 12.12) in the 'refractory' group. At 6 months of follow-up, 48/55 (87%) patients showed response, 31/31 (100%) in 'treatment-naïve' and 17/24 (70%) in 'refractory' cases, P = 0.006*. In the refractory group, seven (29%) had stable disease. The mean changes in MMT8 were significantly more in the 'treatment-naïve' group [13.41 (s.d. 7.31)] compared with 'refractory' IIM [8.33 (s.d. 7.92)] (P = 0.017*). The majority of patients were able to reduce the dose to <5 mg/day before 6 months. No major adverse events were reported over the median follow-up of 24 (interquartile range 36) months.

CONCLUSIONS

RTX is effective and safe across the spectrum of IIM. Early use in disease is associated with better outcomes.

Physical activity and quality of life of children and adolescents with juvenile idiopathic arthritis, juvenile systemic lupus erythematosus and juvenile dermatomyositis during the COVID-19 pandemic

OBJECTIVES

1) To assess the level of physical activity of children and adolescents with IMRD (juvenile idiopathic arthritis - JIA, juvenile systemic lupus erythematosus-JSLE, or juvenile dermatomyositis - JDM) throughout the COVID-19 pandemic in a tertiary reference service, and 2) To assess the HRQoL and fatigue in these patients.

METHODS

The authors included 57 children and adolescents with JIA, JSLE, and JDM, who were clinically inactive according to the assisting physician evaluation. The control group consisted of healthy children. Data was collected during the period of social isolation. The instruments used for the assessments were the International Physical Activity Questionnaire (IPAQ), the Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0), and the Pediatric Quality of Life Inventory - Fatigue Module (PedsQL - Fatigue Module).

RESULTS

About 68.5 % of patients and 79.3 % of controls were considered active regarding physical activity, without any difference between physical activity intensity scores between the groups. Regarding HRQoL, the authors observed lower scores in patients' physical, social, and school functioning domains. The authors observed that patients had higher levels of fatigue according to parents and caregivers.

CONCLUSION

The impact on physical activity levels of children and adolescents with IMRD throughout the COVID-19 pandemic was positive, with the majority of patients being classified as active, according to the IPAQ questionnaire. Furthermore, the patients engaged in moderate and light physical activities, similar to healthy controls. Regarding HRQoL, the present data showed that patients had lower scores in most of the dimensions assessed.

Validation of the International Myositis Assessment and Clinical Studies Group guideline on cancer risk stratification

OBJECTIVES

Adult-onset idiopathic inflammatory myopathies (IIMs) are associated with cancer. Guideline on cancer risk stratifications and screening in IIM patients was recently published, but their external validity remains verified. We evaluated its applicability and reliability among a Hong Kong IIM cohort.

METHODS

The longitudinal observational cohort collected data from IIM patients fulfilling relevant classification criteria from eight rheumatology centres in Hong Kong. Demographic, clinical and laboratory data were reviewed from 2004 to 2023. IIM patients were stratified into standard, intermediate or high-risk subgroups according to the IMACS guideline. The occurrence of malignancy at or after IIM diagnosis was analysed. Independent risk factors for cancer were evaluated.

RESULTS

A total of 479 patients were included with 327 females (68.3%) and mean age of IIM diagnosis at 54.5 ± 13.6 years. In total, 214 (44.7%) and 238 (49.7%) patients were stratified to high and intermediate risk groups, respectively. Only 5.6% belonged to the standard-risk group. Sixty patients (12.5%) had cancer within 3 years of IIM diagnosis. Nasopharyngeal (25%), lung (21.1%) and breast (10.5%) were the top three cancers. Significantly more patients (44, 20.6%) in the high-risk group developed cancer within 3 years, compared with intermediate (6.7%, P < 0.001) and standard-risk (0%, P = 0.009) groups. Risk factors for cancer included older age (OR: 1.048, 95%CI: 1.019-1.078), Gottron's rash (OR: 2.453, 95%CI: 1.123-5.356), absence of interstitial lung disease (OR 2.695, 95% CI: 1.154-6.295), anti-TIF1g positivity (OR: 4.627, 95% CI: 2.046-10.461) and anti-SAE1 positivity (OR: 5.325, 95% CI: 1.271-22.300).

CONCLUSIONS

Our real-world study supported the accuracy of cancer risk stratification. The vast majority of IIM patients would be subjected to extensive cancer screening when the guideline was applied.

Histopathologic Features of Acral Skin Biopsies in Dermatomyositis Patients and Comparison to Histopathologic Features in Non-Acral Biopsies

BACKGROUND

Acral lesions may represent the best/only skin lesions to biopsy in patients suspected to have dermatomyositis (DM). However, histopathologic features of acral DM skin lesions are poorly characterized.

METHODS

We reviewed 50 acral biopsies from 46 DM patients and assessed numerous histopathologic features. The majority of biopsies (42/50; 84%) were sampled from either Gottron papules or signs. We compared histopathologic features in acral biopsies to those in 197 non-acral DM skin biopsies. We also compared histopathologic features in acral biopsies based on the presence of various clinical features.

RESULTS

Interface dermatitis, dyskeratotic keratinocytes, and superficial perivascular inflammation were common in DM acral biopsies. However, the absence of > 1 hallmark histopathologic feature (interface dermatitis, dyskeratosis, dermal mucin) was relatively common (56%). The presence of all three hallmark histopathologic features was significantly more likely in non-acral compared with acral DM biopsies (68% vs. 44%; p = 0.0021). The hallmark histopathologic feature most commonly lacking in acral compared with non-acral biopsies was increased dermal mucin. Histopathologic features in acral biopsies did not significantly differ based on acral location, DM subtype, therapeutic regimen, or myositis-associated/myositis-specific antibody status.

CONCLUSIONS

Pathologists should recognize that acral biopsies in DM patients may lack hallmark histopathologic features commonly seen in biopsies from non-acral locations.

Established and novel insights to guide cancer assessment in patients with idiopathic inflammatory myopathies

OBJECTIVE

Older age, dermatomyositis, and specific serum autoantibodies such as anti-TIF1-γ are associated with higher cancer risk in patients with myositis. We evaluated a vast cohort of patients with myositis for the prevalence of cancer, the association to disease features, and the performance of the recent IMACS guidelines.

METHODS

A retrospective cohort analysis was performed and in all cases serum autoantibodies were tested using HEp-2, immunoassays, RNA- and protein-immunoprecipitation. Myositis was defined as cancer-associated if malignancy occurred within 3 years prior to or after the onset of myositis.

RESULTS

Ninety-five patients with IIM were followed-up for a median of 6 years (interquartile range 3-11), the majority were classified as 'high-risk' or 'intermediate-risk' of cancer based on IMACS guidelines. A diagnosis of cancer was made in 22/95 (23 %) of cases and, based on the timing of the diagnosis, 14 % patients were cancer-associated myositis, with no significant differences compared to patients without cancer. Both groups of patients with overall cancer and cancer-associated myositis had more respiratory comorbidities, anemia, and hypergammaglobulinemia, and dermatomyositis phenotype. Anti-TIF1-γ antibody positivity predicted cancer-associated myositis but not the overall cancer rate; malignancy was observed in particular in patients with isolated anti-TIF1-γ antibodies, while a lower prevalence occurred in case of additional specificities identified by immunoprecipitation.

CONCLUSIONS

Recent IMACS guidelines perform well in the interception of cancer, yet adjunctive history and laboratory features should be considered. Patients with anti-TIF1-γ antibodies are at risk of cancer-associated myositis, but concurrent autoantibodies negatively correlate with malignancy and warrant characterization.

Age-Related Differences Between Juvenile and Adult Autoimmune Inflammatory Myopathies

BACKGROUND

Clinical features and prognosis of autoimmune inflammatory myopathies (AIMs) can vary depending on the age of disease onset. The aim of this study was to compare the demographic characteristics, clinical features, laboratory findings, and long-term prognosis of juvenile and adult AIMs.

METHODS

Patients diagnosed with AIM between 2009 and 2023 in the pediatric rheumatology and rheumatology departments of our hospital were included in this medical records review study. Demographic characteristics, clinical features, laboratory findings, treatments, and prognosis of juvenile and adult AIM patients were compared with statistical methods.

RESULTS

Of the 94 patients diagnosed with AIM, 34 (36.2%) patients were juvenile and 60 (63.8%) patients were adult. At the time of diagnosis, while Gottron papules, dysphonia, and subcutaneous edema were more common in juvenile patients, fever was more common in adult patients ( p = 0.003, p = 0.05, p = 0.005 p = 0.05, respectively). During follow-up, while calcinosis was more common in juvenile patients, lung involvement and malignancy were more common in adult patients ( p = 0.022, p = 0.009, p = 0.006, respectively). The methylprednisolone pulse therapy requirement was significantly higher in juvenile patients ( p = 0.0001). Clinically inactive disease was more common in juvenile patients ( p = 0.01).

CONCLUSIONS

AIM with different onset ages is associated with distinct clinical manifestations and outcomes. The present study reported that in AIM patients, lung involvement and malignancy increase with age while clinically inactive disease decreases.

Evaluating CA-125 and PET/CT for cancer detection in idiopathic inflammatory myopathies

OBJECTIVE

This study aims to evaluate the diagnostic accuracy of CA-125 and PET/CT in detecting cancer among adult patients with idiopathic inflammatory myopathy (IIM).

METHODS

We conducted a retrospective study of a single-centre cohort of adult IIM patients enrolled from 2003 to 2020. Data on CA-125 and PET/CT tests conducted within five years of IIM symptom onset were extracted from electronic medical records. The outcomes assessed included true-positive, false-positive, true-negative and false-negative results.

RESULTS

Among 1432 patients with IIM, 250 CA-125 tests were conducted on 205 patients within the first five years of symptom onset, yielding a false-positive rate of 3.1% and a false-negative rate of 14.3%. Most false-positives were associated with endometriosis or uterine fibroids, but additional medical procedures were often carried out to investigate the false-positive results. For PET/CT, 149 tests were performed on 139 patients, resulting in a false-positive rate of 5.5% and a false-negative rate of 28.6%. Lymphadenopathy and lung nodules were the predominant causes of false-positives, while melanoma, low-stage breast cancer and prostate cancer were the most frequent cancers missed (false-negatives).

CONCLUSION

False-positive and false-negative results are prevalent in cancer antigen 125 (CA-125) and PET/CT testing for adult patients with newly diagnosed idiopathic inflammatory myopathy. Understanding the causes of these inaccuracies can aid clinicians in making informed decisions during patient care.

Pulse corticosteroid therapy in interstitial lung disease-associated with anti-aminoacyl-tRNA synthetase antibodies: Comparable efficacy with potential for reduced adverse events

BACKGROUND AND OBJECTIVE

The optimal treatment modality for interstitial lung disease (ILD) associated with anti-aminoacyl-tRNA synthetase (ARS) antibodies remains controversial. This study aimed to compare the efficacy and safety of pulse corticosteroid therapy with that of conventional corticosteroid therapy in patients with anti-ARS ILD.

METHODS

This retrospective cohort study included 62 patients with anti-ARS ILD. Patients were divided into two groups: Those who received pulse corticosteroid therapy (500-1000 mg of methylprednisolone intravenously for three days) and those who received conventional corticosteroid therapy. Primary outcomes included initial treatment response at one year and disease recurrence. Secondary outcomes were alterations in pulmonary function tests, KL-6 levels, prednisolone dose, and adverse events.

RESULTS

Both the pulse corticosteroid therapy group and the conventional therapy group had similar rates of initial treatment improvement (90.3 % vs. 77.4 %, p = 0.301), with no significant differences in recurrence-free survival. Improvements in pulmonary function tests were comparable between the two groups. At 12 months, the mean daily prednisolone dose was 3.9 mg in the pulse therapy group compared with 6.0 mg in the conventional therapy group. The pulse corticosteroid therapy group also experienced fewer adverse events (25.8 % vs. 61.3 %, p = 0.010).

CONCLUSION

Pulse corticosteroid therapy provides similar treatment efficacy, earlier reduction in corticosteroid dosage, and a lower incidence of adverse events compared to conventional therapy in patients with anti-ARS ILD. These findings highlight the potential benefit of a steroid-sparing strategy, suggesting that pulse corticosteroid therapy may be considered an effective and safer option in managing this condition.

Snapshot of a Decade: Idiopathic Inflammatory Myopathies in Chile-A 10-Year Short Report

BACKGROUND

Idiopathic inflammatory myopathies (IIMs) are rare autoimmune diseases with limited epidemiological data from Latin America.

OBJECTIVE

To characterize IIMs through incident rate patterns and clinical features in a major Chilean referral center over a 10-year period.

METHODS

Historical cohort study (2012-2021) reviewing clinical records from rheumatology outpatient clinic of patients with IIM diagnosis. Incident rates were calculated as IIM cases per specialty consultations. Clinical characteristics, antibody profiles, and treatment outcomes were analyzed. Both consultation-based and population-based estimates for incidence and prevalence were determined.

RESULTS

Among 3,594,047 specialty consultations, 100 IIM cases were identified (2.78 cases per 100,000 consultations; 95% confidence interval, 2.27-3.39). Mean annual incidence was 0.58 cases per 100,000 adults (95% confidence interval, 0.47-0.69), with 2021 prevalence ranging from 5.07 to 8.57 per 100,000 adults, depending on the denominator population. Dermatomyositis was the most frequent subtype (71%).

CONCLUSIONS

This first consultation-based analysis of IIMs in Chile provides baseline data for health care resource utilization. The methodology offers a practical approach for rare disease epidemiology in similar health care settings, whereas the findings align with international reports.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cardiac Involvement in Idiopathic Inflammatory Myopathies

Idiopathic inflammatory myopathies (IIMs) are a group of autoimmune diseases that includes the main subtypes dermatomyositis, polymyositis, immune-mediated necrotizing myopathy, and inclusion body myositis. IIMs are characterized by the involvement of skeletal muscle and multiple organs, including the heart. This review summarizes the pathology, prevalence, biomarkers, imaging and treatment of cardiac involvement in patients with IIMs. The cardiac involvement in these patients is usually subclinical and rarely considered as the main clinical feature at the time of initial consultation, with a prevalence ranging from 4% to 26%. However, it results in a worse prognosis and represents the main cause of mortality in patients with IIMs. The selection of specific serum cardiac biomarkers is essential for the early detection of cardiac involvement in patients with IIMs, such as cardiac troponin I (cTnI), which is preferred over cardiac troponin T (cTnT), followed by diagnostic evaluations including electrocardiography (ECG), echocardiography (ECHO), and cardiac magnetic resonance imaging (CMR). The combination of glucocorticoids, immunosuppressants, and conventional cardiac medications is effective for the management of IIM patients with confirmed cardiac involvement.

Cardiovascular risk and cardiac involvement in idiopathic inflammatory myopathies: insights from a cross-sectional Swedish single-centre study

OBJECTIVE

We aimed to investigate the cardiovascular profile, including risk factors and cardiovascular abnormalities, in patients with idiopathic inflammatory myopathies (IIMs).

METHOD

In this cross-sectional study, 109 IIM patients and 20 age- and gender-matched healthy controls were enrolled and underwent electrocardiographic and transthoracic echocardiographic examinations. We analysed blood levels of cardiac troponin I (cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP), assessed IIM disease-specific features, and evaluated the medical history of cardiovascular risk factors. IIM patients were stratified into two groups: those with previous cardiac involvement and those without.

RESULTS

IIM patients had a higher body mass index (BMI) and a greater prevalence of diabetes mellitus and dyslipidaemia than healthy controls (p = 0.023, p = 0.024, and p = 0.042, respectively). They also showed significantly higher rates of arrhythmia, cardiac axis deviation, negative T-waves, and suspected pulmonary hypertension, along with elevated NT-proBNP levels (p = 0.041, p = 0.004, p = 0.041, p = 0.012, and p = 0.034, respectively). A significantly higher proportion (p = 0.037) of immune-mediated necrotizing myopathy (IMNM) subtype (50%) was found among IIM with previous cardiac involvement compared to those without (20%). cTnI levels were significantly higher in IIM with cardiac involvement than in IIM without cardiac involvement (p = 0.009).

CONCLUSIONS

Cardiovascular complications in patients with IIM may result from an increased prevalence of traditional cardiovascular risk factors, such as higher BMI, diabetes mellitus, and dyslipidaemia, and/or from direct cardiac involvement, such as previous myocarditis. Cardiac involvement in IIM is notably associated with the IMNM subtype.

Enhanced systemic oxidative stress response in patients with idiopathic inflammatory myopathies

BACKGROUND

Idiopathic inflammatory myopathies (IIM) are characterized by chronic inflammation, endothelial dysfunction, and muscle tissue mitochondrial defect, leading to the local oxidative stress response. However, data on its systemic intensity and correlation with IIM clinical and laboratory characteristics remains scarce.

METHODS

In clinically stable dermatomyositis (n = 18) and myositis (n = 38) patients and matched controls (n = 50), we measured global oxidative stress response in peripheral blood using a novel coumarin boronic acid (CBA) assay enabling real-time detection of protein hydroperoxides (HP) formed in serum.

RESULTS

We documented 36% faster kinetics (p < 0.001) and a 68% increase in the cumulative (p = 0.003) fluorescent product generation in the IIM group compared to the control, which indicates higher HP formation associated with systemic oxidative stress. The dynamics of fluorescent product growth were similar in the dermatomyositis and myositis groups. Interestingly, myositis patients with a marked increase in HP formation were characterized by lower serum myoglobin levels (p = 0.038). There was also an inverse correlation between serum myoglobin and the kinetics of HP formation (e.g., for cumulative in-time generation r = -0.35, p = 0.03). The systemic oxidative stress response measures were not related to clinical characteristics of the disease and treatment, internal medicine comorbidities, smoking status, or autoantibody profile.

CONCLUSIONS

IIM are characterized by a global pro-oxidant imbalance reflected by enhanced HP generation in serum. Furthermore, muscle weakening without active signs of muscle damage may be related to the increased local and systemic oxidative stress response, suggesting non-inflammatory pathomechanism of the disease that our technically undemanding assay may evaluate.

Anti-synthetase syndrome with anti-PL-7 antibody positive in a child: a case report and literature review

Background

Anti-synthetase syndrome (ASS) is a rare autoimmune myopathy and forms part of the idiopathic inflammatory myopathies (IIMs). A distinctive feature of ASS is the presence of anti-aminoacyl tRNA synthase (ARS) antibodies, which target synthetases, leading to inflammation in muscles, lungs, and other tissues.

Case presentation

A case of a 12-year-old Chinese girl with recurrent fever, myalgia, and Gottron's papules is reported. Serum creatine kinase was markedly elevated, and chest CT revealed interstitial changes. Magnetic Resonance Imaging (MRI) of the left thigh indicated soft tissue swelling and interstitial fluid accumulation. Electromyography demonstrated myogenic injury. Pathological examination of a left thigh muscle biopsy revealed local edema, focal lymphocyte infiltration, and proliferation and dilation of interstitial small vessels. The myositis antibody spectrum test was positive for anti-PL-7 antibodies. Treatment with glucocorticoids and methotrexate led to significant improvement in her condition.

Conclusion

This case represents the youngest reported patient with PL-7 positive ASS to date.

Epidemiology of myositis

PURPOSE OF REVIEW

This review aims to synthesize recent developments in the epidemiology of idiopathic inflammatory myopathies (IIMs), focusing on incidence, prevalence, disease classification, and clinical outcomes.

RECENT FINDINGS

IIM is a rare group of autoimmune diseases characterized by muscle weakness and systemic involvement, with incidence rates ranging from 0.2 to 2 cases per 100 000 person-years. The role of myositis-specific autoantibodies (MSAs) in stratifying disease risk and prognosis is increasingly recognized, such as in anti-MDA5 positive DM, which is associated with a high risk of rapidly progressive interstitial lung disease. Furthermore, patients with IIM exhibit elevated risks of comorbidities, including cardiovascular disease and malignancy.

SUMMARY

IIM diseases are complex disorders with significant health impacts, necessitating enhanced awareness and research. Improved classification and understanding of MSAs are crucial for earlier diagnosis and tailored therapeutic strategies. Continued epidemiological research is essential to elucidate underlying mechanisms and inform future interventions, ultimately aiming to enhance the quality of life and clinical outcomes for affected patients.

Idiopathic inflammatory myopathies related lung disease in adults

Interstitial lung disease (ILD) is common in idiopathic inflammatory myopathies in adults, especially in patients with antisynthetase syndrome and anti-MDA5 antibody-associated dermatomyositis. Pulmonary manifestations can range from subclinical ILD to rapidly progressive respiratory failure. Coexistent myositis, characteristic skin lesions, arthritis, and Raynaud's phenomenon are common. However, 16-65% of patients present with isolated lung disease. Detection of myositis-specific and myositis-associated antibodies can aid in diagnosis and disease characterisation. Chest imaging and pathology most commonly show non-specific interstitial pneumonia and organising pneumonia patterns. Immunosuppression is the mainstay of management with aggressive combination treatment for rapidly progressive disease and incremental escalation as needed for chronic ILD. The addition of antifibrotic agents is an option in progressive fibrotic disease, and lung transplantation can be considered in severe, end-stage disease. Most patients respond to treatment, but short-term mortality remains high for patients with rapidly progressive disease associated with anti-MDA5 antibody ILD.

Machine learning-driven immunophenotypic stratification of mixed connective tissue disease, corroborating the clinical heterogeneity

OBJECTIVE

The objective of this study was to stratify patients with MCTD, based on their immunophenotype.

METHODS

We analysed the immunophenotype and transcriptome of 24 immune cell subsets [from patients with MCTD, SLE, idiopathic inflammatory myopathy (IIM) and SSc] from our functional genome database, ImmuNexUT (https://www.immunexut.org/). MCTD patients were stratified by employing machine-learning models, including Random Forest, trained by immunophenotyping data from SLE, IIM and SSc patients. The transcriptomes were analysed with gene set variation analysis (GSVA), and the clinical features of the MCTD subgroups were compared.

RESULTS

This study included 215 patients, including 22 patients with MCTD. Machine-learning models, constructed to classify SLE, IIM and SSc patients, based on immunophenotyping, were applied to MCTD patients, resulting in 16 patients being classified as having an SLEimmunophenotype and 6 as having a non-SLE immunophenotype. Among the MCTD patients, patients with the SLE immunophenotype had higher proportions of Th1 cells {2.85% [interquartile range (IQR) 1.54-3.91] vs 1.33% (IQR 0.99-1.74) P = 0.027} and plasmablasts [6.35% (IQR 4.17-17.49) vs 2.00% (IQR 1.20-2.80) P = 0.010]. Notably, the number of SLE-related symptoms was higher in patients with the SLE immunophenotype [2.0 (IQR 1.0-2.0) vs 1.0 (IQR 1.0-1.0) P = 0.038]. Moreover, the GSVA scores of interferon-α and -γ responses were significantly higher in patients with the SLE immunophenotype in central memory CD8+ T cells, while hedgehog signalling was higher in patients with the non-SLE immunophenotype, in five-cell subsets.

CONCLUSION

This study describes the stratification of MCTD patients, based on immunophenotyping, suggesting the presence of distinct immunological processes behind the clinical subtypes of MCTD.

Development and Evaluation of the Dermatomyositis Outcomes for Muscle and Skin as an Outcome Measure in Dermatomyositis Clinical Trials

The Total Improvement Score (TIS), which is used as the primary efficacy measure in dermatomyositis (DM) clinical trials, lacks a skin-specific measure. However, skin is a defining feature of DM. In this study, data were analyzed from the phase 3 trial of lenabasum in DM. Cutaneous Dermatomyositis Disease Area and Severity Index-Activity scores and all components of the TIS were collected at baseline and weeks 16, 28, 40, and 52. From these assessments, a composite outcome was developed, named Dermatomyositis Outcomes for Muscle and Skin, which includes certain components of the TIS and the Cutaneous Dermatomyositis Disease Area and Severity Index-Activity scores. The relative sensitivities of the TIS and Dermatomyositis Outcomes for Muscle and Skin to detect improvement in DM skin and muscle disease activity were analyzed. A total of 174 patients with DM were included, 82% were female, and 75% were White. Mean (SD) age was 51.9 (12.20) years. Treatment effect using the TIS ranged between 17.6 and 21.7 points for muscle and skin responders versus nonresponders across time points. The Dermatomyositis Outcomes for Muscle and Skin score displayed a statistically significantly greater treatment effect of 25.9-40.0 points for responders than for nonresponders, depending on the response assessed and the time point. Dermatomyositis Outcomes for Muscle and Skin is a more sensitive composite measure that reflects improvement from baseline in both skin and muscle disease activity, suggesting usefulness for use in future DM clinical trials.

Emerging mechanisms and therapeutics in inflammatory muscle diseases

Idiopathic inflammatory myopathies (IIMs), or myositis, are rare diseases marked by immune-driven muscle damage and complications like skin lesions and interstitial lung disease (ILD). Despite advances, challenges in diagnosis and treatment persist, particularly in inclusion body myositis (IBM), where no effective therapy exists. Recent breakthroughs, including transcriptomics and insights into antibody-mediated immunity and interferon (IFN) signaling, have clarified IIM pathophysiology and spurred the development of new therapies, such as chimeric antigen receptor (CAR) T cells and Janus kinase (JAK) inhibitors. We explore the latest findings on the mechanisms underlying adult-onset IIMs, emphasizing IBM pathobiology and its unique immune and degenerative pathways, such as a selective type 2 myofiber damage and severe cell stress. Finally, we highlight the recent advances in transcriptomics, single-cell analysis, and machine learning in transforming IIM research by improving diagnostic accuracy, uncovering therapeutic targets, and supporting the development of personalized treatment strategies.

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.

ADAM17/PTGS2 Facilitates Pulmonary Fibrosis by Regulating Ferroptosis

Pulmonary fibrosis (PF) is a chronic and progressive interstitial lung disease characterised by excessive deposition of extracellular matrix (ECM), resulting in high mortality rates. In this study, we provide evidence that ADAM17/PTGS2 plays a crucial role in inducing ferroptosis in fibroblasts, promoting PF. Initially, an assessment was made of ADAM17 protein levels in patients diagnosed with connective tissue diseases-interstitial lung diseases (CTD-ILD), using ELISA assays. Confirmation of the relationship between ADAM17 and fibrosis was achieved by stimulating cells with PMA or TAPI-1 (the ADAM17 inhibitor), in conjunction with the fibrosis-inducing factor, TGFβ1. To further explore the major downstream proteins of ADAM17 contributing to altered PF, we employed mRNA transcriptomics. To further investigate the role of ADAM17/PTGS2 in promoting ferroptosis and fibrosis, we employed western blot assays, immunofluorescence and transmission electron microscopy (TEM). Furthermore, the effects of the ADAM17/PTGS2/ferroptosis pathway in PF were verified using Adeno-associated virus (AAV)-mediated ADAM17 gene knockdown in mice. In CTD-ILD patients, ADAM17 expression was significantly elevated. Upon PMA stimulation, lung fibroblasts exhibited increased fibrosis-related proteins, and the combined stimulation of PMA and TGFβ1 synergistically promoted cellular fibrosis. Conversely, TAPI-1 alleviated fibrotic stimulation induced by TGFβ1. Transcriptomic analysis of lung fibroblast specimens overexpressing ADAM17 revealed significantly elevated PTGS2 expression levels. Knockdown and ferroptosis inhibition assays demonstrated that ADAM17 regulates ferroptosis in lung fibroblasts via PTGS2, ultimately inducing fibrosis. Furthermore, the deficiency of ADAM17 alleviated bleomycin-induced PF and inflammation in mice. These findings first verified that ADAM17/PTGS2/ferroptosis is a novel mechanism for regulating PF; it provides a new theoretical basis for further exploring the treatment of PF.

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.

Comparison of Chest High-Resolution Computed Tomography Findings in Patients with Anti-Melanoma Differentiation-Associated Gene 5 Antibody-Positive and Antibody-Negative Progressive Pulmonary Fibrosis with Polymyositis/Dermatomyositis

Background/Objectives: This study compared chest high-resolution computed tomography (HRCT) findings between patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive and antibody-negative progressive pulmonary fibrosis (PPF) with polymyositis/dermatomyositis (PM/DM). Methods: Of the 85 patients with PM/DM-interstitial lung disease (ILD), 17 were anti-MDA5 antibody-positive, and 68 were antibody-negative. Among these, 5 anti-MDA5 antibody-positive and 9 antibody-negative cases met the criteria for PPF and were enrolled in the study. The chest HRCT findings and the duration from treatment initiation to the appearance of key fibrotic changes were analyzed. Results: In the anti-MDA5-positive group, all patients were diagnosed with PPF within 6 months of treatment initiation, compared to only 22.2% in the anti-MDA5-negative group. While there was no difference between the anti-MDA5 antibody-positive and antibody-negative groups in terms of chest HRCT findings associated with PPF, the duration to the appearance of increased traction bronchiectasis and bronchiolectasis, and new ground-glass opacity with traction bronchiectasis was significantly shorter in the anti-MDA5-positive group (p = 0.016 and p = 0.023, respectively). The appearance of new fine reticulations and increased coarseness of reticular abnormalities tended to be shorter in the anti-MDA5 antibody-positive group than in the antibody-negative group. Conclusions: Pulmonary fibrosis in patients with anti-MDA5 antibody-positive ILD can rapidly progress within 6 months, despite immunosuppressive therapy. Frequent HRCT monitoring and early combination therapy with antifibrotic agents are crucial for managing the progression of fibrosis.

A cohort study in HigAshi-nippon of Pulmonary hyPertensIoN in systEmic SclerosiS (HAPPINESS study): protocol and baseline data for an observational study

BACKGROUND

Pulmonary hypertension (PH) is the leading cause of death among patients with systemic sclerosis (SSc). Recently, early therapeutic intervention to improve the prognosis was suggested, and the definition of PH was recently revised by lowering the cut-off value of mean pulmonary arterial pressure (mPAP) from ≥ 25 to > 20 mmHg. However, the optimal threshold for therapeutic intervention remains unclear. We aim to evaluate the prognosis of patients with SSc and its relationship with mPAP.

METHODS

For this non-interventional retrospective and prospective cohort study, we enrolled patients with SSc or scleroderma spectrum disorders accompanied by other connective tissue diseases who underwent right heart catheterization (RHC) for suspected PH from 2010 to 2023. The date of the first RHC was defined as the baseline. Enrolled patients were classified into three groups based on their mPAP at the first RHC (≤ 20, 21-24, and ≥ 25 mmHg) and are being observed from baseline up to three years. The primary endpoint is the time between the first RHC and the first hospitalisation or death due to worsening PH.

RESULTS

This study was approved by the Ethics Committee of Hokkaido University Hospital. A total of 229 patients were enrolled from 12 participating centres, with 41 prospectively followed up and 188 retrospectively followed up. The number of patients in each group (an mPAP of ≤ 20, 21-24, and ≥ 25 mmHg) is 79, 26, and 124, respectively. The observation is expected to be completed by December 2026. Findings will be disseminated at scientific conferences, peer-reviewed journals.

CONCLUSIONS

The findings of this study that we will obtain are expected to provide important information that will lead to improvements in the diagnosis of PH and the prognosis of patients.

TRIAL REGISTRATION

This study was approved by the Ethics Committee of Hokkaido University Hospital (approval number 022-0109). It has been registered in the Japan Registry of Clinical Trials as jRCT1010220025 since November 7, 2022.

Contrast of muscle magnetic resonance imaging and pathological findings of muscle tissue in patients with anti-aminoacyl transfer RNA synthetase antibodies

OBJECTIVES

To determine whether magnetic resonance imaging (MRI) findings reflect the pathological features of inflammatory myopathies.

METHODS

Patients with idiopathic inflammatory myopathies (IIMs) diagnosed using the 2017 European League Against Rheumatism/American College of Rheumatology classification criteria in our university between 2005 and 2020 were retrospectively reviewed. IIMs were subclassified into the anti-aminoacyl transfer RNA synthetase syndrome [anti-synthetase syndrome (ASSD)], immune-mediated necrotizing myositis, dermatomyositis (DM), and others. Fat-suppressed T2-weighted MRI and muscle biopsy specimens were assessed in IIMs followed by the comparison among the four subgroups.

RESULTS

MRI findings were available for 62 patients and histopathological findings were available for 27 patients. Perifascicular atrophy or necrosis in the muscle tissues from the patients with IIM was more frequently observed in patients with subcutaneous and fascial high signal intensity (HSI) on MRI than those without. Four-group comparison among ASSD, immune-mediated necrotizing myositis, DM, and others revealed that HSI in fasciae on MRI was more frequently observed in patients with ASSD and DM than in others. Perifascicular atrophy or necrosis in muscle tissues was more frequently observed in patients with ASSD than in others.

CONCLUSION

Patients with ASSD had distinct MRI features compared with anti-aminoacyl transfer RNA synthetase negative patients. The fascial HSI on MRI may reflect distinctive pathological features of muscles.

Dapagliflozin for rheumatic musculoskeletal disease in patients with chronic kidney disease

OBJECTIVES

To elucidate the effectiveness of dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, on renal function in patients with rheumatic musculoskeletal diseases complicated by chronic kidney disease (CKD).

METHODS

We conducted a retrospective analysis of patients with rheumatic musculoskeletal disease and chronic kidney disease who were treated with dapagliflozin for more than a year. The good response was defined as an improvement in the estimated glomerular filtration rate slope per year after dapagliflozin treatment compared to that before treatment. Additionally, we investigated the response rate and its predictive factors.

RESULTS

In this analysis, 43 patients were included. The average estimated glomerular filtration rate slope demonstrated a significant improvement after dapagliflozin treatment compared to that before the treatment (0.04 vs -0.55 ml/min/1.73 m2/year, P = .001). A good response rate was 69.8% and was associated with low average levels of C-reactive protein, a high frequency of angiotensin II receptor blocker (ARB) use, and a low frequency of tacrolimus use compared to nonresponse (0.08 ± 0.18 vs 0.25 ± 0.29 mg/dl, P = .03; 80.0 vs 38.4%, P = .01; 10.0 vs 76.9%, P < .01).

CONCLUSIONS

Dapagliflozin is effective for rheumatic musculoskeletal disease patients with CKD for preventing deterioration of renal function. Antihypertensive treatment with ARB and inflammation control without tacrolimus was associated with a high likelihood of favourable response to dapagliflozin.

Integrated analysis of dermatomyositis reveals heterogeneous immune infiltration and interstitial lung disease-associated endotype

BACKGROUND

Dermatomyositis (DM) is an autoimmune disease with a high rate of disability and mortality especially in DM with concurrent interstitial lung disease (DM-ILD). Little is known about inflammatory signature and heterogeneous endotypes of DM.

OBJECTIVE

We aimed to illustrate the systemic inflammatory signature of DM and define an ILD-associated endotype.

METHODS

Olink proteomic analysis was performed on serum samples obtained from DM patients (n = 32), DM patients with ILD (n = 16), and healthy controls (n = 19). Transcriptomic data from skin samples was utilized to assess immune infiltration and investigate the correlation between protein and mRNA levels of biomarkers. Additionally, the prognostic value and clinical significance of identified biomarkers were validated through follow-up studies of DM patients and immunofluorescence analysis of skin tissues.

RESULTS

Proteomic data revealed the inflammatory signature of DM, with GO and KEGG enrichment analyses identifying chemotaxis-related pathways. Transcriptomic analysis of skin samples indicated upregulated inflammatory responses and M1 macrophage infiltration in DM. Two chemokines, CXCL10 and CXCL11, were identified as highly associated with immune infiltration and DM progression.

CONCLUSIONS

Our data suggest that serum CXCL10 and CXCL11 reflect the inflammatory burden of DM. The identified biomarkers hold promise for determining an ILD-associated endotype and predicting clinical outcomes, thereby paving the way for timely management of DM and prevention of complications.

Clinical Features of Dermatomyositis Associated with Myositis-Specific Antibodies in Moroccan Patients

Background/Objectives: Dermatomyositis (DM) is a rare idiopathic inflammatory myopathy characterized by muscle weakness and typical cutaneous rash. Dermatomyositis-specific antibodies, such as anti-TIF1γ, anti-SAE, anti-Mi2, anti-MDA5, and anti-NXP2, have been associated with specific clinical phenotypes. Our study aimed to describe the clinical profile of Moroccan patients with DM and clinical associations with myositis-specific antibodies. Methods: We recruited 54 adult patients with DM according to the Bohan and Peter criteria, admitted to the internal medicine and dermatology departments of the University Hospital Center Ibn Rochd of Casablanca from January 2020 to December 2023. Testing for myositis-specific autoantibodies (MSAs) was conducted using an Immunodot assay. Statistical analysis was performed using the Chi-square test. Results: Among our patients, 74% were female. The mean age of the patients at the time of diagnosis was 45.8 years (±12.95 years). The main clinical manifestations were a V-neck sign (70.4%), myalgia (70.4%), Gottron's papules (68.5%), heliotrope rash (63%), arthritis/arthralgia (48.1%), proximal muscle weakness (68.5%), periungual erythema (46.3%), and dysphagia (59.3%). Of the 54 patients, 37 (68.5%) showed dermatomyositis-specific antibody positivity. The most frequently found autoantibody was anti-Mi2 (22.2%), followed by anti-TIF1γ (14.8%), anti-NXP2 (9.2%), anti-MDA5 (7.4%), and anti-SAE (7.4%). The association between clinical manifestations and MSAs showed that anti-TIF1γ antibodies were associated with the V-neck sign (p < 0.05), and the MSA-negative group was protected from periungual erythema (p < 0.05). No other significant association was found. Conclusions: This study shows the autoantibody profile of Moroccan patients with DM and the associations of MSAs with clinical manifestations.

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.

Paraneoplastic Dermatoses: A Clue for Underlying Malignancies

Paraneoplastic dermatoses (PDs) belong to a group of rare and polymorphous dermatoses, and they can often be the first sign of underlying malignancies. Therefore, dermatologists should be able to identify skin features to identify earlier underlying neoplasms. Indeed, lack of familiarity with cutaneous clues of internal malignancies can lead to a delay in the diagnosis and an impairment of the prognosis of the patients. In this review, we described several PDs, including more common and rarer PD. Indeed, while malignant acanthosis nigricans, characterized by velvety, verrucous, hyperpigmented plaques that usually affect intertriginous areas, is a well-known PD, necrolytic migratory erythema is usually misdiagnosed because its clinical features can be similar to seborrheic dermatitis. Furthermore, we focused on two paradigmatic PDs, namely paraneoplastic autoimmune multiorgan syndrome (PAMS) and paraneoplastic dermatomyositis. Indeed, PAMS represents a paradigmatic form of obligate PD, which is always associated with an underlying neoplasm, while paraneoplastic dermatomyositis belongs to the facultative PD, which can be associated with neoplasia in a variable percentage of cases.

Clinical features and prognosis of anti-MDA5-positive dermatomyositis with coexistent anti-aminoacyl-tRNA synthetase antibodies

OBJECTIVES

This study aimed to evaluate the incidence and clinical significance of coexistence of anti-aminoacyl-tRNA synthetase (anti-ARS) antibody in patients with anti-melanoma differentiation-associated gene 5-positive dermatomyositis (anti-MDA5 + DM).

METHODS

We assessed a cohort of 246 consecutive patients with anti-MDA5 + DM. Clinical characteristics and survival rates were compared between patients with and without anti-ARS antibodies.

RESULTS

Of these 246 patients, 15 (15/246, 6.1%) were positive for anti-ARS antibodies. The anti-ARS-positive group had a higher proportion of mechanic's hands (53.3% vs 25.5%, P = 0.019), and the positivity rates for antinuclear antibody (ANA) (80.0% vs 50.6%, P = 0.033) and anti-Ro52 antibodies (93.3% vs 62.3%, P = 0.013) were also higher. However, the CRP levels were comparatively low [4.0 (0.5, 7.8) vs 6.0 (3.1, 12.2), P = 0.019]. In the overall population, no difference in survival rates was observed between anti-MDA5 + DM patients with or without anti-ARS antibodies (log-rank P = 0.339). The multivariate Cox regression analysis revealed that elevated lactate dehydrogenase (LDH) levels and the presence of rapidly progressive interstitial lung disease (RPILD) were associated with poor prognosis [hazard ratios of 1.002 (95% CI 1.001, 1.002, P < 0.001) and 11.096 (95% CI 5.006, 24.598, P < 0.001), respectively].

CONCLUSION

Among the 246 patients with anti-MDA5 + DM, only 15 patients (6.1%) tested positive for anti-ARS antibodies. The presence of anti-ARS antibodies is associated with the occurrence of mechanic's hands, as well as an increased positive rate of ANA and anti-Ro52 antibodies. Elevated LDH levels and the presence of RPILD are poor prognostic risk factors for patients with anti-MDA5 + DM. Key Points • The presence of anti-ARS antibodies is associated with the occurrence of mechanic's hands, as well as an increased positive rate of ANA and anti-Ro52 antibodies. • Elevated LDH levels and the presence of RPILD are poor prognostic risk factors for patients with anti-MDA5 + DM. • Understanding the clinical characteristics of these patients will help clinicians to develop individualised treatment plans for each patient.

Pain is common in myositis and associated with disease activity

BACKGROUND

Understanding pain in myositis remains challenging. This study aimed to assess patient-reported pain and its correlation with myositis core set measures (CSMs), patient-reported outcomes (PROs) and functional measures.

METHODS

Fifty subjects underwent baseline, 3-month and 6-month assessments, evaluating myositis CSMs, functional measures and PROs. Pain was measured using three methods: (i) a 10-cm visual analogue scale, (ii) the pain score from the HAQ Disability Index and (iii) the Short Form 36 survey pain questions. Correlations between disease activity measures and pain were examined at baseline, and changes in both were assessed at 6 months, along with longitudinal change of pain. The change in pain was also correlated with the published 2016 ACR/EULAR myositis response criteria, physician/patient's assessment of change.

RESULTS

Nearly half of patients (45%) reported moderate to severe pain in all three pain scales, with higher severity of pain in PM/necrotizing myopathy subset. At baseline, pain severity showed a strong correlation with most CSMs, PROs and functional outcomes in all three pain scales, and similar trends were noted for change in pain at the 6 months. On longitudinal analysis, the physical function scores and fatigue showed strong correlation with pain. Pain improved in myositis patients with improvement in disease activity over time.

CONCLUSIONS

Pain is common in myositis and is associated with multiple measures of disease activity, PROs and functional outcomes in myositis. Most importantly pain improves with improvement in disease activity. SF-36 pain questions have good psychometric properties.

Pulmonary and serum cytokine profiles of patients with anti-ARS and anti-MDA5 antibodies

The present study aimed to determine the pulmonary cytokine profiles of patients with anti-RNA synthetase (ARS) and anti-melanoma differentiation-associated protein 5 (MDA5) antibodies. The study included patients with ARS and MDA5 whose serum or bronchoalveolar fluid (BALF) was available. Sandwich enzyme-linked immunoassay microarray multiplex assay was used to measure 18 cytokine levels in serum and BALF. The cytokine patterns were investigated using factor and cluster analyses. Pulmonary cytokine production was examined using the BALF/Seum cytokine ratio. Forty participants were enrolled in the study: 19 with ARS and 21 with MDA5. All patients had interstitial lung disease (ILD). BALF was collected from 10 patients with ARS and 6 with MDA5. Serum type 1 IFN, IP-10, MCP-1, and TNF-α were elevated in both ARS and MDA5. IL-6, IL-10, and IL-15 were elevated in MDA5. Serum cytokine patterns differed between ARS and MDA5. In BALF, IFN-α, IP-10, MCP-1, and ferritin were increased in both ARS and MDA5. Higher levels of IFN-α, IL-6, and ferritin were observed in MDA5. One patient with severe MDA5-ILD showed higher levels of multiple cytokines, including IL-6 and IFN-α. BALF cytokine patterns were similar in ARS and MDA5 cases except the one with severe MDA5-ILD. IL-6, IP-10, IL-15, MCP-1, and ferritin were produced in the lungs in ARS and MDA5 and IFN-α in MDA5. In conclusion, IFN-α and pulmonary macrophage activation play important roles in ILD development in both ARS and MDA5-ILD. MDA5-ILD could be characterized by higher production of multiple cytokines and macrophage activation, particularly in severe cases.

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.

Pre-screening of endomysial microvessel density by fast random forest image processing machine learning algorithm accelerates recognition of a modified vascular network in idiopathic inflammatory myopathies

Biomarkers for discrimination among different subgroups of idiopathic inflammatory myopathies (IIM) are difficult to identify and may involve multiple laboratory tests and time-consuming procedures. We assessed the potential for artificial intelligence (AI) to extract features such as density of endomysial microvessels based on automatic analysis of the CD31+ vascular network on muscle biopsy images. We also assessed the potential of this technique to save time and its agreement rate with analyses based on the manual selection of microvessels from the same images. A total of 84 images from 84 patients with IIM, diagnosed between 2014 and 2020, were retrieved and analyzed using the Fast Random Forest (FRF) technique. We built a lightweight and explainable algorithm for calculating the pixel percentage of CD31+ endomysial capillaries. The FRF technique applied on images of CD31-stained muscle sections achieved a good performance in the recognition of microvessels by estimating their density over a standard area corresponding to a sample of microscope image. The time spent for this analysis was 90% less than the manual choice of microvessels (estimated time considering the computational time and the time spent to manually detecting the microvessels features). The good performance of the FRF demonstrates that the CD31 pixel percentage of endomysial capillaries is sufficient for a correct estimation. Finally, the paper proposes a procedure to integrate AI in the pre-screening process.

Identification of clinical subgroups in anti-SRP positive immune-mediated necrotizing myopathy patients using cluster analysis

Background

Anti-signal recognition particle immune-mediated necrotizing myopathy (anti-SRP IMNM) is a rare autoimmune disorder characterized by muscle weakness and necrosis. Identifying clinical subgroups within this patient population could facilitate the management of the disease.

Objectives

To identify distinct clinical subgroups of anti-SRP IMNM patients.

Design

A retrospective study was conducted on anti-SRP IMNM patients treated at West China Hospital of Sichuan University between January 2010 and October 2023.

Methods

Clinical data were collected. Unsupervised cluster analysis was conducted to classify patients into distinct subgroups based on their clinical features. Statistical analyses were performed to compare the clinical characteristics and outcomes among the identified clusters.

Results

A total of 116 patients were included in the study, and 3 distinct clinical subgroups were identified: Cluster 3 (acute), Cluster 2 (subacute), and Cluster 1 (poor prognosis). Patients in Cluster 3 exhibited a short disease course (median 3 months), severe muscle weakness (78.38% with Medical Research Council (MRC) score ⩽3), high muscle enzyme levels, and a good response to treatment. Cluster 2 patients were younger (mean age 45.83 years), had a longer disease course (median 6.5 months), milder muscle damage, and lower autoantibody titers. Cluster 1 patients were older (mean age 58.10 years), predominantly male (70.97%), and had higher incidences of interstitial lung disease (70.97%) and cardiac injury (45.16%). In Cluster 1, 16.13% of cases were refractory, and the relapse rate was 38.71%, which was significantly higher compared to the other two clusters.

Conclusion

This study highlights the clinical heterogeneity among anti-SRP IMNM patients and identifies three distinct clinical subgroups with unique characteristics. These findings provide insights for personalized management.

Recognition of Idiopathic Inflammatory Myopathies Underlying Interstitial Lung Diseases

Interstitial Lung Disease (ILD) is one of the most common causes of mortality in idiopathic Inflammatory Myopathies (IIM). Despite these conditions being commonly associated with proximal weakness, skin rashes and arthritis, ILD can be the first or the sole clinical feature in up to 60% of patients, potentially leading to incorrect diagnosis. The early recognition of an underlying IIM in ILD patients can allow for prompt treatment, which could potentially stabilize or even improve the lung disease, also avoiding the development of other clinical features associated with the condition. The objective of this review is to describe the clinical, serological and radiological features associated with IIM-ILD, mainly focusing on dermatomyositis and antisynthetase syndrome.

Efficacy, safety, and target engagement of dazukibart, an IFNβ specific monoclonal antibody, in adults with dermatomyositis: a multicentre, double-blind, randomised, placebo-controlled, phase 2 trial

BACKGROUND

Dermatomyositis is a chronic autoimmune disease with distinctive cutaneous eruptions and muscle weakness, and the pathophysiology is characterised by type I interferon (IFN) dysregulation. This study aims to assess the efficacy, safety, and target engagement of dazukibart, a potent, selective, humanised IgG1 neutralising monoclonal antibody directed against IFNβ, in adults with moderate-to-severe dermatomyositis.

METHODS

This multicentre, double-blind, randomised, placebo-controlled, phase 2 trial was conducted at 25 university-based hospitals and outpatient sites in Germany, Hungary, Poland, Spain, and the USA. Adults aged 18-80 years with skin-predominant dermatomyositis were enrolled during stages 1, 2, and 2a, and had to have a Cutaneous Dermatomyositis Disease Area and Severity Index-Activity (CDASI-A) score of 14 or more and at least one unsuccessful systemic treatment with standard of care; whereas those with muscle-predominant dermatomyositis were enrolled in stage 3 and had to have active moderate muscle involvement. Patients were randomly assigned using an interactive response technology system to dazukibart 600 mg or placebo in stage 1; dazukibart 600 mg, dazukibart 150 mg, or placebo in stage 2; dazukibart 600 mg then placebo, dazukibart 150 mg then placebo, placebo then dazukibart 600 mg, or placebo then dazukibart 150 mg in stage 2a; and dazukibart 600 mg then placebo or placebo then dazukibart 600 mg in stage 3. For stage 2a and stage 3, treatments were switched at week 12. Patients, investigators, outcome assessors, and funders were masked to the treatment assignment. Dazukibart and placebo were administered intravenously on day 1 every 4 weeks, up to and including week 8 (stages 1 and 2, and stages 2a and 3 for patients starting dazukibart), or on week 12 every 4 weeks, up to and including week 20 (stages 2a and 3 for patients who started placebo and switched to dazukibart). The primary outcome for the skin-predominant cohorts was the change from baseline in CDASI-A score at week 12 assessed in the full analysis set (FAS; stage 1) and the pooled skin FAS (stages 1, 2, and 2a), and safety in the muscle-predominant cohort. This study is registered with ClinicalTrials.gov, NCT03181893.

FINDINGS

Between Jan 23, 2018, and Feb 23, 2022, 125 adults were assessed and 50 were excluded. 75 patients were randomly assigned and treated (15 to dazukibart 150 mg, 37 to dazukibart 600 mg, and 23 to placebo). Most patients were female (53 [93%] of 57 in the skin-predominant cohort vs 13 [72%] of 18 in the muscle-predominant cohort and four [7%] vs five [28%] were male). In the FAS in stage 1 at week 12, the mean change from baseline in CDASI-A for dazukibart 600 mg was -18·8 (90% CI -21·8 to -15·8; placebo-adjusted difference -14·8 [-20·3 to -9·4]; p<0·0001). In the pooled skin FAS at week 12, the mean change from baseline in CDASI-A for the dazukibart 600 mg group was -19·2 (-21·5 to -16·8; placebo-adjusted difference -16·3 [-20·4 to -12·1]; p<0·0001), whereas the dazukibart 150 mg group was -16·6 (-19·8 to -13·4; placebo-adjusted difference -13·7 [-18·3 to -9·0]; p<0·0001). Treatment-emergent adverse events occurred in 12 (80%) of 15 patients in the dazukibart 150 mg group versus 30 (81%) of 37 in the dazukibart 600 mg group versus 18 (78%) of 23 in the placebo group, with the most common being infections and infestations (two [13%] vs 12 [32%] vs seven [30%]). Four (11%) patients in the dazukibart 150 mg group and one (4%) in the placebo group reported serious adverse events. One patient in stage 3 received dazukibart 600 mg then placebo and died during follow-up due to haemophagocytic lymphohistiocytosis and macrophage activation syndrome.

INTERPRETATION

Dazukibart resulted in a pronounced reduction in disease activity and was generally well tolerated, supporting IFNβ inhibition as a highly promising therapeutic strategy in adults with dermatomyositis.

FUNDING

Pfizer.

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.

A Case of Juvenile Dermatomyositis Presenting with Inverse Gottron's Papules: A Case Report

Introduction

Inverse Gottron's papules are an uncommon presentation of dermatomyositis, with a paucity of studies published in children with juvenile dermatomyositis (JDM).

Case Presentation

A 5-year-old girl presented with progressive bilateral eyelid erythema and edema, mild erythematous rash over the face, painful palmar papules (inverse Gottron's papules), and proximal muscle weakness for 3 months. Additional symptoms included intermittent fever, decreased appetite, joint pain, and mild abdominal pain. Physical examination revealed upper and lower eyelid erythema with mild edema (heliotrope sign), Gottron's papules over the dorsal distal interphalangeal joint (DIP), Gottron's sign over the dorsal metacarpophalangeal (MCP) joints, proximal interphalangeal (PIP) joints and elbows, inverse Gottron's sign over the palmar surface of the hands (PIP and DIP), and ragged nailfold cuticles with no dilated capillaries. Laboratory investigations showed elevated muscle enzymes, positive myositis-specific antibodies, and elevated liver function tests. High-resolution computed tomography (HRCT) chest revealed no signs of interstitial lung disease (ILD). Whole-body magnetic resonance imaging (MRI) revealed bilateral upper limb subcutaneous edema and generalized myositis, particularly in the pelvis and thigh muscles, confirming the diagnosis of JDM. Treatment involved intravenous methylprednisolone 30 mg/kg/day for 3 days followed by tapering, and topical corticosteroids over dermatomyositis-affected areas.

Conclusion

Inverse Gottron's papules are an uncommon cutaneous manifestation of dermatomyositis (DM) that have an association with ILD in both adults and children. Thus, patients with dermatomyositis and inverse Gottron's papules should be investigated for ILD. Our patient represents the first reported case of JDM with inverse Gottron's papules in Saudi Arabia.

Low serum S100A6 levels are associated RP-ILD risk in anti-MDA5-positive dermatomyositis

INTRODUCTION

Anti-MDA5-positive dermatomyositis (anti-MDA5-DM) is a rare autoimmune disease that often leads to rapid-progressive interstitial lung disease (RP-ILD). The lack of effective prediction and treatment methods makes RP-ILD a major risk factor for death in patients with this condition. S100A6 is a member of the S100 Ca2 + - binding protein family, which plays important roles in inflammation, tumor, injury, and fibroblast reparation. This study aims to explore the correlation between serum S100A6 and RP-ILD in anti-MDA5-DM, and to determine whether S100A6 can be used as a specific biomarker to predict RP-ILD.

METHODS

The authors enrolled 80 participants, including 20 healthy volunteers, 20 patients with anti-synthase syndrome, and 40 patients with anti-MDA5-positive dermatomyositis. Serum samples were collected and the levels of S100A6 were measured using ELISA. Logistic regression was used to analyze the relationship between serum S100A6 levels and RP-ILD, along with other clinical and laboratory parameters.  RESULTS: Serum S100A6 levels were significantly lower in anti-MDA5-DM patients with RP-ILD than those without RP-ILD (odds ratio:0.393 (95% CI, 0.164-0.943, p = 0.036)). High serum S100A6 level was found to be a protective factor for RP-ILD. This study shows that high serum S100A6 level may be a protective factor for RP-ILD in anti-MDA5-DM patients. Serum S100A6 may be used as a specific biomarker to predict whether RP-ILD occurs in anti-MDA5-DM. Key Points • This research discovers and reports a biomarker (S100A6) for distinguishing potential RP-ILD in Anti-MDA5 positive dermatomyositis.

Idiopathic Inflammatory Myopathies-Associated Interstitial Lung Disease in Adults

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

Predictive factors of progression in mild fibrosing interstitial lung disease patients with gender-age-physiology score of 3 or less

BACKGROUND

The prognostic factors in mild fibrosing interstitial lung disease (FILD) have not been established.

METHODS

We retrospectively attempted to identify predictive factors of annual progression in mild FILD with gender-age-physiology (GAP) score of 3 or less using logistic regression analysis. Annual FILD progression was defined as meeting any two or more of the following conditions: 1, more than 10% decrease in forced vital capacity (FVC) or 15% decrease in diffusing capacity of the lungs for carbon monoxide (DLCO); 2, worsening of dyspnea; 3, worsening of fibrotic change on CT at 1 year after admission.

RESULTS

Univariate analysis showed that diagnosis of connective tissue disease-associated ILD, CT-definite usual interstitial pneumonia (UIP) pattern, composite physiologic index, FVC, DLCO, lowest SpO2 and decrease in SpO2, and walk distance in the 6-minutes walk test (6MWT), chronic pulmonary emphysema assessment test (CAT) score, and some variables in Short-Form 36 were significantly associated with incidence of annual progression. Multivariate analysis showed that independent predictive factors were diagnosis of idiopathic pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (HP), CT-definite UIP pattern, lowest SpO2 and decrease in SpO2 in the 6MWT, and CAT score. In logistic regression analysis among 63 patients with non-IPF-ILD, diagnosis with fibrotic HP, lowest SpO2 and decrease in SpO2 in the 6MWT, and CAT score were also independent risk factors for annual FILD progression.

CONCLUSIONS

Exercise-induced hypoxia, patient-reported outcome, radiological UIP pattern, and diagnosis with fibrotic HP are independent predictors of annual progression in mild FILD.

Achieving Medication-Free Remission in Patients With Juvenile Dermatomyositis

OBJECTIVE

Prognostic factors associated with medication discontinuation in children with juvenile dermatomyositis (JDM) remain largely elusive. We aim to identify the predictors of medication-free remission (MFR) in children with JDM.

METHODS

In this retrospective study, patients diagnosed with JDM according to Peter & Bohan criteria and followed for ≥18 months at a tertiary care center from 2006 through 2022 were included. Data extracted included demographics, physical examination, laboratory results, and medications. MFR was defined as inactive JDM after discontinuation of all systemic immunosuppressives for ≥6 months, in line with international consensus guidelines for trials of therapies in idiopathic inflammatory myopathies. A two-sided P < 0.05 was considered statistically significant.

RESULTS

Of 55 patients with JDM (63.6% female, age median [interquartile range (IQR)] 6 [3.5-12] years), 29 (52.7%) achieved MFR after a median (IQR) of 33 (22.5-55.2) months. MFR was more common in those who were younger at JDM diagnosis (median 5 vs 8 years, P = 0.008), had early resolution of disease activity (median 11 vs 18 months, P < 0.001), and presented with Gottron papules (χ2 = 5.25; P = 0.022) and elevated lactate dehydrogenase (χ2 = 4.82, P = 0.028). Diagnosis of JDM before 5 years old (odds ratio 4.5, 95% confidence interval [CI] 1.2-16.7) was the only predictor of MFR in our multivariate model (area under the curve 0.65, 95% CI 0.53-0.76).

CONCLUSION

Half of our patients with JDM achieved MFR. Age at JDM diagnosis may be an important predictor of achieving MFR.

Comprehensive Enteroviral Serology Links Infection and Anti-Melanoma Differentiation-Associated Protein 5 Dermatomyositis

OBJECTIVE

Idiopathic inflammatory myopathies (IIMs) are a group of heterogeneous, systemic autoimmune diseases characterized by specific clinical features and, frequently, skeletal muscle inflammation. Specific subtypes of IIMs can be characterized by myositis-specific autoantibodies and are associated with distinct clinical phenotypes. Here, we focus on anti-melanoma differentiation-associated protein 5 (MDA5)-positive myositis and anti-signal recognition particle (SRP)-positive myositis, both of which exhibit seasonality but lack known environmental triggers.

METHODS

We employed Phage ImmunoPrecipitation Sequencing to profile serum antibodies against the human proteome, the human virome, and a comprehensive enterovirus library. We analyzed sera from 57 patients with anti-MDA5 autoantibodies and 57 patients with anti-SRP autoantibodies, as well as 57 healthy controls. All groups were matched for age, sex, and race.

RESULTS

Our autoantibody profiling results define specific immunogenic regions within the MDA5 and SRP autoantigens. We also discovered that in MDA5 sera, versus SRP sera, there was an elevated antibody response to the viral capsid protein 1 (VP1) of enterovirus B, which was accompanied by a decreased antibody response to rhinovirus A.

CONCLUSION

Considering the role of MDA5 as a sensor of picornaviral infections and a mediator of inflammatory signaling, our data suggest a novel etiologic link between enterovirus infection and anti-MDA5 dermatomyositis.