Nailfold capillaries and myositis specific antibodies in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis

Microvascular abnormalities between anti-TIF1-γ-associated dermatomyositis with and without malignancy

BACKGROUND

Dermatomyositis (DM) is an immune-mediated myopathy characterized by proximal muscle weakness, inflammation, and cutaneous manifestations. Up to 25% of DM patients have an associated malignancy. Those with cancer-associated DM often face worse prognoses, poorer treatment responses, and reduced survival rates. Interestingly, anti TIF1γ-positive DM patients are notably at increased risk for malignancy, yet the underlying mechanisms and clinical correlation remain poorly understood. Nailfold video capillaroscopy (NVC) is a safe, non-invasive method for assessing vascular abnormalities, previously explored in various DM subsets but not specifically in anti TIF1γ-positive DM patients with malignancy. This study aims to characterize NVC findings in anti-TIF1γ-positive DM and assess their clinical relevance, particularly in malignancy-associated cases.

METHODS

A retrospective review at Mayo Clinic, Jacksonville from January 1st, 2010 to May 16th, 2024 was conducted. 19 cases with anti TIF1γ-positive DM and 18 idiopathic inflammatory myopathy controls were included.

RESULTS

We observed anti TIF1γ-positive DM cases to have significantly increased capillary density loss and higher microhemorrhages (p = 0.057). Cases also had higher frequencies of dilated capillaries, capillary ramifications, and capillary disorganization. Although no statistically significant differences in NVC pattern were identified in cancer vs. non-cancer anti TIF1γ-positive DM, there were greater hemorrhages and ramifications noted in the cancer anti TIF1γ-positive subset.

CONCLUSION

This study investigated NVC differences among anti TIF1γ-positive DM with malignancies versus idiopathic inflammatory myopathy controls. Our findings indicate promising microvascular differences with a potential for predicting cancer development that warrant further exploration in larger studies.

CLINICAL TRIAL NUMBER

Not applicable.

The role of nailfold video-capillaroscopy in the assessment of dermatomyositis

OBJECTIVES

The clinical manifestations of dermatomyositis (DM) are diverse, nailfold video-capillaroscopy (NVC) can reflect microangiopathy, a process believed to contribute significantly to the clinical manifestations of DM. We aimed to explore the distinctive alterations and implications of nailfold capillary for evaluating disease progression in individuals with DM.

METHODS

We gathered clinical data from 76 DM patients who underwent NVC in the Affiliated Hospital of Nantong University between September 2017 and September 2022. Additionally, we recruited 26 anti-synthase antibody syndrome (ASS) patients and 33 systemic sclerosis (SSc) patients as controls. Utilizing an unsupervised machine learning method (hierarchical clustering analysis) to categorized patients based on NVC results and compared clinical characteristics and survival outcomes. The follow-up period ended in December 2022.

RESULTS

Anomalous NVC patterns were detected in 73.7% of the 76 DM patients and manifested as diminished capillary density and abnormal capillary morphology. Patients displaying abnormal NVC findings exhibited a significantly higher prevalence of Raynaud's phenomenon and a greater likelihood of being managed with triple combination therapy. Compared with SSc patients, milder NVC changes were observed in patients with DM, nonetheless, NVC abnormalities were more prominent in DM patients when contrasted with individuals with ASS. Furthermore, the patients were classified into two different clusters according to NVC data. Patients in cluster 1 were more likely to develop interstitial lung disease (ILD). Survival outcomes did not differ significantly between the two clusters.

CONCLUSION

DM patients can experience varying degrees of aberrant NVC patterns, which can impact ILD risk and warrant clinical vigilance.

Appearance of anti-MDA5 antibody-positive dermatomyositis after COVID-19 vaccination

The direct causes of dermatomyositis, a common autoimmune disease, have not yet been accurately identified, but several studies have linked this condition to various patient-associated and environmental factors, such as viral infections and area of residence. In the present report, we describe our experience with a patient presenting with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis, which developed after vaccination against coronavirus disease 2019 (COVID-19). This patient was simultaneously diagnosed with anti-glutamic acid decarboxylase antibody-positive slowly progressive insulin-dependent diabetes (SPIDDM); her human leucocyte antigen test revealed that she expressed the DRB1*04:05 allele. This is important as this genotype is known to increase susceptibility to both anti-MDA5 antibody-positive dermatomyositis and type I diabetes. To the best of our knowledge, this is the first case of dermatomyositis complicated by SPIDDM identified after COVID-19 vaccination against COVID-19 and presenting with an underlying susceptible genotype. The patient's genetic predisposition may also be important for the development of autoimmune disease after COVID-19 vaccination.

The Expression of Cytokine Profiles and Related Receptors in Idiopathic Inflammatory Myopathies

Background: Cytokines play a vital role in the pathogenesis of idiopathic inflammatory myopathies (IIMs). Here, we investigated the expression of serum cytokine profiles in untreated IIMs and their correlations with clinical indicators, and further studied the expression of related cytokines receptors in IIMs. Methods: The Human 48-Plex Luminex assay for cytokines was performed in the serum of IIMs, including 93 untreated and 18 follow-up (39 samples) patients, and 32 healthy controls (HC). Mann-Whitney U test with bonferroni adjusted was used to identify the differentially expressed cytokines among groups. Celltalker software was used to identify the receptors of differentially expressed cytokines. The expression of receptors was further validated by published GEO datasets (muscle, blood and skin), RT-qPCR, western blot and flow cytometry. Results: The serum levels of Eotaxin, IL7, IL18, IP10, MCP1, MCSF, MIG and SCGFβ were elevated in the 93 untreated patients. Except for IL7, all other cytokines were decreased after treatment and their levels were positively correlated with clinical indices such as LDH, ESR, CRP, ALT, IgA, AST and IgG while negatively correlated with albumin and MMT8. According to the serum myositis-specific antibodies (MSAs), patients were classified into three groups: anti-ARS (Jo-1, OJ, EJ, PL7, PL12), anti-MDA5 positive, and anti-TIF1γ positive. Compared with HC, the levels of IP10 and MIG were increased in three groups. Moreover, IL18 and MSCF were increased in anti-ARS patients, and CTACK, Eotaxin, IL1Rα, IL7, IL18, MCP1, MCP3, MCSF and SCGFβ were elevated in anti-MDA5 patients. Twenty receptors of the 8 differentially expressed cytokines were matched by celltalker software, among them, IL18R1 and CCR1 were up-regulated in blood, muscle and skin of IIMs from the analysis of GEO published datasets. RT-qPCR and western blot further validated IL18R1 was upregulated in the muscle tissues of dermatomyositis. The number of IL18R1⁺CD4⁺ cells was increased while IL18R1⁺CD8⁺ cells was decreased in peripheral blood of anti-MDA5 patients. Conclusion: This study showed that cytokine profiles were significantly changed in IIMs, and different MSA groups had unique cytokine expression patterns. The levels of some cytokine were correlated with clinical indices. The IL18 receptor IL18R1 might play important roles in IIMs.