Long-term changes in nail fold capillary abnormalities and serum fibroblast growth factor 23 levels in dermatomyositis patients with anti-melanoma differentiating antigen 5 antibody

Anti-MDA5 antibody-positive dermatomyositis: pathogenesis and clinical progress

Anti-melanoma differentiation-associated protein 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is a subtype of dermatomyositis. Although the aetiology and pathology remain unclear, increasing evidence suggests that viral infection is a potential trigger of MDA5-DM. Multiple factors, including T cells, B cells, neutrophils and macrophages, are implicated in the pathophysiology of MDA5-DM. Distinctive skin rashes, rapidly progressive interstitial lung disease, peripheral lymphopenia and elevated serum ferritin levels are the most prominent clinical and laboratory features of MDA5-DM. Concomitant infection is a common complication of MDA5-DM. The proper evaluation of patients with MDA5-DM requires knowledge of the disease heterogeneity and clinical course variability. Several biomarkers, including serum levels of anti-MDA5 antibodies and biomarkers related to macrophage activation, have been identified as useful tools for monitoring disease activity and prognosis. MDA5-DM shows a poor response to conventional glucocorticoid and immunosuppressant therapy and has a poor overall prognosis. Therefore, there is an urgent need to explore the key pathogenic mechanisms of MDA5-DM and develop novel therapeutic options for patients. This Review discusses recent clinical progress and pathogenic findings of MDA5-DM.

Trichoscopic, oral, and periungual fold findings as activity and damage markers in dermatomyositis patients and their correlation with myositis antibodies

There is little clarity about the clinical manifestations of dermatomyositis (DM) in the periungual folds, scalp, and oral cavity and their association with disease activity and damage. The objective of this study was to compare the prevalence of trichoscopic, oral, and periungual changes between DM and healthy patients and assess their possible association with disease activity and damage. We conducted an observational, transversal, and analytical study between 2020 and 2021. Forty DM patients were matched by sex and age with 40 healthy individuals. On the same day, all patients had a clinical evaluation of the hands, periungual folds, scalp, and oral cavity. Photographs of these areas and peripheral venous blood tests, including myositis-associated (MAAs) and myositis-specific antibodies (MSAs), were taken. Two dermatologists blinded to their diagnosis, damage, and activity levels registered the lesions. The disease activity and damage were evaluated using the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). The presence of mechanic's hands, Gottron's sign, and Gottron's papules in hands; capillary dilation, capillary tortuosity, cuticular hemorrhage, avascular areas, and cuticular hyperkeratosis in periungual folds; thick tortuous capillaries in scalp; gingival telangiectasias in the oral cavity; and positive MSAs associated with severe cutaneous involvement in DM patients (Anti-TIF1g, Anti-MDA5, Anti-SAE1/2) were associated with a higher CDASI activity score. The presence of MSAs associated with intense muscle involvement in DM patients (Anti-Mi2a, Anti-Mi2b, Anti-NPX2, and Anti-SAE1/2) was related to a lower CDASI activity score. Gottron's sign and Gottron's papules in hands; capillary dilation, capillary tortuosity, cuticular hemorrhage, avascular areas, and cuticular hyperkeratosis in periungual folds; basal erythema in scalp; and gingival telangiectasias in the oral cavity were associated with a higher CDASI damage score. There are trichoscopic, oral and periungual fold findings and some myositis-specific antibodies that correlate with disease activity and damage in DM patients.

Longitudinal changes in nailfold videocapillaroscopy findings differ by myositis-specific autoantibody in idiopathic inflammatory myopathy

OBJECTIVE

To assess the longitudinal changes in nailfold videocapillaroscopy (NVC) in patients expressing myositis-specific autoantibodies [anti-aminoacyl-tRNA synthetase (ARS), anti-transcriptional intermediary factor 1 (TIF1), and anti-melanoma differentiation-associated gene 5 (MDA5)].

METHODS

This study was performed retrospectively, at a single site, on an observational cohort. Seventy-one idiopathic inflammatory myopathy patients were included (25 patients expressed anti-MDA5 Abs, 24 patients expressed anti-TIF1 Abs, and 22 patients expressed anti-ARS Abs). NVC findings included giant, enlarged, and reduced capillaries, haemorrhages, capillary ramification, disorganization of the vascular array, and capillary loss. NVC findings were compared from baseline to after disease activity stabilization.

RESULTS

The frequency of enlarged capillaries at baseline was different among the three groups, and was significantly higher in patients with anti-TIF1 Abs compared with those with anti-ARS Abs (88% vs 55%, P < 0.05). Reduced capillaries were significantly increased in patients with anti-TIF1 Abs compared with those with anti-MDA5 (96% vs 44%, P < 0.0001) or anti-ARS Abs (96% vs 50%, P < 0.0005). Both enlarged and reduced capillaries improved after stabilization in patients with anti-MDA5 Abs (P < 0.0001 and P < 0.05, respectively). These improvements were not observed in patients expressing anti-TIF1 and anti-ARS Abs. However, a significant reduction in haemorrhages was observed in all three groups (P < 0.0001 for each group).

CONCLUSIONS

The results of this study demonstrate that longitudinal changes in NVC findings may vary depending on myositis-specific Ab expression. Therefore, it is crucial to assess individual NVC findings separately, as each finding may impact disease activity in a different manner.

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

OBJECTIVES

This study aimed to quantify nailfold capillary (NFC) abnormalities in anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis (DM) patients and to evaluate the association with clinical parameters, including serum biomarkers. In addition, we aimed to clarify the period leading to remission of NFC abnormalities during immunosuppressive treatment in patients with DM.

METHODS

A prospective observational study was conducted including patients (n = 10) who first visited Hiroshima University Hospital and were diagnosed with DM or clinically amyopathic dermatomyositis (CADM) with anti-MDA5 antibodies. We compared the NFC abnormalities detected by nailfold-video capillaroscopy (NVC), physical findings, blood tests, respiratory function tests, and vascular-related growth factors measured using a LEGENDplexTM Multi-Analyte Flow Assay Kit.

RESULTS

NFC abnormalities improved in all patients from 2-17 weeks after the initiation of immunosuppressive treatment. The NVC scores were inversely correlated with anti-MDA5 antibody titres at baseline. NVC scores and forced vital capacity (FVC) were positively correlated. Baseline with macrophage colony-stimulating factor (M-CSF) and stem cell factor (SCF) was correlated with anti-MDA-5 titres.

CONCLUSION

Our study suggests that NVC scores and disease activity are inversely correlated before treatment. Vascular-related growth factors, such as M-CSF and SCF, may be associated with the disease mechanism in patients with anti-MDA5 antibody-positive DM.