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.