Dermatomyositis-Related Encephalopathy: Clinical, Neuroimaging and Immunological Characterization

Background/Objectives: Dermatomyositis (DM) is an autoimmune disease with rarely reported central nervous system involvement, such as encephalopathy. However, no objective characterization of dermatomyositis patients with neurocognitive decline has been previously addressed. Methods: Herein, we describe the immunophenotype, clinical, and neuroimaging features of three DM patients with encephalopathy. Results: The neurocognitive profile of the three patients was characterized by abnormalities in attention, working memory, and language. PET/CT demonstrated temporal and occipital cortical hypometabolism with hypermetabolism in the mesial temporal region, cerebellar, and basal nuclei. The peripheral immunophenotype of DM patients with encephalopathy demonstrated enhanced expression of PD-1+ in CD4+ and CD8+ T cells in comparison with DM patients without encephalopathy. In comparison to healthy controls, DM patients with encephalopathy had increased naïve CD4+, CD57+, and CD4+ T cells, effector memory (TEM), and CD73+ and CD8+ T cells. Additionally, the normalization of cerebral metabolism and clinical behavior after immunosuppressive treatment was evidenced. Conclusions: The PET/CT profile and peripheral immunophenotype (PD-1+, TEM, CD57+, and CD73+) could help to recognize DM patients who are prone to developing encephalopathy symptoms in order to avoid sequelae.