There are differences related to age and thymoma among patients with myasthenia gravis in terms of aberrant plasmacytoid and conventional dendritic cell distribution, according to a new study published in Neuroimmunomodulation. These differences could contribute to impaired immune tolerance and lead to the onset of the disease, the authors of the study said.
To identify the roles of different subtypes of dendritic cells in the pathogenesis of myasthenia gravis, a team of researchers from China measured the levels of 3 main subsets of dendritic cells in patients with myasthenia gravis: CD303-positive plasmacytoid dendritic cells, CD1c-positive conventional dendritic cells, and CD141-positive conventional dendritic cells.
The study included 160 newly diagnosed patients and 160 matched controls.
The results showed that the frequencies of all 3 subtypes of circulating dendritic cells were higher in the blood of patients with myasthenia gravis than in that of healthy controls.
Read more about the pathophysiology of myasthenia gravis
Patients with early-onset disease (ie, those whose disease developed before the age of 50 years) had a lower frequency of circulating plasmacytoid dendritic cells and a higher frequency of circulating CD1c-positive conventional dendritic cells than those whose disease developed at or after 50 years of age (late-onset myasthenia gravis).
The frequency of circulating plasmacytoid dendritic cells was associated with the clinical severity of the disease in patients with late-onset myasthenia gravis.
The majority (64.2%) of myasthenia gravis thymomas were type B2, while only 33.3% of control thymomas were this type. The myasthenia gravis thymomas had a significantly higher frequency of plasmacytoid dendritic cells and a lower frequency of CD1c-positive conventional dendritic cells than control thymomas.
The researchers said more research is needed to clarify the definitive role of different subsets of dendritic cells in the pathogenesis of myasthenia gravis.
Myasthenia gravis is an autoimmune disease affecting the neuromuscular junction. It is known that dendritic cells play a major role in the pathogenesis of the disease.
Song Y, Xing C, Lu T, et al. Aberrant dendritic cell subsets in patients with myasthenia gravis and related clinical features. Neuroimmunomodulation. Published online February 13, 2023. doi:10.1159/000529626