To review autoimmune associations in moyamoya disease and moyamoya angiopathy. And examine type 1 diabetes mellitus as part of a broader immune-associated moyamoya phenotype outside classic epidemiologic/genetic risk profiles.

Moyamoya disease (MMD) is a non-atherosclerotic steno-occlusive vasculopathy involving the distal internal carotid arteries(ICA) and proximal circle of Willis. MMD is most commonly recognized in the context of genetic and epidemiologic risk factors. Particularly in East-Asian ancestry and trisomy-21. However, MMD is increasingly being reported in patients outside these traditional risk groups, and in autoimmune comorbidities. These include Graves disease, systemic lupus erythematosus, antiphospholipid-syndrome, and rheumatoid arthritis.

We performed a focused literature review of published reports and cohort studies describing autoimmune comorbidities in MMD or moyamoya angiopathy. This review was informed by our previously reported clinical case of MMD in a young woman with T1DM, which served as a clinical framework rather than a new case presentation.

Published case reports and cohort studies of moyamoya angiopathy have repeatedly described coexisting autoimmune histories. This suggests that systemic autoimmunity may represent an underrecognized clinical pattern rather than an isolated coincidence. Prior literature describing the autoimmune-moyamoya association includes case reports, case series, and retrospective reviews. This is supporting the possibility that autoimmune disorders may be part of a broader immune-associated phenotype rather than an isolated comorbidity. Proposed mechanisms include immune-mediated endothelial injury, inflammatory vascular remodeling, abnormal angiogenic signaling, and interactions between systemic inflammation and underlying MMD susceptibility pathways. 

Our previously reported clinical case, involving a young woman with T1DM, elevated inflammatory markers, hyperglycemia and angiographic findings consistent with MMD, served as the rationale for examining this association in the literature.