2025 Volume 53 Issue 2 Pages 96-101
The RNF213 gene mutation is the primary susceptibility factor for moyamoya disease, with the p.R4810K mutation present in over 80% of Japanese patients. While other risk factors, such as low HDL levels, have been reported, the pathogenesis of the disease remains poorly understood. RNF213 has been shown to play a role in immune responses against pathogens such as bacteria and viruses, suggesting a potential involvement of these pathogens in moyamoya disease. To explore this, we conducted a study to determine whether past viral infections or the gut microbiota are linked to the disease. The results revealed a significantly lower infection rate of the HHV6 virus in patients and a significant increase in the relative abundance of the gut microbiota Ruminococcus gnavus. Both factors were found to be associated with the disease, independent of the p.R4810K mutation. Previous reports indicate that HHV6 suppresses IL-13 and IL-5, cytokines involved in type 2 inflammation, while Ruminococcus gnavus increases these levels. This suggests that while atherosclerosis is primarily driven by type 1 inflammation, moyamoya disease may be predominantly characterized by type 2 inflammation.
