HHV-6B, HHV-7, and B19V Are Frequently Found DNA Viruses in the Human Thymus but Show No Definitive Link with Myasthenia Gravis

Abstract

Myasthenia gravis (MG) is a rare autoimmune disorder characterised by muscle weakness resulting from autoantibody-mediated disruption of the neuromuscular junction. Notably, it is also frequently associated with thymic pathology. This study explores the relationship between MG and DNA viruses in the thymus, employing targeted NGS and qPCR to analyse thymic tissue samples from both MG patients and healthy controls. We detected HHV-6B, HHV-7, EBV, and B19V across various tissue groups. However, no significant enrichment of these viruses was observed in the thymic tissue of MG patients. Additionally, we confirmed a dormant persistence of B19V within the thymus of seropositive individuals. These findings indicate that DNA viruses are unlikely to serve as primary environmental triggers for MG.