Sjögren's syndrome
Viral proteins, engulfed molecules, or degraded self-structures may initiate autoimmunity by molecular mimicry and increase the chances of Sjögren's syndrome development. Epstein–Barr virus, hepatitis C, and human T-cell leukemia virus-1 are among the most studied infectious agents in Sjögren's syndrome. To date, no direct causes and effect relationship has been identified between these pathogens and the development of Sjögren's syndrome. Damaged self-structures targeted for apoptosis may be mistakenly exposed to the immune system, triggering autoimmunity in exocrine glands, which are often prone to autoimmune responses.