Involvement of Polyomaviruses in the Pathogenesis of Autoimmune Thyroiditis and Goitrigenesis.

Autoimmune thyroiditis and goitres are frequent pathologies. On a predisposing genetic ground, environmental factors are potentially at their origin. Viral infections are the main factors involved in autoimmunity (herpes virus, viral hepatitis C, Erythrovirus B19 ..). However some viruses have an oncogenic potential and could be involved in goitrigenesis. It is also possible that some viruses are specifically implicated in the pathogenesis of Graves' disease or Hashimoto thyroiditis which combines goitre and autoimmunity.

The intrathyroidism of the viral genome of a polyomavirus, the BK virus, has recently been reported in patients with goitre or cancer. The BK virus is a small ubiquitous virus of 40 nm diameter with double-stranded DNA contained in a non-enveloped icosahedral capsid. It is mainly known for triggering renal and bladder pathologies including urothelial tumors in the immunocompromised patient, tubulo-interstitial nephropathy in the renal transplant patient, as well as hemorrhagic cystitis in the patient grafted to the bone marrow.