title: The role of human parvovirus B19 and hepatitis C virus in the development of thyroid disorders.
abstract: The presence of viruses in the thyroid has been shown, but whether they are implicated in thyroid diseases or are only spectators is under investigation. The most important candidate viruses for autoimmune thyroid disorders (AITD) are hepatitis C virus (HCV) and human parvovirus B19 (or Erythrovirus B19 or EVB19). Retrospective and prospective case-control studies conducted on pathology slides showed (by PCR, in situ hybridization or immunohistochemistry) EVB19 was present in thyroid tissues of patients with autoimmune thyroiditis (AT), Graves' disease and thyroid cancer. Though AITD can be associated with acute EVB19 infection, it is not clear whether EVB19 could have a pathogenetic role in autoimmune thyroid diseases pathophysiology. Many studies have shown that frequently, patients with HCV chronic infection (CHC) show elevated serum anti-thyroperoxidase (TPOAb) and/or anti-thyroglobulin autoantibodies levels, ultrasonographic signs of chronic AT, and subclinical hypothyroidism. In patients with HCV-associated mixed cryoglobulinemia (MC + HCV), AITD were more prevalent with respect to controls, and also vs HCV patients without cryoglobulinemia. Papillary thyroid cancer was more prevalent in MC + HCV or CHC patients than in controls, especially in patients with AT. Recently it has been shown an elevated incidence of new cases of AT and thyroid dysfunction in MC patients. These results suggest an attentive monitoring of thyroid function and nodules in HCV patients with risk factors (female gender, a borderline high initial thyrotropin, TPOAb positivity, a hypoechoic and small thyroid) for the development of thyroid disorders.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Savi, 10, I-56126, Pisa, Italy.
authors.forename: Poupak
authors.initials: P
authors.lastname: Fallahi
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Savi, 10, I-56126, Pisa, Italy.
authors.forename: Silvia Martina
authors.initials: SM
authors.lastname: Ferrari
authors.affiliation: Department of Clinical & Experimental Medicine, University of Messina, Messina, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Vita
authors.affiliation: Department of Clinical & Experimental Medicine, University of Messina, Messina, Italy.|Master Program of Childhood, Adolescence and Women's Endocrine Health, University of Messina, Messina, Italy.|Interdepartmental Program of Molecular & Clinical Endocrinology, and Women's Endocrine Health, University Hospital, Policlinico G. Martino, 98125, Messina, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Benvenga
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Via Savi, 10, I-56126, Pisa, Italy. alessandro.antonelli@med.unipi.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Antonelli
mesh_terms: D016174:Hepacivirus / Q000472:pathogenicity*; D006801:Humans; D007037:Hypothyroidism / Q000473:pathology / Q000821:virology; D016732:Parvovirus B19, Human / Q000472:pathogenicity*; D013959:Thyroid Diseases / Q000473:pathology* / Q000821:virology*; D013961:Thyroid Gland / Q000473:pathology / Q000821:virology; D013964:Thyroid Neoplasms / Q000473:pathology / Q000821:virology
keywords: Autoimmune thyroid disorders; Autoimmune thyroiditis; Hepatitis C virus; Hypothyroidism; Parvovirus B19; Thyroid cancer