Mixed cryoglobulinemia and thyroid autoimmune disorders.

In patients with hepatitis C virus-associated mixed cryoglobulinemia (MC+HCV) the following thyroid disorders are significantly more frequent than in HCV not infected controls: 1) high levels of serum anti-thyroperoxidase autoantibody (AbTPO), 2) high levels of serum AbTPO and/or anti-thyroglobulin (AbTg) autoantibody; 3) humoral and ultrasonographical signs of thyroid autoimmunity (35%); 4) prevalence of subclinical hypothyroidism (11%). Also, the prevalence of papillary thyroid cancer has been found higher in MC+HCV patients than in controls, in particular in patients with autoimmune thyroiditis. These results suggest a careful monitoring of thyroid function in these patients.