Advances in Microbiology, Infectious Diseases and Public Health

Rizzo, Roberta, Zatelli, Maria Chiara, Rotola, Antonella, Cassai, Enzo, Degli Uberti, Ettore, Di Luca, Dario, Caselli, Elisabetta, Roberta Rizzo, Maria Chiara Zatelli, Antonella Rotola, Enzo Cassai, Ettore Degli Uberti, Dario Di Luca, Elisabetta Caselli

Gianfranco Donelli

Hashimoto's thyroiditis (HT) is a very common autoimmune disease of the thyroid. In addition to genetic background, several viruses, including herpesviruses, have been suggested to play a role as possible environmental triggers of disease, but conclusive data are still lacking. Previous results showed that HT patients have an increased cellular immune response directed against the HHV-6 U94 protein and increased NK activity directed against HHV-6 infected thyrocytes.In this study, we characterized the antiviral antibody response and the NK cells activity and subtype in HHV-6 infected HT patients. The results showed that HT subjects have increased prevalence and titer of anti-U94 antibodies and a higher amount of CD3-CD56(bright)CD16(-)NK cell percentages compared to controls. Furthermore, the cell activation of CD3(-)CD56(bright) NK cells in HT patients significantly correlates with TPO and Tg Ab levels.The results suggest that HHV-6 might contribute to HT development, increasing NK cell secretion of inflammatory cytokines that could sustain the persistence of an inflammatory status in HT patients.