Autoimmune thyroid disease following hematopoietic stem cell transplantation in childhood cancer survivors.

Thyroid dysfunction has been observed in childhood cancer survivors (CCSs) who have undergone hematopoietic stem cell transplantation (HSCT). We retrospectively analyzed the thyroid function of 54 CCSs who underwent HSCT and were referred to our endocrinology department at Chiba Children's Hospital between January 1, 2008, and December 31, 2019. Three patients developed autoimmune thyroid disease (AITD) after HSCT. Two of these patients had Graves' disease (GD), and the third had autoimmune thyroiditis. The association between HSCT and AITD remains unclear. All three patients had chronic graft versus host disease (GVHD). AITD was reported to be induced by the transmission of abnormal T or B lymphocyte clones from the donor to the recipient. One patient with GD was treated with a high dose of anti-thymocyte globulin (ATG). Some studies have reported that ATG is associated with a risk of severe T cell depletion and GD onset. In conclusion, CCSs who received HSCT rarely developed AITD. We suggest that CCSs treated with ATG and/or experiencing an onset of chronic GVHD should be carefully monitored for thyroid function because it might reveal AITD.