Autoimmune thyroiditis after bone marrow transplantation in a boy with Wiskott-Aldrich syndrome

We report a boy with Wiskott-Aldrich syndrome (WAS) who developed autoimmune thyroiditis 19 months after allogenic bone marrow transplantation (BMT). Possible causes of his autoimmune illness were 1) transference of autoimmune cells from the donor, which was ruled out because of the absence of autoimmune illness in his healthy HLA-identical brother (donor); 2) persistent mixed chimerism after BMT ruled out by post-BMT molecular analysis of the proband's peripheral lymphocytes; and 3) patient's predisposition to autoimmune disease secondary to an dysregulated immune system because of WAS and his HLA haplotype. This case brings previously unreported findings to the spectrum of WAS.