Marrow Makes Thyroid but Not Adrenal Tissues in Humans.

Human marrow has shown potential to contribute to organ various organs. We previously demonstrated marrow contribution to the brain in humans, without evidence for fusion. Given the observations of marrow contributing to the other end-organs, we questioned whether marrow also repair endocrine glands like the thyroid and adrenal glands. To address this question, we identified thyroid (n=3) and adrenal tissues (n=3) obtained from women who received hematopoietic cell transplantation from male donors. Thyroid tissues were stained for thyroid peroxidase (TPO), CD45, and XY FISH. Adrenal tissues were stained for synaptophysin, CD45, and XY FISH. Analysis of 450 thyroid follicles (150 per patient) found 2% to 5% of follicles containing a male/marrow-derived thyroid follicle demonstrating follicular orientation, TPO expression, lacking CD45, and containing a Y chromosome. The median number of male/marrow-derived cells in follicles was 1. None of the male/marrow-derived cells demonstrated a fusion karyotype (XXY or XXXY). In contrast, adrenal tissues analyzed in the women demonstrated no male cells throughout all layers. In conclusion, our results show that human marrow can contribute to thyroid follicles and express thyroid proteins, however at a modest level. Furthermore, adrenal tissues in these women demonstrated no evidence of marrow contribution. These results expose a potential strategy of thyroid repair by illuminating the potential of marrow contribution to thyroid epithelia.