Thyroid function after autologous bone marrow transplantation

Thyroid function was prospectively analysed in 111 consecutive patients in relation to autologous bone marrow transplantation (ABMT). Median follow-up time was 12 (range 3-60) months. As part of the conditioning treatment 58 patients had received total body irradiation (TBI) as a single dose of 7.5 Gy (dose rate 0.15 Gy/min). Thyroxine, triiodothyronine, thyrotropin (TSH) and thyroid antibodies were analysed before ABMT, every third month during the first year afterwards and then once annually. Thyroid dysfunction was seen in 20 patients (after TBI in 16, after non-TBI treatments in four). Five of these, all treated with TBI, developed primary hypothyroidism and in 15 compensated hypothyrosis, transient in eight (40%), was seen. There was a highly significant (p less than 0.001) increase, within the normal range, in median TSH level, prior to ABMT compared with 1 year following ABMT. In patients who developed thyroid dysfunction, the TSH level before ABMT was significantly higher (p less than 0.001) than in those who remained euthyroid. In four patients persistent elevated thyroid antibody titers appeared and in two of them hypothyrosis developed. No correlation between thyroid dysfunction and age was noted. The findings are similar to those after allogeneic BMT described by others.