Plasmapheresis rapidly eliminates thyroid hormones from the circulation, but does not affect the speed of TSH recovery following prolonged suppression.

OBJECTIVE

To report an attempt to shorten the preparation interval before radioactive iodine administration using plasmapheresis in a 77-year-old woman with a history of papillary thyroid carcinoma with local recurrence and lung metastases, in whom the administration of a high dose of radioactive iodine was intended as a desperate rescue procedure.

METHODS

The patient was initially started on cholestyramine. Two days later, plasmapheresis was performed.

RESULTS

Plasmapheresis rapidly decreased free tri-iodothyronine (FT(3)) and free thyroxine (FT(4)). Serum FT(4) subsequently remained low, while FT(3) recovered the next day. Thyroid-stimulating hormone (TSH) reached 25 mIU/l in 14 days, which is within the time frame required to reach the target TSH level by withdrawing levothyroxine alone.

CONCLUSION

Plasmapheresis is very effective in eliminating thyroid hormones from the circulation. However, it does not seem to accelerate thyrotroph recovery to a considerable extent after prolonged suppression.