Acute-on-Chronic Kidney Injury in Thyroid Hormone Withdrawal: A Case with Possible Implications for Radioactive Iodine Planning

Figure 1

Time course of renal decompensation associated with acute hypothyroidism in levothyroxine withdrawal. At the time of thyroidectomy, the patient had CKD stage III with a normal TSH (0.27–4.2 uIU/mL), normal free T4 (0.93–1.70 ng/dL), and an eGFR of 53 mL/min/1.73 m². After withdrawal of levothyroxine in preparation for RAI therapy, the TSH increased to 93 μIU/mL corresponding to a decrease in the free T4; this was accompanied by an acute decrease in the eGFR to 32 mL/min/1.73 m². After restarting levothyroxine to achieve TSH suppression for management of his intermediate-risk papillary thyroid cancer, the eGFR trended back toward baseline and was restored by 7 months of thyroid hormone replacement.