Advantages of monitoring rT3 and dividing LT3 dose in the treatment of consumptive hypothyroidism associated with infantile hepatic hemangioma.

OBJECTIVES: In consumptive hypothyroidism associated with infantile hepatic hemangiomas (IHH), elevated reverse triiodothyronine (rT3) is known due to elevated D3. This report shows that rT3 is a new indicator of IHH progression and that three divided doses of LT3 per day were more effective than a single dose. CASE PRESENTATION: A 23 day-old boy was diagnosed with diffuse IHH and severe hypothyroidism with high rT3. Propranolol and LT4 were administered. Hemangiomas gradually diminished and rT3 decreased, but the thyroid-stimulating hormone remained elevated, and free triiodothyronine (fT3) did not normalize after 2 weeks of treatment. Liothyronine (LT3) was started as a single dose and then divided into three doses after 1 week, which stabilized thyroid function. CONCLUSIONS: rT3 levels were less variable and decreased in conjunction with tumor shrinkage; thus, rT3 is an indicator of therapeutic outcomes for IHH. LT3 administered in divided doses aided in managing IHH-associated hypothyroidism.

A Case of Consumptive Hypothyroidism in a 1-Month-Old Boy with Diffuse Infantile Hepatic Hemangiomas.

Consumptive hypothyroidism is a rare paraneoplastic syndrome characterized by excessive inactivation of the thyroid hormones due to increased type 3 iodothyronine deiodinase activity of tumors. We report the case of severe consumptive hypothyroidism in a 1-month-old boy with infantile hepatic hemangiomas who presented with cardiac failure and cholestasis. Diffuse infiltration of hepatic hemangiomas was detected on abdominal imaging studies, and thyroid function screening test revealed severe hypothyroidism, which necessitated the administration of higher-than-usual doses of levothyroxine for the normalization of thyroid function. The patient was successfully treated with propranolol, prednisolone, and levothyroxine, and he showed normal thyroid function at 3 months of age and normal neurodevelopment at 9 months of age. This case highlights the importance of early recognition and prompt management of consumptive hypothyroidism in patients with infantile hepatic hemangiomas.

The establishment of zebrafish Dio3b gene knockout model / 中华内分泌代谢杂志

Objective To set up the model of deiodinase ( Dio) 3b-/- zebrafish and to observe the effect of which on embryo development. Methods The zebrafish model of Dio3b-/- was set up by CRISPR-Cas9 gene editing technology, PCR and sequencing was used to confirm the efficiency of deletion. The heart rate of embryos at 48 hours post fertilization was counted. The locomotor activity of 5-7 days post fertilization larve was detected using behavior tracking system. Results The model of Dio3b knockout zebrafish was set up successfully. The heart rate of embryos Dio3b-/- increased ( P＜0. 001) and the locomotor activity of 5-7 days post fertilization larves lacking Dio3b gene increased (P＜0.05) significantly compared with that of wild type control respectively. Conclusion The deletion of zebrafish Dio3b gene results in the phenotype of hyperthyroidism and the model of Dio3b-/- is proper for studying the effect of partial excess thyroid hormone on embryo development.