Endocrine Abstracts

Introduction: We do not fully understand why some hypothyroid patients complain of persistent symptoms despite normalisation of TSH with levothyroxine therapy. Recent evidence in adults suggests that polymorphism in deiodinase2 enzyme could lead to lower level of T₃ in some tissues and persistence of symptoms. A combination therapy with T₃/T₄ may improve symptoms especially psychological well-being, mood and memory in such patients. Combination therapy is used in adults but rarely in children.

Methods: We describe two patients with autoimmune hypothyroidism who responded well to combination therapy with T₃ and T₄.

Results: Case 1: Despite normalisation of TSH, HT complained of low mood, poor memory and tiredness, affecting her school performance. With increasing doses of levothyroxine, she had transient symptomatic relief only. After exclusion of alternative causative pathology, liothyronine (T₃) was added with significant improvement of her symptoms and patient-reported quality of life.

Case 2: BB also continued to be symptomatic despite increasing doses of levothyroxine, and the TSH continued to be marginally high. T₃ was added to her therapy with good effect and patient-reported improvement in quality of life.

Discussion/conclusion: Our paediatric patients with autoimmune hypothyroidism showed a good symptomatic response to T₃/T₄ combination treatment after a limited response to T₄ alone. Both patients opted to continue combination treatment despite increased frequency of dosing.