Does transitory steroid-induced central hypothyroidism in children treated for haematological malignancies warrant clinical intervention?

Introduction
Steroid-induced central hypothyroidism (CH) is a frequent but under-diagnosed hormonal disturbance in children treated for acute lymphoblastic leukaemia (ALL) and lymphoma.

Aim of the study
To determine the occurrence, frequency of symptoms, replacement therapy administration, and association of CH with glucocorticoid therapy in children treated for haematological malignancies.

Material and methods
A prospective clinical survey was conducted on 21 patients (61.9% male, mean age 9.1 years) treated in the Children’s Hospital Zagreb during 2019, of whom 12 were treated for for ALL and 6 for Hodgkin lymphoma (HL), based on clinical (signs and symptoms) and laboratory data (hormonal status).

Results
Overt CH was verified in 15 (71.4%) and mild CH in 3 patients (14.2%). The most common symptoms and signs were fatigue, apathy, and electrolyte imbalance, observed in 50% of CH cases. Hormonal substitutional therapy was initiated in 44.4% of affected patients, during a mean of 2.08 months, with significant clinical improvement. Overt CH was more prevalent in patients with ALL than in those with HL (p = 0.025). Among children with ALL there was no difference in CH occurrence between the prednisone and dexamethasone groups; however, dexamethasone-induced CH was more frequently symptomatic (p = 0.03). The prednisone dosage played no role in CH incidence in patients with HL.

Conclusions
Further studies are needed to determine the real incidence of thyroid dysfunction during intensive chemotherapy treatment in children with ALL and lymphoma. Recommendations for optimal hormonal replacement therapy and a follow-up plan for paediatric oncology patients with CH are also urgently required.