The Thyroid After Stem Cell Transplantation In Children And Adolescents. Results Of A German-Austrian Long-Term Follow-Up Study In 416 Patients

Objective. Evaluation of thyroid dysfunction before and after stem cell transplantation (SCT) in children and adolescents.Methods. A total of 416 patients were registered in a complex, longitudinal and multicentre German-Austrian follow-up programme after stem cell transplantation between 1996 and 2002.Results. As part of the investigation of the endocrine system, thyroid function was evaluated: before SCT, primary hypothyroidism was observed in 7/269 cases (3%), latent hypothyroidism in 28/269 cases (11 %) and secondary hypothyroidism in 18/269 cases (7%). Longitudinal data on 123 patients with a follow-up interval of 36.0 months showed thyroid dysfunction in 42 cases (34%): primary hypothyroidism in one case (1%), latent hypothyroidism in 33 cases (27%) and secondary hypothyroidism in eight cases (7%). Patients who developed a latent hypothyroidism were more likely to have had radiotherapy than patients who remained euthyroid [odds ratio of 2.55 (1.08-6.05), chi(2)(1)=4.86, P < 0.03]. Among patients with only chemotherapy, 3/70 (4%) developed a secondary and 15/70 (21%) a latent hypothyroidism. A papillary carcinoma of the thyroid, as a secondary neoplasm, was diagnosed in one patient with a medulloblastoma 7 years after primary treatment and 3 years after SCT. The observed thyroid dysfunction developed over the entire follow-up period of 5 years.Conclusions. Regular functional evaluations (fT4/TSH) before SCT, 6 monthly for the first year and yearly thereafter, and morphological evaluations (ultrasound) before SCT and yearly thereafter are recommended within a follow-up protocol.