Iron deposition in the anterior pituitary in homozygous beta-thalassemia: MRI evaluation and correlation with gonadal function.

OBJECTIVE: Iron deposition in the anterior pituitary continues to pose a serious problem in older patients with homozygous beta-thalassemia particularly in terms of gonadal function. This study aimed to investigate whether iron loading within the pituitary correlated with endocrine function. PATIENTS: 33 patients above 15 years of age, with transfusion-dependent homozygous beta-thalassemia and iron overload were studied. All had been receiving deferoxamine since 1978. DESIGN AND MEASUREMENTS: The endocrine status of the patients was assessed on clinical examination by an endocrinologist, and by a gonadotropin releasing hormone stimulation test. MRI of the pituitary was carried out for each patient.
RESULTS: Anterior pituitary function (GnRH stimulation test) correlated well with MRI results. However, no correlation was found between the MRI measurements, the GnRH stimulation test and the clinical status of the patients, as 28 out of the 33 patients achieved normal puberty.
CONCLUSIONS: MRI in conjunction with a GnRH stimulation test may be useful in predicting future impairment of pituitary function; however, further studies are needed to assess the effect of chelation therapy on the iron overload in the gland.