The Prevalence of Hypoparathyroidism in Group of Transfusion Dependent B-Thalassemia (TDT) and its Relation to Iron Chelation

Abstract

Background: Hypoparathyroidism (HPT) due to siderosis in thalassemic patients was firstly described by Gabriele 1971. Hypoparathyroidism is a result of iron overload seen in transfused thalassemic major patients. It may cause a lot of neurological manifestations, including tetany, seizures, carpopedal spasms, paresthesia and even abnormal cerebral computed tomography findings have been reported.
Objectives: To identify the prevalence of hypoparathyroidism among groups of patients with transfusion dependent B-thalassemia (TDT) and the associated risk factors.
Patients and Methods: Across sectional randomized study has been conducted at Thalassemia Center at Al-Zahraa Teaching Hospital in Al-Najaf City from the beginning of October 2016 to the end of May 2017. Eighty patients (49 male and 31 female) with transfusion dependent β-thalassemia involved in our study, they subdivided into two groups according to PTH level, and these two groups are thalassemic patients with hypoparathyroidism and thalassemic patients without hypoparathyroidism.
Result: The prevalence of hypoparathyroidism is 65% in the study population. We find that (older age patients, younger age at diagnosis, large number of transfusion per year, high serum ferritin, prolong duration of transfusion and chelation) are associated with significant risk. Patients that use oral deferasirox (Exjade) are significantly lower affected by hypoparathyroidism than that use mixed type (defirasirox and deferoxamine) chelation. Those with good compliance with chelation are significantly lower affected by hypoparathyroidism.
Conclusions: High prevalence of hypoparathyroidism 65% were found in transfusion dependent thalassemic major patients, mainly in the second decade of life.