Secondary hypoparathyroidism in thalassaemia and sickle cell anaemia
Katerina Thisiadou1, Ioannis Karamouzis1, Stella Arampatzi1, Kiriaki Chalvatzi1, Eleni Hasapopoulou2 & Despoina Michailidou1
Background: The diagnosis of hypoparathyroidism, a clinical situation characterised by reduced production of parathyroid hormone despite the low calcium level, depends on patients anamnesis, clinical aspect and the biochemical parameters.
Thalassaemia, an inherited autosomal recessive blood disease, caused by the reduced capacity of erythroblasts to synthesize one of the chains that build up hemoglobine. The combination of transfusion and chelation therapy has dramatically extended the lifes patients with thalassaemia. However, despite of chelation therapy, the regular blood transfusions lead to iron overload and frequently to endocrine complications such as hypoparathyroidism.
Aim: The aim of this study was to determine the prevalence and characterize the role of secondary hypoparathyroidism in β-thalassaemia, intermedia thalassaemia and in sickle cell anaemia, by measuring serum calcium, phosphorus and intact parathyroid hormone levels.
Patients and methods: Fifty patients with β-thalassaemia (β-thal), intermedia thalassaemia (int.thal)and sickle cell anemia (s.c.-an) were sudied. We also used a control group of 35 healthy subjects (h.s), The serum calcium (Ca), phosphorus (P) and intact parathyroid hormone (i-PTH) levels were checked. Ca and P levels were determined using photometric method while PTH was measured by electrochemiluminescence immunoassay.
Results: No statistically significant difference was found in the concentrations of Ca, P and i-PTH, in comparison to healthy individuals.
In our study, we didnt observed an overall low calcium and i-PTH levels in contrast to what expected. Nevertheless a small number of patients presented reduced i-PTH levels (<1.6 pmol/l). The phosphorus levels were normal.
Conclusions: During the study neither disturbances in the infusion of i-PTH, or in the homeostasis of calcium and phosphorus were noticed, probably because of transfusion programs and chelation therapy. Our results are comparable to those of similar projects.