Hypoparathyroidism is a rare disease manifesting as hypocalcemic seizures, developmental delay, sluggishness, paresthesias and/or dyskinesia. Symptoms reveal hypocalcaemia associate with increased serum phosphorus and undetectable, low or unadapted PTH levels. Known causes of hypoparathyroidism are cervical surgeries causing irreversible damage to the parathyroid tissue, toxic attack of the parathyroid cells by antibodies, and genetic defects affecting parathyroid development, PTH secretion, or excessive signalization of the calcium-sensing receptor. Except for the transient inhibition of PTH secretion by proton pump inhibitors or alcohol, once diagnosed, hypoparathyroidism is definitive and unrepairable. The majority of hypoparathyroidism cases are well controlled under conventional treatment with calcium and vitamin D analogs. As such therapy increases filtered load of calcium in absence of PTH-driven calcium reabsorption, physicians advise their patients to avoid normalization of serum calcium because it can cause hypercalciuria and heterotopic calcification. As a consequence, patients -including infants and children- spend most of their life in hypocalcaemia. In spite of this precaution, the rate of complications appears substantial.
During the past 10 years, several groups have reported the efficacy of recombinant PTH184 or teriparatide PTH134 in children and/or adults in restoring near normal levels of serum calcium. Although not approved by regulatory agencies, recPTH may be an alternative to current therapy in patients with refractory hypoparathyroidism who experience life-threatening complications of their disease. Normalization of serum calcium to ensure proper cognitive development, and restoration of normal urinary calcium excretion to prevent renal failure should be the objectives of recPTH.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology