Background: Hypoparathyroidism (HPT) is present in 80% of patients with Autoimmune Polyendocrinopathy Syndrome type 1 (APS-1) rare monogenic complex disease characterized also by adrenal failure, chronic candidiasis and a spectrum of other autoimmune disorders, including enteropathy and malabsorbtion. Active vitamin D and calcium are currently used for HPT treatment to maintain normal serum calcium levels.
Objective and hypotheses: To describe a severe case of APS-1 with HPT and a role of parathyroid hormone therapy in controlling normal calcium level.
Clinical case: A 26-year-old female patient with confirmed APS type 1 has been followed up in our department since she was 10. She manifested with chronic candidiasis at 4 years, thereafter she developed other APS-1 components: HPT and adrenal insufficiency at 10 years, malabsorbtion and alopecia areata at 20 years, ovarian failure at 21 years. She was diagnosed with acquired pigmented retinopathy at 26 years. Two heterozygous mutations, R257Xand W78R, were found in AIRE gene. Alfacalcidol and calcium therapy was effective to maintain near normal serum calcium levels, however, calcium fluctuations were seen. Severe malabsorbtion was observed since 20 years and has led to clinically significant hypocalcemia. Progressive increasing of alfacalcidol doses up to 20 mcg/day did not normalize calcium level. Gastroscopic study showed an atrophy of the mucosa of the stomach and small intestine. The patient had cholelithiasis and cataracta. Parathyroid Hormone (PTH 1-34) treatment was initiated and normocalcaemia was achieved in two weeks on the dose 40 μg per day (twice a day) without vitamin D and calcium supplementation. Calcium level remained within normal range and was controlled several times a day first three weeks of PTH treatment, once a week for the next three months and once in two weeks during further eighteen months follow-up period. Urinary calcium excretion was measured on PTH therapy at 8 and 12 months and was in normal range (2.8 mmol/day).
Conclusion: Hypocalcemia in severe APS-1 cases could be difficult to control with vitamin D metabolites. PTH replacement therapy of HPT could be a treatment of choice in case of severe malabsorbtion.
01 - 03 Oct 2015
European Society for Paediatric Endocrinology