Endocrine Abstracts

We present the case of a 57 year old male that presented to a tertiary centre with a week’s history of lethargy, muscle cramps and peri-oral paraesthesia. He was otherwise fit and well. His examination revealed no evidence of Chvostek’s, Trousseau’s or tetany. His reflexes were not assessed. Initial electrolyte screening confirmed a hypocalcaemia with a serum adjusted calcium of 1.47 mmol/l (2.2–2.6), his phosphate was elevated at 1.64 mmol/l (0.8–1.5) and a serum magnesium was below target range at 0.67 mmol/l (0.7–1.0). Serum PTH was 0.2 pmol/l (1.3–9.3). Vitamin D level was normal. Haematinics revealed a folate deficiency. USS of the neck identified no masses. Despite adequate parenteral replacement of Calcium, Magnesium, oral alpha calcidol and high doses of Vitamin D, his calcium levels remained low. As a work up for malabsorption, an IgA antibody screen returned positive and he was commenced on a gluten-free diet and treated for concurrent coeliac disease. Idiopathic hypoparathyroidism (IH) occurs with atrophic, infiltrative or autoimmune mediated destruction of the parathyroids. Injury must be severe as there is adequate reserve in a single parathyroid gland for normal function. It is distinct to the more common acquired hypoparathyroidism that occurs mostly after surgery and at a permanent incidence between 0.4 to 33% depending on the centre. The autoimmune hypoparathyroid patient load has been estimated via population studies at 3 per 100,000. The condition is recognised to be strongly associated with both adrenal antibodies (26%) and thyroid antibodies (12%), such that combinations of these contribute to the Autoimmune polyglandular syndrome type 1. APS1 has been associated with malabsorption in up to 15% of patients. However, despite epidemiological reviews recognizing the existence of coeliac disease as a co-morbid state sparse work has been done on the immunological factors underpinning it. Thus, Saha et al examined the co-presentation of this in 2016 and in a particular patient group of confirmed IH, found co-existing Coeliac Autoimmunity is present at 6.4% and biopsy proven coeliac disease at 1.2%. This is not significantly different from the incidence in the general population. These are small numbers when taken as per head of population, but they do present a confounding variable in the face of recalcitrant hypocalcaemia independent of copper or magnesium levels. The authors would therefore recommend anti-tissue transglutaminase antibody with total IgA levels to screen all similar patients as in our case, who can affirm compliance to medication.