Endocrine Abstracts

Case history: A 55-year-old man presented to the Emergency Department with worsening breathlessness 11 days after testing positive for severe acute respiratory syndrome coronavirus 2 (SARS CoV 2). He reported ongoing diarrhoea, starting 1 week prior to the SARS CoV 2 infection. He was previously fit and well, on no regular medication. On examination he was alert, with all clinical observations within normal limits and there were no significant findings in the chest and abdomen.

Investigations, results and treatment: Day 1 Sodium 127 mmol/l (133-146) Potassium 3 mmol/l (3.5-5.3) eGFR 58 ml/min CRP 41 mg/l (0-10) Serum osmolality 267 mosmol/Kg (280-300) Provisional Diagnosis: Hypovolaemic hyponatraemia and hypokalaemia secondary to diarrhoea. Treatment: Intravenous fluids. Day 2 Adjusted Calcium 0.98 mmol/l (2.2-2.6) Phosphate 1.01 mmol/l (0.74-1.62) ALP 78 U/l (40-150) PTH 5 ng/l (15-68) Magnesium 0.52 mmol/l (0.7-1.0) Vitamin D 34 nmol/l (50-200) Stool culture – Campylobacter sp. ECG – Prolonged QTc Provisional Diagnosis: Profound hypocalcaemia secondary to hypomagnesaemia due to campylobacter diarrhoea. Treatment: Intravenous fluids replacement of calcium and magnesium, and oral loading dose cholecalciferol. Day 11 (discharged from hospital) Adjusted Calcium 1.96 mmol/l (2.2-2.6) PTH 4 ng/l (15-68) Magnesium 0.92 mmol/l (0.7-1.0) Sodium 137 mmol/l (133-146) Potassium 4.8 mmol/l (3.5-5.3) eGFR >90 ml/min Provisional Diagnosis: Resolving hypocalcaemia and other electrolyte disturbances secondary to campylobacter diarrhoea. Treatment: Cholecalciferol 20,000 units once weekly for 6 weeks, Adcal-D3 4 tablets daily and Alfacalcidol 0.5 micrograms once weekly. 3 Months Later Parathyroid antibodies - Negative Adjusted Calcium 2.08 mmol/l (2.2-2.6) Phosphate 1.4 mmol/l (0.74-1.62) PTH 6 ng/l (15-68) Magnesium 0.82 mmol/l (0.7-1.0) Final Diagnosis: SARS CoV 2 infection-induced hypoparathyroidism, complicated by campylobacter diarrhoea (resolved). Treatment: Adcal-D3 2 tablets daily and Alfacalcidol 1 microgram daily.

Conclusions and points for discussion: Hypocalcemia is a prevalent symptom of SARS CoV 2 infection, and appears to be a predictor of severe infection but is largely self-resolving. Several reports have shown SARS CoV 2 infection leading to autoimmune diseases but rarely involve the parathyroid gland. Hypoparathyroidism is typically caused by injury to the parathyroid gland from surgery, autoimmune disease, genetic causes, or infiltrative diseases. Three case studies have described SARS CoV 2 infection-induced hypoparathyroidism, but none with as profound hypocalcaemia requiring ongoing active vitamin D therapy.