A 76-year-old renal transplant patient due to autosomal dominant polycystic kidney disease who resumed chronic haemodialysis was admitted to our hospital for confusion and lassitude. He was afebrile and physical examination revealed diffuse bilateral rales with decreased respiratory sounds in lower right lung. Laboratory data showed hypercalcaemia (total calcium 3.92 mmol/L (normal range 2.2–2.6 mmol/L), ionised calcium 1.87 mmol/L (1.15–1.35 mmol/L)), low intact parathyroid hormone (iPTH) 15 ng/L, (15–65 ng/L) and high 1,25(OH)2D3 128.9 pg/mL, (15.2–90.1 pg/mL). Chest CT-scan revealed bilateral apical lung lesions after 15 days of antibiotics. Bronchoalveolar sample was PCR positive for Pneumocystis jirovecii. He was treated with an extra session of haemodialysis with 1.25 mmol/L dialysate calcium concentration, oral trimethoprim-sulfamethoxazole was started and oral corticosteroid dose increased to 1 mg/kg for 1 week. Hypercalcaemia decreased progressively after initiation of these treatments. We concluded a case of hypercalcaemia secondary to P. jirovecii infection.
Serum ionised calcium concentration: measurement versus calculation.