特発性副甲状腺機能低下症に対するVitamin D療法中に尿路結石を生じた1例

Abstract

30歳女.中学生頃より両手に力が入らなくなることが時々あったが放置した.その後, 血液検査で低カルシウム血症, 高リン血症を指摘され, 精査で特発性副甲状腺機能低下症と診断された.活性型ビタミンD製剤α-カルシドールで血中カルシウム濃度をコントロールしており, 尿中カルシウム・クレアチニン比も低値であった.α-カルシドール投与を続けたが, 右尿管結石を指摘されESWL, TULを施行された.血中カルシウム濃度は正常範囲に保たれているにも拘わらず, 尿中カルシウム排泄が増加した.α-カルシドールを減量したが尿中カルシウム高値は続き, 左尿管結石・左水腎症を指摘された.結石に対しTULを行い, 結石は消失し, 水腎症も軽快した.術後腎尿細管のカルシウム再吸収作用を期待してサイアザイド系利尿薬トリクロルメチアジドを投与した

We report a case of urolithiasis in a patient with idiopathic hypoparathyroidism treated with vitamin D therapy. A 30-year-old woman with idiopathic hypoparathyroidism, who had been treated with vitamin D therapy with 2-4 micrograms/day of alpha-calcidol for 9 years, was admitted for recurrence of bilateral renal stones and progressing left hydronephrosis. Laboratory data revealed normal serum calcium level and remarkable hypercalciuria. The dose of oral administration of alpha-calcidol was reduced to 1 microgram/day and 2 mg/day of trichlormethiazide was started. Now her serum calcium concentration and the total amount of urine calcium was completely under control. Bilateral renal stones are no longer progressive and tetany has not been recognized. We considered it essential to monitor closely not only the serum but also the urine calcium level in the vitamin D therapy for idiopathic hypoparathyroidism.