Hypercalcemia with the Elevation of Serum PTHrP Level in Sarcoidosis

Abstract

We reported two cases of sarcoidosis patients who showed hypercalcemia with the elevation of serum PTHrP level. Case one was complicated by rheumatoid arthritis and Sjögren's syndrome showed hypercalcemia fourteen years later the onset of sarcoidosis. Case two was complicated by Sjögren's syndrome and had hypercalcemia with sarcoid myopathy. Both cases showed hypercalcemia and hypercalciuria with the elevation of serum PTHrP levels. However, both cases showed normal 1.25(OH)₂D₃ value and low PTH value during the course of the disease. In case one, serum calcium and PTHrP levels were decreased spontaneously. In case two, hypercalcemia and serum PTHrP level improved with corticosteroid therapy. These data suggested that PTHrP may play a role in the development of hypercalcemia in sarcoidosis.