Severe hypocalcemia in a patient with protein-losing enteropathy

Abstract

We report a 53-year-old woman with hypocalcemia associated with protein-losing enteropathy. She had had lymphedema of the left lower extremity since 20 years of age and had loose bowels and hypoproteinemia. Her daily fecal excretion of α1-antitrypsin was extremely high, suggesting massive intestinal protein loss. This was demonstrated by scintigraphy using 99 mTc-labeled human serum albumin, in which significant amounts of radioactivity were first accumulated in the lower part of the small intestine and then went down along the colon. She not only had hypocalcemia, but also an increased serum concentration of immunoreactive parathyroid hormone (PTH) and 1,25 (OH)2D, and increased percent tubular reabsorption of phosphate. In addition, she had low serum levels of fat-soluble vitamins including 25 (OH) D. In the Ellsworth-Howard test, urinary excretion of cyclic AMP and phosphate in response to exogenous PTH was rather exaggerated. These results suggest that hypocalcemia in this case was due mainly to malabsorption of calcium and vitamin D secondary to protein-losing enteropathy.