Protein-losing gastroenteropathy with severe hypoalbuminemia associated with Sjögren's syndrome: A case report and review of the literature.

A 30-year-old man with severe hypoalbuminemia (serum albumin: 0.9 g/dL) was admitted with severe bilateral leg edema and unilateral pleural effusion. Serum anti-SS-A and SS-B antibody levels were abnormally elevated, and his symptoms fulfilled the diagnostic criteria for Sjögren's syndrome. Technetium-99m albumin scintigraphy revealed protein leakage from a large area of the small intestine. Immunohistochemistry revealed perivascular deposition of C1q, C3d, and immunoglobulin G in the duodenal mucosa. The patient was diagnosed with protein-losing gastroenteropathy associated with Sjögren's syndrome. Within 2 months of treatment with oral prednisolone and mycophenolate mofetil, the clinical symptoms of hypoalbuminemia and Sjögren's syndrome disappeared completely.