Type III membranoproliferative glomerulonephritis in primary Sjögren's syndrome.

Glomerulonephritis is a rare complication of primary Sjögren's syndrome. When glomerulonephritis does occur, it is usually due to membranous, focal proliferative, or membranoproliferative lesions. There have been fewer than 20 reported cases of glomerulonephritis in primary Sjögren's syndrome, only three of which have been membranoproliferative. We report a case of primary Sjögren's syndrome complicated by Type III membranoproliferative glomerulonephritis, a specific type of mesangiocapillary glomerulonephritis never before reported in this setting, and describe a clinical course terminating in rapidly progressive renal failure.