A case of mixed connective tissue disease presenting with nephrotic syndrome.

A 70-year-old woman was admitted to our hospital for the treatment of diffuse scleroderma and marked edema in the lower extremities. Renal biopsy revealed membranous change, interstitial nephritis, and intimal hyperplasia of the small arteries. The patient was diagnosed as having mixed connective tissue disease (MCTD) presenting with nephrotic syndrome (NS). She responded well to a combination treatment consisting of methylprednisolone (m-PSL) pulse therapy, oral PSL, and cyclosporine A (CsA). We speculated on the actual pathogenesis of NS in this case of MCTD.