Kidney Week

Abstract: TH-PO539

Secondary Membranous Nephropathy Was Induced by Gastrointestinal Stromal Tumor in Patient with Idiopathic Membranous Nephropathy

Session Information

• Trainee Case Reports - I
  October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Trainee Case Reports

• 1100 Geriatric Nephrology

Authors

• Nakayama, Maiko, Juntendo University Faculty of Medicine, Tokyo, Japan

Maiko Nakayama,

• Suzuki, Hitoshi, Juntendo University Faculty of Medicine, Tokyo, Japan

Hitoshi Suzuki,

• Sasaki, Yu, Juntendo University Faculty of Medicine, Tokyo, Japan

Yu Sasaki,

• Tomita, Shigeki, Juntendo University Urayasu Hospital, Urayasu, Chiba, Japan

Shigeki Tomita,

• Suzuki, Yusuke, Juntendo University Faculty of Medicine, Tokyo, Japan

Yusuke Suzuki,

Introduction

The membranous nephropathy (MN) is a major cause of nephrotic syndrome. The major causes of secondary MN are malignancy, autoimmune disease, infection, and drug toxicity. However, gastrointenstinal stromal tumor (GIST) rarely induces secondary MN. We report here a biopsied case with onset of secondary MN accompanied by GIST on idiopathic MN successfully treated by the resection of GIST.

Case Description

A 77-year-old man was diagnosed as the idiopathic MN at 60-year-old, and treated by oral corticosteroid, resulted in incomplete remission. From age of 71, serum levels of CA19-9 had increased at 1278 U/mL, however, any malignancy was not detected. He was hospitalized because of exacerbation of urinary protein (5.1g/gCr) at 77-year-old. Although steroid pulse therapy was initiated, level of urinary protein was not improved. To rule out complication with other glomerular injuries, we performed renal biopsy. Light microscopic finding indicated MN, but not other glomerulonephritis. Immunofluorescence analysis of IgG subclass showed IgG1 and IgG2 dominant, despite IgG4 deposits were dominant in previous renal biopsy specimens. Furthermore, serum anti-PLA2R antibody was negative. We thus diagnosed as the secondary membranous changes on idiopathic MN. We further surveyed complication of malignant disease and could find GIST by PET-CT. After 1 month from resection of GIST, serum CA19-9 decreased within normal range, and the level of proteinuria also improved to 1.4 g/gCr.

Discussion

This is the novel case with onset of secondary MN on idiopathic MN. Moreover, GIST typically does not show increased levels of serum CA19-9 and rarely induced secondary MN.