Abstract: TH-PO674
Anti-phospholipase A2 Receptor (PLA2R)-Positive Membranous Nephropathy Triggered by Sunitinib in Patients with Gastrointestinal Stromal Tumor (GIST): A New Association?
Session Information
- Glomerular Diseases: Case Reports - 1
October 24, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Pascoal, Mateus, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
- Tors, Antony Jose, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
- Hickmann de Moura, Juliana, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
- de Mattos Marques, Cassiano, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
- Guardao barros, Elvino Jose, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
- Veronese, Francisco Veríssimo, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
- Wolffenbuttel, Luciano, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil
Introduction
Tyrosine Kinase Inhibitors are classically associated with hypertension and proteinuria due to thrombotic microangiopathy. We report the second case of Membranous Nephropathy associated with anti-PLA2R antibody in the literature, developed shortly after starting Sunitinib, in patients with metastatic GIST.
Case Description
A 55-year-old female was diagnosed with metastatic duodenal GIST in May 2018, and treated with Imatinib 400 mg/day. Oral Sunitinib was started in September 2023 due to disease progression. She developed proteinuria (1450 mg/24 hours) after two doses, leading to treatment discontinuation. Despite that, proteinuria increased to nephrotic levels with urine protein/creatinine ratio (UPCR) of 11 g/g of creatinine. A renal biopsy revealed Membranous Nephropathy and serum anti-PLA2R was positive at 259 UR/ml (<14). The patient was treated with Rituximab, with serologic remission and a marked improvement in proteinuria (UPCR 2.6 g/g of creatinine) shortly after (1 week) completion of treatment.
Discussion
In 2021, Zonoozi et al (BMJ Case Rep 2021;14:e243567) reported a very similar case: proteinuria developed after a few weeks of treatment with Sunitinib in a patient with metastatic GIST that progressed on Imatinib. As in the case reported here, renal biopsy revealed Membranous Nephropathy with serology and tissue IF positive for anti-PLA2R. Both patients were treated with Rituximab, with complete serologic remission. To our knowledge, this is the second case reported of anti-PLA2R Membranous Nephropathy associated with Sunitinib in the literature, coincidentally or not, in patients with GIST. Since there is no known association between Membranous Nephropathy and GIST, and anti-PLA2R antibodies are usually associated with “primary” Membranous Nephropathy, we hypothesize that the Tyrosine Kinase Inhibitor Sunitinib elicited the production of anti-PLA2R antibodies in both cases