Abstract: PO1793
Is It Systemic Lupus Erythematosus Nephritis or Not?
Session Information
- Glomerular Diseases: Lupus and Membranous
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Pennekamp, Alexander, The Christ Hospital, Cincinnati, Ohio, United States
- Pembaur, Karl Berthold, The Kidney and Hypertension Center, Cincinnati, Ohio, United States
Introduction
IC-MPGN (immune complex-mediated glomerulonephritis) is a histopathological finding that is associated with infection, immune-complex deposition, monoclonal gammopathies as well as autoimmune disorders such as lupus, Sjögren's, and rheumatoid arthritis. MPGN traditionally has been classified as I-III depending on the pathology findings. More recently, an alternative classification system based on the pathological process has been developed (immune complex-mediated vs complement-mediated). In cases of IF showing IgG +/- C3, a tentative diagnosis of immune-complex mediated MPGN can be made. MPGN treatment is aimed first at treating the underlying cause. In the case where a cause cannot be found, as in our case of biopsy-proven IC-MPGN with negative serologies, the underlying mechanism is not clear.
Case Description
71-year-old female with PMHx aortic valve replacement, HTN, CKD-I presented with constitutional symptoms, and AKI on CKD with proteinuria. She was found to have biopsy-proven immune complex mediated MPGN, but the etiology was unclear due to negative: ANA, anti-Smith, anti-Ro/SS, anti-La/SSB, Hep B/C, cryoglobulins, CCP, CRP, ESR, K/L. The biopsy pattern was consistent with Lupus Type IV/V, with EM findings showing scattered sub endothelial dense deposits and full house IF staining pattern. CT abdomen/pelvis was negative. Further testing and workup for malignancy were negative. She was started on high-dose steroids for initial treatment of presumptive seronegative lupus nephritis. Serologies were repeated and all were negative. Patient showed improvement with initiation of mycophenolate + steroids; proteinuria and creatinine improved on follow-up.
Discussion
The optimal initial treatment of idiopathic/seronegative immune complex-mediated MPGN has not been established. In this case, the patient improved with aggressive steroid treatment with a tapering dose after starting mycophenolate. Proteinuria which was initially nephrotic at 14 g/g is now near 0.2 g/g.