Abstract: SA-PO816
C3 Glomerulonephritis and Neuromyelitis Optica in a Patient with Systemic Lupus Erythematosus (SLE)/Sjogren Overlap Syndrome
Session Information
- C3G, TMA, MGRS, Amyloidosis, and More
October 26, 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
- Chelikani, Vijaya, The University of Alabama at Birmingham, Birmingham, Alabama, United States
- Rosenblum, Frida, The University of Alabama at Birmingham, Birmingham, Alabama, United States
- Rajasekaran, Arun, The University of Alabama at Birmingham, Birmingham, Alabama, United States
Introduction
C3 glomerulopathy (C3G) that includes dense deposit disease (DDD) and C3 glomerulonephritis (C3GN) are rare glomerular disorders triggered by dysregulation of the alternative complement pathway with an estimated incidence of 2-3 cases per million. We describe a rare case of C3GN and neuromyelitis optica in a patient with known SLE/Sjogren overlap syndrome.
Case Description
51-year-old African-American female with SLE/Sjogren overlap syndrome presented with proteinuric AKI on CKD and newly diagnosed transverse myelitis. Baseline Cr 0.8 mg/dL. Labs on admission: Cr 1.7 mg/dL, Sr albumin 2.8 g/dL, UPCR 5511 mg/g, urinalysis revealed acanthocytes. C3 152, C4 38, ANA 1:320 [speckled], ds-DNA (-), SSA > 150, SSB 106, NMO/AQP4 (+) at 1:10000. Rest of serological workup negative. No e/o infection. Kidney USG unremarkable. Kidney biopsy - LM: 35 glomeruli, no segmental or global sclerosis. Glomeruli normal, no endocapillary hypercellularity noted. IFTA <5%. Mild to moderate arterial and arteriolar sclerosis. IF: Fine granular reactivity for C3 [3+] along capillaries and in mesangium that are chunky. Rest of immunoreactants negative. Pronase IF negative. EM: Few scattered medium to large-sized electron dense deposits present in the mesangium and paramesangial area. Alternative complement pathway functional panel revealed low APFA and Fb levels and elevated C5 levels. C3GN genetic panel revealed a VUS in the THBD and MPLA gene. Patient received repeated doses of rituximab and has attained complete remission of proteinuria and resolution of AKI.
Discussion
C3GN affecting younger patients usually are mediated by genetic abnormalities of the alternative complement pathway. In addition to renal manifestations, a number of other extra-renal manifestations have also been associated with C3G including retinal involvement [drusen] and lipodystrophy, particularly in DDD. To date, concomitant NMO (+) transverse myelitis presenting concomitantly with C3GN has not been described. It remains unclear if the C3G-dominant immune complex-mediated glomerulonephritis was precipitated by the underlying SLE/Sjogren overlap syndrome.