Abstract: PO1829
Collapsing Glomerulopathy in Mixed Connective Tissue Disease: Case Report
Session Information
- Glomerular Diseases: IgA, C3G, and FSGS
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
- Atari, Mohammad, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Ambruzs, Josephine M., arkana laboratory, Little Rock, Arkansas, United States
- Nakkar, Talal, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Sharshir, Moh'd, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Saqqa, Osaid, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Simon, Eric E., Tulane University School of Medicine, New Orleans, Louisiana, United States
Introduction
Collapsing glomerulopathy (CG) is a form of podocytopathy with segmental or global wrinkling and collapse of capillary walls and overlying epithelial cell proliferation but may be distinct from other forms of focal and segmental glomerular sclerosis (FSGS). CG may be idiopathic or associated with infections, autoimmune diseases, malignancies, genetic diseases, certain drugs and in post-transplant setting. Although CG has been reported in lupus nephritis, it was rarely reported in the setting of mixed connective tissue disease (MCTD).
Case Description
A 30 y/o African American male with a history of muscle aches, nontraumatic rhabdomyolysis, evanescent skin rashes and weight loss was found to have a creatinine of 5.1 mg/dl (1.4 1 year earlier) with urine protein/creatinine ratio (uPCR) of 10,136 mg/g. CPK was 1697 U, erythrocytes sedimentation rate > 120, a positive speckled ANA of 1:640, positive anti-SSA 5.9, anti-chromatin >8, anti-sm 7.2, anti-sm RNP >8, anti-RNP >8. Kidney biopsy showed mesangial immune complex deposition, collapsing glomerulopathy and diffuse podocytopathy, immunofluorescence showed global mesangial IgG staining (3+), IgM (1+), C3 (2+), and kappa (2-3+) and lambda (3+) light chains. Electron microscopy revealed several mesangial electron-dense deposits with mild increase in mesangial matrix and hypercellularity and severe epithelial foot processes effacement without glomerular or tubular basement membrane deposits. Muscle biopsy confirmed the diagnosis of dermatomyositis. The patient was treated with pulse methylprednisolone 1 gm IV for three days followed by prolonged prednisone taper. Later, MMF was started at 500 mg bid, lisinopril 40 mg daily, hydroxychloroquine 200 mg bid and bumetanide 2 mg bid. By 4 months creatinine had stabilized at 2.6 mg/dl, uPCR was 1,824 mg/g, and CPK was 55 U.
Discussion
Here we describe a case of collapsing glomerulopathy in the setting of MCTD (SLE and dermatomyositis), with at least partial response to high dose prednisone for 16 weeks, hydroxychloroquine and late initiation of MMF. CG can present in association with autoimmune diseases including but not limited to SLE. This case represents the second such as this case of CG in the setting of MCTD and is notable for its response to immunosuppressive therapy.