Abstract: PO1787
An Atypical Presentation of Lupus Nephritis
Session Information
- Glomerular Diseases: Lupus and Membranous
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Kiri, Gaurav, USF Health Morsani College of Medicine, Tampa, Florida, United States
- Hingorani, Jaideep U., Charlotte Nephrology Associates, P.A., Port Charlotte, Florida, United States
Introduction
Lupus nephritis in the absence of ANA and dsDNA, and normal C4 levels is a rare, atypical presentation. To arrive at the diagnosis requires EM examination of renal biopsies and is responsive to immunosuppressive therapy. We present a report of such a case.
Case Description
A 49-year-old female was referred for asymptomatic hematuria and nephrotic-range proteinuria (4.9 g/g) in March 2014. Her creatinine (0.77 mg/dL), C4, ANA, dsDNA, and Rheumatoid factor were normal with low C3. Labs were normal for Hepatitis B, C, HIV, ANCA, RNP, and Sm antibodies. She was started on lisinopril, and initially the proteinuria improved (2.3 g/g) and renal functions were stable. Hematuria was initially suspected to be secondary to MPGN. Renal biopsy immunofluorescence showed IgG, C3, IgM, kappa/lamda, and C1q (in lesser quantitiy). EM showed deposits in subendothelial, subepithelial and mesangium. She was diagnosed with immune complex glomerulonephritis without evidence of systemic lupus. Over the next 2 years, proteinuria worsened from 1.9 to 5.7 g/g despite increasing lisinopril to maximum dosage (40 mg/day). Hematuria and low C3 levels persisted. In February 2017, creatinine worsened (1.33 mg/dL). Cellcept (1000 mg/day) was started in March; by June, there was no response. Lisinopril was stopped in May due to low BP. A second renal biopsy (November 2017) showed a lupus picture with a full house pattern (3+ IgG, 1+ IgM, 2+ C3, 3+ C1q, 2+ kappa/lambda, IgA+ tubular casts). EM showed subendothelial and scattered subepithelial deposits, and GBM duplication. She was diagnosed with Class IV Lupus Nephritis. She was started on Cytoxan (500 mg q 2 weeks x6 weeks) and prednisone (60 mg/day). She showed improvement and was started on Imuran in May 2018 for maintenance. Her proteinuria (400mg/g) and creatinine (0.93mg/dL) improved, C3 normalized, and hematuria resolved.
Discussion
Diagnosis of lupus nephritis can be missed on the basis of atypical labs and requires a high degree of suspicion and a biopsy. This case represents such an atypical presentation without systemic lupus. Initially, thought to have C3 nephritis; but later, the diagnosis was confirmed by renal biopsy and electron microscopy. The Full House immunofluorescence pattern seen in this patient is characteristically indicative of lupus nephritis, and she was responsive to immunosuppressive therapy.