Abstract: FR-PO0777
An Unusual Overlap: Myeloperoxidase-ANCA Glomerulonephritis in Mixed Connective Tissue Disease
Session Information
- Glomerular Diseases: ANCA Vasculitis, Anti-GBM Disease, and Crescentic GN
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Shastri, Rujul Piyush, New York City Health and Hospitals Jacobi, New York, New York, United States
- Rodriguez, Marcos Alejandro, New York City Health and Hospitals Jacobi, New York, New York, United States
- Bhandari, Sanjeev, New York City Health and Hospitals Jacobi, New York, New York, United States
- Anis, Kisra, New York City Health and Hospitals Jacobi, New York, New York, United States
- Jim, Belinda, New York City Health and Hospitals Jacobi, New York, New York, United States
Introduction
Renal manifestations of mixed connective tissue disorders(MCTD) typically involve immune complex mediated glomerulonephritis , most commonly in the form of membranous or mesangial proliferative glomerulonephritis. We report an unusual case of a patient with an established diagnosis of MCTD who subsequently developed pauci-immune crescentic glomerulonephritis associated with myeloperoxidase ( MPO ) -antineutrophilic cytoplasmic antibody(ANCA) positivity
Case Description
A 54 year old woman with a decade long history of MCTD, complicated by sclerodactyly, interstitial lung disease and pulmonary arterial hypertension was referred to Nephrology clinic for evaluation of rapidly progressive renal dysfunction. Investigations revealed hematuria, worsening proteinuria and dysmorphic red blood cells on urine micrscopy and markedy elevated MPO antibody titer of greater than 1:1280, with a positive p-ANCA. Kidney biopsy demonstrated focal necrotizing, crescentic, sclerosing,pauci-immune glomerulonephritis associated with MPO-ANCA antibody positivity with mild tubular atrophy and interstitial fibrosis. Patient was treated with pulse dose intravenous methylprednisolone 500 mg daily for three days, followed by tapering dose of oral corticosteroids. She received two doses of rituximab two weeks apart. Following this, patient demonstrated modest clinical improvement. Serum creatinine declined from 2 mg/dl to 1.74 mg/dl and urine protein creatinine ratio( UPCR) decreasing from 1615 mg/g to 725 mg/g.
Discussion
Renal pathology in connective tissue disorders is not always confined to immune complex mediated disease. Patients with connective tissue disorders who develop ANCA-positive glomerulonephritis are predominantly female and carry higher burden of non renal relapses and venous thromboembolic events as compared to those without underlying connective tissue disease. This case highlights the importance of renal biopsy as it dictates therapeutic mangement and prognosis.