Abstract: SA-PO901
Myeloperoxidase (MPO)-ANCA: From Confounding to Confirming a Case of Lupus Nephritis (LN) in a Silent Patient
Session Information
- Glomerular Diseases: Case Reports - 2
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
- Rajendran, Jackson, RWJBarnabas Health, Toms River, New Jersey, United States
- Toma, Katherine, RWJBarnabas Health, Toms River, New Jersey, United States
- Seeburun, Sheilabi, RWJBarnabas Health, Toms River, New Jersey, United States
Introduction
ANCA is positive in up to 23% of LN cases, of which 82% represent MPO-ANCA. Despite this, SLE-ANCA overlap syndrome is very rare (2%). We present a case of an 18-year-old female with supposed Acute Renal Failure (ARF) whose high MPO-ANCA titer confounded her treatment course.
Case Description
An 18-year-old African American female with developmental delay presented with malaise, periorbital edema, oliguria, nausea, and vomiting for one week. No joint pain/swelling, oral ulceration, rash, or alopecia were noted by family. Past medical and surgical histories were otherwise unremarkable. There was no family history of kidney or rheumatologic disease.
Upon examination, the patient weighed 51 kg and was hypertensive (205/145 mmHg) and tachycardic (133 beats per minute). She had generalized facial edema without peripheral edema. No cutaneous lesions were found. Labs revealed ARF (Blood Urea Nitrogen 57 mg/dL, creatinine 5.08 mg/dL), anemia (hemoglobin 8.6 g/dL), nephrotic range proteinuria (Protein-creatinine-ratio 4.818) and metabolic acidosis (bicarbonate 18 mEq/L, anion gap 10). She was also found to have a large pericardial effusion with tamponade, which was evacuated. Pathology eventually yielded granulation tissue. Empiric high-dose methylprednisolone and hemodialysis were initiated. Kidney biopsy revealed Class IV and Class V Lupus Nephritis with minimal activity and severe chronicity. Further serology evaluation is summarized in the table.
The end-stage nature of the pathology did not warrant aggressive immunosuppression. She was placed on a steroid taper and was given one dose of Rituximab (1 gram) due to the very high MPO-ANCA titer and unclear systemic involvement. Further rheumatologic evaluation confirmed no systemic ANCA-mediated disease. A second dose of Rituximab was therefore not given. The patient remains dialysis-dependent and will eventually undergo renal transplant evaluation.
Discussion
Our patient with limited ability to provide a history presented with severe ARF, pericardial tamponade, and anasarca with nephrotic range proteinuria. Clinical suspicion for LN was confirmed with renal biopsy. High MPO-ANCA titer caused concern for a second autoimmune process but ultimately confirmed the chronicity of her silent chronic renal failure.