Abstract: PUB208
When Phospholipase A2 Receptor (PLA2R) Antibody Is Negative: A Diagnostic Puzzle in Membranous Nephropathy
Session Information
Category: Pathology and Lab Medicine
- 1700 Pathology and Lab Medicine
Authors
- Sultana, Syeda Salima, New York City Health and Hospitals South Brooklyn Health, New York, New York, United States
- Roy, Arthi, Pabna Medical College, Pabna, Rajshahi Division, Bangladesh
- Islam, Nayeemul, Sir Salimullah Medical College, Dhaka, Dhaka Division, Bangladesh
- Mumin, Muhammed, Geneva General Hospital, Geneva, New York, United States
Introduction
Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in adults and can occur as either a primary or secondary disease. The detection of phospholipase A2 receptor (PLA2R) antibodies has improved the distinction between primary and secondary MN; however, PLA2R-negative cases remain diagnostically challenging and often require extensive evaluation for underlying etiologies such as malignancy, autoimmune disease, or chronic infection.
Case Description
A 61-year-old woman with a history of coronary artery disease, hypertension, chronic kidney disease, and smoking presented with worsening renal function, generalized edema, and nephrotic-range proteinuria. She also reported several months of left-sided abdominal pain, poor oral intake, and chronic diarrhea. Laboratory investigations revealed approximately 6 g/day proteinuria and severe hypoalbuminemia (2.1 g/dL), consistent with nephrotic syndrome. Renal ultrasonography demonstrated mild renal atrophy without hydronephrosis. Kidney biopsy confirmed membranous nephropathy, while immunostaining for PLA2R antibodies was negative, raising suspicion for secondary membranous nephropathy.
Discussion
PLA2R-negative membranous nephropathy in older adults should prompt thorough evaluation for secondary causes, particularly malignancy. In this patient, additional risk factors including smoking history and gastrointestinal symptoms further increased concern for occult malignancy. Current management guidelines emphasize identifying and treating the underlying cause rather than initiating empirical immunosuppressive therapy in secondary MN.