Differential Diagnosis for Nephrotic Range Proteinuria
Single Most Likely Diagnosis
- Focal Segmental Glomerulosclerosis (FSGS): This is the most common cause of nephrotic syndrome in adults, characterized by the presence of nephrotic range proteinuria, hypoalbuminemia, hyperlipidemia, and edema. FSGS can be primary (idiopathic) or secondary to other conditions such as obesity, hypertension, or viral infections.
Other Likely Diagnoses
- Minimal Change Disease (MCD): A common cause of nephrotic syndrome in children, but can also occur in adults. It is characterized by minimal glomerular changes on light microscopy but significant proteinuria.
- Membranous Nephropathy: An immune-mediated disease that can be primary (idiopathic) or secondary to infections (e.g., hepatitis B), autoimmune diseases (e.g., lupus), or drugs. It is characterized by the deposition of immune complexes on the glomerular basement membrane.
- Diabetic Nephropathy: A complication of long-standing diabetes mellitus, leading to nephrotic range proteinuria, often accompanied by renal insufficiency and other diabetic complications.
Do Not Miss Diagnoses
- Amyloidosis: A condition characterized by the deposition of amyloid fibrils in various organs, including the kidneys, leading to nephrotic range proteinuria. It can be primary (AL amyloidosis) or secondary to chronic infections or inflammatory diseases.
- Lupus Nephritis: A complication of systemic lupus erythematosus (SLE), which can present with nephrotic range proteinuria, hematuria, and renal insufficiency. Prompt recognition and treatment are crucial to prevent long-term renal damage.
- HIV-Associated Nephropathy: A condition that occurs in HIV-infected individuals, characterized by FSGS-like lesions on renal biopsy, leading to nephrotic range proteinuria.
Rare Diagnoses
- Alport Syndrome: A genetic disorder affecting the type IV collagen in the glomerular basement membrane, leading to hematuria, proteinuria, and progressive renal failure.
- Nephropathy associated with Monoclonal Gammopathies: Conditions such as multiple myeloma or monoclonal gammopathy of undetermined significance (MGUS) can lead to nephrotic range proteinuria due to the deposition of light chains in the kidneys.
- Lymphoma-Associated Nephropathy: Certain types of lymphoma can cause nephrotic range proteinuria, either by direct renal involvement or by the production of nephrotoxic factors.