Intrinsic Kidney Injury Differentials
Intrinsic kidney injury refers to damage that occurs within the kidney itself, as opposed to extrinsic factors such as obstruction or vascular issues. The differential diagnosis for intrinsic kidney injury can be categorized as follows:
Single Most Likely Diagnosis
- Acute Tubular Necrosis (ATN): This is often the most common cause of intrinsic kidney injury, particularly in the context of ischemia (reduced blood flow) or nephrotoxins (such as certain medications or substances). ATN can result from a variety of insults, including severe hypotension, sepsis, or exposure to nephrotoxic agents.
Other Likely Diagnoses
- Glomerulonephritis: This refers to a range of conditions characterized by inflammation of the glomeruli, the filtering units of the kidneys. It can be caused by immune system disorders, infections, or vasculitis.
- Pyelonephritis: An infection of the kidney, typically caused by bacteria. It can lead to inflammation and damage to the renal parenchyma.
- Interstitial Nephritis: Inflammation of the spaces between the renal tubules, which can be caused by allergic reactions, infections, or certain medications.
Do Not Miss Diagnoses
- Vasculitis (e.g., ANCA-associated vasculitis): Although less common, vasculitis affecting the kidneys can lead to severe and irreversible damage if not promptly treated.
- Thrombotic Microangiopathy (TMA): Conditions like thrombotic thrombocytopenic purpura (TTP) or hemolytic-uremic syndrome (HUS) can cause intrinsic kidney injury through microvascular thrombi formation.
- Sickle Cell Nephropathy: In patients with sickle cell disease, sickling of red blood cells within the kidney can lead to chronic damage and dysfunction.
Rare Diagnoses
- Membranoproliferative Glomerulonephritis: A type of glomerulonephritis characterized by changes in the glomeruli that can lead to kidney dysfunction.
- Light Chain Cast Nephropathy (Myeloma Kidney): Associated with multiple myeloma, where light chains produced by malignant plasma cells can cause kidney damage.
- Cystinosis: A rare genetic disorder that leads to the accumulation of cystine within cells, including those in the kidney, causing damage and dysfunction.