Differential Diagnosis for Sudden Increase in ACR with Stable eGFR
Single Most Likely Diagnosis
- Acute Glomerulonephritis: This condition is characterized by the sudden inflammation of the glomeruli, which can lead to a rapid increase in albuminuria (as reflected by an increased ACR) without necessarily affecting the eGFR immediately. The stable eGFR suggests that the overall kidney function, in terms of filtration, is not yet compromised, which is consistent with early stages of glomerulonephritis.
Other Likely Diagnoses
- Diabetic Nephropathy Progression: In patients with diabetes, a sudden increase in ACR can indicate progression of diabetic nephropathy. Even if the eGFR remains stable, an increase in albuminuria is a significant marker of kidney damage.
- Hypertension: Uncontrolled or poorly controlled hypertension can lead to increased pressure on the kidneys, resulting in increased albuminuria. The eGFR might remain stable if the hypertension is not severe enough to cause significant renal impairment.
- Nephrotic Syndrome: Although typically associated with a significant decrease in eGFR, early stages or certain types of nephrotic syndrome could present with a sudden increase in ACR without an immediate drop in eGFR.
Do Not Miss Diagnoses
- Renal Vein Thrombosis: This is a potentially life-threatening condition that can cause a sudden increase in ACR, especially in patients with nephrotic syndrome or other predisposing conditions. It requires immediate diagnosis and treatment to prevent severe kidney damage.
- Pregnancy-Related Conditions (e.g., Preeclampsia): In pregnant women, a sudden increase in ACR with stable eGFR could be indicative of preeclampsia or other pregnancy-related kidney issues, which are critical to diagnose and manage to prevent maternal and fetal complications.
Rare Diagnoses
- Alport Syndrome: A genetic disorder affecting the type IV collagen in the kidneys, which can lead to hematuria and progressive kidney disease. While it's rare, it could present with an increase in ACR, especially if there's a family history.
- Fabry Disease: A genetic disorder that can affect the kidneys and lead to albuminuria. It's rare but should be considered in patients with unexplained kidney disease, especially those with a family history of the condition.
- Amyloidosis: A condition characterized by the deposition of amyloid proteins in various organs, including the kidneys, leading to kidney damage and potentially an increase in ACR. It's rare but can be serious and requires specific treatment.