Nephritic syndrome vs Nephrotic syndrome
How to tell Nephritic syndrome and Nephrotic syndrome apart when a board question makes them look alike.
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Red blood cell casts on urine microscopy identify nephritic syndrome rather than nephrotic syndrome.
Side by side
Hematuria with red blood cell casts, hypertension, and reduced GFR suggests nephritic syndrome.
Heavy proteinuria with edema and hypoalbuminemia, often with hyperlipidemia, suggests nephrotic syndrome.
Nephritic syndrome reflects inflammatory glomerular injury with capillary wall damage and reduced filtration.
Nephrotic syndrome reflects podocyte or filtration barrier injury causing massive protein loss.
Urine microscopy shows dysmorphic red cells or red blood cell casts, protein is usually below 3.5 g/day, creatinine may rise, and complements can be low in immune-complex causes.
Urine protein is above 3.5 g/day or urine protein-creatinine ratio above 3.5 g/g, serum albumin is often below 3.0 g/dL, LDL is elevated, and lipiduria with oval fat bodies may appear.
The trap
Marked edema can appear in nephritic disease, leading to mistaken nephrotic labeling if sediment is ignored. Urine microscopy findings and protein burden must be interpreted together before treatment choice.
The repair move
Next best step: confirm urine sediment and quantify proteinuria, then control blood pressure and volume overload with loop diuretic and renin-angiotensin blockade when tolerated. If rapidly progressive features appear, such as creatinine rise with active urinary sediment, pursue urgent serologic workup and kidney biopsy for cause-specific immunosuppressive therapy.
Try a free question
CoreA 28-year-old woman has edema and frothy urine. BP 128/76 mm Hg, HR 80/min, temp 36.8 C. Urine protein is 5.2 g/day and serum albumin is 2.4 g/dL; microscopy shows no red blood cell casts. What is the most likely diagnosis?
Show answer and explanation
Answer: B. Nephrotic syndrome. Heavy proteinuria above 3.5 g/day with hypoalbuminemia and absent RBC casts is nephrotic syndrome.
Why the other choices are tempting
- A. Nephritic syndrome is less likely without RBC casts and with massive protein loss.
- C. Pyelonephritis would present with infection symptoms and pyuria.
- D. Prerenal azotemia does not explain nephrotic-range proteinuria.
- E. Nephrolithiasis causes colicky pain and hematuria, not this protein-losing pattern.
Flashcards
Tap a card to flip it.
Which urinary finding is the fastest discriminator for nephritic syndrome?
Red blood cell casts are the key discriminator for nephritic syndrome.
What proteinuria threshold defines nephrotic-range loss?
Proteinuria above 3.5 g/day defines nephrotic-range protein loss.
Quick answers
What is the fastest way to tell Nephritic syndrome from Nephrotic syndrome?
Red blood cell casts on urine microscopy identify nephritic syndrome rather than nephrotic syndrome.
What is the key clue for Nephritic syndrome?
Hematuria with red blood cell casts, hypertension, and reduced GFR suggests nephritic syndrome.
What is the key clue for Nephrotic syndrome?
Heavy proteinuria with edema and hypoalbuminemia, often with hyperlipidemia, suggests nephrotic syndrome.
What is the common trap with Nephritic syndrome vs Nephrotic syndrome?
Marked edema can appear in nephritic disease, leading to mistaken nephrotic labeling if sediment is ignored. Urine microscopy findings and protein burden must be interpreted together before treatment choice.