Last week at Intern Report, Dr. Balster presented a case of a patient with HCV who presented with anasarca and was found to have neprhotic range proteinuria at 14 g/d.
How much proteinuria defines nephrotic syndrome?
3.5 g/d of urine protein, hypoalbuminemia less than 3, and peripheral edema. Patients also can have high cholesterol and lipiduria as well as hypercoagulable states. This is because the liver has ramped up particular protein synthesis due to the significant hypoalbuminemia.
We discussed the differential for edema and clumped it into four etiologies:
Nephrology Pearl: a spot protein/creatinine ratio estimates the total protein loss in grams/day! However, it may be falsely elevated in AKI (Dr. Weiss spoke of this in her recent Essentials lecture).
One can think about nephrotic syndrome as primary or secondary
There may be more lab workup needed to rule out secondary causes (A1c, HIV, HBV, ANA, SPEP etc). A biopsy is the gold standard for diagnosis and may help determine if steroids can lead to clinical improvement. Our patient did not receive biopsy or steroids because his active HCV was felt to be a contraindication to high dose steroids.
One can think of the treatment for nephrotic syndrome in terms of the clinical presentation (see below).