24-hour Urinary Protein Quantitative and Nephrotic Syndrome

24-hour urinary protein quantitative is a urine test in which the urine output within 24 hours is collected and then is tested.

Nephrotic syndrome is a group of clinical manifestations and it can be divided into two major categories---primary and secondary which are all caused by glomerular diseases. There are 3 steps that need to be followed strictly in the diagnosis of NS. The first is weather it is NS and the second is weather it is primary NS and the third what is the primary glomerular cause.

There are four typical symptoms of NS that are:

① Massive proteinuria (urine protein is more than 3.5g/d)

② Hypoalbuminemia (plasma protein is less than 30g/l)

③ Edema (its severity varies and severe conditions there will be effusion in body cavities)

④ Hyperlipidemia (increase of serum cholesterol or triglyceride)

The first two are the essential conditions for diagnosing NS and only when there are ①②③ or ①②④ or ①②③④ can the diagnosis of NS be confirmed.

Massive proteinuria is the basis of all other symptoms of NS. When the synthesis of protein in the liver can not compensate the protein loss in the urine, there will be hypoalbuminemia which will in turn cause decrease of plasma osmotic pressure and form edema or even effusion in chest, abdomen and other body cavities. Since the liver has no selectivity while synthesizing protein and the synthesis of both lipoprotein and albumin will increase. The lipoprotein is not easy to be discharged and this causes hyperlipidemia.

Therefore we can see that the amount of protein in urine is the crucial premise for diagnosing NS. In this regard, 24-hour urinary protein quantitative should be done to have accurate measuring of the protein in urine within 24 hours.