What's the specific amount? When the 24-hour urine protein quantification result is greater than 300 mg, there may be some disease.
According to the mechanism of proteinuria (the condition of proteins found in urine) and the location of the primary disease, proteinuria can be divided into the following types:
1. Glomerular proteinuria is the condition of increased plasma protein permeability of the glomerular filtration membrane. It is the most common type. It is due to ischemia, poisoning, or immunopathological damage that destroys the integrity of the filtration membrane; or due to the weakening of the filter membrane charge barrier. The characteristics of this kind of proteinuria are that the protein content is often large, and the discharge range is 1-30 g/d; the second is that the composition is mainly albumin, or it is mainly albumin and a protein with a larger molecular weight.
2. Tubular proteinuria is the condition of the tubular reabsorption of filtered proteins by the renal tubules. It's found in tubulointerstitial lesions, pyelonephritis, congenital renal tubular disease, hypokalemia and so on. This type of proteinuria is characterized by a generally small amount of urinary protein, generally <1g/d; and contains only a small amount of albumin, and low molecular weight lysozyme, β2-microglobulin, light chain protein, vitamin A binding protein.
3. Overflow proteinuria is the abnormal increase of certain lower molecular weight (<6~70,000) proteins in the blood circulation, which is filtered out by the glomerulus and exceeds the renal tubular reabsorption capacity. There is no kidney disease in the early stage of this proteinuria. It's found in patients with multiple myeloma (primary-peripheral protein in urine), myoglobinuria in severe crush injury, lysozyme and urine in myeloma and monocytic leukemia.
4. Secretory and histological proteinuria (secretary and histuria proteinuria) is caused by the secretion of proteins in the structure of the kidney and the urinary tract itself or the secreted and excreted proteins in the urine. Such as Tamm-Horsfall protein secreted by the medullary ascending branch, IgA in the kidney and urinary tract infection, fibrin (original) and its degradation products, complement components, glomerular basement membrane components, etc. in urine of some nephritis patients.