The Damages of Proteinuria to the Kidneys

Nephrotic syndrome is characterized by large amount of proteinuria (protein in urine) and it is well known that the protein leakage is caused by kidney damages while most do not know that long term proteinuria will in turn cause damages to the glomeruli and renal tubules if left untreated.

The glomerular mesangial damages

The accumulation of serum protein in the glomerular mesangial areas will cause damages, proliferation of mesangial cells and the increase of mesangial matrix, thus causing glomerular sclerosis. The loss of large amount of protein in urine will cause the increased synthesis of proteins in the liver and since the liver has no selectivity while synthesizing proteins, the production of lipoprotein will increase. And the accumulation of apolipoprotein A and apolipoprotein B of low density lipoprotein and very low density lipoprotein in the glomeruli can also cause hardening of the glomeruli.

The damages to the renal proximal convoluted tubules

In case of proteinuria, there will be more protein entering into the epithelial cells of the renal tubules and this will increase the activity of the lysosomeand then the damages to the epithelia cells will stimulate the formation of inflammation and scarring.

Cell biological change of the renal tubules

Proteinuria can cause abnormal proliferation of renal intrinsic cells and this will lead to kidney failure. It has been proved by more and more evidences that proteinuria has direct influence on renal tubules by altering its growth characteristics and the phenotypic expression of the cell factors and matrix protein and induce the start of renal fibrosis.

Aggravate the hypoxia of the tubulointerstitium

The re-absorption and digestion of massive protein will consume extra energies and this will cause lack of oxygen in the renal tubules and cause damages to the renal tubular cells.

Therefore in case of persistent proteinuria (bubble urine) and if it is confirmed being caused by nephrotic syndrome or other renal diseases, proper and effective treatments should be received as soon as possible.