Yunnan Digital-analog Technology Co.,Ltd

Cys C is a cysteine protease inhibitor, also known as γ-microprotein and γ-post-globulin. It is widely present in nucleated cells and body fluids of various tissues, which is an alkaline non-glycosylated protein with a low molecular weight of 13.3 KD. Composed by 122 amino acid residues, it can be produced by all nucleated cells in the body with a constant rate of production. Cystatin C in the circulation is only cleared by glomerular filtration and is an endogenous marker that reflects changes in glomerular filtration rate. It is reabsorbed in proximal tubules but is completely metabolized after reabsorption, and does not return to the bloodstream. Therefore, its blood concentration is determined by glomerular filtration, rather than depending on any external factors such as gender, age, diet. It is an ideal homologous marker reflecting changes in glomerular filtration rate.

Under normal conditions, the concentration of Cys C in serum and plasma is 0.51-1.09 mg/L (reference range). When the renal function is impaired, the concentration of Cys C in the blood varies with the glomerular filtration rate.When renal failure occurs, the glomerular filtration rate decreases, and the concentration of Cys C in the blood increases by more than 10 times. When glomerular filtration rate is normal, but the renal tubule is in malfunctions, it will hinder the absorption of Cys C in the renal tubules and rapidly decompose, increasing the concentration in urine by more than 100 times