What are the dangers of low cystatin C

The determination of cystatin C is a new clinical detection method in recent years, mainly used to monitor kidney disease. Cystatin C is an essential substance for the human body and is not affected by gender, age or lifestyle habits. After monitoring, if the level is high, it may be a kidney disease, but if it is low, there is no need to worry and there will be no harm. Please read this article for more specific details.

[Definition of Marker] Cystatin C in the circulation is only cleared by glomerular filtration. It is an endogenous marker that reflects changes in glomerular filtration rate and is reabsorbed in the proximal tubule. However, it is completely metabolized and decomposed after reabsorption and does not return to the blood. Therefore, its blood concentration is determined by glomerular filtration and does not rely on any external factors, such as gender, age, and diet. It is an ideal homologous marker that reflects changes in glomerular filtration rate.

Normal range

The concentration of CysC in serum and plasma is 0.51-1.09 mg/L (reference range).

Clinical significance

1. Increase - When renal function is impaired, the concentration of CysC in the blood changes with the glomerular filtration rate. In renal failure, the glomerular filtration rate decreases, and the concentration of CysC in the blood can increase by more than 10 times;

2. Reduction: When the glomerular filtration rate is normal but the renal tubular function is abnormal, it will hinder the absorption of CysC in the renal tubules and its rapid decomposition, increasing the concentration in the urine by more than 100 times.

【Problem Analysis】

The significance of elevated cystatin C is renal damage.

Inhibin C is a cysteine ​​protease inhibitor, also known as γ-trace protein and γ-post-globulin. It is widely present in nucleated cells of various tissues and body fluids. It is a low molecular weight, alkaline non-glycosylated protein with a molecular weight of 13.3KD. It is composed of 122 amino acid residues and can be produced by all nucleated cells in the body with a constant production rate. Cystatin C is regarded as a good marker for detecting renal function. Since it is not affected by many physiological and pathological factors, it has many advantages compared with other markers of glomerular filtration rate. Cystatin C also plays a role in a series of physiological and pathological processes and has important clinical significance.

What happens if cystatin C is low?

Cystatin C in the circulation is only cleared through glomerular filtration. It is an endogenous marker that reflects changes in glomerular filtration rate and is reabsorbed in the proximal tubule. However, it is completely metabolized and decomposed after reabsorption and does not return to the blood. Therefore, its blood concentration is determined by glomerular filtration and does not depend on any external factors, such as gender, age, and diet. It is an ideal homologous marker that reflects changes in glomerular filtration rate. Under normal circumstances, the concentration of cystatin C in serum and plasma is 0.51-1.09 mg/L (reference range). When renal function is impaired, the concentration of cystatin C in the blood changes with the glomerular filtration rate. In renal failure, the glomerular filtration rate decreases and the concentration of cystatin C in the blood can increase by more than 10 times; if the glomerular filtration rate is normal but the renal tubular function is abnormal, it will hinder the absorption of cystatin C in the renal tubules and rapidly decompose it, causing the concentration in the urine to increase by more than 100 times. If cystatin C is low, it is generally harmless, has no clinical diagnostic significance, and will not cause diseases such as diabetes and kidney failure.