CLIA Reagents of Inflammation (PⅢNP)

PIIINP is an amino-terminal tail peptide that enters the blood circulation after being cleaved by related enzymes before PCIII forms procollagen outside the cell. Intact PIIINP is mainly cleared through endocytosis mediated by sinusoidal endothelial cell receptors. Therefore, when collagen metabolism is active and liver function is damaged, serum PIIINP increases, and PIIINP is regarded as a serological indicator of liver fibrosis. The content of PIIINP can effectively distinguish mild and moderate/severe chronic hepatitis, indicating active liver fibrosis, and it is an index reflecting the activity and degree of chronic liver fibrosis. Long-term follow-up of serum PⅢNP levels can determine the prognosis of chronic liver disease. Primary biliary cirrhosis, chronic persistent hepatitis, chronic active hepatitis, and autoimmune hepatitis were followed up for 2 to 10 years.

Regardless of drug treatment, serum PIIINP was always elevated in patients with primary liver cirrhosis. After liver transplantation, it returned to normal; in chronic persistent hepatitis, the level of PIIINP was at the upper limit of normal; in chronic active hepatitis that developed cirrhosis, serum PIIINP continued to increase, and in remission stage, serum PIIINP was normal.

With the exception of autoimmune hepatitis, serum values ​​have not increased. Serum PIIINP can evaluate chronic liver disease, especially the process of chronic active hepatitis and fibrosis. Its clinical judgment and prognostic value have been recognized, but the overall sensitivity and specificity are not high. It has been reported that the sensitivity and specificity of serum PIIINP levels in distinguishing liver fibrosis are 76% and 71%, respectively. However, normal or slightly elevated PIIINP cannot rule out existing but slowly progressing fibrosis.

PⅢNP can effectively reflect the synthesis of type Ⅲ collagen in the liver, and its serum content is consistent with the degree of liver fibrosis, and is significantly correlated with the level of serum γ-globulin. PⅢNP is closely related to the activity of liver fibrosis, and it is not only valuable in the early diagnosis of liver fibrosis, but also in the prognosis judgment of chronic liver disease. At present, the four domestically recognized indicators, namely HA, LN, PIIINP, and CIV, have a sensitivity of 60-70% and a specificity of over 90% for the diagnosis of liver fibrosis. Therefore, it provides a convenient and quick monitoring method for early clinical diagnosis and early treatment of patients.

Type Ⅲ procollagen N-terminal peptide is currently measured in clinical and laboratory methods including enzyme-linked immunosorbent assay, colloidal gold method, fluorescence immunoassay, and chemiluminescence method.

【Inspection Principle】
This kit adopts the principle of direct sandwich method, uses magnetic microparticles as the solid phase of immune reaction, and uses chemiluminescence enzyme-linked immunoassay method and chemiluminescence analyzer to detect the content of PIIINP in human serum.
The technical principle is: Fluorescein isothiocyanate (FITC)-labeled mouse monoclonal anti-PIIINP antibody and alkaline phosphatase (AP)-labeled paired mouse monoclonal anti-PIIINP antibody and samples, calibrators or quality control substances.

The NT-proBNP binds to form a "sandwich" complex. Subsequently, the magnetic particles linked with goat anti-fluorescein isothiocyanate (FITC) antibody were added, and the antigen-antibody immune complexes were bound to the magnetic particles through the specific binding of the anti-FITC antibody to FITC. Under the action of an external magnetic field, the complex formed by the immune reaction is separated from other unbound substances, and after washing the complex, an enzymatic chemiluminescent substrate (adamantane derivative) is added. The substrate is catalytically cleaved under the action of the enzyme to form an unstable excited state intermediate.

When the excited state intermediate returns to the ground state, photons are emitted to form a luminescence reaction, and the luminescence intensity of the reaction can be detected by a chemiluminescence instrument. In the range of measuring wavelength (230-700nm), the luminescence intensity is proportional to the content of PIIINP in the sample, and the PIIINP concentration in the sample can be calculated by fitting with the improved four-parameter Logistic equation.