Introduction to PIVKA Ⅱ raw materials

1、 Basic information

l  Project background

Abnormal prothrombin (DCP), also known as vitamin K deficiency or antagonist II induced protein (PIVKA-II), has a molecular weight of 720KDa. Normal prothrombin mainly depends on vitamin K in liver cells γ With the participation of glutamyl carboxylase and related coenzymes, 10 Glu residues at positions 6, 7, 14, 16, 19, 20, 25, 26, 29 and 32 in the structural Gla domain γ Carboxylation to Gla, making it an active normal prothrombin. Incomplete carboxylation of one or more Glu residues at any of the above sites may lead to the formation of DCP and loss of coagulation function [1,2]. Abnormal prothrombin elevation is mostly seen in patients with vitamin K deficiency, warfarin treatment and hepatocellular carcinoma (HCC), so DCP can be used as a marker for the diagnosis of HCC [3]. The value of this target combined with the traditional tumor marker alpha fetoprotein (AFP) in the early diagnosis of HCC has been widely recognized [2,4].

The key is that at present, both antibody and antigen raw materials of the project are scarce and expensive in the domestic and international markets, and the prototype reagents formed by antibody pairing and recombinant antigen assembly that we independently developed have ideal correlation with the current mainstream and only two imported reagents Abbott and Fuji Ribeo.

l  Clinical significance：

Chinese and foreign guidelines have listed DCP (PIVKA II) as an extremely important indicator for liver cancer detection：

1.The Asia Pacific Society of Hepatology and the Japanese Society of Hepatology have written DCP into the guidelines, and recommended it as a tool for screening high-risk groups, auxiliary diagnosis of liver cancer, monitoring treatment effects, and predicting prognosis and recurrence. The Japanese clinical practice guidelines for hepatocellular carcinoma (HCC) recommend that for people with high risk of HCC, such as patients with chronic HBV and HCV infection or liver cirrhosis, it is recommended to monitor HCC with liver ultrasound, AFP and DCP levels, and review every 6 months; For people with high risk of HBV or HCV cirrhosis, the interval should be shortened to 3 to 4 months。

2.In the 2015 version of China's latest Guidelines for the Prevention and Treatment of Chronic hepatitis B, it is recommended to use DCP as an important indicator for the diagnosis of HCC, which can complement AFP to improve the early diagnosis rate of HCC。

3.Parameter, APASL, JSH and other authoritative guidelines and consensus recommended DCP as a specific serum marker for HCC screening and diagnosis。

l  Suggested detection/monitoring population：

?           People with chronic HBV infection

?           People with chronic HCV infection

?           Patients with liver cirrhosis and other liver diseases

?           Smoking, elderly and other high risk groups of HCC

l  test method：

Chemiluminescence and immunofluorescence

2、 Product Information

l  Basic product information

l  Product positioning and detection target

Combination 1:11H8-3/9H9-1 double antibody sandwich method to detect specific types of DCP (PIVKA II)

l  Recommended applicable platforms and corresponding methods:

The paired antibodies are recommended to be applied to the chemiluminescence platform, which does not rule out the possibility of being applied to other platforms, and can be adjusted according to the actual situation：

Combination 1: 11H8-3 is recommended as coating and 9H9-1 as marking；

3、 Product performance evaluation

?  Basic performance

Combination 1:11H8-3/9H9-1 in the correlation between chemiluminescence evaluation and Abbott (99 samples) and Fuji Ribeo (169 samples)

Quantitative range: 5.0-30000 mAu/ml, R2 of Abbott (99 samples) and Fuji Ribeo (169 samples) can reach above 0.95。

Quantitative range of similar reagents

Abbott：Chemiluminescence method：5.06-30000 mAu/ml;

Fuji Ribeo: Chemiluminescence5-75000 mAu/ml)

l  Analogue cross reactivity analysis

No relevant evaluation

4、 Product Summary

ü  This product should be the first antibody pairing that can be applied to the development of diagnostic reagents in China

ü  The sensitivity and quantitative range of paired detection are equivalent to those of Abbott, meeting the needs of reagent development

ü  The paired test results have ideal correlation with the only two imported reagents Abbott and Fuji Ribeo

5、 Main precautions in application

None

reference

[1]Toru Naraki, et al. Q-Carboxyglutamic acid content of hepatocellular carcinoma-associated des-Q-carboxy prothrombin. Biochimica et Biophysica Acta 1586 (2002) 287-298

[2] Yoshinori Inagaki, et al. Des-γ-carboxyprothrombin: Clinical effectiveness and biochemical Importance. BioScience Trends 2008; 2(2):53-60.

[3]J.Widdershoven,et al. Four Methods Compared for Measuring Des-Carboxy-Prothrombin (PIVKA-II). CLIN.CHEM.33/11, (1987)2074-2078

[4] Masahiko Tameda, et al. Des-c-carboxy prothrombin ratio measured by P-11

and P-16 antibodies is a novel biomarker for hepatocellular carcinoma. Cancer Sci 2013; 104: 725–731)