There are two parts to evaluate ELISA Kits. The first one is evaluate reagents quality. The reagents can be produce if it meets certain requirements. The other is evaluating reagents clinical value. Take the hepatitis ELISA Kit as example. It can get the production license after it passes the Chinese Pharmaceutical and biological products determination. Testing items contain not only packaging, labeling, instructions but also reagents performance. The performance of reagent such as specificity, sensitivity, precision and linearity, should be check one by one. The reagents which pass the detection of reference materials are qualified productions. The clinical quality evaluation of ELISA Kit is using reagent to test clinical sample. The clinical text center do exam on hepatitis ELISA Kit. This can increase the quality of ELISA Kit.

 

A.      Clinical quality assessment points

Whether can distinguish health and disease is the basic requirement for ELISA Kits clinical evaluation. At present, 100% suitable reagent is difficult to find, any experiment will produce false positive or false negative result. Evaluate reagents reliability usually take its sensitivity and specificity as assessment standard. Clinical sensitivity is display by percentage of patients positive test result. The specificity means health peoples negative exam result.

 

In order to process this evaluation, patients serum should be collected and exam by most reliability reagent to determine its positive or negative.

 

The series serum which can display the positive or negative of determine called serum panel. The relationship of reagent determination result and serum panels result is display in the following table.

In the table, a means true positive, b means false positive, c means false negative, d means true negative. The determination reagents are calculated by following fraction.

Sensitivity (100%) = a/(a+c)100%

Specificity (100%) = b/(b+d)100%

Compliance Rate (100%) = (a+d)/(a+b+c+d)100%

 

Generally consider that sensitivity and specificity over 90% are good reagents. The compliance rate connects sensitivity and specificity together.

 

B.      How to produce serum panel for clinical evaluation

1.       Using human serum

2.       Serum plaint should be standard

3.       Serum samples without or only contains small amount preservatives which can not affect the text results.

4.       Negative samples and positive samples are half and half in serum panel.

5.       There should have certain amount of strong positive and weak positive samples in positive samples.

6.       Some certain amount samples which value around threshold should be included in serum panel. This can test reagents specificity.

7.       In order to test reagents specificity, serum panel should contain test related disease sample and RF factor.

 

C.      Some suggestions for clinical serum panel evaluation.

Take anti-HBc-IgM as an example, the examination center collect nearly hundred clinical hepatitis patients sample, which screening test by United States abbott company reagent anti-HBc-IgM repeatedly. They choice 70 serums to compose anti-HBc-IgM serum panel for clinical examination, of which 29 are positive, 41 are negative. In 70 samples, 7 are free of medical records serum. The 22 positive HBc-IgM include 16 cases for diagnose acute hepatitis, 5 cases for chronic active hepatitis, 1 case for severe hepatitis. In 40 negative samples, 24 are chronic persisting hepatitis (both recovering from blood samples), 8 cases for chronic active hepatitis (5 cases are restoration of blood).

 

Therefore, this antiserum is using for reagent clinical test. It has clinical diagnosis value which can distinguish acute hepatitis and chronic active patients.