Experience of Anti-HCV antibody immunoblot test in Korean Blood Donors

Oh, Heung Bum; Hwang, Yoo Sung; Cho, Youn Jung; Kim, Doo Sung; Kim, Sang In

Abstract

BACKGROUND
All donated bloods collected by the Korean Red Cross Blood Centers are tested for anti-HCV (Hepatitis C Virus) antibody by enzyme immunoassay (EIA) kits made in Korea. EIA test has sustaining problem of false positivity in spite of great progress in manufacturing kits. So, many healthy donors have been reported as being infected with HCV and excluded from next donation.
METHODS
Among blood samples of 2,040,151 donors which were tested by two kinds of EIA kits (DONG-A HCV 3.0 and LG HCD 3.0) from 16 blood centers during 12 months, repeatably reactive samples, total 6,851 samples, were supplementally tested by LG HCD CONFIRM immunoblot test.
RESULTS
Positive, indeterminate and negative rate in immunoblot tests were 39%, 9%, and 12% respectively among 6,851 repeatably reactive samples. Estimated true positive rate of anti-HCV antibody in Korean blood donors was 0.13%, showing geographical difference between 0.03% and 0.46%. Of EIA repeatably reactive samples, 28% showed greater than 5 signal to cutoff (S/C) ratio and most of them (94%) was revealed to be positive.
CONCLUSION
True positive rate of EIA test results is so low that it would be necessary to increase the confidence of such results by immunoblot tests.