[Positive predictability and predictive factors of the third generation anti-hepatitis C virus (HCV) ELISA test for HCV infection].
OBJECTIVE
Anti-HCV positivity suggests past or present infection of HCV, or false positivity. The positive predictability of this test can differ according to the subjects. This study examines the positive predictability of the third generation anti-HCV ELISA and factors predicting HCV infection with special emphasis on the significance of the anti-HCV sample/cut-off (S/CO) ratio.


METHODS
One hundred and ninety patients who were anti-HCV positive were enrolled, from November 1998 to January 2002 in Kyung Hee University Hospital. RT-PCR was performed to confirm HCV infection.


RESULTS
One hundred and seven patients were RT-PCR positive (56.3% positive predictability). The positive predictability changed with the S/CO ratio: 17.9% in cases below 6, 58.3% between 6 and 50, 78.6% between 51 and 75, and 60% over 75. Those with the S/CO ratio more than 6 showed significantly higher predictability, but it did not increase further when the ratio got higher. Factors predicting HCV infection were the presence of liver cirrhosis (OR 5.5, p=0.000), hepatocellular carcinoma (OR 11.67, p=0.004), liver diseases (OR 2.99 p=0.001), and increase of AST (OR 2.49, p=0.002), ALT (OR 2.32, p=0.005), alpha-FP (OR 3.49, p=0.040), and the S/CO ratio of more than 6 (OR 7.82, p=0.000). However, liver cirrhosis was the sole factor in multivariate analysis (OR 8.32, p=0.02).


CONCLUSIONS
The positive predictability of the third generation anti-HCV test was 56.3% with a significant difference between those with the S/CO ratio below 6 (18%) and above 6 (63%). In liver cirrhosis, positive predictability of anti-HCV test was relatively high as 85%.
Kim
Young Ki
YK
Department of Internal Medicine, Kyung Hee University College of Medicine, Seoul 130-702, Korea.
Kim
Byung Ho
BH
Jin
Eun Seon
ES
Nam
Ki Deuk
KD
Jang
Jae Young
JY
Kim
Nam Hoon
NH
Lee
Sang Kil
SK
Joo
Kwang Ro
KR
Dong
Seok Ho
SH
Kim
Hyo Jong
HJ
Chang
Young Woon
YW
Lee
Joung Il
JI
Chang
Rin
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016174:Hepacivirus / Q000276:immunology; D006526:Hepatitis C / Q000175:diagnosis*; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors
D018937:Hepatitis C Antibodies