Kyung Hee University Hospital 대한소화기학회지 2005;45: 세대 Anti-HCV ELISA 검사의 진단 양성예측도 및 예측 인자 - Anti-HCV ELISA sample/Cutoff 비의 임상 의의를 중심으로 - 김영기, 김병호, 진은선, 남기덕, 장재영, 김남훈, 이상길, 주광로, 동석호, 김효종, 장영운, 이정일, 장 린

Kyung Hee University Hospital Kyung Hee University Hospital Background  anti-HCV ELISA positive ; present or past infection, false positive…   serum ALT, anti-HCV ELISA sample to cut-off ratio (S/CO ratio), RIBA positive  3 세대 anti-HCV ELISA 양성 -> HCV RNA 검사  anti-HCV ELISA sample to cut-off ratio (S/CO ratio) 에 따른 양성 예측 도, 영향 인자

Kyung Hee University Hospital Kyung Hee University Hospital Method  1998 년 11 월 ~2002 년 1 월  190 명 후향 연구 -> RT-PCR 양성군 / 음성군  예측인자 - 과거력, 간기능 검사, B 형 간염 표지자,  -FP, LC or HCC  recombinant HCr43, c200, c100-3,NS5 항원 - 3 세대 ELISA  anti-HCV ELISA S/CO ≥ 1 이면 양성 - > HCV RNA RT-PCR ( 검출한계 1000copies/mL ) 진단 기준 LC ; pathology or imaging + portal HTN ( GE varix or PLT≤130K /mm 3 ) HCC–pathology, 2 imaging or 1 imaging +  -FP ≥400 ng/mL)  stastical analysis

Kyung Hee University Hospital Kyung Hee University Hospital Result Table 1. Comparison of Demographic Features in the 3 rd Generation Anti-HCV ELISA Positive Patients according to RT-PCR Result

Kyung Hee University Hospital Kyung Hee University Hospital Table 2. Comparison of the Laboratory Data in the 3 rd Generation Anti-HCV ELISA Positive Patients according to RT-PCR Result

Kyung Hee University Hospital Kyung Hee University Hospital Fig. 1. Positive predictability of HCV infection according to the 3 rd generation anti-HCV ELISA sample to cut- off (S/CO) ratio. The patients with anti-HCV ELISA S/CO ratio below 6 have a significantly lower positive predictability compared to those with S/CO ratio more than 6. The patients who had abnormal liver function tests, liver cirrhosis, or hepatocellular carcinoma show higher positive predictive values (black bar), compared to the patients without any evidence of abnormal liver function tests, liver cirrhosis, or hepatocellular carcinoma (gray bar). The white bar means the percentage of positive predictive values of the total subjects. 17.9% 58.3% 78.6% 60%

Kyung Hee University Hospital Kyung Hee University Hospital Fig. 2. Accumulated positive predictability of HCV infection according to the 3rd generation anti-HCV ELISA sample to cut-off (S/CO) ratio at each specific value. The patients with anti-HCV ELISA S/CO ratio more than 6 show 63% of positive predictability, which plateau even though the S/CO value gets higher. The solid line means the cases that had abnormal liver function tests, liver cirrhosis, or hepatocellular carcinoma. The broken line means the cases with normal liver function tests that did not have liver cirrhosis or hepatocellular carcinoma.

Kyung Hee University Hospital Kyung Hee University Hospital Table 3. Univariate Analysis of Potential Risks for RT-PCR Positivity in the 3rd Generation Anti-HCV ELISA Positive Patients

Kyung Hee University Hospital Kyung Hee University Hospital Table 4. Univariate analysis of Laboratory Data for RT-PCR Positivity in the 3rd Generation Anti- HCV ELISA Positive Patients

Kyung Hee University Hospital Kyung Hee University Hospital Table 5. Multivariate Analysis of Laboratory Data for RT-PCR Positivity in the 3rd Generation Anti-HCV ELISA Positive Patients

Kyung Hee University Hospital Kyung Hee University Hospital Conclusion  The positive predictability of the third generation anti-HCV test was 56.3%  significant difference between 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%