Kao-Chi Chang1, Chih-Yi Lee2, Te-Sheng Chang3, Chao-Hung Hung4, Wei-Ming Chen1, Mei-Yen Chen5, Tung-Jung Huang6, Wen-Nan Chiu7, Jing-Hong Hu7, Yu-Chih Lin8, Wei-Cheng Huang9, Nien-Tzu Hsu10, Sheng-Nan Lu11. 1. Division of Hepatology and Gastroenterology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan. 2. Department of Laboratory Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan. 3. Division of Hepatology and Gastroenterology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan; Department of Gastroenterology and Hepatology, Chang Gung Memorial Hospital, Yunlin, Taiwan; School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan. 4. Department of Internal Medicine, Division of Hepato-Gastroenterology, Kaohsiung Chang Gung Memorial Hospital, Taiwan. 5. College of Nursing, Chang Gung University of Science and Technology, Chiayi, Taiwan. 6. Division of Thoracic Medicine, Chang Gung Memorial Hospital, Yunlin, Taiwan. 7. Department of Gastroenterology and Hepatology, Chang Gung Memorial Hospital, Yunlin, Taiwan. 8. Division of Family Medicine, Chang Gung Memorial Hospital, Yunlin, Taiwan. 9. Department of Geriatric, Chang Gung Memorial Hospital, Chiayi, Taiwan. 10. Biostatistics and Bioinformatics Center of Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan. 11. Department of Internal Medicine, Division of Hepato-Gastroenterology, Kaohsiung Chang Gung Memorial Hospital, Taiwan; Biostatistics and Bioinformatics Center of Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan. Electronic address: juten@ms17.hinet.net.
Abstract
BACKGROUND/ PURPOSE:Low viral load (LVL) of hepatitis B virus (HBV) is a predictor of chronic HBV infection. However, the usefulness of quantitative hepatitis B surface antigen (qHBsAg) in predicting LVL in community-based screening has not been well studied. We aimed to measure the prevalence of LVL in HBV carriers and validate the efficacy of qHBsAg in predicting LVL. METHODS: This community-based screening study was conducted in Taiwan. HBV DNA was assayed in HBsAg carriers. Participants were randomized to training and validation sets to determine the ability of qHBsAg to predict LVL. Receiver operating characteristic curves were used to identify the best cutoff values in the training set. RESULTS: Among the 2919 participants, 359 (12.2%) were HBsAg carriers. There were 132 and 137 carriers in the training and validation sets, respectively. Significant correlations were found between qHBsAg and HBV DNA in both training and validation sets. Thirty and 29 participants with qHBsAg <8 IU/mL in the training and validation sets, respectively, had LVL. Using 8 IU/mL as the cutoff, negative predictive value (NPV) of qHBsAg for HBV DNA levels >2000 IU/mL was 100%. The best cutoff level of qHBsAg to predict HBV LVL was 200 IU/mL, with a sensitivity, specificity, and accuracy of 75.0%, 76.1%, and 75.8%, respectively, in the training set. The positive predictive value and NPV were 70.0% and 77.9%, respectively, in the validation set. CONCLUSION: Approximately 60% of HBsAg carriers had HBV LVL, and qHBsAg <8 IU/mL accurately predicts LVL. This quantitative test provides additional information for community-based screening.
RCT Entities:
BACKGROUND/ PURPOSE: Low viral load (LVL) of hepatitis B virus (HBV) is a predictor of chronic HBV infection. However, the usefulness of quantitative hepatitis B surface antigen (qHBsAg) in predicting LVL in community-based screening has not been well studied. We aimed to measure the prevalence of LVL in HBV carriers and validate the efficacy of qHBsAg in predicting LVL. METHODS: This community-based screening study was conducted in Taiwan. HBV DNA was assayed in HBsAg carriers. Participants were randomized to training and validation sets to determine the ability of qHBsAg to predict LVL. Receiver operating characteristic curves were used to identify the best cutoff values in the training set. RESULTS: Among the 2919 participants, 359 (12.2%) were HBsAg carriers. There were 132 and 137 carriers in the training and validation sets, respectively. Significant correlations were found between qHBsAg and HBV DNA in both training and validation sets. Thirty and 29 participants with qHBsAg <8 IU/mL in the training and validation sets, respectively, had LVL. Using 8 IU/mL as the cutoff, negative predictive value (NPV) of qHBsAg for HBV DNA levels >2000 IU/mL was 100%. The best cutoff level of qHBsAg to predict HBV LVL was 200 IU/mL, with a sensitivity, specificity, and accuracy of 75.0%, 76.1%, and 75.8%, respectively, in the training set. The positive predictive value and NPV were 70.0% and 77.9%, respectively, in the validation set. CONCLUSION: Approximately 60% of HBsAg carriers had HBV LVL, and qHBsAg <8 IU/mL accurately predicts LVL. This quantitative test provides additional information for community-based screening.