Prediction of Liver Fibrosis in Chronic Hepatitis B Patients by Using Score of Routine Laboratory Tests

Background: The prognosis and management of patients with chronic hepatitis B depend on the amount and progression of the liver fibrosis. Liver biopsy is currently the gold standard for staging of fibrosis and histological activity, but it is poor tolerated. Noninvasive methods are now used increasingly to reduce the need for liver biopsy. Our aim is to validate simpler model, consisting of routine laboratory markers for predicting liver fibrosis in chronic hepatitis B patients. Methods: Sixty patients with chronic hepatitis B virus infection who underwent liver biopsy before anti-viral treatment at Vajira Hospital from June 2012 to January 2014 were recruited. On the day of scheduled liver biopsy, complete laboratory tests were done. Liver histology was evaluated and grading by METARVIR scoring system. S index (S index = 1000*GGT/(Plt*Alb) was validated in this cohort and by receiver operating characteristics (ROC) analysis. Results: For predicting significant fibrosis, S index cut point value ≥ 0.771 had sensitivity 80%, specificity 44.4%, PPV 32.4%, NPV 87%, and the area under the ROC curve (AUROC) of 0.597. For predicting significant histology (significant fibrosis and/or histological activity), the S index cut point value ≥ 0.587 had sensitivity 82.6%, specificity 35.1%, PPV 44.2%, NPV 76.7%, and AUROC 0.609. As in our study, for significant fibrosis and significant histology diagnosis, we can reduce the need for liver biopsy by 33.34% and 27% with missed diagnosis rate of 20% and 17% respectively. Conclusions: The S index may be used as a screening method for considering liver biopsy in chronic hepatitis B patients, but it had fair accuracy.