Optimal linear combination of ARFI, transient elastography and APRI for the assessment of fibrosis in chronic hepatitis B.

Accurate assessment of liver fibrosis in patients with chronic hepatitis B (CHB) is necessary not only to predict the long-term clinical course but also to determine an appropriate antiviral therapy scheme. Several noninvasive approaches - serum markers and elastography - have been proposed as alternatives for the histopathological analysis of liver biopsies. The aim of this study was to evaluate two ultrasound elastography methods (ARFI and TE) and one biochemical test (APRI), as well as their optimal linear combination, in the assessment of liver fibrosis in CHB.Ninety five patients with CHB and 16 volunteers underwent ARFI, TE and APRI; and liver fibrosis was staged in the patients by a liver biopsy. An optimal linear combination of the three methods was developed, and its diagnostic performance was evaluated by a 10-fold cross-validation.The accuracy of the linear combination was 83.86% and 91.88% for significant fibrosis (≥F2) and cirrhosis (F4), respectively, higher than those obtained for ARFI (83.50%, 88.76%), TE (75.27%, 87.61%) and APRI (73.29% and 81.67%). The combination also increased the sensitivity and the negative predictive values for the diagnosis of significant fibrosis and cirrhosis.The optimal linear combination algorithm is effective for noninvasive staging of liver fibrosis in CHB. However, linear combination has its own limitations; nonlinear methods may eventually reveal even clearer diagnostic results.