Concordance of non-invasive mechanical and serum tests for liver fibrosis evaluation in chronic hepatitis C

AIM To determine the sensitivity and specificity of liver stiffness measurement（LSM） and serum markers（SM） for liver fibrosis evaluation in chronic hepatitis C.METHODS Between 2012 and 2014,81 consecutive hepatitis C virus（HCV） patients had METAVIR score from liver biopsy compared with concurrent results from LSM [transient elastography（TE） [FibroS can;/ARFI technology（Virtual Touch;）] and SM [FIB-4/aspartate aminotransferase-toplatelet ratio index（APRI）].The diagnostic performance of these tests was assessed using receiver operating characteristic curves.The optimal cut-off levels of each test were chosen to define fibrosis stages F ≥ 2,F ≥ 3 and F = 4.The Kappa index set the concordance analysis.RESULTS Fifty point six percent were female and the median age was 51 years（30-78）.Fifty-six patients（70%） weretreatment-na?ve.The optimal cut-off values for predicting F ≥ 2 stage fibrosis assessed by TE were 6.6 kP a,for acoustic radiation force impulse（ARFI） 1.22 m/s,for APRI 0.75 and for FIB-4 1.47.For F ≥ 3 TE was 8.9 kP a,ARFI was 1.48 m/s,APRI was 0.75,and FIB-4 was 2.For F = 4,TE was 12.2 kP a,ARFI was 1.77 m/s,APRI was 1.46,and FIB-4 was 3.91.The APRI could not distinguish between F2 and F3,P = 0.92.The negative predictive value for F = 4 for TE and ARFI was 100%.Kappa index values for F ≥ 3 METAVIR score for TE,ARFI and FIB-4 were 0.687,0.606 and 0.654,respectively.This demonstrates strong concordance between all three screening methods,and moderate to strong concordance between them and APRI（Kappa index = 0.507）.CONCLUSION Given the costs and accessibility of LSM methods,and the similarity with the outcomes of SM,we suggest that FIB-4 as well as TE and ARFI may be useful indicators of the degree of liver fibrosis.This is of particular importance to developing countries.