Utility and limitations of APRI and FIB4 to predict staging in a cohort of nonselected outpatients with hepatitis C

Background. Chronic hepatitis C(CHC) staging is important for therapeutic decision-making. Identification of noninvasive markers can provide alternatives to liver biopsy. Aim. To assess the value of APRI and FIB4 for CHC fibrosis staging in a cohort of nonselected outpatients from a referral center in Sao Paulo Brazil. Material and methods. Medical records of 798 adult outpatients were analyzed retrospectively. For calculations of APRI and FIB4, the original descriptions were considered, and markers were compared with degree of liver injury. Results. Overall, 49.3% of participants were female, and mean age was 56.9 +/- 12.5 years. Genotype 1 was predominant (71.7 vs. 23.7% genotype 3); 64% had significant librosis, 44% had advanced librosis, and 28% had cirrhosis. The areas under the receiver operating curve for significant fibrosis, advanced fibrosis and cirrhosis, respectively, were 0.809, 0.819, and 0.815 for the APRI marker and 0.803, 0.836 and 0.852 for FIB4. Using the recommended cut off values, approximately 30-40% of the patients could not be classified. In the remainder, either APRI or FIB4 alone correctly diagnosed 80-85% of cases. Concomitant or consecutive use of both APRI and FIB4 increased the number of the cases correctly diagnosed only slightly, but also increased the number of patients not classified within the cutoff values. Conclusions. In conclusion, use of the APRI or FIB4 markers for detection of hepatic fibrosis may be a viable alternative at referral centers for treatment of CHC in low- and middle-income countries. Despite relatively good accuracy, a significant number of patients could not be assessed by these methods.