Fibrosis assessment using Fibro Meter combined to first generation tests in hepatitis C

AIM To evaluate the performance of FibroMeter^(Virus3G) combined to the first generation tests aspartate aminotransferase-to-platelet ratio index(APRI) or Forns index to assess significant fibrosis in chronic hepatitis C(CHC).METHODS First generation tests APRI or Forns were initially applied in a derivation population from Rio de Janeiro in Brazil considering cut-offs previously reported in the literature to evaluate significant fibrosis.FibroMeter^(Virus3G) was sequentially applied to unclassified cases from APRI or Forns.Accuracy of non-invasive combination of tests,APRI plus FibroMeter^(Virus3G) and Forns plus FibroMeter^(Virus3G) was evaluated in the Brazilian derivation population.APRI plus FibroMeter^(Virus3G) combination was validated in a population of CHC patients from Angers in France.All patients were submitted to liver biopsy staged according to METAVIR score by experienced hepatopathologists.Significant fibrosis was considered as METAVIR F≥2.The fibrosis stage classification was used as the reference for accuracy evaluation of non-invasive combination of tests.Blood samples for the calculation of serum tests were collected on the same day of biopsy procedure or within a maximum 3 mo interval and stored at-70 ℃.RESULTS Seven hundred and sixty CHC patients were included(222 in the derivation population and 538 in the validation group).In the derivation population,the FibroMeter^(Virus3G) AUROC was similar to APRI AUROC(0.855 vs 0.815,P=0.06) but higher than Forns AUROC(0.769,P<0.001).The best FibroMeter^(Virus3G) cut-off to discriminate significant fibrosis was 0.61(80% diagnostic accuracy;75% in the validation population,P=0.134).The sequential combination of APRI or Forns with FibroMeter^(Virus3G) in derivation population presented similar performance compared to FibroMeter^(Virus3G) used alone(79% vs 78% vs 80%,respectively,P=0.791).Unclassified cases of significant fibrosis after applying APRI and Forns corresponded to 49% and 54%,respectively,of the total sample.However,the combination of APRI or Forns with FibroMeter^(Virus3G) allowed 73% and 77%,respectively,of these unclassified cases to be correctly evaluated.Moreover,this combination resulted in a reduction of FibroMeter^(Virus3G) requirement in approximately 50% of the entire sample.The stepwise combination of APRI and FibroMeter^(Virus3G) applied to the validation population correctly identified 74% of patients with severe fibrosis(F≥3).CONCLUSION The stepwise combination of APRI or Forns with FibroMeter^(Virus3G) may represent an accurate lower cost alternative when evaluating significant fibrosis,with no need for liver biopsy.