Teshale E et al. reported that APRI and FIB-4 distinguished significant fibrosis F2-F4 from none to minimal fibrosis F0-F1 with good sensitivity and specificity with liver biopsy as a control in chronic hepatitis B (
30). A cross-sectional study with liver biopsy as a control reported that APRI and FIB-4 had a similar and good overall performance in the diagnosis of significant fibrosis (METAVIR stage ≥ 2) in chronic hepatitis C, the positive predictive value and negative predictive value for APRI and FIB-4 were, respectively, 77% and 92% as well as 83% and 81% (
31). Berenguer J et al. compared the prognostic value of baseline liver biopsy and FIB-4 in HIV/HCV coinfection, the results showed that FIB-4 outperformed liver biopsy as a predictor of overall death and liver-related events (
32). In view of the above study, taking into account the small number (16 cases) of patients with liver biopsy in this study, we did not compare liver biopsy and noninvasive fibrosis methods.
To our knowledge, this study first evaluated predictive value of annual changes in FIB-4 and APRI in liver disease prognosis in Chinese CHC patients. Due to the fact that Fibroscan was not introduced into the 2 tertiary hospitals until 2015 and patients who underwent liver stiffness measurement had limited follow-up time, we did not evaluate liver stiffness measurement in the study.
Follow-up time in this retrospective study was 47.0 (29.5 - 72.0) months. Patients who received IFN or PEG-IFN plus ribavirin antiviral therapy were followed up for more than 22 months (about 96 weeks), due to the fact that it is sufficient to complete an antiviral treatment and observe the efficiency of the treatment. Our study focused on the predictive value of baseline FIB-4 and APRI, ACs of FIB-4 and APRI, antiviral therapy, and Child-Pugh scores for liver disease progression. A total of 29 patients had liver disease progression. Since only 4 patients died of non-liver-related causes, mortality unrelated to liver disease was not evaluated.
This study showed that baseline FIB-4 > 3.25 and baseline APRI > 2 were significantly associated with liver disease progression. The results are consistent with previous studies (
18-
21). Univariate and multivariate analysis showed that AC of FIB-4 was a strong predictor for monitoring liver disease development. Patients with AC of FIB-4 > 0.22 had a significantly worse prognosis than patients with AC of FIB-4 ≤ 0.22. Patients with baseline FIB-4 > 3.25 and AC of FIB-4 > 0.22 had the highest cumulative incidence of liver disease progression among the 4 groups defined according to baseline FIB-4 and AC of FIB-4 (
Figure 2B). Patients with baseline FIB-4 > 3.25 and AC of FIB-4 ≤ 0.22 had a similar prognosis to patients with baseline FIB-4 ≤ 3.25 and AC of FIB-4 > 0.22 (P = 0.853). Patients with baseline FIB-4 ≤ 3.25 and AC of FIB-4 ≤ 0.22 had excellent prognosis. Patients with high baseline FIB-4 and rapidly increasing FIB-4 should be monitored every year or even over a shorter time interval for the purpose of identifying disease development and starting an appropriate treatment.
AC of APRI was not associated with disease progression in multivariable analysis in this study. Previous studies have also pointed to the limited value of change in APRI in predicting liver disease progression (
20,
22). FIB-4 contains age (a strong predictive factor of overall survival), AST, ALT, and platelet count; thus, it is considered a more complex and better prognostic indicator than APRI for evaluating the progression of liver-related diseases. Vergniol J reported that FIB-4 was as accurate as liver stiffness measurement in predicting death (
20). Berenguer et al. reported that FIB-4 outperformed liver biopsy as a predictor of overall death and liver-related events (
32). The components of the FIB-4 index are based on simple serum and hematology tests, which are easily performed at all clinics. In addition, FIB-4 is cheaper and easier to calculate than Fibrotest and enhanced liver fibrosis test (ELF) (
15,
33), therefore, this index can be used for identifying progression of liver disease in CHC patients in resource-limited settings.
We evaluated the prognostic value of baseline Child-Pugh class. Due to the fact that this score increased in a small number of patients (4.6%), usually in patients with high baseline FIB-4 or high AC of FIB-4, we did not assess the change in Child-Pugh class. The results showed that Child-Pugh class C was an independent risk associated with liver disease progression.
Host IL28B genotype CC (rs12979860) and HCV genotype 1b were reported to be predominant in China, which may contribute to the higher rate of SVR (61% - 82%) with peg-IFN plus ribavirin as compared with that (54% - 61%) in Caucasian patients (
24,
34,
35). A total of 131 patients received IFN or PEG-IFN plus ribavirin treatment, 86 of whom achieved SVR (64.9%) in this study. SVR to IFN-based therapy has been found to be associated with HCC and all-cause mortality risk reduction (
36-
39). This study showed that non-SVR had a borderline significance in Cox Model 2 (therapy, baseline APRI, and AC of APRI) (P = 0.058) and significance in Cox Model 4 (ALP, therapy, Child-Pugh class, and AC of APRI) (P = 0.035). Patients with non-SVR and AC of FIB-4 > 0.22 had the highest incidence of liver disease progression among the 4 subgroups according to SVR and AC of FIB-4 (
Figure 2C). Non-SVR had significance in cumulative incidence of liver disease progression in patients with AC of FIB-4 ≤ 0.22. Patients with SVR and AC of FIB-4 ≤ 0.22 had excellent prognosis. Therefore, it is recommended that physicians should provide as far as possible effective antiviral therapy for patients, especially patients with rapidly increasing liver fibrosis tests, with the commercialization of direct-acting antivirals (DAAs).
The HCV genotype 1b was identified in 89.3% patients. This is consistent with previous findings (
24). It was reported that HCV genotype 1b was a risk factor of HCC (
40). There was no significant association between HCV genotype and liver disease progression in this study, probably due to the fact that most of the patients in our study were genotype 1. Further studies with larger cohorts that include a larger number of non-genotype 1 infected patients are recommended.
The present study has many limitations, including it being a retrospective analysis with a limited number of cases, no liver stiffness measurements, and no consideration of the effect of hepato-protective drugs as an intervention. Since hepato-protective drugs can reduce AST and ALT concentrations (
41), further studies considering the effect of hepato-protective drugs on APRI and FIB-4 are necessary.
In conclusion, an increased FIB-4, over time, is a strong predictor of liver disease progression in Chinese CHC patients. Monitoring FIB-4 annually can help physicians predict the prognosis in CHC patients, especially for patients with obvious fibrosis or cirrhosis. Further studies are needed to confirm the predictive value of repeated noninvasive fibrosis tests in other causes of chronic liver diseases, in order to improve recommendations and initiate HCC screening.