Direct antiviral agent treatment of chronic hepatitis C results in rapid regression of transient elastography and fibrosis markers fibrosis-4 score and aspartate aminotransferase-platelet ratio index

Background Novel direct antiviral agents (DAA) targeting hepatitis C virus (HCV) have revolutionized the treatment of chronic hepatitis C infection (CHC). Rates of sustained virological response (SVR) to treatment have drastically improved since introduction of DAA. Transient Elastography (TE) is an ultrasound based, non-invasive technique to assess liver stiffness (LS). We examined the changes in TE values and fibrosis scores FIB-4 and APRI after DAA treatment of CHC. Methods 549 patients who received a DAA based treatment for CHC were screened and 392 were included. TE values recorded prior to therapy and within 18months after therapy were evaluated. In addition, FIB-4 and APRI scores were calculated and histopathological results were recorded if available. Results Median TE prior to DAA treatment was 12.65kPa (IQR 9.45-19.2kPa) and decreased to 8.55kPa (IQR 5.93-15.25) post-treatment. This finding is statistically significant (P<.001) and equals a TE regression of 32.4% after DAA treatment. Median FIB-4 and APRI values significantly decreased from 2.54 (IQR 1.65-4.43) and 1.10 (IQR 0.65-2.43) to 1.80 (IQR 1.23-2.84, P<.001) and 0.43 (IQR 0.3-0.79, P<.001) respectively. Conclusion Patients with SVR after DAA therapy showed significant regression of TE values. Rapid decrease in TE was in concordance with regression of validated fibrosis scores FIB-4 and APRI. It remains to be examined whether this indicates a true regression of fibrosis or merely resolution of chronic liver inflammation with subsequent improvement of TE values and laboratory parameters.