Aging impairs fibrosis-4 index after sustained virologic response by direct-acting antivirals in chronic hepatitis C infection

INTRODUCTION AND OBJECTIVES Sustained virologic response (SVR) is achieved in most cases of C-type liver disease after direct-acting antiviral (DAA) therapy. Although liver fibrosis improves, the degree of improvement is different. This study aimed to analyze the factors involved in improving liver fibrosis using the fibrosis 4 (FIB-4) index. MATERIAL AND METHODS Patients were monitored for >3 years after SVR. At the start of therapy (SOT), liver fibrosis was categorized as either mild ( 3.25 n = 236) based on the FIB-4 index. The FIB-4 index in the advanced group decreased significantly compared to that of the other two, so we selected the advanced group as the analysis target. SOT and end of therapy (EOT) factors that contributed to the FIB-4 index ≤3.25 at 3 years after therapy were examined using a multivariate analysis. RESULTS Among the SOT factors, age (<72 years old), absence of liver cirrhosis (LC), alanine transferase (ALT) (≥50 U/L), platelet (PLT) (≥10.2 × 104/mm3), and total bilirubin (T.Bil) (<0.8 mg/dl) were the significant factors contributing to the improvement of the FIB-4 index. Among the EOT factors, age (<72 years), PLT (≥12.0 × 104/mm3), and hemoglobin (Hb) (≥12.1 g/dl) were the significant factors contributing to the improvement of FIB-4 index. CONCLUSIONS Factors involved in the improvement of liver fibrosis after SVR were young age, absence of LC, low T.Bil., high ALT, high PLT, and high Hb levels. The levels of T.Bil, PLT, and Hb were considered to be related to portal hypertension. Aging strongly impaired the improvement in liver fibrosis.