The Predictive Role of miRNAs in Hepatitis B Vaccine Response of Metabolic Dysfunction-Associated Steatotic Liver Disease Patients

(1) Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease. Although the changes in the expression levels of microRNAs (miRNAs) in hepatitis B virus-related diseases have been evaluated, no study has evaluated the role of miRNAs in HBV vaccine response in MASLD patients. We aimed to determine the miRNA expression profile in MASLD patients according to HBV vaccine response. (2) Methods: Overall, 100 MASLD patients and 100 controls were included, and anti-HBs levels were measured after three doses of HBV vaccine administration. After collecting blood samples, 22 different miRNA expression profiles were analyzed by RT-PCR analysis, and changes in the expression levels of potential miRNAs were further verified in all study groups. (3) Results: The miR-146a expression level considerably increased in MASLD patients compared to the control group. Furthermore, miR-99a and miR-640 expression levels significantly increased in AntiHBs (-) healthy individuals. (4): Conclusions: miR-146a could be used as the diagnostic marker in MASLD patients. Furthermore, the miR-99a and miR-640 expression levels could predict hepatitis B vaccine response. However, validation studies are required to verify the biomarker potential of miRNAs within a more significant number of patients.