Low HBV replication does not aggravate disease progression in patients with superinfection with HEV.

In China, co-infection with HEV and HBV is relatively common, and the impact of low HBV DNA load on coinfected patients remains unknown. This study aimed to assess the effect of low-replication hepatitis B virus (HBV) infection on disease progression in patients with hepatitis E virus (HEV) superinfection. This study included 260 consecutive patients diagnosed with sporadic acute hepatitis E (AHE) who were admitted to two hospitals in Jiangsu Province, China, between January 2018 and December 2023. Patients were categorized into two groups: those who were HBsAg-positive with low HBV replication (defined as HBV DNA levels < 2000 IU/mL) and those who were HBsAg-negative. Clinical and laboratory data were retrospectively collected and analyzed to evaluate biochemical parameters, disease progression, and clinical outcomes across the two groups. Of the 260 patients, 24 (9.23%) were HBsAg-positive, while 236 (90.77%) were HBsAg-negative. The average age of participants was 53.48 ± 13.3 years, with no significant differences in age or gender between the two groups. Liver damage manifestations and biochemical indicators were comparable at admission and throughout follow-up. Importantly, there were no significant differences in disease progression or clinical outcomes between the groups. The cumulative rates of liver enzyme and bilirubin normalization were also similar. Although the follow-up period was longer in the HBsAg-positive group (442.79 ± 474.58 days vs. 215.65 ± 346.11 days, P = 0.031), no differences in clinical outcomes were identified. In this retrospective cohort, low replication HBV infection did not appear to significantly influence short-term disease progression in patients with HEV superinfection, though larger prospective studies are needed to confirm these findings.