Large spontaneous HBV DNA fluctuations and potential usefulness of a single-point measurement of combined HBV DNA and quantitative HBsAg for the exclusion of HBeAg-negative chronic hepatitis B: A prospective Tunisian cohort study

Abstract

Background and study aim: During the natural course of HBeAg-negative chronic hepatitis B (CHB), fluctuations in hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) levels are often observed, making the classification of patients difficult. We aimed to describe spontaneous short-term HBV DNA level fluctuations and to assess the usefulness of qHBsAg in Tunisian patients with HBeAg-negative chronic HBV infection.

Patients and methods: We included 174 treatment-naive Tunisian patients with HBeAg-negative chronic HBeAg-negative HBV infection. A prospective 1-year follow-up was conducted with serial determinations of HBV DNA, ALT levels, and qHBsAg. The patients were classified into three groups: inactive carriers (G1), patients with negative HBeAg CHB (G2), and patients with an "indeterminate state" (G3). For the latter group, a liver biopsy was indicated.

Results: Only genotype D was detected. During follow-up, 21.6% and 19.5% of patients with a low initial (<2,000 IU/ml) and intermediate viral load (2,000-20,000 IU/ml) experienced a subsequent increase in their HBV DNA levels above 2,000 and 20,000 IU/ml, respectively. Significant variations in viral load were observed in 61.1% of patients at 6-month intervals. Among the 174 patients, 89 (51.1%) belonged to G1, 33 (19%) to G2, and 52 (29.9%) to G3. Fourteen patients have undergone a liver biopsy, of whom seven showed moderate to severe liver disease. Combination of HBV DNA < 2,000 IU/ml and qHBsAg < 832 IU/ml excluded CHB in 98.4% of cases. A cutoff point for qHBsAg < 100 IU/ml associated with an annual decline of > 0.5 log ₁₀ IU/ml is a good predictor marker of functional cure for hepatitis B.

Conclusions: This study highlights the large short-term fluctuations in HBV DNA in patients with HBeAg-negative chronic HBeAg-negative HBV infection with genotype D. Thus, using the cutoff value of 832 for qHBsAg combined with that of 2,000 for HBV DNA makes it possible to exclude CHB for most patients.

Keywords: Chronic hepatitis B; Genotype D; HBV DNA; Hepatitis B virus; Quantitative HBsAg.