What is the benefit of prophylaxis to prevent HBV reactivation in HBsAg-negative anti-HBc-positive patients? Meta-analysis and decision curve analysis

Background and aims: Patients with overt or occult hepatitis B virus (HBV) infection receiving immunosuppressive treatments have a wide risk of HBV reactivation (HBVr). We performed meta-analysis with decision curve analyses (DCA) to estimate the risk of HBVr in HBsAg-negative anti-HBc-positive patients naïve to nucleos(t)ide analogues (NAs) receiving immunosuppressive treatments. Approach and results: Studies were identified through literature search until October 2022. Pooled estimates were obtained using random-effects model. Subgroup analyses were performed according to underlying disease and immunosuppressive treatments. DCA was used to identify the threshold probability associated with the net benefit of antiviral prophylaxis in HBsAg-negative anti-HBc-positive patients. We selected 68 studies (40 retrospective and 28 prospective), including 8034 patients with HBsAg negative anti-HBc positive. HBVr was 4% (95% CI 3%-6%) in HBsAg-negative anti-HBc-positive patients, with a significantly high heterogeneity (I2 69%; p < .01). The number-needed-to-treat (NNT) by DCA ranged from 8 to 24 for chemotherapy plus rituximab, from 12 to 24 for targeted therapies in cancer patients and from 13 to 39 for immune-mediated diseases. Net benefit was small for monoclonal antibodies. Conclusions: Our DCA in HBsAg-negative anti-HBc-positive patients provided evidence that NA prophylaxis is strongly recommended in patients treated with chemotherapy combined with rituximab and could be appropriate in patients with cancer treated with targeted therapies and in patients with immune-mediated diseases. Finally, in patients with cancer treated with monoclonal antibodies or with chemotherapy without rituximab, the net benefit is even lower.