Occult hepatitis B virus infection (OBI), characterized by extremely low viral loads and the persistent intrahepatic presence of cccDNA, poses a profound challenge to global public health security. With a prevalence ranging from 0.06% to over 15% in different donor populations, OBI maintains a risk of transmission and can progress to hepatocellular carcinoma. Its prevention and control have long been limited by the sensitivity constraints of conventional detection methods, highlighting the urgent need for more sensitive diagnostic innovations. Emerging technologies offer distinct breakthroughs: ddPCR facilitates absolute quantification; CRISPR-Cas systems coupled with isothermal amplification enable rapid, point-of-care testing; third-generation sequencing resolves viral integration and mutations; and nanomaterials enhance the signal detection. This review synthesises advancements in OBI diagnostic technologies and provides a comparative overview of their strengths, limitations, and transfusion safety implications, as well as their potential applications in blood transfusion. Recommendations are also proposed to inform the advancement of OBI risk control in blood transfusion and to guide the development of novel diagnostic technologies, particularly relevant to regions with high HBV endemicity, such as China.

Alzheimer’s disease (AD) is a common neurodegenerative disease that currently has no known cure. Intravenous immunoglobulin (IVIG), which contains AD-related antibodies and has anti-inflammatory properties, has shown potential as a treatment for AD. However, the efficacy of clinical trials involving AD patients treated with IVIG has been inconsistent. Our previous study found that different IVIGs had significantly varied therapeutic effects on 3xTg-AD mice. In order to investigate the relationship between the composition and function of IVIG and its efficacy in treating AD, we selected three IVIGs that showed notable differences in therapeutic effects. Then, the concentrations of specific antibodies against β-amyloid (Aβ)₄₂, tau, and hyperphosphorylated tau (p-tau) in three IVIGs, as well as their effects on systemic inflammation induced by lipopolysaccharide (LPS) in Balb/c mice, were analyzed and compared in this study. The results indicated that these IVIGs differed greatly in anti-Aβ₄₂/tau antibody concentration and anti-p-tau ratio, and improved LPS-stimulated peripheral inflammation, liver and kidney injury, and neuroinflammation in Balb/c mice to varying degrees. Combined with our previous results, the efficacy of IVIG against AD may be positively correlated with its level of AD-related antibodies and anti-inflammatory ability. AD-related antibody analysis and functional evaluation of IVIG should be given sufficient attention before clinical trials, as this may greatly affect the therapeutic effect of AD treatment.