Wang Q Sachse P Semmo M Lokhande M Montani M Dufour JF Zoulim F Klenerman P Semmo N 2015 A serologic response to hepatitis B virus (HBV) defined as 'anti-HBc alone' is commonly observed, but its significance remains unclear. This study aimed to define the relationship between 'anti-HBc alone' serostatus and HBV infection, including HBV-specific T- and B-cell memory responses. We enrolled 31 'anti-HBc alone' patients. Total HBV DNA and cccDNA were tested by nested polymerase chain reaction (PCR) analysis in liver samples from 22 'anti-HBc alone' patients vs controls (chronic or resolved HBV infection), followed by HBsAg/HBcAg immunohistochemical (IHC) staining. IFN-γ secretion by HBV-specific T cells was compared in individuals who were 'anti-HBc alone' (n = 27), resolved HBV (n = 21), chronic HBV (n = 24) and 12 healthy controls using enzyme-linked immunospot (ELISpot) assays. An HBsAg-IgG B-cell ELISpot assay was performed in 'anti-HBc alone' patients before and after one dose of recombinant HBsAg vaccine. The majority (23/31, 74.2%) of the 'anti-HBc alone' individuals were co-infected with HCV. Infrequent intrahepatic total HBV DNA (2/22, 9.1%) and cccDNA (1/22, 4.5%) were detected in biopsies; HBsAg and HBcAg IHC staining was negative. HBV-specific T-cell responses were similar between 'anti-HBc alone' individuals and HBV resolvers. Circulating HBV-memory B-cell responses were detected in all 'anti-HBc alone' individuals, consistent with an HBsAg-specific memory pool. After one HBV vaccine dose, increased anti-HBs antibody levels were observed, accompanied by an expansion of HBsAg-specific memory B cells (P = 0.0226). 'Anti-HBc alone' individuals showed HBV-specific T-cell and memory B-cell responses typical of previous viral exposure and protective memory, suggesting a resolved infection. https://sonar.ch/global/documents/263725 eng info:eu-repo/semantics/altIdentifier/doi/10.1111/jvh.12428 info:eu-repo/semantics/altIdentifier/pmid/26075501 Journal of viral hepatitis. - 2015 T cells anti-HBc alone hepatitis B memory B cells Adult Antibodies, Viral B-Lymphocytes Female Hepatitis B Antibodies Hepatitis B Core Antigens Hepatitis B Surface Antigens Hepatitis B Vaccines Hepatitis B virus Hepatitis B, Chronic Humans Immunohistochemistry Interferon-gamma Male Middle Aged T-Lymphocytes Vaccination Viral Load T- and B-cell responses and previous exposure to hepatitis B virus in 'anti-HBc alone' patients. http://purl.org/coar/resource_type/c_6501