{"term":{"id":"12975","title":"CD5+ B lymphocyte","longtitle":"IUPAC Gold Book - CD5+ B lymphocyte","doi":"10.1351\/goldbook.12975","code":"12975","status":"current","definitions":[{"id":1,"text":"Lymphocyte of type B-1a, which is predominant in fetal lymphoid organs and in neonatal cord blood.","notes":{"1":"In adults, these cells range from \\(\\pu{2}\\) to \\(\\pu{6\\%}\\) of total mononuclear cells in peripheral blood. They utilize an immunoglobulin (Ig) variable (V) gene repertoire different from that of CD5– B cells and they produce natural autoantibodies.","2":"The expansion of autoreactive B1-a cells has been reported in peripheral blood of patients with autoimmune diseases [e.g., rheumatoid arthritis (RA), Sjögren syndrome, antiphospholipid syndrome (APS)]. In RA these cells can account for up to \\(\\pu{20\\%}\\) of circulating B cells and may produce rheumatoid factor."},"links":[{"term":"B cells","url":"https:\/\/goldbook.iupac.org\/terms\/view\/12937"},{"term":"Lymphocyte","url":"https:\/\/goldbook.iupac.org\/terms\/view\/13399"},{"term":"Sjögren syndrome","url":"https:\/\/goldbook.iupac.org\/terms\/view\/13680"},{"term":"antiphospholipid syndrome (APS)","url":"https:\/\/goldbook.iupac.org\/terms\/view\/12899"},{"term":"natural autoantibodies","url":"https:\/\/goldbook.iupac.org\/terms\/view\/13497"},{"term":"rheumatoid arthritis (RA)","url":"https:\/\/goldbook.iupac.org\/terms\/view\/13651"},{"term":"rheumatoid factor","url":"https:\/\/goldbook.iupac.org\/terms\/view\/13652"},{"term":"variable (V) gene","url":"https:\/\/goldbook.iupac.org\/terms\/view\/13772"}],"sources":["PAC, 2012, 84, 1113. 'IUPAC glossary of terms used in immunotoxicology (IUPAC Recommendations 2012)' on page 1138 (https:\/\/doi.org\/10.1351\/PAC-REC-11-06-03)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/12975\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/12975\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/12975\/plain"},"citation":"Citation: 'CD5+ B lymphocyte' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.12975","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2026-06-30T04:30:12+00:00"}}