[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-456770-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-456770-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","anti-kpa-antibody-getting-to-know-a-strange-and-dangerous-specificity","Anti-Kpa antibody: Getting to know a strange and dangerous specificity","","Anti-Kpa is an irregular red blood cell antibody of clinical significance targeting the Kpa antigen of the Kell system. It is rare in the general population, so it is an uncommon cause of transfusion reactions or hemolytic complications, often seen after alloimmunization following transfusion exposure or during pregnancy. Because it may be difficult to detect in routine pre-transfusion testing, it can lead to missed identification. When present, Anti-Kpa can mediate hemolytic reactions and cause hemolytic disease in the fetus through immune destruction and suppression of fetal erythropoiesis.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/healthcare/","Healthcare",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/anti-kpa-antibody-getting-to-know-a-strange-and-dangerous-specificity/456770/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/anti-kpa-antibody-getting-to-know-a-strange-and-dangerous-specificity/456770.png","ImageObject",300,407,{"name":42,"@type":43},"Levi","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-30","2026-09-30",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",8,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"What is Anti-Kpa and which blood group antigen does it target?","Question",{"text":63,"@type":64},"Anti-Kpa is an irregular antibody directed against the red blood cell antigen Kpa of the Kell system. It is uncommon and clinically significant when it occurs.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"Why is Anti-Kpa difficult to detect before transfusion?",{"text":68,"@type":64},"Its low incidence in routine clinical practice can make it challenging to identify in standard pre-transfusion testing, increasing the risk of failure to detect the antibody prior to transfusion.",{"name":70,"@type":61,"acceptedAnswer":71},"How can Anti-Kpa cause harm in patients and fetuses?",{"text":72,"@type":64},"Anti-Kpa can mediate hemolytic reactions in recipients of incompatible blood. It can also cause hemolytic disease in the fetus by immune-mediated red blood cell destruction and suppression of fetal erythropoiesis, leading to severe anemia.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},456770,1790806122,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,101,106,110,114,119,122,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":97,"doc_module":4,"doc_module_name":25,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":102,"doc_module":4,"doc_module_name":25,"category_name":103,"show_sort_weight":104,"slug":105},6,"Technology",50,"technology",{"id":107,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":108,"slug":109},7,40,"healthcare",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":111,"show_sort_weight":112,"slug":113},"Research & Report",30,"research-report",{"id":115,"doc_module":4,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},9,"Religion & Spirituality",20,"religion-spirituality",{"id":117,"doc_module":4,"doc_module_name":25,"category_name":120,"show_sort_weight":117,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":97,"slug":129},19,"General","general",{"code":4,"msg":82,"data":131},{"doc_id":79,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":107,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":33,"language":139,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":12,"update_tm":143,"read_time":123,"preview_page_count":4},7971461740909,"https://ap-avatar.wpscdn.com/davatar_155a257f0dc6eb9ab79c44ca47cae57d","hematol transfus cell ther. 2026;48(2):106269  \nHematology, Transfusion and Cell Therapy  \n[www. htct. com. br](www. htct. com. br)  \n| Review article\u003Cbr>Anti-Kpa antibody: Getting to know a strange and dangerous specificity\u003Cbr>Marcela Quintero Santacruz  * Universidad del Valle, Cali, Colombia |  |  | |\n| --- | --- | --- | --- |\n| A R T I C L E I N F O |  | A B S T R A C T |  |\n| Article history:\u003Cbr>Received 1 October 2024\u003Cbr>Accepted 30 November 2025 Available online 12 March 2026 |  | Anti-Kpa is an irregular antibody of clinical significance directed against the red blood cell antigen Kpa of the Kell system. It is rare in the general population and, therefore, uncommon as a cause of transfusion or hemolytic complications. It has been documented in isolated cases, mainly in the context of alloimmunization after transfusion exposure or during pregnancy; its incidence in clinical practice is limited and can be difficult to detect in routine pre-transfusion testing, which could lead to failure to identify the antibody prior to transfusion. The production of Anti-Kpa antibodies is less common than antibodies against other Kell system antigens, such as anti-K. However, when generated, these antibodies can mediate hemolytic reactions in patients receiving incompatible blood and can cause hemolytic disease in the fetus since in addition to immune destruction of red blood cells, Kell system antibodies such as Anti-Kpa can cause suppression of fetal erythropoiesis, resulting in severe anemia.\u003Cbr>􀀁 2026 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier España, S.L.U. This is an open access article under the CC BY license ([http://creativecommons.org/licenses/by/4.0/](http://creativecommons.org/licenses/by/4.0/)). |  |\n| Keywords: Alloantibodies Red blood cells Antigens\u003Cbr>Hemolytic transfusion\u003Cbr>Hemolytic disease |  |  |  |\n\nIntroduction  \nErythrocyte alloimmunization is a complex immunological process that occurs in patients who have been exposed to foreign erythrocyte antigens, either through blood transfusions or gestation, and who develop irregular antibodies against these antigens [1] . This phenomenon is particularly relevant in patients who require repeated transfusions, such as those with chronic anemia, as the presence of clinically significant antibodies can complicate transfusion management and increase the risk of hemolytic reactions [1] .  \n* Corresponding author at: School of Bacteriology and Clinical Laboratory, Faculty of Health, Universidad del Valle, Cali, Colombia.  \n[E-mail address:](E-mail address: quintero.marcela@correounivalle.edu.co)[ quintero.marcela@correounivalle.edu.co](E-mail address: quintero.marcela@correounivalle.edu.co)  \nThe Anti-Kpa antibody is a rare specificity within the Kell blood group system. Due to its low prevalence in the general population, it is an infrequent cause of hemolytic transfusion reactions or hemolytic complications [2] . This antibody, directed against the Kpa antigen, has been documented in isolated cases, mainly in the context of alloimmunization following transfusion exposure or during pregnancy, but its incidence in clinical practice is limited [2] .  \nThe aim of this review is to provide comprehensive and up-to-date information on the Anti-Kpa antibody and its relevance in transfusion medicine.  \nRelevant characteristics of the Kpa antigen  \nThe Kpa antigen is part of the Kell blood group system (ISBT 006) . This system comprises 38 antigens carried by a 732-amino acid transmembrane glycoprotein known as CD238 .  \n[https://doi.org/10.1016/j.htct.2026.106269](https://doi.org/10.1016/j.htct.2026.106269)  \n2531-1379/􀀁 2026 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier España, S.L.U. This is an open access article under the CC BY license ([http://creativecommons.org/licenses/by/4.0/](http://creativecommons.org/licenses/by/4.0/)).  \nThe nomenclature derives from ‘Kelleher’, the first producer of a","cbCairLJyhWFaHw2","https://ap.wps.com/l/cbCairLJyhWFaHw2","pdf",123474,"English","# Introduction\n## Relevant characteristics of the Kpa antigen\n## Relevant characteristics of anti-Kpa","[{\"question\":\"What is Anti-Kpa and which blood group antigen does it target?\",\"answer\":\"Anti-Kpa is an irregular antibody directed against the red blood cell antigen Kpa of the Kell system. It is uncommon and clinically significant when it occurs.\"},{\"question\":\"Why is Anti-Kpa difficult to detect before transfusion?\",\"answer\":\"Its low incidence in routine clinical practice can make it challenging to identify in standard pre-transfusion testing, increasing the risk of failure to detect the antibody prior to transfusion.\"},{\"question\":\"How can Anti-Kpa cause harm in patients and fetuses?\",\"answer\":\"Anti-Kpa can mediate hemolytic reactions in recipients of incompatible blood. It can also cause hemolytic disease in the fetus by immune-mediated red blood cell destruction and suppression of fetal erythropoiesis, leading to severe anemia.\"}]","Anti-Kpa antibody: Getting to know a strange and dangerous specificity | PDF",1790747053]