Editing Blood type (section)

===Other blood group systems===
{{Main|Human blood group systems}}
As of October 2024, 47 blood-group systems have been identified by the International Society for Blood Transfusion in addition to the ABO and Rh systems.<ref name=":1" /> Thus, in addition to the ABO antigens and Rh antigens, many other antigens are expressed on the RBC surface membrane. For example, an individual can be AB, D positive, and at the same time M and N positive ([[MNS antigen system|MNS system]]), K positive ([[Kell antigen system|Kell system]]), Le<sup>a</sup> or Le<sup>b</sup> negative ([[Lewis antigen system|Lewis system]]). Many of the blood group systems were named after the patients in whom the corresponding antibodies were initially encountered. Blood group systems other than ABO and Rh pose a potential, yet relatively low, risk of complications upon mixing of blood from different people.<ref name="GoodellUhl2010">{{cite journal |last1=Goodell |first1=Pamela P. |last2=Uhl |first2=Lynne |last3=Mohammed |first3=Monique |last4=Powers |first4=Amy A. |title=Risk of Hemolytic Transfusion Reactions Following Emergency-Release RBC Transfusion |journal=American Journal of Clinical Pathology |date=August 2010 |volume=134 |issue=2 |pages=202–206 |doi=10.1309/AJCP9OFJN7FLTXDB |pmid=20660321 |doi-access=free }}</ref>

Following is a comparison of clinically relevant characteristics of antibodies against the main human blood group systems:<ref name="Mais 2014">{{cite book | last=Mais | first=Daniel | title=Quick compendium of clinical pathology | publisher=American Society for Clinical Pathology Press | publication-place=United States | year=2014 | isbn=978-0-89189-615-9 | oclc=895712380 | page=}}{{pn|date=November 2024}}</ref>
{|class="wikitable"
!  !! [[ABO blood group system|ABO]] !! [[Rh blood group system|Rh]] !! [[Kell antigen system|Kell]] !! [[Duffy antigen system|Duffy]] !! [[Kidd antigen system|Kidd]]
|-
! Naturally occurring
| Yes || No || No || No || No
|-
! Most common in immediate hemolytic transfusion reactions
|  A|| ||  Yes||  Fy<sup>a</sup>||  Jk<sup>a</sup>
|-
! Most common in delayed hemolytic transfusion reactions
| ||  E, D, C|| || ||  Jk<sup>a</sup>
|-
! Most common in [[hemolytic disease of the newborn]]
|  Yes||  D, C||  Yes|| ||
|-
! Commonly produce intravascular hemolysis
|  Yes|| || || ||  Yes
|}