The Leeds Teaching Hospitals NHS Trust


Common RBC Antibodies

Red Blood Cell Antibodies

The red blood cell membrane contains a vast array of antigenic molecules which may induce the production of plasma antibodies. Currently there are some 330 known red cell antigens, categorised into 39 blood group systems (the first 9 of which contain the most commonly encountered antibodies)*.  Immunisation is caused by exposure to 'foreign' red cells via pregnancy or transfusion though some plasma antibodies are naturally occurring.

Detection of these plasma antibodies is an essential part of the group and cross match process ensuring compatible blood for the recipient. Patients with plasma antibodies may require their transfusion to be delayed until compatible blood is found. This delay may be longer in patients who have multiple antibodies.

* ISBT Table of blood group antigens v.9.0, 12th July 2019.IMPORTANT: Patients with known antibodies SHOULD NOT BE GIVEN EMERGENCY O NEGATIVE BLOOD - contact the Bloodbank.

 The table below lists antigens to which antibodies are more commonly encountered.

System Name System Symbol System Number  Number of Antigens Major Antigens
 ABO  ABO  001  4  A, A1, B 
 MNS  MN  002  49  M, N, S, s, U
 P  P  003  3  P1 
 Rh (Rhesus)  Rh  004  55  C, Cw, c, D, E, e
 Lutheran  Lu  005  27  Lua
 Kell  K  006  36  K, k, Kpa
 Lewis  Le  007  6  Lea, Leb
 Duffy  Fy  008  5  Fya, Fyb
 Kidd  Jk  009  3  Jka, Jkb 

The table below lists antibodies to the more common antigens.

Antibody HDN HTR Approx. % Compatible Notes
Anti-C Yes Yes 30 Anti-C is most often found in combination with anti-D and/or anti-E in rr individuals.
Anti-Cw Rare Yes 98  
Anti-c Yes Yes 20  
Anti-D Yes Yes 15 When a D variant person makes partial anti-D, the antibody is of the same clinical significance as when a D negative person makes complete anti-D.
Anti-E Yes Yes 70 Naturally occurring anti–E appears not to cause transfusion reactions or in-vivo haemolysis.
Anti-e Yes Yes 2  
Anti-K Yes Yes 91 Kx is the precursor antigen for the Kell system antigens and Kx negative cells are known as the McLeod phenotype which is associated with X linked Chronic Granulomatous Disease.
Anti-k Yes Yes <0.1 Some fatal hydropic instances of HDN due to maternal anti-k are known
Anti-M No No 22 Anti-M is often unable to fix complement and has a thermal range of activity below 37oC and is considered to be of no clinical significance in that instance. Anti-M is far more common in children than adults.
Anti-N No No 28 Most examples are naturally occurring.
Anti-S Yes Yes 45  
Anti-s Yes Yes 11  
Anti-U Yes Yes <0.001 U- cells need to be ordered from the frozen bank in Liverpool. Patients with anti-U are also S-s- and can form both these antibodies. Known U- people are encouraged to donate.
Anti-P1 No Rare 22 The P1 antigen is described in many instances throughout nature.
Anti-Lea Rare No 77 Frequently naturally occurring. Can be stimulated by pregnancy and disappears postnatally.
Anti-Leb No No 26  
Anti-Jka Yes Yes 23 These may not be detectable in subsequent samples but the antibody may still cause haemolytic transfusion reactions - accurate transfusion records are essential in these patients. Involved in urea membrane transport.
Anti-Jkb Yes Yes 24
Anti-Fya Yes Yes 35 Fy(a-b-) red cells are resistant to invasion by the malarial parasites Plasmodium vivax and knowlesi.
Anti-Fyb Yes Yes 19
HTLA Ab's No No Low Antibodies of the HTLA type include:-  Knops (Kna/Knb), McCoy (McCa), York (Yka), Chido (Cha), Rogers (Rga), Cost (Csa/Csb) and JMH (John Milton Hagen).