See also Biological structure and function and Immunology.
International standards and resources
The International Society for Blood Transfusion defines the terminology associated with human blood groups(Opens in a new tab/window).
Australian conventions and resources
The Australian Red Cross Blood Service(Opens in a new tab/window) and the National Blood Authority(Opens in a new tab/window) both provide information about blood groups and other blood-related terminology.
Blood groups
The 2 major blood group (also called blood type) classifications are the ABO system and the rhesus system. Use capitals for the ABO system:
A B AB O
Use lower case for the term group (or type):
His blood was group B.
The rhesus system consists of 50 defined blood-group antigens, among which the 5 antigens D, C, c, E and e are the most important. The commonly used terms Rh factor, Rh positive and Rh negative refer to the D antigen (which is the most immunogenic of the 5 Rh antigens). Use the following notation to denote the presence or absence of the D antigen:
Rh(D) positive Rh(D) negative [no space between Rh and (D)]
Rhesus disease (hemolytic disease of the newborn) occurs if an RhD-negative woman carries an RhD-positive baby.
Treatment is with anti-RhD immunoglobulin (referred to in Australia as ‘anti-D’).
Blood products
Use capital roman numerals to denote clotting factors and a lower-case initial f for factor:
factor VII factor XI
Use lower case for other blood products:
antithrombin III fibrogammin protein C prothrombin complex
See also Immunology.