HLA-B21 (B21) is an
HLA -
B serotype
A serotype or serovar is a distinct variation within a species of bacteria or virus or among immune cells of different individuals. These microorganisms, viruses, or cells are classified together based on their surface antigens, allowing the epi ...
. B21 is a broad antigen serotype that recognizes the
B49 and
B50 split antigen serotypes.
References
{{HLA-B serotypes
2