Table 1.
Representative erythrocyte antigens and key features.
| Protein family | Common antigen designations | Examples of high frequency epitopes | Function | Expression level | MW (kDa) | Other considerations |
|---|---|---|---|---|---|---|
| Glycophorins (MNS system) | ||||||
| Glycophorin A | M, N | En(a) | Structural membrane sialoglycoprotein | High (8e5/ cell) | 43 | Most commonly used histologic marker of erythroid lineage; major sialic acid containing structure |
| Glycophorin B | S, s, U | U, En(a) | Structural membrane sialoglycoprotein | Moderate (2e5/cell) | 25 | Significant sialic acid containing structure |
| Band 3 (Diego system) | Di, Wr, Rb | Wr(b) | Anion transporter, structural | Very high (>1e6/cell) | 95–105 | Majority of ABO antigens are attached to band 3; Deficiency can result in HS, HO, HE phenotypes |
| Rh family | ||||||
| RhCEce | C, c, E, e | Rh17 (Hr0), Rh29 | Ammonia transporter | Moderate | 30–32 | Involved in regulation of ammonium transport, high polymorphism |
| RhD | D | None | Ammonia transport; structural component | Low to moderate (1e5-2e5/cell) | 30–32 | Expressed by 85% of population, historically most important antigen in HDFN |
| RhAG | Duclos | Duclos, DSLK | Drives expression of other Rh family members | Low to moderate (1e5-2e5/cell) | 45–100 | Ancestral precursor to other Rh family members |
| GLUT1 | No significant antigen grouping | No significant polymorphism | Glucose transporter | Moderate (2e5-5e5/cell) | 45–65 | Mutations in GLUT1 associated with pathogenic phenotype including hemolytic anemia |
| Dombrock | Do(a), Do(b), Jo(a) Gy(a) | Jo(a), Gy(a), Hy | Mono-ADP-ribosyltransferase | Uncertain | 47–58 | Apparent lack of enzymatic function in RBCs, clinical significance of Do-null phenotype uncertain |
| Kell | K, k | k | Endothelin-3- converting zinc endopeptidase | Low (1e4/ cell) | 93 | Deficiency known as McLeod phenotype; expressed on other tissues including brain, lymphoid organs, muscle |
| CD59, DAF (Cromer system) | Cr, Tc, Dr, Es | Cr(a), Tc(a), Dr(a) | Complement regulation | Low (2e4/ cell) | 60–70 | Also expressed on leukocytes and platelets; low levels of soluble form in plasma |
Note that for simplicity several antigens systems are not included above. For more comprehensive discussion of red cell antigen families see Reid [194].
ABO: ABO blood group; HDFN: Hemolytic disease of the fetus and newborn; HE: Hereditary elliptocytosis; HO: Hereditary ovalocytosis; HS: Hereditary spherocytosis.