Facts about the S and s antigens and antibodies:
- Part of the MNS system.
- S and s antigens are located on the red blood cell surface glycoprotein, glycophorin B.
- Antigens are also expressed in the kidney and epithelium.
- S and s antibodies are capable of causing mild to moderate transfusion reactions as well as HDN.
- Anti-S can be demonstrated at Room Temperature, as well as IAT.
- U is a high prevalence antigen found in the MNS system.
- S-s-U- phenotype is found in blacks. Lack of the U antigen is due to a deletion of the coding region of the GYPB gene.
- U is not destroyed by enzyme treatment.
- Anti-U has been associated with HTR's and HDFN.
- Anti-U is resistant to enzyme treatment.
Table 6. S and s Facts.| Ag/Ab | Ag Frequency (White) | Ag Frequency (Black) | Dosage? | Enzyme Interaction | Antibody Class | Compliment Binding | Clinically Significant |
| S | 55% | 31% | Yes | Destroyed by | IgG | No | Yes |
| s | 89% | 93% | Yes | Destroyed by | IgG | No | Yes |
