Antibody post-immunization

The antibody responsiveness to these two antigens is measured 4-5 days post-immunization by counting the number of PFC per spleen using SE coated with the corresponding antigen. No significant inter-line difference appears on Figure 5.20A in the PFC response for the doses of 1-3 fdg of levan. The... 

This scenario can be prevented by administration of anti-Rh (usually anti-D) antibodies to Rh-negative mothers immediately upon the birth of a Rh-positive baby. The administered antibodies bind the fetal Rh-positive erythrocytes, marking them for destruction before a maternal immunological reaction is triggered. Usually a dose of 200-300/ig of antibody is administered immediately post-delivery. This would be sufficient to suppress an immune response for up to 10 ml of Rh-positive red blood cells. 

Hepatitis B immunoglobulin (pooled plasma selected for high titres of antibodies to the virus) provides passive immunity for post-exposure prophylaxis e.g. after accidental needlestick injury. 

Delayed reactions are difficult to prevent. Incompatibility may not be demonstrable before transfusion, and at the time of the reaction the relevant antibodies may not be detectable. Post-transfusion blood samples must therefore be subjected to repeated serological testing. Delayed reactions usually occur as a result of a secondary anamnestic response within 3-21 days after the transfusion of apparently compatible blood, at a time when the antibody concentration has risen sufficiently to bring about hemolysis of the donor s erythrocytes. A primary immune response can also evoke this kind of reaction (61). 

---