Weakened or missing antibodies are most often associated with geriatric patients, neonates, and immunosuppressed individuals.
| Geriatric patients||By nature, the immune system weakens as we age; therefore, patients more advanced in age will naturally demonstrate weaker reactions in reverse typing. |
| Neonates|| Children are not born with a functioning immune system. It takes approximately 6 to 9 months for ABO antibodies to be detectable in vitro.|
| Immunosuppression|| Individuals on immunosuppressants or with immune compromising conditions can demonstrate weakened or missing reactions in the reverse type.|