Group I discrepancies are classified as ones where reaction patterns in reverse typing are affected by either missing or weakened naturally occurring ABO antibodies.
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.|