Mechanism 2. iver and spleen: (1)1/3 platelets are held within the spleen (2) spleen produces platelet associated Ab (3) liver and spleen erase platelet 7-11 days in normal persons, 1-3 days in patientsMechanism 2.liver and spleen: (1)1/3 platelets are held within the spleen (2)spleen produces platelet associated Ab (3)liver and spleen erase platelet:7-11 days in normal persons, 1-3 days in patients