Thrombocytopenia from increased destruction of platelets

Thrombocytopenia from increased destruction of platelets is divided according to the cause into:
 * Megakaryocytic forms with a normal/increased number of megakaryocytes in the bone marrow ,
 * Immune thrombocytopenia – excessive breakdown of platelets in the monocyte-macrophage system,
 * Other causes: large intravascular consumption in the coagulation process, losses from the organism, Thrombocytopenia from increased sequestration (redistribution of platelets outside the circulating blood - e.g. in the spleen ).

Consumption thrombocytopenia

 * Consumption of platelets in the process of intravascular microthrombotization,
 * Most often with DIC ; further with TTP and HUS.

Allergic thrombocytopenic purpura

 * Similar to the acute form of ITP,
 * Remedies (quinidine, sulfonamides ), food components → circulating immunocomplexes.

Post-transfusion thrombocytopenia

 * By the action of immunocomplexes, which are created by immunization with components of blood products (mainly plasma proteins, leukocyte antigens ) with an affinity for platelets,
 * About a week after the blood transfusion,
 * Even as a result of incompatibility in platelet antigens.

Neonatal thrombocytopenia

 * Similar to neonatal hemolytic anemia ,
 * Action of antibodies against fetal platelet antigens.

Heparin-induced thrombocytopenia (HIT)

 * About 3% of patients,
 * Type I – occurs within 2 days after administration, caused by direct reaction of heparin with platelets, leads to mild thrombocytopenia, which resolves within 4 days after discontinuation of heparin,
 * Type II - occurs within 5-14 days of administration, caused by the formation of anti-platelet factor 4 antibodies that bind to and activate platelets in a complex with heparin, which can lead to thromboembolic complications in up to a third of patients with type II HIT.

Thrombocytopenia from increased losses

 * Sometimes in the case of major bleeding, polytrauma, complicated surgical procedures, which are covered by transfers of stored blood,
 * Also during operations using extracorporeal circulation.

Related articles

 * Thrombocytopenia
 * Thrombocytopenia of the newborn
 * Hematological examination
 * Pre-transfusion examination
 * Examination of blood coagulation
 * Purpura