THROMBOCYTOPENIA
PSEUDO-THROMBOCYTOPENIA:
Platelet clumping by EDTA-dependant Ig
Platelet satellitism
Giant platelets
TRUE THROMBOCYTOPENIA:
Acquired:
-Reduced synthesis:
Aplastic anaemia
Megaloblastic anaemia
Marrow infiltration
Myelodysplastic syndrome (except del 5q)
Liver disease
-Dilutional:
Massive blood transfusion
Gestational
-Pooling:
Splenic: Hypersplenism
Hepatic: Hypothermia
-Destruction:
Primary autoimmune thrombocytopenia (ITP)
Secondary autoimmune thrombocytopenia:
Infections; Pregnancy; Collagen vascular disease; Lymphoproliferative disease; Drugs e.g. Heparin
Alloimmune thrombocytopenia: Post-transfusion purpura; Passive alloantibodies
-Consumption:
Disseminated intravascular coagulation
Thrombotic thrombocytopenic purpura
Haemolytic-Uraemic syndrome
Pre-eclampsia
HELLP
Congenital:
-Inherited:
Reduced platelet size: Wiskott-Aldrich syndrome
Normal platelet size: Congenital deficiency of megakaryocytes
Increased platelet size: Bernaurd-Soulier Syndrome, May Hegglin anomaly, Grey platelet syndrome
-Non-inherited:
Drugs (Thiazide, Tolbutamide, Quinine)
Infection (TORCH)
Others (SLE, APS)