LABORATORY DIAGNOSIS OF ITP

Idiopathic thrombocytopenia (ITP) is disease characterized by decreased number of platelets due to immune destruction of platelets
Autoimmune antibodies against platelets are formed from previous viral infection (acute ITP) or from underlying dysregulation (chronic ITP)
Antigens against which antibodies are formed are present on surface of platelets like GP IIb-IIIa or GP Ib-IX
Laboratory diagnosis
- Isolated thrombocytopenia
- Normal or increased number of megakaryocytes on bone marrow examination
- Anti platelet antibodies detection
- Bleeding time prolonged
- Tests of coagulation are essentially normal
  - Prothrombin time (PT)- normal
  - Activated Partial Thromoplastin time (APTT) – normal