USMLE (Fach) / Kaplan - Pathology (Lektion)
Immune-mediated attack (usually IgG antiplatelet antibodies) against platelets leading to decreased platelets (thrombocytopenia) which result in petechiae, purpura (bruises), and a bleeding diathesis (eg, hematomas).
- Antiplatelet antibodies against platelet antigens such as GpIIb-IIIa and GpIb-X (type II hypersensitivity reaction)
- Antibodies are made in the spleen and the platelets are destroyed peripherally in the spleen by macrophages, which have Fc receptors that bind IgG-coated platelets.
Acute ITP: Seen in children following a viral infection and is self-limiting
Chronic ITP: Usually seen in women in their childbearing years and may be the first manifestation of SLE.
- Decreased platelet count, prolonged bleeding time
- Normal prothrombin time and partial thromboplastin time
- Peripheral blood smear: thrombocytopenia with enlarged immature platelets (megathrombocytes)
Treatment: Corticosteroids, splenectomy
Diese Karteikarte wurde von estoffel erstellt.