Immune Thrombocytopenic Purpura (ITP)

Immune thrombocytopenic purpura can be idiopathic, triggered by medications, or associated with other disorders, such as systemic lupus erythematosus, chronic lymphocytic leukemia, lymphoma, HIV, hepatitis C, or Helicobacter pylori infection.

May be 1° (idiopathic) or 2° to autoimmune disorder, viral illness, malignancy, or drug reaction

1. Drug-induced: commonly linked to heparin and certain antibiotics, but any new drug, supplement, or herbal remedy could be causative
2. Disease associated: HIV, hep C, hyper-/hypothyroidism, SLE, and lymphoproliferative malignancy (CLL, HL, NHL)
3. Idiopathic

anti-GpIIb/IIIa antibodies --> splenic macrophage consumption of platelet-antibody complex

Adult-onset ITP is characterized by an isolated decrease in platelet count due to autoantibody destruction of platelets

Normal-sized spleen

Peripheral blood smear is normal in contrast to HUS-TTP or DIC, which show microangiopathic hemolysis (schistocytes)

Anemia and Renal failure are not as common as in HUS

Dx

CBC and film (to rule out TTP-HUS)

increased megakaryocytes on bone marrow biopsy

Screen for HIV and hepatitis C (if risk factors are present)

Tx

Read this article. http://www.bloodadvances.org/content/1/24/2295?sso-checked=true

1. No bleeding, count >30 = No treatment
2. Mild bleeding, count <30 = glucocorticoids (e.g. Prednisone)