Episode 15  

Host David Henry, MD, welcomes David J. Kuter, MD, of Harvard and Massachusetts General Hospital to talk about idiopathic thrombocytopenic purpura. He answers questions like: what are the causes? When do you treat?

In Clinical Correlation this week, Ilana Yurkiewicz, MD, explores pregnant patients. 

 

Show notes

By Hitomi Hosoya, MD, PhD, resident in the department of internal medicine, Pennsylvania Hospital of the University of Pennsylvania Health System, Philadelphia

 

Causes of idiopathic thrombocytopenic purpura :

• Secondary causes include chronic lymphocytic leukemia, lymphoma, and autoimmune conditions and account for 30%-50% of ITP.
• Idiopathic ITP is associated with pregnancy, post-viral infection, and vaccination and accounts for 50%-75% of ITP.

 

Pathophysiology:

• Antibodies attach to platelets, which are cleared by the liver or spleen (increased consumption).
• T cells or B cells attack bone marrow (reduced production).

 

When to treat:

• Major bleeding.
• Platelet count less than 20 x 109/L.

 

Initial treatment:

• Corticosteroids (dexamethasone or prednisone). These drugs should not be used for more than 6 weeks.
• Intravenous immunoglobulin is appropriate with major bleeding or when a patient requires immediate surgery.

 

Subsequent treatment:

• Platelet count less than 20 x 109/L during steroid taper.
• Rituximab (50%-70% response rate).
• Thrombopoietin receptor agonist (90% response rate); eltrombopag (oral) or romiplostim (subcutaneous).