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Chapter 131 Diseases of Platelet Number 1947

A B

C D
Fig. 131.1 BLOOD FILM EXAMINATIONS FROM PATIENTS WITH THROMBOCYTOPENIA.
(A) Pseudothrombocytopenia showing marked platelet clumping. (B) Schistocytes (fragmented red blood cells)
and reticulocytosis in a patient with thrombotic thrombocytopenic purpura. (C) Macrothrombocyte (left panel)
and neutrophil-containing cytoplasmic inclusions (Döhle bodies, right panel) in a patient with May-Hegglin
anomaly. (D) A patient with immune thrombocytopenia with low platelets and postsplenectomy Howell-Jolly
bodies (arrows).

lines such as anemia, leukopenia, or macrocytosis. Most patients with
typical ITP do not require BM examination. Quantitative Ig levels
may be useful in children to exclude common variable immune
deficiency and thyroid testing can uncover subclinical hypothyroid-
ism if surgery is planned.

First-Line Therapy

Corticosteroids with or without IVIg are first-line treatments for
patients with newly diagnosed ITP. Second-line therapies include
rituximab, splenectomy, TPO receptor agonists, or immunosuppres-
sant medications. ASH guidelines for the management of ITP were
developed using GRADE methodology to assess the level of evidence
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associated with each recommendation. Aligned with these guidelines,
the authors recommend a treatment approach starting with those that Fig. 131.2 STAIRCASE MODEL OF IMMUNE THROMBOCYTOPE-
are least toxic (Fig. 131.2). NIA TREATMENT. Therapies build on each other, often cumulatively, in a
stepwise fashion starting from the least toxic. After a period of observation,
corticosteroid-based treatment is the accepted first-line therapy. Splenectomy,
Observation rituximab, and thrombopoietin receptor agonists may be reasonable second-
line therapies. Rituximab is not currently licensed for immune thrombocy-
One of the ASH 2014 Choosing Wisely recommendations is that topenia. Thrombopoietin (TPO) receptor agonists are indicated for immune
patients with ITP should not be treated unless they are bleeding or thrombocytopenia (IVIg) patients who have failed to respond to other thera-
8
have very low platelet counts. Most patients with platelet counts pies, including splenectomy. (Modified with permission from Arnold DM, Kelton
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above 30 x 10 /L and no bleeding can be managed safely with JG: Current options for the treatment of idiopathic thrombocytopenic purpura. Semin
observation alone. This is especially true for children with ITP who Hematol 44:S12, 2007.)
are at low risk of serious bleeding. Furthermore, in up to 80% of
cases, childhood ITP resolves within 6 months with no treatment. If