Essential Thrombocythemia in children and adolescents

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Essential Thrombocythemia inchildren and
adolescents

• Y. Haskel, R. Elhasid, E. Shabad, A. Ballin

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Background

• E. T. is an uncommon myeloproliferative disorder,
  characterized, mainly, by increased number of
  platelets and tendency to clot formation and / or
  bleeding.
• E. T. may terminate in AML or pure red cell
  aplasia.
• Thromboembolic complications may be fatal.
• E. T. is rare in children and adolescents.
• High / low (?) risk of thrombosis in young
  adults.

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Background (contin.)

• The clinical picture of pediatric E. T.
• - asymptomatic (lower PLT)
• - headache, bleeding, Thrombotic events.
• - Physical exam splenomegaly, hepatomegaly
• - Familial thrombocythemia - lower PLT counts, no
  thrombotic events and no malignancies (auto-dom).
• -

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Background (contin.)

• Thrombopoietin level - normal (increased
  sensitivity in vitro ?).
• Cytogenetic studies - normal
• Treatment aspirin, Hydrea, Anagrelide (!), IFN
  alfa
• 2/36 (6) patients developed AML (similar to
  adults).
• mortality - 11

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(No Transcript)
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The aim of the study

• To assess the incidence of E.T. in the pediatric
  population in Israel.
• To describe the clinical picture and the natural
  history of the disease in children and
  adolescents.

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Methods and patients

• Retrospective review of all charts of pediatric
  patients (to age 18 y) in Israel, diagnosed to
  suffer from E.T. between Jan. 1990 and Dec. 2001.
• E. T. - Platelet number gt600000/mL, normal RBC
  mass, no Philadelphia chromosome and absence of
  any etiology for secondary thrombocytosis.
• Demographic and clinical data were compared
  between the pediatric patients and randomly
  chosen adults with E. T.

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Results (I)

• Four children and adolescents were diagnosed to
  have E. T.
• Two boys and two girls
• Median age 11 y (7-15 y)
• The incidence of pediatric E. T. in Israel is
  approximately 1 500,000
• Median follow-up 5.5 years.
• No death / serious hematological sequel occurred.

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Results (II)

• Hematological data at presentation
• pediatric pts
  adult pts
• platelet, med. 1754 (1038-4500) 735
  (573-1249)
• MPV, median 8.7 (8.1-8.8) 9.9
  (8.6-10.1)
• Hgb, median 12.7 (12.4-15.7) 13
  (12.6-14.4)
• leukocytes 10600 (7200-14300) 9350 (7820-10840)
• normal aggregation of platelets
• collagen 4
  4
• adrenalin 0
  0
• ADP 1
  2

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Results (III)

• All pediatric E. T. patients were treated with
  aspirin and Hydrea or Agrylin.
• All pediatric patients are doing well.
• Two of them need no chemotherapy now.
• The adults patients with E. T. are dependent on
  the treatment. All suffer from side effects of
  Hydrea or Agrylin.

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Summary

• 1) E. T. is a rare disease in the pediatric
  population.
• 2) Unlike adult patients with E. T., children and
  adolescents have a mild course of the disease
  with no complications or any hematological
  disorder.
• 3) Further investigation is warranted to better
  characterize E. T. in children and adolescents.