Contemporary management of essential thrombocythemia in children

ABSTRACT

Introduction: Essential thrombocythemia (ET) is a disease which is extremely rare in children. Only recently, data on pediatric ET have become available.

Areas covered: In children with sustained platelet count over 450 x 10⁹/L, secondary thrombocytosis must be ruled out. ET workup comprehends research of JAK2V617F, CALR and MPL mutations and bone marrow biopsy (BM).

In asymptomatic children wait and watch is the best option. Aspirin controls headache and other microvascular disturbances. Patients with venous thrombosis need anticoagulation. Cytoreductive drugs in children with ET should be prescribed as a last choice. Hydroxyurea and IFN-a are first-line therapy at any age including children; Anagrelide is not licensed as first-line therapy for ET in Europe. New JAK2-inhibitors are not clearly useful in ET and hence not approved for ET.

Expert opinion: The most challenging problem is to understand if a child with prolonged not secondary thrombocytosis really has ET. Diagnostic workup requires molecular and histological studies. The rare children with clonal ET have features like those of adults. Patients with ET have long expected survival and the treatment in children must be long-term efficacious and well tolerated.

KEYWORDS:

• Pediatric essential thrombocythemia
• myeloproliferative disorders
• thrombocytosis
• pediatric thrombocythemia

Article highlights

• A child with prolonged and apparently not secondary thrombocytosis really may have an ET

• Children with clonal ET rarely have thrombotic and hemorrhagic events and can be considered as low-risk patients.

• The diagnostic WHO criteria for ET can be used in children as in adults

• In asymptomatic children wait and watch is the best managing option.

• Cytoreductive drugs in children with ET should be prescribed as a last choice.

• There are insufficient data to recommend a specific agent in children, and the choice should be individually tailored.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded