Pathophysiology and Management of Childhood Idiopathic Thrombocytopenic Purpura

• Published in: The Japanese Journal of Pediatric Hematology Vol. 16; no. 3; pp. 109 - 122
• Main Author: FUJISAWA, Kohji
• Format: Journal Article
• Language: Japanese
• Published: THE JAPANESE SOCIETY OF PEDIATRIC HEMATOLOGY/ONCOLOGY 2002; 特定非営利活動法人 日本小児血液・がん学会
• Subjects: ITP immune thrombocytopenia; platelet glycoprotein; TPO
• ISSN: 0913-8706; 1884-4723
• DOI: 10.11412/jjph1987.16.109

Idiopathic thrombocytopenic purpura (ITP) is a common hemorrhagic disorder characterized by isolated thrombocytopenia with no identifiable systemic disease. It is classified as either acute or chronic, depending on its duration. Although it is widely believed that the autoantibody-mediated platelet clearance through the phagocytic system contributes to thrombocytopenia, the lack of an unequivocal way to distinguish immune thrombocytopenia from other thrombocytopenia, even with platelet protein-specific autoantibody testing, makes it difficult to clearly discriminate clinical entities. Moreover, especially in chronic disease, the alteration of megakaryocyte maturation and subsequent platelet production is also evidenced, indicating a “mixed” pathophysiology of ITP. Therefore each therapeutic option besides splenectomy currently used in the management of ITP is limited in its efficacy because it may not always target an underlying specific mechanism responsible for platelet destruction and impaired production. Approximately 80% of those afflicted in childhood have an acute self-limited disease most have minimal bleeding and achieve a spontaneous recovery of platelet count. Even for the remaining 20% who become chronic, defined by persistent thrombocytopenia more than 6 months from the onset, high rates of complete or partial remission are also predicted. Because of a generally benign outcome in childhood ITP and a limited efficacy of treatment, which is no more than a temporary benefit, pharmacological intervention in newly diagnosed ITP with severe thrombocytopenia or in symptomatic chronic disease for the prophylaxis of major hemorrhage continues to be a subject of much controversy.