Diagnosis and classification of immune-mediated thrombocytopenia.

Immune thrombocytopenia, or ITP, has been recognized as a clinical entity for centuries, and the importance of humoral mechanisms in the pathophysiology of ITP has been recognized for decades. Despite the long history of the syndrome, progress in understanding its epidemiology and management has been hindered by inconsistencies in nomenclature and classification schema together with the inherent heterogeneity in characteristics of global populations and ITP-associated disorders. In the past decade, great strides have been made in devising a common language for caregivers and investigators alike through standardization definitions and outcome measures, while new tools have become available for management of its clinical manifestations. In 2009, an International Working Group presented proposed standards for definitions, classification criteria, and outcome measures. The American Society of Hematology adopted these standards in 2011, including them in that body's guideline for immune thrombocytopenia. Despite the progress made so far, 20th century interventions such as corticosteroids and IVIg remain the mainstay of therapy. However, advances in treatment have led to the introduction of targeted therapies for select patients with chronic disease. In this paper, we review aspects of the epidemiology and pathophysiology of ITP and discuss the recent changes in guidelines for nomenclature, diagnosis, and treatment.