Guidelines for the investigation and management of idiopathic thrombocytopenic purpura in adults, children and in pregnancy.

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by persistent thrombocytopenia (peripheral blood platelet count < 150 · 10 ⁄ l) due to autoantibody binding to platelet antigen(s) causing their premature destruction by the reticuloendothelial system, and in particular the spleen (Woods et al, 1984a,b). Although the basic underlying pathophysiology of ITP has been known for 50 years (Harrington et al, 1951), the literature shows that the investigation and management of patients with thrombocytopenia vary widely, and is not evidence-based, due to a lack of clinical trials and quality research. Despite major advances in our understanding of the molecular basis of many blood disorders, the diagnosis of ITP remains one of exclusion; there are currently no robust clinical or laboratory parameters that are able to establish the diagnosis of ITP with accuracy. This guideline aims to assess available diagnostic tests and therapies, and attempts to provide a rational approach to the diagnosis and treatment in adults, children and in pregnancy. Although natural history data are becoming available (Cohen et al, 2000; Djulbegovic & Cohen, 2001; Portielje et al, 2001), there are few randomized trials in ITP and many of the recommendations, like those of the American Society of Hematology (ASH) Panel (George et al, 1996), are based on expert opinion.