Clinical Pearls & Morning Reports
Immune thrombocytopenia (ITP) is defined as a platelet count below 100,000 per cubic millimeter in patients in whom other causes of thrombocytopenia have been ruled out. Read the Clinical Practice article here.
Q: Is ITP a chronic disease?
A: ITP may be a primary condition or it may be caused by other diseases. Although some patients have one episode of ITP followed by an immediate remission, chronic ITP develops in up to 70% of adults with this condition. Both spontaneous and treatment-induced remission can occur many years after diagnosis.
Q: How common is severe bleeding in patients with ITP?
A: Although only 5% of patients with ITP present with severe bleeding, bleeding leading to hospital admission within 5 years after diagnosis develops in approximately 15%. Irrespective of bleeding problems, patients with ITP often report fatigue and impaired health-related quality of life. The risk of venous thromboembolism is twice as high among patients with ITP as among persons in the general population; the management of venous thromboembolism may be especially problematic given the concomitant risk of bleeding.
A: Glucocorticoid treatment is the standard initial therapy for patients with ITP. Although 60 to 80% of patients with ITP have an initial response to glucocorticoids, only 30 to 50% of adults have a sustained response after glucocorticoids are discontinued. In some studies, continued use has been associated with a higher incidence of long-term remission, but prolonged exposure to glucocorticoids is not recommended because of adverse effects. Medical therapies for patients with ITP who do not have an initial response to glucocorticoids or who have recurrent decreases in platelet counts after glucocorticoids are discontinued include thrombopoietin-receptor agonists and immunomodulators. In the absence of randomized trials directly comparing these therapies or of biomarkers to guide the choice of medication, treatment decisions are based on other factors, including the availability of medications, adverse effects, the required speed of response, and patient or physician preference. Among the available options, thrombopoietin-receptor agonists, rituximab, and fostamatinib have undergone the most rigorous study. Other immunomodulatory agents such as mycophenolate mofetil, azathioprine, dapsone, and danazol are also used in patients with ITP. Data to support their use are largely limited to retrospective observational studies that suggest that 30 to 60% of patients have a response.
A: A systematic review showed that splenectomy, which remains the most effective therapy for ITP, induced long-lasting remissions in 60 to 70% of patients. Nevertheless, owing to the emergence of effective medical therapies, the potential complications of splenectomy, and the inability to predict which patients will have a response, consideration of splenectomy is usually limited to patients who do not have a response to or cannot receive standard medical therapies because of side effects and in whom at least a year has passed since diagnosis (to allow for remission to occur). The frequency of splenectomy has decreased substantially during the past two decades.