The course of severe autoimmune thrombocytopenia in patients not undergoing splenectomy

Splenectomy is the most effective treatment for patients with severe autoimmune thrombocytopenia (AITP) who do not have a spontaneous or drug- induced remission. However, this treatment has some short and long term risks. There is no consensus on the indications and optimal timing of splenectomy, since it is unknown up to which time from onset of symptoms a remission can be expected without splenectomy.

We studied the incidence of complete or partial remissions in a cohort of 114 adult patients (68 women, 46 men, median age 49.8 years, interquartile range 28.3-68.4) with severe AITP (platelet count < 20x10(9)/L at diagnosis) using Kaplan Meier analysis. Patients who underwent splenectomy during the observation period were censored at the time of splenectomy.

The probability of a complete remission was 61% and that of at least a partial remission was 86% at 5 years. The incidence of complete remission was highest within the first 6 months (30%), but increased up to 53% between 6 months and 3 years after diagnosis. The probability of a remission was not related to age, gender, or the presence or absence of platelet antibodies, but was higher in patients with an acute onset of symptoms in comparison to those with an insidious onset (p = 0.0003). The chance of a late remission was higher in patients with an insidious onset of disease.

These data indicate that splenectomy may be delayed for up to 3 years, in particular in those patients whose AITP has had an insidious onset.