Adults immune thrombocytopenic purpura has an evolution which is generally chronic defined by the persistence of the thrombocytopenia 6 months after the diagnosis. The treatment is then based on the splenectomy which is proposed by the majority of the teams when the platelets are lower than 30x109/L. The splenectomy is effective at 70 to 80 % of the patients whereas no medicamentous treatment makes it possible to obtain a comparable result. Nevertheless, it exposes to immediate post-operative complications and to a risk of mortal fulminant infections by encapsulated germs, in particular the pneumococcus. However, its long-term effectiveness is discussed with a risk of relapse which would reach 50 % for certain teams.