The primary objective of the study is the evaluation of sustained response rate after discontinuation of treatment with TPO-RAs, Eltrombopag and Romiplostim, in persistent or chronic pITP patients who failed one or more therapy lines, splenectomy included.

Increasing evidence exists in the literature on the persistent response after TPO-RAs discontinuation. However, the available data consist of description of case reports from different patients' series. At this time, systematic data collections on this topic do not exist and the real incidence of such persistent response is unknown. Therefore, because of the increasing interest in this new and challenging therapeutic field, also for the therapeutic implications, we would like to investigate the impact of TPO- RAs on the achievement of sustained and persistent responses after their discontinuation in the Italian adult patients affected by pITP who have been referred to the GIMEMA Centers.

Inclusion Criteria:

• Signed written informed consent according to ICH/EU/GCP and national local laws;
• Persistent or chronic pITP adult patients who have been treated with TPO-RAs therapy after failure of one or more therapy lines, splenectomy included;
• Age > 18 years.

Exclusion Criteria:

• Active malignancy;
• Active malignancy;
• HCVAb, HIVAb, HBsAg, HBcAb seropositive status;
• Chronic liver disease;
• Treatment with Rituximab less than 8 weeks before TPO-RAs start;
• Recent splenectomy (less than 8 weeks) before TPO-RAs start. Active malignancy;
• HCVAb, HIVAb, HBsAg, HBcAb seropositive status;
• Chronic liver disease;
• Treatment with Rituximab less than 8 weeks before TPO-RAs start;
• Recent splenectomy (less than 8 weeks) before TPO-RAs start. HCVAb, HIVAb, HBsAg, HBcAb seropositive status;
• Chronic liver disease;
• Treatment with Rituximab less than 8 weeks before TPO-RAs start;
• Recent splenectomy (less than 8 weeks) before TPO-RAs start.

Patients affected by primary immune thrombocytopenia (pITP)