Long-term survival is reduced in patients with chronic immune thrombocytopenia (ITP), according to a new population-based study published in the journal Transfusion. However, it seems to be improving compared to the past. The study also found that secondary ITP and comorbidities are associated with a poor prognosis.

To investigate long-term survival in patients with primary ITP as well as explore factors that affect prognosis and causes of death in patients with both primary and secondary ITP, a team of researchers from Denmark led by Henrik Frederiksen MD, PhD, of the Department of Hematology at Odense University Hospital analyzed data from the nationwide Danish health registries between 1980 and 2016.

Read more about the prognosis of ITP

The team identified 1762 patients with chronic primary ITP, 37 to 73 years of age, and 128 patients with chronic secondary ITP, 40 to 73 years of age.

The researchers calculated that the overall median survival of patients with primary ITP was reduced by 5.1 years while that of patients with secondary disease was reduced by 11.1 years compared to the general population.

However, the 5-year survival rate of patients with primary ITP increased from 69% in the 80s to 80% between 2010 and 2016. On the contrary, for patients with secondary ITP, 5-year overall survival decreased from 100% to 64% in the same period. The authors noted however that “numbers were small” for secondary ITP. 

The 5-year survival rate of patients with primary ITP with a high Charlson Comorbidity Index was 41% compared to 85% for those with a low Charlson Comorbidity Index (the Charlson Comorbidity Index predicts mortality for a patient who may have a range of comorbidities).

The common causes of death of patients with primary ITP included bleeding, infection, and hematological cancer while for patients with secondary ITP, the most frequent cause of death was hematological cancer.

“These novel data show that survival is reduced, but seems to be improving over the past decades for patients with chronic ITP,” the researchers concluded. “The increased risk of death from hematological malignancy, infection, and bleeding should direct clinical attention to recognize events and symptoms preceding or indicating these”. 

ITP is a rare bleeding disorder characterized by very low platelet counts. Primary ITP is defined as ITP that is idiopathic while secondary ITP is ITP associated with an underlying condition.

Reference

Mannering N, Hansen DL, Pottegård A, Frederiksen H. Survival in adult patients with chronic primary and secondary immune thrombocytopenia: a population-based study. Transfusion. Published online January 5, 2023. doi:10.1111/trf.17212