PO24 - Inmune thrombocytopenia after bone marrow transplantation: Experience and management in a Spanish center

Background: Immune thrombocytopenia is a hematological disorder characterized by severe decrease in peripheral platelet count. After hematopoietic stem cell transplantation, thrombocytopenia is a frequent finding, with diverse origin. The most frequent cause is poor engraftment, however, the immune origin is not negligible, so an etiological diagnosis and therapeutic intervention are necessary.

Aims: There is no standardized treatment. In recent years, thrombopoietin receptor analogues (TRO-RA) have shown promising results, but their indication in this area is not established.

Methods: We present the case of three patients diagnosed with immune thrombocytopenia after bone marrow transplantation, who required treatment with second-line drugs

Results: Three patients were included, with a median age of 54 (46-64) years, two of them female. Two underwent autologous hematopoietic progenitor transplantation and one allogeneic transplantation. Debut occurred at a median of 67 days (32-613) after transplantation, with platelet count less than 10 x10^9/L. Only one had a recent history of respiratory infection. Two patients presented cutaneous and mucosal bleeding. None of the patients responded to first line treatment, one of them was corticodependent. As second line they started TPO-RA, two of them reached complete response. The third patient received treatment with Romiplostim, Eltrombopag and azathioprine, in addition to a third line with Fostamatinib with no response, and subsequent spontaneous remission. All three patients remain in complete response one year later, none of them has presented during the treatment any thrombotic complication.

Conclusion(s): Immune thrombocytopenia after bone marrow transplantation is a rare complication that increases morbidity and mortality.
There are patients with refractoriness to first-line treatment, in whom the use of ORT-AR could be useful and safe. More studies are needed to support its efficacy.
As in primary ITP, in some cases there are spontaneous remissions.