[Development of chronic myelogenous leukemia during treatment with TPO receptor agonist for ITP]

Improvement of immune thrombocytopenia with imatinib therapy following chronic myeloid leukemia

Immune thrombocytopenia (ITP) and chronic myeloid leukemia (CML) are rarely observed concurrently. Here we report the case of a patient with ITP who developed CML that has been well controlled with tyrosine kinase inhibitor (TKI) therapy. A 55-year-old man was diagnosed with ITP. No cytogenetic abnormalities were found at the time of initial diagnosis. Four years later, he began corticosteroid therapy for progression of thrombocytopenia. At that time, the Philadelphia (Ph) chromosome was observed in 7 of 20 bone marrow (BM) cells, suggesting concurrent CML in the subclinical stage. Prednisolone resulted in a partial response. Seven months after starting prednisolone, he exhibited hematological features of CML with an increase in Ph-positive cells. TKI therapy with imatinib mesylate was started to treat CML and maintained at a daily dose of 400 mg. The patient achieved and sustained a major molecular response. His platelet count also increased, enabling discontinuation of corticosteroid therapy. TKIs have been reported to show various immunological off-target effects. In this case, off-target effects of TKI might have improved ITP by suppressing the autoimmune response. Alternatively, reconstitution of immune systems by Ph-negative cells or cancellation of immunoreaction against CML could have exerted favorable effects on ITP.

Chronic Myeloid Leukemia in a Patient with Previous Idiopathic Thrombocytopenic Purpura: How to Manage Imatinib Together with Eltrombopag

The occurrence of chronic myeloid leukemia (CML), or other myeloproliferative diseases, after the development of idiopathic thrombocytopenic purpura (ITP) is very rare in the current medical literature. Considering the advances in ITP management, and the wide use of new drugs for ITP and CML, we report an unusual case with this association. Our case report focused on a 64-year-old man with long-standing ITP treated with eltrombopag, who developed hyperleukocytosis during follow-up; after specific laboratory exams, it was diagnosed as CML and he began treatment with imatinib. The treatment with eltrombopag was balanced with imatinib to stabilize his platelet count. Data on bcr-abl and JAK2 transcripts were collected and revealed an optimal response with the achievement of negativization of both molecular signatures. We could demonstrate that treatment with imatinib and eltrombopag was well tolerated and allowed complete molecular remission of CML to be achieved, as well as of ITP.