Page 199 - 2021_05-Haematologica-web

ITP associated with MDS and CMML
patients with a platelet count <70 x 109/L in this study, 15% (n=9) had a reduced platelet lifespan, and six were treated with splenectomy, allowing a platelet response in three patients.16 In another series, 3.3% (n=46) of 1,408 MDS patients developed ITP.4 Among 2,882 French ITP patients, 2.3% (n=67) had MDS, suggesting a role for MDS in the peak incidence of ITP in the elderly.17 In anoth- er French series of 565 ITP patients, 1.4% (n=8) had CMML.7 Among 62 MDS patients, Braun et al. reported that an isolated 20q deletion, which is associated with a good prognosis, was associated with a lower platelet count than that among MDS patients without a 20q dele- tion.18
The main difficulty in the setting of MDS/CMML is to distinguish immune-related peripheral thrombocytopenia from that of central origin (i.e., due to bone marrow fail- ure). Arguments for the peripheral immune origin of thrombocytopenia in MDS could be supported by the existence of common immune-mediated pathophysiolog- ical mechanisms, in particular humoral and cellular immune activation directed against both peripheral blood cells and bone marrow precursors, or impaired megakary- opoiesis attributed to autoantibodies cross-reacting against platelet glycoproteins or cytokine dysregulation.19- 22 Barcellini et al. hypothesized a shift from autoimmunity against circulating blood cells to bone marrow precursors,
Figure 2. Response rates to second-line treatment in patients with myelodysplastic syndrome/chronic myelomonocytic leukemia and primary immune thrombo- cytopenia. ITP: immune thrombocytopenia; MDS: myelodysplastic syndrome; CMML: chronic myelomonocytic leukemia; TPO-RA: thrombopoietin receptor agonist; CR: complete response; PR: partial response; NR: no response; ITP: immune thrombocytopenia; MDS: myelodysplastic syndrome.
AB
Figure 3. Overall survival (A) and leukemia-free survival (B) of patients with myelodysplastic syndrome/chronic myelomonocytic leukemia (MDS/CMML)-associated immune thrombocytopenia (ITP), MDS/CMML without ITP and primary ITP. ITP: immune thrombocytopenia; MDS: myelodysplastic syndrome; CMML: chronic myelomonocytic leukemia.
haematologica | 2021; 106(5)
1419