Cytopenias and Qualitative Defects in Blood Cell Function

Cytopenias

Patients with myelodysplastic syndromes (MDS) experience significant cytopenias, which are typically progressive and may result in1-4:

  • Anemia
    • Hemoglobin <10 g/dL2
    • The most common cytopenia, affecting approximately 90% of patients at the time of MDS diagnosis3
  • Neutropenia
    • Absolute neutrophil count <1.8 x 109/L of blood2
    • Observed in approximately 50% of patients4
  • Thrombocytopenia
    • Platelet count <100 x 109/L2
    • Occurs in approximately 40% of patients1

The most common signs and symptoms of MDS are related to cytopenias.5

Qualitative defects

Blood counts may be reduced, and blood cells in patients with MDS may also be abnormal in terms of function.4,6-8

Bone marrow cells of a patient with refractory cytopenia

Patient had multilineage dysplasia, and erythroid precursors with nuclear irregularity and myeloid precursors with hypogranulation and hyposegmentation.6

Blood cell characteristics in MDS

Red Blood Cells In the bone marrow, immature erythroblasts accumulate due to differentiation arrest and apoptosis.7
Neutrophils Neutropenia (spontaneous or transiently worsened by treatment) likely represents the major reason for increased risk of infection in MDS. However, qualitative neutrophil defects may also contribute to the risk of infection.4

  • Functional neutrophil defects may include decreased bactericidal and fungicidal activities, as well as other changes, such as morphological abnormalities, reduced phagocytosis and production of oxygen intermediates, or impaired gene expression
Platelets Platelet function may be impacted in terms of impaired or absent aggregation when the platelets are stimulated with epinephrine, arachidonic acid, ADP, collagen, and ristocetin.8

  • An abnormal bleeding time, even with normal platelet counts, was found in a small cohort of 21 MDS patients; up to 81% of patients had impaired platelet aggregation in response to one or more stimulants

ADP, adenosine diphosphate.

References: 1. Greenberg PL, Tuechler H, Schanz J, et al. Revised International Prognostic Scoring System for myelodysplastic syndromes. Blood. 2012;120(12):2454-2465. 2. Arber DA, Orazi A, Hasserjian R, et al. The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia. Blood. 2016;127(20):2391-2405. 3. Zeidan AM, Shallis RM, Wang R, et al. Epidemiology of myelodysplastic syndromes: why characterizing the beast is a prerequisite to taming it. Blood Rev. 2019;34:1-15. 4. Toma A, Fenaux P, Dreyfus F, Cordonnier C. Infections in myelodysplastic syndromes. Haematologica. 2012;97(10):1459‐1470. 5. Steensma DP. Myelodysplastic syndrome: diagnosis and treatment. Mayo Clin Proc. 2015;90(7):969-983. 6. Gupta G, Singh R, Kotasthane DS, Kotasthane VD. Myelodysplastic syndromes/neoplasms: recent classification system based on World Health Organization Classification of Tumors — International Agency for Research on Cancer for Hematopoietic and Lymphoid Tissues. Journal of Blood Medicine 2010:1 171-182 and Dove Medical Press Ltd. 7. Lefèvre C, Bondu S, Le Goff S, et al. Dyserythropoiesis of myelodysplastic syndromes. Curr Opin Hematol. 2017;24(3):191-197. 8. Li W, Morrone K, Kambhampati S, et al. Thrombocytopenia in MDS: epidemiology, mechanisms, clinical consequences and novel therapeutic strategies. Leukemia. 2016;30(3):536-544.