Telomeres in Myelodysplastic Syndrome and Its Related Disorders: Does Telomere Length Reflect Stem Cell Turnover in Clonal Hematopoietic Disorders

摘要

Summary: Normal hematopoietic cells express telomerase activity, however the presence of telomerase does not necessarily imply stable and thus unchanging telomere length. Age-adjusted telomere length was lower in patients with both refractory anemia (a low grade subtype of myelodysplasric syndrome: MDS) and apiastic anemia. Telomere length may reflect both the cellular proliferative history and genomic instability in MDS, while telomere shortening in apiastic anemia might depend on the severity of stem celi pool contraction. Telomere length in limited number of patients with paroxysmal nocturnal hemoglobinuria (PNH) was highly variable. Gradual telomere loss with rapid cycling of hematopoietic stem cells might contribute to immunosenescence, exhausted hematopoiesis, and increased likelihood of malignant transformation. Therefore, detailed analysis of telomere dynamics in different cell population is needed to clarify the pathogenesis of MDS and related disorders.