Persistent Elevated Bone Marrow Plasma Levels of Thrombopoietin in Patients with Aplastic Anemia

Acquired aplastic anemia (AA) is an immune-mediated bone marrow (BM) failure syndrome. Plasma thrombopoietin (TPO) levels are elevated in AA patients with reduced blood counts. However, whether elevated TPO can recover to normal level in AA patients in complete remission (CR) after efficient immunosuppressive therapy (IST) is unknown. We measured TPO levels of BM plasma in a large cohort of AA patients with focusing on patients in CR after IST. Our data showed that BM plasma TPO levels were still high in patients who had reached normal blood counts levels for a long time. We speculate that downregulated expression of MPL (TPO receptor) in HSPC (hematopoietic stem and progenitor cells) may be related to the upregulated TPO in AA.