Plasma thrombopoietin (TPO) levels and expression of TPO receptor on platelets in patients with myelodysplastic syndromes

H. Tamura, K. Ogata, S. Luo, K. Nakamura, N. Yokose, K. Dan, K. Tohyama, Y. Yoshida, H. Hamaguchi, H. Sakamaki, T. Kuwaki, T. Tahara, T. Kato, T. Nomura

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Data on endogenous thrombopoietin (TPO) levels and their regulation in myelodysplastic syndromes (MDS) are sparse. We examined the plasma TPO level of 85 MDS patients by a sensitive enzyme immunoassay and the platelet expression of TPO receptor (TPO-R) protein, which metabolizes endogenous TPO, in 19 MDS patients with an equilibrium binding assay using 125I-TPO. The MDS patients had higher plasma TPO levels (7.0 ± 9.3 fmol/ml) than 52 normal subjects (P<0.0001). Refractory anaemia (RA) patients (n = 39) had higher plasma TPO levels than patients (n = 28) with RA with excess blasts (RAEB) or RAEB in transformation (RAEB-t) (P = 0.0002), irrespective of similar platelet counts in these groups. The plasma TPO level correlated inversely with the platelet count in RA patients (P = 0.0027) but not in RAEB and RAEB- t patients (P = 0.7865). These data suggest that the physiological pathway for TPO production and metabolism is conserved, at least partially, in RA, but deranged in RAEB/RAEB-t. The number of TPO-R per platelet was significantly smaller in 19 MDS patients (17.5 ± 13.3) than in normals (P = 0.0014), but similar between RA patients and patients with RAEB and RAEB-t. Further, the bone marrow megakaryocyte count, determined in 31 MDS patients, was quite similar between RA patients and patients with RAEB or RAEB-t. Thus, in addition to thrombocytopenia, a reduced platelet TPO-R number may contribute to elevated plasma TPO levels in MDS, and a regulatory pathway for circulating TPO other than platelet TPO-R and marrow megakaryocytes, such as blasts expressing TPO-R, may operate in RAEB/RAEB-t.

Original languageEnglish
Pages (from-to)778-784
Number of pages7
JournalBritish Journal of Haematology
Volume103
Issue number3
DOIs
Publication statusPublished - 1998 Dec 10
Externally publishedYes

Keywords

  • Myelodysplastic syndromes
  • Thrombopoietin
  • Thrombopoietin receptor

ASJC Scopus subject areas

  • Hematology

Fingerprint Dive into the research topics of 'Plasma thrombopoietin (TPO) levels and expression of TPO receptor on platelets in patients with myelodysplastic syndromes'. Together they form a unique fingerprint.

  • Cite this

    Tamura, H., Ogata, K., Luo, S., Nakamura, K., Yokose, N., Dan, K., Tohyama, K., Yoshida, Y., Hamaguchi, H., Sakamaki, H., Kuwaki, T., Tahara, T., Kato, T., & Nomura, T. (1998). Plasma thrombopoietin (TPO) levels and expression of TPO receptor on platelets in patients with myelodysplastic syndromes. British Journal of Haematology, 103(3), 778-784. https://doi.org/10.1046/j.1365-2141.1998.01054.x