Thrombopoietin receptor agonists increase splenic regulatory T-cell numbers in immune thrombocytopenia

Br J Haematol. 2022 Sep;198(5):916-922. doi: 10.1111/bjh.18309. Epub 2022 Jun 14.

Abstract

Thrombopoietin receptor agonists (TPO-RA) are a valid therapy for immune thrombocytopenia (ITP), due to megakaryocyte stimulation and (poorly characterised) immune-modulatory effects. The spleen is pivotal in the pathogenesis of ITP, yet little is known on its immune microenvironment and on effects of TPO-RA on this organ. To address these topics, we analysed 35 spleens removed for primary refractory ITP. Pre-splenectomy TPO-RA administration correlated with increased splenic regulatory T cells (Tregs), type 2 T-helper cells and histiocyte density and with reduced red pulp sinusoids. Surgical outcome was not associated with TPO-RA administration, other pre-splenectomy therapies and/or Treg density. In conclusion, TPO-RA affect the splenic microenvironment, but this has no impact on splenectomy outcome.

Keywords: TPO receptor agonist; immune microenvironment; immune thrombocytopenia; splenectomy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Purpura, Thrombocytopenic, Idiopathic* / etiology
  • Receptors, Fc
  • Receptors, Thrombopoietin / agonists
  • Recombinant Fusion Proteins
  • Spleen / pathology
  • T-Lymphocytes, Regulatory / pathology
  • Thrombocytopenia* / complications
  • Thrombopoietin / pharmacology
  • Thrombopoietin / therapeutic use

Substances

  • Receptors, Fc
  • Receptors, Thrombopoietin
  • Recombinant Fusion Proteins
  • Thrombopoietin