Distinct alterations of CD68+CD163+ M2-like macrophages and myeloid-derived suppressor cells in newly diagnosed primary immune thrombocytopenia with or without CR after high-dose dexamethasone treatment

J Transl Med. 2018 Mar 2;16(1):48. doi: 10.1186/s12967-018-1424-8.

Abstract

Background: Although impaired myeloid-derived suppressor cells (MDSCs) recently have been studied in immune thrombocytopenia (ITP), another myeloid-derived cell population signified as M2 macrophages has not been investigated properly in ITP patients. In the present study, we intended to determine the features of circulating M2-like macrophages, to examine its relationship with MDSCs, and to explore their prognostic values in ITP.

Methods: Peripheral blood mononuclear cells from healthy controls and primary ITP patients were isolated to test the circulating M2-like macrophages and MDSCs. The circulating M2-like macrophage population defined as CD68+CD163+ and circulating MDSC population as CD11b+CD33+HLA-DR- were determined by flow cytometry. Plasma inflammatory cytokines were measured by multiplex ELISA.

Results: The percentages of MDSCs were found to be expanded in newly diagnosed patients of ITP, especially among those of the complete response (CR) group (p < 0.0001). Positive linear correlation was verified between percentages of M2-like macrophages and MDSCs. The same correlation was also determined in the CR group. After treatment, the percentages of M2-like macrophages and MDSCs were both increased significantly in CR group, while those patients among the PR + NR group manifested a significant numeric decrease of MDSCs but only a moderate decrease in M2-like macrophages. MIP-1α/CCL3 was negatively correlated with M2-like macrophages while MCP-1 possessed a positive correlation with M2-like macrophages, eotaxin-1/CCL11 was negatively correlated with MDSCs and interleukin-1β (IL-1β) was found to be negatively correlated with both M2-like macrophages and MDSCs.

Conclusions: The present findings indicated critical roles of both circulating M2-like macrophages and MDSCs in ITP. The positive correlation between them might be related to inflammatory factors-mediated bidirectional interactions or partially due to their similar background patterns during differentiation. MIP-1α/CCL3, MCP-1, eotaxin-1/CCL11 and IL-1β might play a critical role in the expansion of both M2 macrophages and MDSCs population in ITP patients, which deserves further investigation.

Keywords: Dexamethasone; Immune thrombocytopenia; M2-like macrophages; MDSCs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antigens, CD / metabolism*
  • Antigens, Differentiation, Myelomonocytic / metabolism*
  • Cell Proliferation / drug effects
  • Cytokines / blood
  • Dexamethasone / pharmacology
  • Dexamethasone / therapeutic use*
  • Female
  • Humans
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Male
  • Middle Aged
  • Myeloid-Derived Suppressor Cells / metabolism*
  • Purpura, Thrombocytopenic, Idiopathic / blood
  • Purpura, Thrombocytopenic, Idiopathic / diagnosis*
  • Purpura, Thrombocytopenic, Idiopathic / drug therapy*
  • Purpura, Thrombocytopenic, Idiopathic / immunology
  • Receptors, Cell Surface / metabolism*
  • Treatment Outcome

Substances

  • Antigens, CD
  • Antigens, Differentiation, Myelomonocytic
  • CD163 antigen
  • CD68 antigen, human
  • Cytokines
  • Receptors, Cell Surface
  • Dexamethasone