Home > D. Systemic pathology > Hematopathology > plasmacytoid monocytes

plasmacytoid monocytes

Tuesday 27 April 2004

Plasmacytoid monocytes (PMOs) could play an essential role in T-cell-dependent immune response.

Indeed, numerous PMOs are found in close topographical association with epithelioid cell granulomas in hypersensitivity-type granulomas, such as tuberculosis and sarcoidosis.

Plasmacytoid monocytes (PMOs) may play a role in monocytoid B-cells-associated granulomatous response and in hypersensitivity granulomatous response.

Plasmacytoid monocytes are immune cells originally identified by pathologists.

Plasmacytoid monocytes are now better identified and present characteristic points at three levels:
- 1) phenotypically, they display a peculiar phenotype lineage negative with expression of CD4 and CD68 and a high level of CD123;
- 2) functionally, they are alpha-interferon producers;
- 3) phylogenically, they likely are precursors of blood dendritic cells.

Etiology

- cat scratch disease (#16352403#)

  • The association with monocytoid B-cells (MBCs) and plasmacytoid monocytes (PMOs) indicates a functional relationship of MBCs with PMOs in the formation of suppurative lesions in cat scratch disease. (#16352403#)

- nodal tumor-forming accumulations of plasmacytoid monocytes in lymph nodes, bone marrow, skin

  • myeloproliferative disorders
    • chronic myelomonocytic leukemia
    • acute myeloid leukemia (monosomy 7 in IPCs)
    • acute monocytic leukemia
    • unclassifiable chronic myeloproliferative
    • myeloproliferative/myelodysplastic disease

Immunochemistry

- CD68+
- CLA/HECA452+
- CD123+
- interferon-alpha (IFN-alpha) inducible protein MxA+
- B-cell oncogene TCL1+
- granzyme-B+
- CD56-

References

- Kojima M, Morita Y, Shimizu K, Itoh H, Masawa N, Nakamura S. Plasmacytoid monocytes in cat scratch disease with special reference to the histological diversity of suppurative lesions. Pathol Res Pract. 2006;202(1):17-22. PMID: #16352403#

- Vermi W, Facchetti F, Rosati S, Vergoni F, Rossi E, Festa S, Remotti D, Grigolato P, Massarelli G, Frizzera G. Nodal and Extranodal Tumor-forming Accumulation of Plasmacytoid Monocytes/Interferon-producing Cells Associated With Myeloid Disorders. Am J Surg Pathol. 2004 May;28(5):585-595. PMID: #15105645#