Objective: We previously reported the accumulation of abnormal myeloid cell populations reacting with CD14 (MY4) monoclonal antibody in the iliac and epiphyseal bone marrow of patients with severe rheumatoid arthritis (RA). Therefore, we investigated in vitro production and modulation of CD14+ myeloid cells from iliac bone marrow cells.
Methods: Mononuclear cells were prepared from iliac bone marrow aspirates from patients with RA. The presence of unusual myeloid cells was assessed by 2 color flow cytometry of cells cultured under various conditions.
Results: Cultured iliac bone marrow cells of patients with severe RA produced 14.7% of CD14+ CD15+ cells on average. Cultures derived from healthy donors and from patients with a milder form of RA produced fewer CD14+ CD15+ cells (< 10%). The production of CD14+ CD15+ cells was enhanced by granulocyte macrophage colony stimulating factor and interleukin 1beta, but inhibited by T lymphocytes.
Conclusion: Production and modulation of CD14+ myeloid cells were observed in iliac bone marrow of patients with severe RA.