Interleukin-6 receptor expression and saturation on the bone marrow cells of patients with multiple myeloma.
Expression of the interleukin-6 (IL-6) receptor on B cells and plasma cells in the bone marrow (n = 18) and peripheral blood (n = 32) of patients with multiple myeloma and the relative saturation of these receptors with endogenous IL-6 has been determined by dual-labelled flow cytometric analyses. B cells were identified using an anti-CD19 monoclonal antibody and plasma cells were identified by gating on cells with high fluorescent staining with anti-CD38. With the exception of one patient, very few bone marrow plasma cells expressed the IL-6 receptor (IL-6R) (mean = 2%). This was in contrast to cells from the U-266 plasma cell line, 90% of which had IL-6R. IL-6R expression was lower on bone marrow B cells (mean = 11%) than on peripheral blood B cells (mean = 69%). Studies using either monoclonal or polyclonal anti-human IL-6 to detect endogenous receptor-bound IL-6 found that the IL-6R on bone marrow B cells and plasma cells from patients with multiple myeloma were not saturated with endogenous IL-6 and the presence of receptor-bound IL-6 tended to be associated with stable disease. Thus dysregulated IL-6R expression was not evident on the B cells and plasma cells of patients with multiple myeloma and the increased IL-6R expression on the U-266 plasma cell line was not found on patients' cells.
Brown
R D
RD
Haematology Department, Royal Prince Alfred Hospital, Sydney, Australia.
Gorenc
B
B
Gibson
J
J
Joshua
D
D
D001402:B-Lymphocytes / Q000737:chemistry*; D001853:Bone Marrow / Q000737:chemistry*; D006801:Humans; D009101:Multiple Myeloma / Q000097:blood / Q000473:pathology; D010950:Plasma Cells / Q000737:chemistry*; D011971:Receptors, Immunologic / Q000032:analysis*; D019947:Receptors, Interleukin-6
D011971:Receptors, Immunologic; D019947:Receptors, Interleukin-6