Abstract: Objective To explore the mechanism of hematolo gic abnormality in patients with systemic lupus erythematosus(SLE).Methods Suppression of granulocytic and ery throid colony formation of bone marrow cells fromhealthy individuals was examined in vitro by using methylcell ulose culture with sera or IgGdelete d sera from patients with SLE.Results ①Both colony-forming units of erythr ocytes(CFU-E)(in 66.7% of samples tested)and granulocytes(CFU-GM)(in 70% of samples tested)of normal bone marrowcells were sign ificantly inhibited by sera frompatients with SLE(P<0.001).②In the IgG deleted group,the CFU-E an d CFU-GMyield rates were higher than those of the sera with IgG group.③Both the numbers of CFU-GM and CFU-E were markedly lower in patients with SLE than those in healthy controls.Conclusion The cytopenia may be related to the in hibition of progenitor cell growth by IgG autoan tibodies and decreased differentiation ability of hematopoietic stem/progenitor cells in patients with SLE.

Key words: Lupus erythematosus,systemic, Plasma, IgG, Hematopoieticstem cells, Colony-forming units assay