In patients with SLE, the frequencies of CD16+ monocytes were positively correlated with serum IgA concentrations (r = 0.267; P < 0.05) and anti-dsDNA antibody levels (r = 0.349; P < 0.01), which implicated that patients with elevated frequencies of CD16+ monocytes would be at a high risk of Ig production or autoantibody development. This evidence concerns the gene CD79A and systemic lupus erythematosus.