Inhibitory effect of monocyte reactive antibodies on monocyte chemotaxis in systemic lupus erythematosus

Presence of different types of autoantibodies is a basic feature of systemic lupus erythematosus (SLE). Though monocytes, macrophages play an important role in cellular immunity, autoantibodies against monocytes have not been sufficiently studied. The authors used automatic fluorochromatic assay to detect monocyte reactive autoantibodies in the sera of SLE patients. Of SLE 35.5% sera showed complement-mediated monocytotoxic activity against healthy monocytes. Monocyte reactive SLE sera as well as monoclonal antibodies against human monocytes inhibited chemotaxis of control monocytes. The results suggest that monocyte reactive autoantibodies may play a role in the decreased monocyte number and defective monocyte functions observed in SLE.