Structural Alterations of Monocytes in Systemic Lupus Erythematosus

Abstract

Systemic lupus erythematosus (SLE) is an autoimmune disease in which the immune system mistakenly attacks multiple organs and tissues of the body. To elucidate the involvement of blood cells in the pathogenesis of SLE, we used transmission electron microscopy to study ultrastructure of monocytes isolated from the blood of SLE patients. We found that in the SLE patients, a substantial fraction of monocytes had abnormal morphology that corresponded to the structural signs of either necrosis or apoptosis. The number of altered monocytes in the SLE patients was significantly higher than in healthy subjects and related directly with the level of anti-dsDNA autoantibodies in the blood. Our results suggest that monocytes are involved in the pathogenesis of SLE and undergo adverse necrotic and/or apoptotic changes, likely induced by autoantibodies.