The significance of M1/M2 macrophage-like monocytes in children with systemic lupus erythematosus

Monocytes/macrophages are important in the development of systemic lupus erythematosus. To research M1 and M2 macrophage-like monocytes in the peripheral blood of children with systemic lupus erythematosus and explore the clinical significance, M1 and M2 macrophage-like monocytes, tumor necrosis factor-alpha, interleukin-1, interleukin-6, interleukin-10, and interleukin-18 are tested in the peripheral blood of children with systemic lupus erythematosus by flow cytometry. A correlation analysis is made between M1 and M2 macrophage-like monocytes and erythrocyte sedimentation rate and C-reactive protein. As we found, the absolute number and percentage of M1 macrophage-like monocytes (CD163(-)CD14(+)) in macrophage-like monocytes (CD14(+)) in peripheral blood of the severe systemic lupus erythematosus group were higher than those of the control group and the mild-moderate systemic lupus erythematosus group (F = 28.4, 21.7, 122, 81.7; P < 0.05). But there was no obvious difference between these three groups in terms of the absolute number of M2 macrophage-like monocytes (CD163(+)CD14(+)). The absolute number and percentage of M1 macrophage-like monocytes in macrophage-like monocytes had positive correlation with C-reactive protein and erythrocyte sedimentation rate (r = 0.46, 0.44, 0.367, 0.47; P < 0.05); whereas, the absolute number and percentage of M2 macrophage-like monocytes in macrophage-like monocytes had negative correlation with CRP and erythrocyte sedimentation rate (r = -0.47, -0.45, -0.47, -0.32; P < 0.05). Thus, M1 macrophage-like monocytes have effective impact on inflammation in children with systemic lupus erythematosus. M2 macrophage-like monocytes, to a large extent, have the opposite functions compared to M1 macrophage-like monocytes. In children with systemic lupus erythematosus, macrophages play important role in the development of systemic lupus erythematosus and M1 macrophage-like monocytes have functions in active systemic lupus erythematosus and they can induce the inflammation and have correlation with severity of systemic lupus erythematosus.