Expression and significance of TWEAK and CD163 in monocytes of patients with newly diagnosed systemic lupus erythematosus with renal involvement

ObjectiveTo detect the expression levels of TWEAK and CD163 in monocytes from the peripheral blood of patients with systemic lupus erythematosus (SLE) complicated with renal involvement (SLE+RI) and to explore the application value of TWEAK and CD163 in the diagnosis of SLE and SLE+RI.MethodsThe expression levels of TWEAK and CD163 in the monocytes of 70 SLE patients and the control group were determined by real-time fluorescence quantitative polymerase chain reaction (RT‒qPCR). To analyse the relationship between TWEAK/CD163 expression levels and laboratory examination and clinical manifestations in monocytes of SLE+RI patients. The sensitivity and specificity of TWEAK and CD163 for the diagnosis and differential diagnosis of SLE+RI were analysed by receiver operating characteristic (ROC) curves. Western blot experiments were used to evaluate the protein expression of TWEAK and CD163 in monocytes.ResultsThe expression levels of TWEAK and CD163 in monocytes were significantly greater in the SLE group than in the healthy control (HC) and rheumatoid arthritis (RA) groups. The expression levels of TWEAK and CD163 in monocytes from anti-double-stranded DNA antibody (anti-dsDNA)-positive patients and patients with proteinuria were respectively greater than those from anti-dsDNA-negative patients and patients without proteinuria. The expression levels of both genes were significantly lower after treatment than before treatment in the SLE+RI group (p < 0.05). The expression levels of TWEAK and CD163 in monocytes were positively correlated with the SLE activity score (SLEDAI) in the SLE+RI group. ROC curve analysis revealed that the area under the curve (AUC) of TWEAK expression was 0.869 in the SLE+RI group. The AUC of CD163 in the SLE+RI group was 0.792, the combined expression of TWEAK and CD163 was 0.842 in the SLE+RI group. TWEAK and CD163 protein expression in monocytes from patients with SLE+RI was significantly increased compared with that in controls.ConclusionThe expression levels of TWEAK and CD163 are increased in SLE patients, and the expression levels in SLE+RI patients are greater than those in SLE-RI patients. These findings are closely related to disease activity, autoantibody production and clinical symptoms and can be used as biomarkers for the diagnosis and activity of SLE+RI.