Assessment of Serum Thrombomodulin in Patients with Systemic Lupus Erythematosus in Rheumatology Research Center

Abstract: At present, some clinical presentations and serological parameters such as products of complement activation and elevation of autoantibodies (e.g. dsDNA antibodies), erythrocyte sedimentation rate (ESR), levels of C-reactive protein (CRP), or cytokines such as IL-2/IL-2 receptor, IL-6 and IL-10 are used as indirect serological markers with variable degrees of significance. To date, no specific serological parameter is available to assess disease activity in SLE. Soluble serum thrombomodulin is a new marker of endothelial cell injury and vasculitis. The objective of this study was to determine in vivo soluble thrombomodulin as a marker of disease activity in SLE patients and compare serum thrombomodulin in SEL patients with and without renal involvement and inactive SLE patients. Sixty-four patients fulfilling ACR criteria with proven SLE with different disease activities were tested for serum levels of Thrombomodulin and dsDNA by ELISA. C3, C4 and FANA were also measured by standard laboratory tests. The clinical disease activity was evaluated by the Systemic Lupus Erythematosus Activity Index (SLEDAI). Elevated soluble thrombomodulin had significant correlations with an increased ANA level (P= 0.037), decrease level of C3 (P =0.017), increase of SLEDAI (P=0.003) and strongly associated with renal involvement in SLE. Thrombomodulin level and Anti dsDNA in active patients with and without renal disease were higher than inactive patients. In SLE, serum thrombomodulin seems to be important marker for evaluation of disease activity. © 2009 Tehran University of Medical Sciences. All rights reserved. Acta Medica Iranica 2009; 47(2): 97-102. Key words: Systemic Lupus Erythematosus, Thrombomodulin, SLE disease Activity