Distribution of thrombomodulin in patients with focal and segmental glomerulosclerosis (FSGS).

Thrombomodulin (TM), an endothelial cell surface glycoprotein, is a regulatory factor in the intravascular anticoagulant system. Furthermore, its plasma level is believed to reflect injury to the endothelial cell. In searching for changes in intraglomerular coagulation and endothelial cell injury during the clinical course of 14 patients with focal and segmental glomerulosclerosis (FSGS), we evaluated the distribution of thrombomodulin (TM) in the kidney by immunohistochemical methods. In the nephrotic stage, intraglomerular staining for TM was weak and segmental and occurred in 6 out of 9 patients (67%), but the incidence of TM expression was not different significantly from that in the normal kidney. Sclerotic lesion was negative for TM. In all patients with incomplete remission and with complete remission, strong and diffuse staining was seen in intra- and extraglomerular endothelial cells. Moreover, TM was scattered in sclerotic lesions. The present study suggest that the over-expression of TM in remission may be linked to recovery from endothelial cell damage and that TM may be closely involved in the repair of FSGS.