Measurement of soluble thrombomodulin in sera from various clinical stages of diabetic nephropathy.

The levels of soluble thrombomodulin (TM) in serum samples were measured by one-step sandwich enzyme immunoassay. The aim of the present study was to determine if levels of soluble TM in sera might correlate with disease activity in patients with diabetic nephropathy. Three hundred and twenty patients with diabetic nephropathy were examined. Patients with diabetic retinopathy were excluded from the present study. This study showed an increase of soluble TM levels in sera from patients with diabetic nephropathy. The levels of soluble TM in sera from the macroalbuminuric stage with renal dysfunction were significantly increased compared with those from the normo-, micro-, or macroalbuminuric stage of diabetic nephropathy without renal dysfunction. The increase of soluble TM in sera paralleled levels of urinary albumin, blood urea nitrogen (BUN), s-creatinine (Cr), and duration of noninsulin-dependent diabetes mellitus (NIDDM). Furthermore, a decrease of TM staining in the glomerular capillary walls was observed in both microalbuminuric and macroalbuminuric stages by immunofluorescence. It appears that the measurement of soluble TM in sera is useful in evaluating the degree of glomerular endothelial injuries in patients with diabetic nephropathy.