Plasma thrombomodulin in renal disease: effects of renal function and proteinuria.

Plasma thrombomodulin (PTM) may be a marker of vascular endothelial damage and is increased in active vasculitis. However, since PTM is a mixture of glycoproteins (MW between 28 to 105 kD), some may be variably excreted by the kidney. PTM level thus may be affected both renal impairment and proteinuria. This study examines patients with varied renal pathology and relates PTM levels to renal function and proteinuria. PTM levels were measured in eighty nine renal patients with varied renal pathology: 23 patients on hemodialysis (HD), 66 with variable renal function (from normal to severe renal impairment), and proteinuria from insignificant to nephrotic range. PTM levels rose as renal function declined and were highest in HD patients. PTM levels also seemed to rise with increasing proteinuria. Indeed, this relationship appeared to be exaggerated in patients with hypertensive and diabetic nephropathy compared to those with primary glomerulonephritis. Measurements of PTM are clearly affected both by renal function and proteinuria. Thus the confidence limits above which an abnormal level is recognised should be increased as renal function declines.