Platelet aggregation and beta-thromboglobulin levels in nephrotic patients with and without thrombosis

Platelet aggregation and beta-thromboglobulin levels were studied in 17 patients with the nephrotic syndrome. Thrombosis or thromboembolic complications occurred in 4 of these patients with serum albumin levels below 2 g/100 ml. Pathologic platelet aggregation assessed by estimating alpha 2-angle values derived from platelet aggregation curves was seen in the 4 patients with thromboembolic complications (alpha 2-angle 69.5 degrees +/- 10.1 degrees), whereas patients without thrombosis showed normal alpha 2-angle values (less than 30 degrees) with only one exception. In addition, patients with thromboembolic complications demonstrated significantly elevated beta-thromboglobulin levels, when compared with those not having thrombosis or thromboembolic complications (76.8 +/- 14.3 ng/ml vs 44.8 +/- 8.6 ng/ml, P less than 0.001). The decrease in serum albumin concentration showed an inverse relationship with both, alpha 2-angle values (r = -0.82, P less than 0.001) and beta-thromboglobulin levels (r = -0.83, P less than 0.001) indicating a regulatory role of serum albumin in platelet aggregation. We conclude, that altered platelet aggregation as well as hypercoagulability may be involved in the pathogenesis of thrombosis and thromboembolic complications in the course of the nephrotic syndrome.