CONCENTRATION OF RGDS-CONTAINING DEGRADATION PRODUCTS IN UREMIC PLASMA IS CORRELATED WITH PROGRESSION IN RENAL-FAILURE

A concentration of protein degradation products containing the RGDS se quence, which could contribute to a lower reactivity of uremic platele ts, has been estimated in both uremic (n = 16) and control (n = 7) pla smas. Degradation products and other small molecules were separated fr om plasma by filtration through AMICON YM-10 filter. RGDS antigen was determined in filtered material using the radioimmunoassay method base d on monospecific anti-RGDS rabbit polyclonal antibodies. The concentr ation of RGDS-containing degradation products in uremic plasma ranged from 0.8 to 353 nM with mean value 58.6 +/- 24.9 nM and was higher tha n in control (0.7 to 5.9 nM, mean value 2.1 +/- 0.9 nM). Moreover, the level of RGDS-antigen positively correlated with plasma creatinine co ncentration (R = 0.87, p < 0.001). The filtered material showed an inh ibitory effect on fibrinogen binding to control platelets in respect t o RGDS-antigen concentration. We conclude that the elevated concentrat ion of RGDS-containing degradation products in uremic plasma is partia lly responsible for bleeding tendency in renal failure.