SERUM LEVELS OF SOLUBLE ADHESION MOLECULES IN CHRONIC-RENAL-FAILURE AND DIALYSIS PATIENTS

Besides cell-bound adhesion molecules, which are of fundamental import ance to a large number of physiological and pathological processes, so luble forms of adhesion molecules have been detected in the circulatin g blood in recent years. Circulating soluble adhesion molecules appear to be biologically active, and raised levels have been reported in a variety of disorders. In the present study, we used ELISA to measure t he serum levels of four soluble adhesion molecules in 23 undialyzed pa tients with chronic renal failure (CRF), 13 patients on continuous amb ulatory peritoneal dialysis (CAPD), 17 on chronic hemodialysis (HD) an d 18 healthy controls having a similar mean and distribution of ages. The investigated soluble (s) molecules included intercellular adhesion molecule 1 (sICAM-1), vascular cell adhesion molecule 1 (sVCAM-1), sE -selectin and sP-selectin. sICAM-1 was found to be elevated in patient s with CRF (p < 0.05), on CAPD (p < 0.02) and HD (p < 0.0001) compared with the controls but levels did not differ between the three patient groups. The higher sVCAM-1 values found in CRF (p < 0.02), CAPD (p < 0.05) and HD (p < 0.0001) as compared to controls again failed to diff erentiate the three groups of patients. Soluble E-selectin was also ra ised in the three groups (p < 0.0001) with no difference between them. Increased sP-selectin was found in CRF (p < 0.05), CAPD (p < 0.02) an d in HD patients (p < 0.0001) compared to controls, and levels in HD w ere significantly higher (p < 0.02) than in CRF patients. Predialysis serum molecule levels did not differ between HD patients treated with cuprophan or with polyacrylonitrile dialyzers. HD sessions with both d ialyzers had no effect on sICAM-1, while a decrease (p < 0.02) in sP-s electin was found after dialysis with cuprophan. In undialyzed patient s with CRF, regression analysis showed a strong linear correlation bet ween serum creatinine and serum levels of each soluble molecule. These results demonstrate that serum levels of soluble adhesion molecules I CAM-1, VCAM-1, E-selectin and P-selectin are elevated in both undialyz ed patients with CRF and patients on CAPD or HD. The elevated serum le vels of these proteins probably reflect inadequate clearance as well a s enhanced synthesis/release.