Abstract
C3b receptor on erythrocytes (E-CR1) has been known to participate in the clearance of circulating immune complex (CIC). In the present study it was aimed to clarify the role of E-CR1 for the increased CIC seen in dialysis patients. The level of E-CR1 and CIC (C1qCIC and C3dCIC) were measured by using flowcytometry in 29 HD (HD duration; 8.1±4.2 [SD] years), 12 CAPD (CAPD duration; 2.9±2.5 years for 5 CAPD patients and 7.4±2.0 years for 7 CAPD patients who had been switched from HD) and the data were compared to 94 normal healthy subjects (N).
Both C1qCIC and C3dCIC in dialysis patients were significantly higher than those in N (C1qCIC: N; 14.3±4.8μg/ml, HD; 31.5±11.5, CAPD; 43.8±24.9, p<0.001), C3dCIC: N; 7.4±4.3μg/ml, HD; 29.6±12.2, CAPD; 29.6±11.6; p<0.001). E-CR1, a percent of CR1-positive cells per 106/ml; FCM%, in both dialysis patients were significantly lower than that in N, N; 71.0±15.0%, HD; 50.3±13.2, CAPD; 46.9±13.2 (p<0.001).
E-CR1 inversely correlated with both C1qCIC and C3dCIC in HD (p<0.05 or less), and with C1qCIC in CAPD (p<0.05). There were no significant differences in either CIC or E-CR1 level between HD and CAPD. These findings suggest that the decreased E-CR1 contributes to the increased level of CIC in dialysis patients, indicative of a poor clearance of CIC.
