Background: Markers of an acute phase reaction, such as C-reactive protein (CRP) or interleukin-6 (IL-6), are predictive for cardiovascular morbidity and mortality in normal subjects and in hemodialysis (HD) patients. Le-vels of acute phase proteins (APP) may vary with time even in the absence of an acute illness and this may weaken the relationship between APP and clinical outcome. We investigated the intra- and inter-individual patterns of several inflammatory markers in HD patients.
Methods: Plasma levels of CRP, IL-10, RANTES, TNF-RI, leptin, ferritin and albumin were measured weekly for 12 weeks after the long inter-dialytic interval by ELISA in ten stable HD patients with no clinical signs of infection.
Results: Considerable variability was observed. Intra-individual differences were largest for RANTES (coefficient of variation - CV - 80%, followed by CRP (51%), and low for albumin (11%) and ferritin (12%). Inter-individual variability was highest for IL-10 (135%) followed by CRP (88%).
Conclusions: The present data suggest that single point measurements of APP, particularly CRP, may not be sufficient to assess the cardiovascular risk in HD patients. Even in patients with no apparent signs of infection, there is considerable variability in plasma levels of APP and repeated measurements are recommended to identify patients at high cardiovascular risk.