Positive acute-phase inflammatory markers in different stages of chronic kidney disease

Abstract

Background: An elevated serum level of acute-phase inflammatory markers is associated with an increased risk of cardiovascular disease. We hypothesized that elevated acute-phase inflammatory markers are directly associated with the different stages of chronic kidney disease (CKD).

Methods: We evaluated the relationship between serum levels of high-sensitivity C-reactive protein (hsCRP) and alpha1-acid glycoprotein (alpha1-AGP), as well as the renal function in 224 adult patients with CKD (mean age 56.6 years, 46% male, and 40% diabetics), stratified according to the glomerular filtration rate (GFR) (based on the National Kidney Foundation/Kidney Dialysis Outcomes Quality Initiatives), and in 94 hemodialysis patients.

Results: The mean hsCRP was 8.2 +/- 12.1 mg/l, and hsCRP levels were >5 mg/l in 44.4% of the patients; alpha1-AGP levels were >125 mg/dl in 33.3% of the patients. Mean hsCRP and alpha1-AGP were significantly higher in more severe stages of CKD. A weak inverse relationship was found between GFR and serum hsCRP (r = -0.2205; p = 0.0006) and between GFR and serum alpha1-AGP (r = -0.3266; p < 0.0001). There was a correlation between hsCRP and alpha1-AGP (r = 0.3417; p < 0.0001). No significant differences were detected between patients with CKD and those undergoing hemodialysis concerning hsCRP (8.2 +/- 12.1 vs. 6.8 +/- 7.4 mg/l; p = 0.2980) and alpha1-AGP (116.3 +/- 42.5 vs. 117.2 +/- 37.9 mg/dl; p = 0.8590). However, the level of hsCRP was significantly reduced in hemodialysis patients compared with patients with stage 5 predialytic disease (12.1 +/- 13.9 to 6.8 +/- 7.4 mg/l; p = 0.005). More patients with stage 5 predialytic CKD had an elevated hsCRP serum level compared with patients on hemodialysis (64.7 vs. 37.9%; chi2 = 6.230, p < 0.01).

Conclusions: Approximately 50% of patients with CKD--even in the early phase of renal failure--exhibit an activated acute-phase response, which is closely related to the stages of CKD. Hemodialysis may partially correct the inflammatory process present in the immediate predialysis phase of CKD.