Israel Medical Association Journal

Background: Atherosclerosis is a chronic inflammatory process resulting in coronary artery disease.

Objectives: To determine the relationship between inflammatory markers and the angiographic severity of CAD[1].

Methods: We measured inflammatory markers in sequential patients undergoing coronary angiography. This included C-reactive protein, fibrinogen, serum cytokines (interleukin-1 beta, IL-1[2] receptor antagonist, IL-6, IL-8, IL-10) and tumor necrosis factor-alpha), all measured by high sensitivity enzyme-linked immunoabsorbent assay.

Results: There was a significant correlation between TNFα[3] and the severity of CAD as assessed by the number of obstructed coronary vessels and the Gensini severity score, which is based on the proximity and severity of the lesions. Patients had more coronary vessel disease (> 70% stenosis) with increasing tertiles of serum TNFα; the mean number of vessels affected was 1.15, 1.33, and 2.00 respectively (P < 0.001). IL-6 correlated with the Gensini severity score and coronary vessel disease (> 70% stenosis). A weaker correlation was present with IL-1 receptor antagonist. A significant correlation was not found with the other inflammatory markers. After adjustment for major risk factors, multivariate analyses showed that significant independent predictors of CAD vessel disease were TNFα (P < 0.05) and combined levels of TNFα and IL-6 (P < 0.05). IL-6 levels were independently predictive of Gensini coronary score (P < 0.05).

Conclusion: TNFa and IL-6 are significant predictors of the severity of coronary artery disease. This association is likely an indicator of the chronic inflammatory burden and an important marker of increased atherosclerosis risk.

Tumor necrosis factor-associated fever syndrome is an autosomal dominant disorder caused by mutations of the TNFRSF 1A gene encoding the 55 kD TNF receptor (p55 TNF-RI).

Background: Advanced glycation end products, formed by the non-enzymatic glycation of proteins with reducing sugars, are thought to play a pathogenetic role in the vascular complications of diabetes, uremia and atherosclerosis. β2-microglobulin is a major constituent of amyloid fibrils in dialysis-related amyloidosis. AGE[1]-modified β2m[2] has been found in amyloid deposits of long-term hemodialysis patients. AGE-modified β2m has also been shown to enhance chemotaxis and increase tumor necrosis factor-alpha and interleukin-1 beta secretion by circulating and tissue monocytes/macrophages.

Objectives: To investigate the effect of AGE-modified β2m and AGE-human serum albumin on TNF-α[3] and IL-1β[4] secretion by human peritoneal macrophages derived from patients on continuous ambulatory peritoneal dialysis.

Methods: Human PMØ[5] were isolated from peritoneal dialysis effluent of stable CAPD[6] patients and were incubated for 24 hours with AGE-modified β2m, β2m, AGE-HSA[7], HSA or lipopolysaccharide. TNF-α or IL-1β secretion was measured by enzyme-linked immunosorbent assay in cell-free culture supernatants.

Results: Both AGE-modified β2m and AGE-HSA significantly increased TNF-α and IL-1β secretion by human PMØ in a dose-dependent manner (50–200 μg/ml). In contrast, β2m or HSA had no such stimulatory effect on TNF-α secretion but had a small significant increase in IL-1β secretion.

Conclusions: AGE-modified β2m promotes in vitro TNF-α and IL-1β secretion by human PMØ of CAPD patients. Activation of these macrophages by AGE-modified β2m may be a contributory factor to the morphologic changes and altered permeability of the peritoneal membrane in long-term CAPD.