Erythrocyte adhesiveness/aggregation: a novel biomarker for the detection of low-grade internal inflammation in individuals with atherothrombotic risk factors and proven vascular disease.

BACKGROUND: We have introduced a concept of using the erythrocyte as a sensor for the detection of enhanced inflammation-sensitive protein concentrations. We presently evaluated the capability of this new biomarker to detect the presence of inflammation in individuals with a history of a vascular disease as opposed to individuals with atherothrombotic risk factors but no clinically evident vascular disease. METHODS: The degree of erythrocyte adhesiveness/aggregation was determined in the peripheral venous blood by using a simple blood test. Blood was drawn into a syringe containing sodium citrate and trickled onto a slide at an angle of 30 degrees. The slides were than scanned by a blinded technician by using an image analyzer to determine the area that is covered by the erythrocytes. RESULTS: One hundred fifty-six subjects (61 women and 95 men) of 2586 (1238 women and 1348 men) met the criteria of a definite vascular disease (history of stroke, myocardial infarction, coronary artery bypass grafting, or peripheral vascular disease). The degree of erythrocyte aggregation was significantly (P = .008) higher in men, but not in women, with vascular disease as opposed to these without a vascular disease. The results of receiver operating characteristic curve analysis confirmed the diagnostic superiority of the erythrocyte aggregation biomarker over other commonly used markers of the acute phase in men. Similar results were obtained by using discriminant analysis. Finally, a significant correlation was found between the degree of erythrocyte aggregation and other markers of the acute phase suggesting its relevance for the detection and quantitation of low-grade inflammation in individuals with atherothrombosis. CONCLUSION: Erythrocyte adhesiveness/aggregation may be a useful biomarker to detect internal inflammation in individuals with atherothrombosis.

A simple biomarker to exclude the presence of low grade inflammation in apparently healthy individuals.

BACKGROUND: Atherosclerosis is accompanied by a low grade inflammatory response. HYPOTHESIS: To use erythrocyte aggregability as a biomarker to exclude the presence of low grade inflammatory response in apparently healthy individuals. METHODS: The adhesiveness/aggregation of red blood cells was quantitated by using a simple slide test and image analysis. RESULTS: We included 121 apparently healthy individuals and found a significant correlation between the degree of erythrocyte adhesiveness/aggregation and either the concentration of high sensitive CRP (r = 0.6, P < 0.001), erythrocyte sedimentation rate (r = 0.5, P < 0.0001) or fibrinogen (r = 0.5, P < 0.0001). By using certain cutoff points for the erythrocyte adhesiveness/aggregation test we could define individuals with a very low grade inflammatory response. CONCLUSIONS: By using this inexpensive and rapid assessment, we could clearly discriminate between individuals with a very low inflammatory response and those with a more intense one. This biomarker should be further evaluated as a possible screening test for use in large populations of apparently healthy individuals in whom the detection of low grade inflammation might contribute to guiding appropriate lifestyle modifications and therapeutic interventions.