TOWARDS NOVEL CIRCULATING MARKERS FOR ABDOMINAL AORTIC ANEURYSM PROGNOSIS

Abstract

Objective: Abdominal aortic aneurysm (AAA) is increasing due to aging of the population and is a major cause of death among the elderly. Ultrasound screening programs are useful in early diagnosis but aneurysm size is not always a good predictor of rupture. Thus, there is an urgent need to find new potential prognostic factors. Our aim is to determine whether a battery of immune, inflammatory and oxidative stress markers, previously described to be involved in other cardiovascular diseases, may be used as potential biomarkers to provide personalized prediction of AAA progression for the clinical practice. Design and method: To address this, human abdominal aneurysmatic aortas (N = 80) and blood samples (N = 94) were obtained from patients undergoing open repair or endovascular surgery repair for AAA, whereas healthy aortas (n = 15) and blood samples (n = 46) were obtained from healthy donors. We studied the immune infiltrate in paraffin sections of human aneurysmatic tissue and quantified IgM and IgG circulating levels in our AAA patient cohort. Circulating levels of ROS, CD38, CD36, GDF15 and S100A4 were measured by ELISA and their tissue expression was studied by real Time PCR and by immunostaining. Potential correlations with the aneurysm diameter or with peak wall stress, determined by finite element analysis, were measured by the Pearson product-moment correlation. Results: Our study shows for the first time the alteration of IgM, IgG, ROS, CD38, GDF15 and S100A4 levels in plasma and in aneurysmatic tissue of AAA patients in comparison with controls. After performing the corresponding statistical analysis we could exclude age and sex as confounding factors of our current observations. Circulating levels of IgG, CD38 and GDF15 were positively correlated with abdominal aortic diameter and peak wall stress. Conclusions: Our data indicate that IgG, CD38 and GDF15 may have potential to aid AAA prognosis as indicators of the progression of the aneurysm growth.