Abstract 9162: Increased Ratio of B2/B1-like Lymphocytes in the Perivascular Adipose Tissue Could Contribute to Plaque Destabilization in Human Coronary Arteries: Preliminary Results

Abstract

Introduction: B-lymphocyte density in the pericoronary adipose tissue (PvAT) was correlated with plaque size in human coronary arteries. However, the subtypes of B cells in the PvAT and atherosclerotic plaque composition have not investigated yet. Hypothesis: We hypothesized that B2 and the ratio of B2/B1-like lymphocytes in the PvAT will correlate with an increase in components related to plaque destabilization and a decrease in components related to plaque stabilization. B1-like lymphocytes will correlate with an increase of components related to plaque stabilization. Methods: Coronary arteries were freshly dissected with adjacent PvAT. The most important atherosclerotic plaque was selected from each main coronary artery. From 107 artery segments, we calculated the percentage of arterial obstruction, intima-media thickness, the minimum fibrous cap thickness, and the percentage of collagen, smooth muscle cells, fibrous cap, calcification, lipid, necrosis, and intraplaque hemorrhage. We considered B2-lymphocytes as CD20 + CD43 - and B1-like lymphocytes as CD20 + CD43 + using the immunohistochemistry double staining technique. The densities of B2, B1-like, and the ratio of B2/B1-like lymphocytes were correlated with plaque composition using linear, negative binomial, or Poisson regressions models with clustering for multiple measures in the same individual and adjusted for age, sex, hypertension, diabetes, body mass index, sedentary lifestyle, smoking, and alcohol consumption. Results: B2 and B1-like lymphocyte density in the PvAT were not correlated with plaque components. However, the increase of the ratio of B2/B1-like lymphocytes was associated with a decrease in intraplaque collagen (β= -0.19, 95%CI= -0.35; -0.03, p=0.01), calcification (β= -0.15, 95%CI= -0.28; -0.02, p=0.01), hemorrhage (β= -0.08, 95%CI= -0.15; -0.02, p=0.009), minimum fibrous cap thickness (β= -0.03, 95%CI= -0.04; -0.01, p<0.001), and an increase in the number of vasa vasorum in adventitia layer (β= 0.006, 95%CI=0.001; 0.01, p=0.006). Conclusions: An increase in the ratio of B2/B1-like lymphocytes in the PvAT could contribute to plaque destabilization by the decrease of atherosclerotic plaque components related to plaque stabilization.