Inverse production of IL-6 and IL-10 by abdominal aortic aneurysm explant tissues in culture

Abstract Background Abdominal aortic aneurysm is considered an atherosclerosis-related disease, but the mechanisms underlying abdominal aortic aneurysm remain poorly defined. Despite the large number of cytokines identified in an aneurysm sample, the relative importance of particular cytokines in aneurysm formation is unknown. We have studied the production of interleukin-6 and interleukin-10 cytokines in plasma and cultures of abdominal aortic aneurysm explant samples obtained from patients subjected to elective surgery and their correlation with cellular composition. Materials and methods Inflammatory cells from the abdominal aortic aneurysm samples were phenotypically characterized using specific monoclonal antibodies (anti-CD3, -CD4, -CD8, -CD19, -CD38, -CD68, -HLA-DR) by means of immunocytochemistry staining. Production of interleukin-6 and interleukin-10 in culture supernatants of abdominal aortic aneurysm explant samples expanded in vitro for 24 h was measured by enzyme-linked immunosorbent assay. Results We showed that the levels of interleukin-6 and interleukin-10 in supernatants of abdominal aortic aneurysm sample cultures were higher by 73 and 86 times compared to their levels in plasma, respectively. In individual abdominal aortic aneurysm explant cultures, a negative correlation between interleukin-6 and interleukin-10 production was observed. Such inverse correlation was not detected in plasma. Based on these results, we divided abdominal aortic aneurysm into two cytokine-producing groups and showed that the interleukin-6hi /interleukin-10lo group contained higher percentages of granulocytes, HLA-DR+ , and CD68+ cells but lower percentages of lymphocytes and plasma cells compared to the interleukin-6lo /interleukin-10hi group. Exogenously added interleukin-10 suppresses the production of interleukin-6 by abdominal aortic aneurysm explants. Conclusion These results suggest that interleukin-6 and interleukin-10 may have a different role in the pathogenesis of abdominal aortic aneurysm.