CD16⁺ Monocyte Subsets Are Increased in Large Abdominal Aortic Aneurysms and Are Differentially Related with Circulating and Cell-Associated Biochemical and Inflammatory Biomarkers

Abstract

Proinflammatory components are present in abdominal aortic aneurysm (AAA). Circulating monocytes display heterogeneity, and three subsets have been identified, based on the differential expression for CD14 and CD16 receptors: CD14⁺CD16^-, classical, CD14⁺CD16⁺, intermediate and CD14^dim CD16⁺, non-classical monocytes. Increased proinflammatory CD16⁺ monocytes with high expression of CD143 are present in CKD patients. D-dimer is increased in AAA patients, and might contribute to the pro-inflammatory response associated to circulating monocytes. We aimed to investigate the frequency of CD14⁺CD16⁺, CD14^dim CD16⁺ monocytes and monocyte CD143 expression in AAA patients, and their relationship with D-dimer, eGFR and other inflammatory parameters. Blood from 74 AAA patients and 30 healthy controls was analyzed to determine the frequency of CD14⁺, CD16⁺, CD14^dim CD16⁺ monocytes and the monocyte CD143 expression by means of flow-cytometry. AAA patients had expanded CD16⁺ SUPsets (CD14⁺CD16⁺: 7.66 ± 0.31% vs 5.42 ± 0.27%; CD14^dim CD16⁺: 7.43 ± 0.48% vs 5.54 ± 0.38%, AAA vs controls, mean ± SE, both p<0.05). CD14⁺ CD16⁺ cells were associated to D-dimer and age, and to reduced eGFR. CD14^dim CD16⁺ cells were associated to uric acid, surface CD143, and reduced count of total leukocytes and neutrophils. Within AAA patients, the two CD16⁺ supsets and the monocyte CD143 expression display different relationships with D-dimer, parameters of renal function and circulating biochemical and inflammatory biomarkers.