Increased intermediate CD14++CD16++ monocyte subset levels associate with restenosis after peripheral percutaneous transluminal angioplasty

Background and aims: We aimed at studying the association of three major human monocyte subsets after percutaneous transluminal angioplasty (PTA) in patients with femoropopliteal disease. Methods: We prospectively studied 67 sequential patients (40 male, 27 female; mean age 71 +/- 11 years) treated with femoropopliteal angioplasty. Multi-color flow cytometry characterized monocyte subsets from venous blood for expression of CD14 and CD16 and intracellular myeloperoxidase (MPO) prior to, and 3, 6 and 12 months post PTA. Analyses tested associations between monocyte subsets and risk for restenosis. Results: 16/67 patients (24%) developed restenosis within 12 months after PTA. Patients with hyperlipidemia had increased risk for restenosis (HR = 1.7, 95% CI 0.7-2.9, p = 0.001). Increased baseline monocytes associated with an increased risk of late restenosis (HR = 4.9, 95% CI: 1.3-18.6, p = 0.047). CD14(++)CD16(++) `intermediate' monocytes assessed at baseline, and after 3, 6, and 12 months significantly associated with the risk for subsequent restenosis: HR = 3.9 (95% CI: 2.4-6.5, p = 0.029), HR = 5.7 (95% CI - 0.7-44.7, p - 0.013), HR - 6.5 (95% CI: 2.5-16.9, p - 0.001) and HR - 1.5 (95% CI - 1.4-15.5 p = 0.001), respectively. Moreover, the probability for freedom of restenosis decreased with increased levels of intermediate subsets at 12 months after PTA. Additionally, intracellular MPO expression in CD14(++)CD16(++) measured at 3, 6 and 12 months associated with an increased restenosis risk (HR similar to 1.5, 95% CI: 0.8-2.1, p = 0.214, HR = 1.9, 95% CI: 1.0-2.3 p = 0.051 and HR = 1.4, 95% CI: 1.0-1.8, p = 0.052). Conclusions: Our results imply altered innate immunity after angioplasty. Elevated CD14(++)CD16(++) intermediate monocyte frequencies and increased MPO expression may identify individuals at heightened risk for restenosis. (C) 2016 Elsevier Ireland Ltd. All rights reserved.