CD14/CD16 Subpopulations of Circulating Monocytes in Type 2 Diabetes Mellitus Patients with/without Coronary Artery Disease

Bae, Sook Young; Yoon, Soo Young; Kim, Young Kee

Abstract

BACKGROUND
Coronary artery disease (CAD) is one of the most important causes of mortality and morbidity among patients with Type 2 Diabetes Mellitus (DM). Monocytes play a major role in the development of atherosclerotic lesions. The majority of circulating monocytes express high levels of the lipopolysaccharide receptor antigen (CD14) and low of the immunoglobulin Fc receptor III (CD16). Changes in the phenotype of circulating monocytes have been reported in patients with type 2 DM and CAD. The purpose of this study is to characterize the circulating blood monocyte subpopulations as potential cellular markers of systemic immunological abnormalities in CAD and DM and to evaluate the relationship among other independent risk factors.
METHODS
Two-color immunofluorescence and flow cytometry was employed for evaluation of the monocyte subpopulations. CRP, HbA1c and lipid profile in patients with CAD (n=36) were also compared with those in a group without CAD (n=40) and healthy nondiabetic individuals (n=56).
RESULTS
The CD14+(dim)/CD16+ (P<0.001) and CD14++/CD16- (P=0.011) subpopulations were significantly elevated in both the Type 2 DM patients' groups, with and without CAD, and compared with normal controls; and further, there were no significant differences between the diabetic groups. There was no correlation of the CD14+(dim)/CD16+ monocytes to any clinical parameter except for the number of CD14++/CD16-, which were positively correlated with the serum HbA1c (r=0.705, P<0.001). CONCLUSTIONS: In conclusion, the circulating blood monocyte subpopulations may not be the specific markers of atherogenesis in DM patients; however, these results suggest that they may play a role in systemic immunologic abnormalities in DM.