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Abstract Background: Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by vasculopathy and fibrosis, which can be subclassified into diffuse cutaneous (dSSc) and limited cutaneous (lSSc) subtypes. Previous studies suggest that an increase in monocytes can be a hallmark of various inflammatory diseases, including SSc. Our aim was to evaluate circulating blood monocyte subpopulations (classical, intermediate and non-classical) of SSc patients and their possible association with disease manifestations. Methods: Fifty consecutive patients fulfilling the 2013 ACR/EULAR classification criteria for SSc were included in a cross-sectional study. Monocyte subpopulations were identified based on their expression of CD64, CD14 and CD16, evaluated by flow cytometry, and were correlated with the clinical characteristics of the patients; furthermore, the expression of HLA-DR, CD163, CD169 and CD206 in the monocytes was studied. Thirty-eight age- and sex-matched healthy individuals were recruited as a control group. Results: SSc patients had an increased number of circulating peripheral blood monocytes with an activated phenotypic profile compared to healthy subjects. Absolute counts of CD16+ (intermediary and non-classical) monocyte subpopulations were higher in SSc patients. There was no association between monocyte subpopulations and the clinical manifestations evaluated. Conclusion: We identified higher counts of all monocyte subpopulations in SSc patients compared to the control group. There was no association between monocyte subpopulations and major fibrotic manifestations. CD169 was shown to be more representative in dSSc, being a promising marker for differentiating disease subtypes.
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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.