title: Comparison of the proportion of non-classic (CD14+CD16+) monocytes/macrophages in peripheral blood and gingiva of healthy individuals and patients with chronic periodontitis.
abstract: BACKGROUND
  Monocyte subsets with low CD14 expression that coexpress CD16 (CD14+CD16+) are called non-classic or hyperinflammatory monocytes. Previous studies have reported an increase in the percentage of CD14+CD16+ monocytes in the peripheral blood of patients with chronic periodontitis (CP). To our knowledge, there are no reports demonstrating the presence of CD14+CD16+ monocyte-derived macrophages (MDMs) in the gingival tissue. The objective of this study is to identify the proportion of non-classic (CD14+CD16+) monocytes/macrophages in peripheral blood and gingiva of healthy individuals and patients with CP.
  
  
  METHODS
  A total of 60 individuals (n = 30 per group) were recruited for the study. Group 1 included 30 individuals with healthy gingiva, and group 2 included 30 patients with CP. Direct immunofluorescent staining was done in 200 μL whole-blood and single-cell suspensions obtained from gingival tissue, with fluorochrome-conjugated monoclonal antibodies against CD14, CD16, and human leukocyte antigen-DR (HLA-DR), and subjected to flow cytometric analysis.
  
  
  RESULTS
  The mean percentage of CD14+CD16+ monocytes in the peripheral blood of healthy individuals was 9.10% ± 1.39%, and for patients with CP it was 14.18% ± 2.69% (P <0.05). The mean percentage of CD14+CD16+ MDMs in the gingival tissue of healthy individuals was found to be 0.93% ± 0.33%, whereas in patients with CP, it was 1.92% ± 0.78% (P <0.01). Non-classic monocytes/macrophages showed a high median fluorescent intensity for HLA-DR (DR++).
  
  
  CONCLUSIONS
  This study demonstrates an increased proportion of CD14+CD16+HLA-DR++ monocytes/macrophages in the peripheral blood and gingiva of patients with CP.
authors.affiliation: Department of Periodontology, Faculty of Dental Sciences, Sri Ramachandra University, Chennai, Tamil Nadu, India.
authors.forename: Raghunathan
authors.initials: R
authors.lastname: Jagannathan
authors.forename: Vamsi
authors.initials: V
authors.lastname: Lavu
authors.forename: Suresh Ranga
authors.initials: SR
authors.lastname: Rao
mesh_terms: D055113:Chronic Periodontitis / Q000097:blood / Q000473:pathology*; D005260:Female; D019085:Fluorescent Antibody Technique, Direct / Q000379:methods; D005456:Fluorescent Dyes; D058851:GPI-Linked Proteins / Q000032:analysis; D005881:Gingiva / Q000473:pathology*; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D018950:Lipopolysaccharide Receptors / Q000032:analysis*; D008264:Macrophages / Q000145:classification* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000145:classification* / Q000276:immunology; D017622:Periodontal Attachment Loss / Q000097:blood / Q000473:pathology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000097:blood / Q000473:pathology; D017452:Receptors, IgG / Q000032:analysis*
chemical_list: C428200:FCGR3B protein, human; D005456:Fluorescent Dyes; D058851:GPI-Linked Proteins; D006684:HLA-DR Antigens; D018950:Lipopolysaccharide Receptors; D017452:Receptors, IgG
keywords: Antigens; CD14; IgG; chronic periodontitis; gingiva; macrophages; monocytes; receptors