title: Lymphocyte subpopulations in lymph nodes and peripheral blood: a comparison between patients with stable angina and acute coronary syndrome.
abstract: OBJECTIVE
  Atherosclerosis is characterized by a chronic inflammatory response involving activated T cells and impairment of natural killer (NK) cells. An increased T cell activity has been associated with plaque instability and risk of acute cardiac events. Lymphocyte analyses in blood are widely used to evaluate the immune status. However, peripheral blood contains only a minor proportion of lymphocytes. In this study, we hypothesized that thoracic lymph nodes from patients with stable angina (SA) and acute coronary syndrome (ACS) might add information to peripheral blood analyses.
  
  
  METHODS
  Peripheral blood and lymph nodes were collected during coronary by-pass surgery in 13 patients with SA and 13 patients with ACS. Lymphocyte subpopulations were assessed by flow cytometry using antibodies against CD3, CD4, CD8, CD19, CD16/56, CD25, Foxp3, CD69, HLA-DR, IL-18 receptor (R) and CCR4.
  
  
  RESULTS
  Lymph nodes revealed a lymphocyte subpopulation profile substantially differing from that in blood including a higher proportion of B cells, lower proportions of CD8(+) T cells and NK cells and a 2-fold higher CD4/CD8 ratio. CD4(+)CD69(+) cells as well as Foxp3(+) regulatory T cells were markedly enriched in lymph nodes (p<0.001) while T helper 1-like (CD4(+)IL-18R+) cells were more frequent in blood (p<0.001). The only significant differences between ACS and SA patients involved NK cells that were reduced in the ACS group. However, despite being reduced, the NK cell fraction in ACS patients contained a significantly higher proportion of IL-18R(+) cells compared with SA patients (p<0.05).
  
  
  CONCLUSIONS
  There were several differences in lymphocyte subpopulations between blood and lymph nodes. However, the lymphocyte perturbations in peripheral blood of ACS patients compared with SA patients were not mirrored in lymph nodes. The findings indicate that lymph node analyses in multivessel coronary artery disease may not reveal any major changes in the immune response that are not detectable in blood.
authors.affiliation: Division of Clinical Immunology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden. karin.backteman@lio.se
authors.forename: Karin
authors.initials: K
authors.lastname: Backteman
authors.forename: Carina
authors.initials: C
authors.lastname: Andersson
authors.forename: Lars-Göran
authors.initials: LG
authors.lastname: Dahlin
authors.forename: Jan
authors.initials: J
authors.lastname: Ernerudh
authors.forename: Lena
authors.initials: L
authors.lastname: Jonasson
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood*; D000368:Aged; D000369:Aged, 80 and over; D060050:Angina, Stable / Q000097:blood*; D000906:Antibodies / Q000737:chemistry; D050197:Atherosclerosis / Q000097:blood; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D002469:Cell Separation; D003324:Coronary Artery Disease / Q000097:blood; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007107:Immune System; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007694:Killer Cells, Natural / Q000166:cytology; D008198:Lymph Nodes / Q000378:metabolism* / Q000473:pathology; D016131:Lymphocyte Subsets / Q000166:cytology*; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D008875:Middle Aged
chemical_list: D000906:Antibodies; D007166:Immunosuppressive Agents