title: Psychosocial factors and T lymphocyte counts in Brazilian peacekeepers.
abstract: To investigate the associations between psychosocial factors and peripheral blood CD4 and CD8 T lymphocyte numbers in Brazilian peacekeepers.
  
  
  
  Venous blood was collected from 759 peacekeepers who had just returned from a peace mission in Haiti. Among the 759 soldiers, 642 individuals completed the psychosocial measures. CD4 and CD8 T lymphocyte counts were measured by flow cytometry using a commercially available kit. Psychosocial factors, including military peace force stressors, clinical stress, anxiety and depression, were recorded. As a reference for T lymphocyte numbers, we measured T lymphocyte counts in 75 blood donors from the Instituto de Biologia do Exército, Rio de Janeiro.
  
  
  
  The median numbers of CD4 and CD8 T lymphocytes in the blood donors were 819 cells/µl and 496 cells/µl, respectively, with a CD4:CD8 ratio of 1.6. Significantly (p<0.05) lower CD4 T cell counts (759 cells/µl) were recorded for peacekeepers, with similar CD8 levels (548 cells/µl) and smaller CD4:CD8 ratios (1.3, p<0.001) compared to blood donors. These differences were due to a group of 14 military personnel with CD4 and CD8 medians of 308 and 266 cells/µl, respectively. Only one (7.1%) of these 14 individuals was diagnosed with clinical stress compared with 13.5% of the individuals with normal levels of CD4 T lymphocytes. One individual out of 628 (0.16%) had a Lipp's Stress Symptom Inventory score of 3, indicating near exhaustion.
  
  
  
  The prevalence of psychological disorders was low and there were no associations with CD4 or CD8 T cell numbers.
authors: Centro de Estudos de Pessoal, Forte Duque de Caxias, Exército Brasileiro, Rio de Janeiro, RJ, Brasil.
authors: Angela M Monteiro da
authors: AM
authors: Silva
authors: Instituto de Biologia do Exército (IBEx), Rio de Janeiro, RJ, Brasil.
authors: Francisco A B
authors: FA
authors: Speranza
authors: Instituto de Biologia do Exército (IBEx), Rio de Janeiro, RJ, Brasil.
authors: Solange Kiyoko
authors: SK
authors: Ishii
authors: Imunologia e Parasitologia, Disciplina de Microbiologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brasil.
authors: Raphael
authors: R
authors: Hirata
authors: Imunologia e Parasitologia, Disciplina de Microbiologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brasil.
authors: Ana Luíza
authors: AL
authors: Mattos-Guaraldi
authors: Imunologia e Parasitologia, Disciplina de Microbiologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brasil.
authors: Lucimar Gonçalves
authors: LG
authors: Milagres
mesh_terms: D000293:Adolescent; D000328:Adult; D001007:Anxiety / Q000097:blood / Q000523:psychology; D001938:Brazil; D017252:CD3 Complex / Q000097:blood; D018791:CD4 Lymphocyte Count / Q000379:methods; D016516:CD4-CD8 Ratio; D003863:Depression / Q000097:blood / Q000523:psychology; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000097:blood; D006205:Haiti; D006801:Humans; D018655:Lymphocyte Count / Q000379:methods; D008297:Male; D008875:Middle Aged; D008889:Military Personnel / Q000523:psychology*; D010555:Personality Inventory; D012016:Reference Values; D013315:Stress, Psychological / Q000097:blood*; D055815:Young Adult
chemical_list: D017252:CD3 Complex