title: Immune function in acute stress.
abstract: The aim of this study was to evaluate immune function in acute stress in medical students before academic examinations. Twenty-five medical students were selected because they presented intense acute stress, evaluated by the presence of the following classic signs: cold hands, intense sudoresis in the extremities, generalized sudoresis, paleness, tachycardia, confused reasoning, nervous irritability, diarrhea, and sleep disorders in the hours preceding the examination (agitated sleep, insomnia).
  
  
  METHODS
  Immediately before the examination, peripheral blood was collected from the 25 students presenting acute stress to analyze T and B cells, CD4+ and CD8+ cells, immunoglobulins, and C3 and C4 complement components, as well as phagocytic activity in neutrophils and monocytes. These investigations were repeated in the same students in situations free of acute stress. The results of the two samples collected from each student were compared.
  
  
  RESULTS
  The means and standard deviations showed no significant differences for any of the parameters analyzed (p> or =0.01).
  
  
  CONCLUSIONS
  We conclude that acute stress did not cause changes in the lymphocyte subpopulations, phagocytic activity of neutrophils and monocytes, serum immunoglobulins, or C3 and C4 complement components in students participating in the present study. In conditions of basal chronic stress, acute stress may cause alterations in immune function.
authors.affiliation: Santa Casa Medical School and Hospital, São Paulo, Brazil.
authors.forename: A B
authors.initials: AB
authors.lastname: Segal
authors.forename: S
authors.initials: S
authors.lastname: Bruno
authors.forename: W C N
authors.initials: WC
authors.lastname: Forte
mesh_terms: D000208:Acute Disease; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D004521:Educational Measurement; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis; D018655:Lymphocyte Count; D008297:Male; D009000:Monocytes / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D010587:Phagocytosis; D013315:Stress, Psychological / Q000097:blood / Q000276:immunology*; D013334:Students / Q000523:psychology; D013732:Test Anxiety Scale
chemical_list: D003176:Complement C3; D003181:Complement C4; D007136:Immunoglobulins