title: [Immune response reduced by intense intellectual stress: changes in lymphocyte proliferation in medical students].
abstract: BACKGROUND
  There is a relationship between stressful situations and the susceptibility towards certain diseases, probably mediated by immune system modifications.
  
  
  OBJECTIVE
  To study T lymphocyte proliferation in medical students during periods of differing academic stress.
  
  
  METHODS
  Blood samples were obtained from 42 medical students during a period of moderate academic stress, immediately before a final examination and after their summer vacations. T lymphocyte proliferation in response to 5, 10 and 20 mg/ml phytohemagglutinin was measured by the incorporation of 3H-thymidine, and plasma cortisol was measured by RIA.
  
  
  RESULTS
  T lymphocyte stimulation index in response to all phytohemagglutinin concentrations was significatively lower in the period before examination than in the other two periods. There were no differences in the index between the period of moderate stress and after summer vacations. Plasma cortisol levels were 15.6 +/- 4.3, 18.6 +/- 5.8 and 16.7 +/- 5.1 mg/dl during the periods of moderate stress, before the examination and after vacations, respectively (p < 0.05 for the difference between examination and the other two periods).
  
  
  CONCLUSIONS
  There is a decrease in lymphocyte proliferation and an increase in cortisol levels during a period of acute academic stress in medical students, suggesting that, the exposure of the healthy subjects to common stressful stimuli, may affect their immunocompetance.
authors.affiliation: Departamento de Psiquiatría, Facultad de Medicina, P Universidad Católica de Chile.
authors.forename: S
authors.initials: S
authors.lastname: Gloger
authors.forename: J
authors.initials: J
authors.lastname: Puente
authors.forename: P
authors.initials: P
authors.lastname: Arias
authors.forename: P
authors.initials: P
authors.lastname: Fischman
authors.forename: I
authors.initials: I
authors.lastname: Caldumbide
authors.forename: R
authors.initials: R
authors.lastname: González
authors.forename: J
authors.initials: J
authors.lastname: Quiroz
authors.forename: O
authors.initials: O
authors.lastname: Echavarri
authors.forename: C
authors.initials: C
authors.lastname: Ramírez
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007107:Immune System / Q000276:immunology*; D007121:Immunocompetence / Q000276:immunology; D008016:Life Change Events; D008297:Male; D010835:Phytohemagglutinins / Q000032:analysis; D013315:Stress, Psychological / Q000276:immunology*; D013337:Students, Medical / Q000523:psychology*; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
chemical_list: D010835:Phytohemagglutinins
vernacular_title: Respuesta inmune disminuida por estrés académico intenso: cambios de la proliferación linfocitaria en estudiantes de medicina.