title: Changes in cellular proliferation rate of lymphocytes after long-distance flights as a possible risk for patients with HIV-infection.
abstract: OBJECTIVE
  Several studies showed that long-distance flights can influence cellular immunity. This might be due to a cortisol- and catecholamin- induced change in immunity with an impairment of T-lymphocyte dependent cellular immunity and an enhancement of B-lymphocyte dependent humoral immunity. Similar results can be found in patients with HIV. It is also known that progress of this disease and affection of T-helper-cells by the virus are induced by stimulation of the immune system, a phenomenon that also occurs during long distance flights. Therefore, a possible interaction between long-distance flights and the progression of HIV-infection should be discussed.
  
  
  METHODS
  Cell cultures of 22 subjects after long-distance flights with and without rapid time zone shifts and of 16 patients with HIV (stage 2 3) were investigated. Mononuclear blood cells were stimulated with different lectins in culture and proliferation was measured by incorporation of bromodesoxyuridine. Moreover, all cultures were titrated with chromate concentrations between 0 to 700 ng/ml to measure the tolerance of the cells against chromate (VI) in vitro as a marker of the functional efficiency of the cellular part of the immune system. Maximal proliferation rate and tolerance against chromate were compared in both groups.
  
  
  RESULTS
  After long distance flights tolerance against chromate decreased significantly during the first 24 h after flight. After 48 h levels were similar to those 1 week after flights. The decrease was similar to the results found in the stage 2 group of HIV-patients, but by far less to the decrease in stage 3 patients. Maximal proliferation rate dropped significantly during the second day after arrival compared to 1-week control values.
  
  
  CONCLUSIONS
  Changes in the cellular immune system in healthy subjects after long-distance flights have been similar to the results of patients with stage 2 of HIV-infection. Mechanisms of changes in both groups are comparable in influencing T-cell-induced immunity. This could point to an additive effect on cellular immunity of HIV-patients by long distance-flights. Rosen neopterin concentrations and increases of apoptotic T-cells in both groups support this assumption. Therefore, further studies are urgently needed to investigate the interactions between HIV-infection and long-distance flights.
authors.affiliation: Institute of Occupational-, Social- and Environmental Medicine of the Johannes Gutenberg University of Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany. rose@mail.uni-mainz.de
authors.forename: D M
authors.initials: DM
authors.lastname: Rose
authors.forename: D
authors.initials: D
authors.lastname: Jung
authors.forename: W
authors.initials: W
authors.lastname: Tamm
authors.forename: A
authors.initials: A
authors.lastname: Keth
authors.forename: A H
authors.initials: AH
authors.lastname: Loos
mesh_terms: D000293:Adolescent; D000328:Adult; D000337:Aerospace Medicine; D002455:Cell Division; D005260:Female; D015658:HIV Infections / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D008214:Lymphocytes / Q000473:pathology*; D008297:Male; D012307:Risk Factors; D013997:Time Factors; D014195:Travel