title: No evidence for altered cellular immune functions in personnel deployed in the Persian Gulf during and after the Gulf War--The Danish Gulf War study.
abstract: Veterans who have participated in the Gulf War suffer from a number of symptoms, collectively referred to as the Gulf War Syndrome. It has been hypothesized that a change in the systemic cytokine balance or other changes in immunological parameters could be responsible for some of the symptoms. We analyzed the peripheral blood natural killer (NK) cell activity of 686 Gulf War personnel who had been present in the Persian Gulf area during and immediately after the Gulf War as well as 231 gender and age-matched controls. The test material included individual samples of frozen peripheral blood mononuclear cells kept at -139 degrees C for a period of 50 to 380 days prior to NK cell analysis of freshly thawed cells. Significant differences in NK-cell activity were not observed by direct comparison of the levels of natural cytotoxic activity in the two groups. However, NK-cell cytotoxicity as such decreased due to cryopreservation. Surprisingly, the NK cells obtained from control donors were significantly (p<0.0001) more sensitive to freezing conditions than cells from the Gulf War personnel, leaving the marginal comparison between the two groups untrustworthy, in particular because of the marked difference between the -139 degrees C storage times used for the two groups. Freshly thawed samples of peripheral blood T lymphocytes (CD2+ cells) from 109 randomly selected Gulf War personnel and 68 gender- and age-matched controls were stimulated for 3 days with phytohemagglutinin followed by 4 h activation by phorbol ester and ionomycin, and were stained for intracellular content of interleukin-2, -5, -10 and interferon-gamma. As with natural cytotoxicity, the length of cell storage at -139 degrees C influenced the production of cytokines. No significant differences in the cytokine production between the two groups were observed when the influence of the storage period was taken into consideration. Together, these data suggest that no overall long-term effects on NK-cell function and T-cell cytokine production are present in the Danish Gulf War personnel. Moreover, cryopreservation is a major potential source of bias when studying the physiology of thawed NK and T cells.
authors.affiliation: Department of Medical Anatomy, The Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Bregenholt
authors.forename: T
authors.initials: T
authors.lastname: Ishøy
authors.forename: L T
authors.initials: LT
authors.lastname: Skovgaard
authors.forename: P
authors.initials: P
authors.lastname: Suadicani
authors.forename: M
authors.initials: M
authors.lastname: Appleyard
authors.forename: B
authors.initials: B
authors.lastname: Guldager
authors.forename: L
authors.initials: L
authors.lastname: Malte
authors.forename: F
authors.initials: F
authors.lastname: Gyntelberg
authors.forename: M H
authors.initials: MH
authors.lastname: Claesson
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000096:biosynthesis; D003602:Cytotoxicity, Immunologic; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D018923:Persian Gulf Syndrome / Q000276:immunology*
chemical_list: D016207:Cytokines