Cellular immune activation in Gulf War veterans

Area of Science:

• Immunology
• Military Medicine
• Epidemiology

Background:

• The health effects of Persian Gulf War deployment remain poorly understood.
• Multisymptom illnesses in veterans are suspected to involve immune system dysfunction.
• Previous research suggests a link between Gulf War deployment and chronic health issues.

Purpose of the Study:

• To investigate the hypothesis that sickness in Gulf War veterans is associated with altered immune function.
• To examine the peripheral blood Th1/Th2 balance in symptomatic versus well Gulf War veterans.
• To explore potential associations between immune alterations and specific exposures.

Main Methods:

• Nested case-control study within a large epidemiological survey.
• Measurement of intracellular cytokine production (IFN-gamma, IL-2, IL-4, IL-10) by CD4 T cells.
• Comparison of symptomatic Gulf War veterans (sGWV) with well GWVs (wGWV) and non-deployed/Bosnian veterans.

Main Results:

• Symptomatic Gulf War veterans exhibited altered immune status compared to controls.
• Elevated levels of IFN-gamma and IL-2 producing CD4+ cells were observed in sGWV, indicating Th1-type immune activation.
• Increased IL-10 producing memory CD4 cells were found in sGWV following in vitro stimulation.

Conclusions:

• Multisymptom illness in Gulf War veterans is characterized by ongoing Th1-type immune activation.
• A biased generation of memory cells secreting the suppressor cytokine IL-10 is associated with sickness.
• Vaccine exposure showed a trend towards reduced IFN-gamma production, suggesting potential immune modulation.