Reduced IFN-gamma production in elderly people following in vitro stimulation with influenza vaccine and endotoxin.

Cytokine interferon gamma (IFN-gamma) is pivotal in the defence against viruses and intracellular pathogens and an age-related decreased IFN-gamma production may explain the increased infectious disease morbidity and mortality in the elderly. Therefore, we performed a series of clinical experiments evaluating the influence of age and health status on IFN-gamma production following in vitro stimulation with influenza vaccine or endotoxin. Both healthy and frail elderly people produced significantly lower amounts of IFN-gamma following ex vivo stimulation with influenza vaccine or endotoxin. We conclude that ageing is accompanied by a decreased capacity to produce IFN-gamma. This may explain the increased incidence and case-fatality caused by viruses and intracellular pathogens in the elderly.