Why do Some People Susceptible to the Flu?

Researchers at Carnegie Mellon University in Pittsburgh identified a biological marker in the our immune system that can predict a person's ability to fight the flu. Identified Biomaker began at the age of 22 years.

The study, led by researcher Sheldon Cohen and published in the Journal of the American Medical Association (JAMA) reveals that the length of telomeres (protein complexes similar to the protective caps at the ends of chromosomes) predicts resistance to upper respiratory tract in adults and middle-aged.

Telomere length is a biomarker of aging due to telomere shortening in conjunction with increasing age. When the telomeres become shorter cells, telomeres will lose its ability to function normally and eventually die.

Short telomeres are associated with the onset of diseases of aging, such as heart disease and cancer, and death in middle-aged people. Until now not known whether telomere length plays a role in health care to middle-aged adults.

"Our research suggests that telomere length is a marker of a relatively consistent across the life span and began to be used to predict disease susceptibility in adulthood," said Cohen, a professor of psychology at the Dietrich College of Humanities and Social Sciences. "We know that people in their late 50's or older who have shorter telomeres are at risk of suffering from disease and death. We also know that in addition to aging, other factors such as chronic stress and poor health behaviors, associated with shorter telomeres in the elderly."

Cohen and his team conducted a study to determine whether shorter telomeres in leukocytes, especially CD8CD28- T cells, are associated with decreased resistance to upper respiratory infection and clinical illness in young to middle-aged adults. Between 2008 and 2011, telomere length was assessed in peripheral blood mononuclear cells (PBMCs) and T-cell subsets (CD4, CD8CD28+ , CD8CD28-) from 152 healthy 18- to 55-year-old residents of Pittsburgh. Participants were subsequently quarantined (single rooms), administered nasal drops containing a common cold virus (rhinovirus 39), and monitored for 5 days for development of infection and clinical illness.

Individuals with shorter leukocyte telomere length demonstrate less resistance to experimentally-induced viral URI. (Picture from: http://www.2minutemedicine.com/)

Sixty-nine percent of participants (n = 105) developed respiratory infections; 22 percent of the entire sample (n = 33) developed a clinical illness (common cold).The researchers found that shorter telomere lengths in all 4 cell types were associated with increased odds of infection following exposure to RV39. However, CD8CD28- telomere length had the largest association with infection. The rate of infection in the CD8CD28- subset was 77 percent among participants in the group with the shortest telomeres and 50 percent for those in the group with the longest telomeres.

Analysis indicated that only telomere length in the CD8CD28- subset was associated with risk for clinical illness, with shorter telomere length associated with increased risk. Among participants with the shortest telomeres, 26 percent became clinically ill. The rate for clinical illness was 13 percent for those in the group with the longest telomeres. Also, the magnitude of the association between CD8CD28- telomere length and infection increased with increasing age.

"In this study of healthy young and midlife adults, shorter CD8CD28- cell telomere length was associated with upper respiratory tract infection and clinical illness following experimental exposure to rhinovirus. Because these data are preliminary, their clinical implications are unknown," the authors conclude.. *** [SCIENCEDAILY | MNT | CARNEGIE MELLON UNIVERSITY | TJANDRA DEWI | KORAN TEMPO 4150]

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