Importance: Although leukocyte telomere length is associated with mortality and many chronic diseases thought to be manifestations of age-related functional decline, it is not known whether it relates to acute disease in younger healthy populations.
Objective: 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 midlife adults.
Design, setting, and participants: 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, Pennsylvania. 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.
Main outcome measures: Infection (virus shedding or 4-fold increase in virus-specific antibody titer) and clinical illness (verified infection plus objective signs of illness).
Results: Rates of infections and clinical illness were 69% (n = 105) and 22% (n = 33), respectively. Shorter telomeres were associated with greater odds of infection, independent of prechallenge virus-specific antibody, demographics, contraceptive use, season, and body mass index (PBMC: odds ratio [OR] per 1-SD decrease in telomere length, 1.71 [95% CI, 1.08-2.72]; n = 128 [shortest tertile 77% infected; middle, 66%; longest, 57%]; CD4: OR, 1.76 [95% CI, 1.15-2.70]; n = 146 [shortest tertile 80% infected; middle, 71%; longest, 54%]; CD8CD28+: OR, 1.93 [95% CI, 1.21-3.09], n = 132 [shortest tertile 84% infected; middle, 64%; longest, 58%]; CD8CD28-: OR, 2.02 [95% CI, 1.29-3.16]; n = 144 [shortest tertile 77% infected; middle, 75%; longest, 50%]). CD8CD28- was the only cell population in which shorter telomeres were associated with greater risk of clinical illness (OR, 1.69 [95% CI, 1.01-2.84]; n = 144 [shortest tertile, 26%; middle, 22%; longest, 13%]). The association between CD8CD28- telomere length and infection increased with age (CD8CD28- telomere length × age interaction, b = 0.09 [95% CI, 0.02-0.16], P = .01, n = 144).
Conclusion and relevance: In this preliminary study among a cohort of healthy 18- to 55-year-olds, shorter CD8CD28- T-cell telomere length was associated with increased risk for experimentally induced acute upper respiratory infection and clinical illness.