American Board of Surgery Qualifying Exam (ABS QE) Practice Test

Which aspect of the immune system is affected by aging?

1. Increased T cell production

2. Unchanged baseline neutrophil count but reduced production capacity

3. Enhanced response to new antigens

4. Lower levels of circulating cytokines

The correct answer is: Unchanged baseline neutrophil count but reduced production capacity

As individuals age, the immune system undergoes various changes that impact its function. One significant aspect of this aging process is related to neutrophil production and function. While the baseline neutrophil count may remain relatively unchanged, the body's ability to produce additional neutrophils in response to infections or inflammatory stimuli declines. This reduced production capacity affects the overall immune response, leading to increased susceptibility to infections and a less effective inflammatory response. Neutrophils are critical for the innate immune response, as they are often one of the first lines of defense against pathogens. As their production capacity diminishes with age, the elderly may experience a longer duration of infections and a delayed recovery due to the impaired ability to mobilize these essential immune cells when needed. The other options do not accurately depict how aging affects the immune system. The immune system does not generally increase T-cell production with age; in fact, the production of new T-cells may decline. The response to new antigens typically weakens, leading to a reduced capability to mount effective immune responses against new pathogens. Additionally, aging is often associated with increased levels of systemic inflammatory cytokines, rather than lower levels. Therefore, the correct understanding of the age-related changes in the immune system highlights the diminished