BACKGROUND:
The challenge of immune senescence has never been addressed in elderly cancer patients. This study compares the thymic output and peripheral blood telomere length in 70≥years old cancer patients.
PATIENTS AND METHODS:
Fifty-two elderly cancer patients and 39 age-matched controls without personal history of cancer were enrolled. All patients underwent a Comprehensive Geriatric Assessment (CGA), from which a multidimensional prognostic index (MPI) score was calculated. Peripheral blood samples were studied for naïve and recent thymic emigrant (RTE) CD4+ and CD8+ cells by flow cytometry. T-cell receptor rearrangement excision circle (TREC) levels, telomere length and telomerase activity in peripheral blood cells were quantified by real-time PCR.
RESULTS:
The percentages of CD8+ naïve and CD8+ RTE cells and TREC levels were significantly lower in cancer patients than in controls (p=0.003, p=0.004, p=0.031, respectively). Telomere lengths in peripheral blood cells were significantly shorter in cancer patients than in controls (p=0.046) and did not correlate with age in patients, whereas it did in controls (r=-0.354, p=0.031). Short telomere (≤median)/low TREC (≤median) profile was associated with higher risk of cancer (OR=3.68 [95%CI 1.22-11.11]; p=0.021). Neither unfitness on CGA nor MPI score were significantly related to thymic output or telomere length in either group.
CONCLUSIONS:
Immune senescence is significantly worse in elderly cancer patients than in age-matched controls. The low thymic output and the shorter telomeres in peripheral blood cells of cancer patients may reflect a pre-existing condition which facilitates the onset of malignancies in elderly people.
© 2013. Published by Elsevier Inc. All rights reserved.
KEYWORDS:
ADL, Activities of Daily Living, CGA, CIRS-CI, CIRS-SI, CMV, Cumulative Illness Rating Scale-Comorbidity Index, Cumulative Illness Rating Scale-Severity Index, Cytomegalovirus, GDS, Geriatric Depression Scale, IADL, Instrumental Activities of Daily Living, MMSE, MNA, MPI, Mini Mental Status Examination, Mini Nutritional Assessment, PBMC, RTE, RU, SPMSQ, Short Portable Mental Status Questionnaire, T-cell receptor rearrangement excision circle, T/S, TREC, cancer, comprehensive geriatric assessment, elderly, immune senescence, multidimensional prognostic index, peripheral blood mononuclear cells, recent thymic emigrant, relative units, telomerase activity, telomere length, telomere/single-copy gene, thymic output
PMID: 24120567
