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Published on: April 16, 2012
Thymopoiesis in elderly human is associated with systemic inflammatory status
Sara Ferrando-Martínez1, Jaime M Franco, Ana Hernandez
1Laboratory of Immunovirology, Biomedicine Institute of Seville (IBIS), Service of Infectious Diseases, Virgen del Rocío University Hospital, Manuel Siurot s/n, 41013, Seville, Spain.
Age (Dordrecht, Netherlands)
|June 10, 2009
Summary
The aging thymus remains active, producing T cells that rejuvenate the immune system. Thymic function in elderly individuals is linked to inflammation markers, impacting immune cell populations.
Area of Science:
- Immunology
- Gerontology
- Cell Biology
Background:
- Immunosenescence, the age-related decline of the immune system, is a significant factor in health and disease.
- Previous studies on immune reconstitution have focused on lymphopenia and androgen blockade, leaving the thymus's role in elderly humans largely unexplored.
- Understanding thymic function in aging is crucial for addressing age-related immune dysfunction.
Purpose of the Study:
- To investigate the extent of lymphopoiesis (the formation of lymphocytes) in the thymus of elderly humans.
- To determine the relationship between thymic cellularity, peripheral T-cell populations, and inflammation markers in aging.
- To assess the thymus's capacity to influence immune reconstitution in older adults.
Main Methods:
- Analysis of 65 adult human thymuses from individuals aged 36 to 81 years (median age 68.6 years).
- Quantification of CD4(+)CD8(+) double-positive (DP) cells within thymuses.
- Correlation analysis with peripheral naive T-cell percentages, neutrophil counts, IL-6 levels, and IL-7 levels.
Main Results:
- A significant inverse correlation was found between DP cells and age, and a direct correlation with peripheral naive T cells.
- Thymopoiesis (thymus-derived lymphocyte production) showed inverse correlations with inflammation markers (neutrophils and IL-6).
- DP cells and IL-7 levels, not age, were independently associated with neutrophil percentages in multivariate analysis.
Conclusions:
- The thymus maintains active thymopoiesis in elderly individuals, contributing to the rejuvenation of the peripheral naive T-cell pool.
- Age-related decline in thymopoiesis is associated with peripheral inflammation markers.
- The thymus remains a relevant factor in immune function even in advanced age.
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