Parameters of the Immune System and Vitamin D Levels in Old Individuals

Abstract

AimThe increased number of individuals older than 80 years, centenarians, and supercentenarians is not a synonym for healthy aging, since severe infections, hospitalization, and disability are frequently observed. In this context, a possible strategy is to preserve the main characteristics/functions of the immune system with the aim to cause less damage to the organism during the aging process. Vitamin D acts on bone marrow, brain, breast, malignant cells, and immune system and has been recommended as a supplement. We aimed to evaluate whether immune parameters and vitamin D serum levels are correlated.MethodsWe evaluated some features of the immune system using the peripheral blood of individuals older than 80 years (n = 12) compared to young subjects (n = 10). In addition, we correlated these findings with vitamin D serum levels.ResultsOld individuals presented metabolic parameters of healthy aging and maintained preserved some features of immunity such as CD4/CD8 ratio, and low production of pro-inflammatory cytokines after stimulus. On the other hand, we observed increase in the frequency of myeloid-derived suppressor cells, reduction in circulating leukocytes, in the percentage of total CD8+, and in CD8+ Naïve T cells, in addition to increase in the percentage of CD8+ effector memory re-expressing CD45RA (EMRA) T cells. We found seropositivity for CMV in 97.7%, which was correlated with the decrease of CD8+ Naïve T cells and increase in CD8+ EMRA T cells. Vitamin D levels were insufficient in 50% of old individuals and correlated positively with total CD8+ T cells and negatively with CD8+ EMRA T cells.ConclusionIn the studied population, longevity was correlated to maintenance of some immune parameters. Considering the limitations of the study as size of the sample and lack of functional assays, it was found that vitamin D in old individuals was correlated to some features of the immune system, mainly in the CD8 compartment.

Why does COVID-19 disproportionately affect older people?

“…Due to a lack of sun exposure and decreased production of vitamin D, about half of all older people have a deficiency in this vitamin [53], which reduces the efficacy of both adaptive and innate immune responses and increases the risk of infection [54]. Vitamin D levels in older people are correlated with preserved features of immunity such as the CD4 + /CD8 + ratio and lower levels of pro-inflammatory cytokines after stimulus [54,55].…”

ER stress activates immunosuppressive network: implications for aging and Alzheimer’s disease

“…Currently, there is convincing evidence that the numbers of immunosuppressive MDSCs increases with aging in the blood of both humans [158,159] and mice [160]. Several studies have also revealed an age-related increase in the accumulation of MDSCs into mouse bone marrow, spleen, and lymph nodes [160,161].…”

Immunosenescence: the potential role of myeloid-derived suppressor cells (MDSC) in age-related immune deficiency

“…There is convincing evidence that the aging process increases the frequencies of circulating MDSCs, in both humans [ 108 , 109 ] and mice [ 110 ]. Verschoor et al [ 108 ] revealed that the levels of the CD11b + CD15 + -positive, granulocytic MDSCs were increased in the blood of community-dwelling seniors (61–76 years) and especially in frail elderly people (67–99 years).…”

“…Verschoor et al [ 108 ] revealed that the levels of the CD11b + CD15 + -positive, granulocytic MDSCs were increased in the blood of community-dwelling seniors (61–76 years) and especially in frail elderly people (67–99 years). Recently, Alves et al [ 109 ] demonstrated that the percentage of MDSCs was significantly higher in the blood of old people (80–100 years) than in their younger counterparts (20–30 years). Especially, the percentage of granulocytic MDSCs was robustly upregulated, while that of monocytic MDSCs was unaffected.…”