Background: Mindfulness-based programs have shown a promising effect on several health factors associated with increased risk of dementia and the conversion from mild cognitive impairment (MCI) to dementia such as depression, stress, cognitive decline, immune system and brain structural and functional changes. Studies on mindfulness in MCI subjects are sparse and frequently lack control intervention groups. Objective: To determine the feasibility and the effect of mindfulness-based stress reduction (MBSR) practice on depression, cognition and immunity in MCI compared to cognitive training. Methods: Twenty-eight MCI subjects were randomly assigned to two groups. MBSR group underwent 8-week MBSR program. Control group underwent 8-week cognitive training. Their cognitive and immunological profiles and level of depressive symptoms were examined at baseline, after each 8-week intervention (visit 2, V2) and six months after each intervention (visit 3, V3). MBSR participants completed feasibility questionnaire at V2. Results: Twenty MCI patients completed the study (MBSR group n=12, control group n=8). MBSR group showed significant reduction in depressive symptoms at both V2 (p=0.03) and V3 (p=0.0461) compared to the baseline. There was a minimal effect on cognition-a group comparison analysis showed better psychomotor speed in the MBSR group compared to the control group at V2 (p=0.0493) but not at V3. There was a detectable change in immunological profiles in both groups, more pronounced in the MBSR group. Participants checked only positive/neutral answers concerning the attractivity/length of MBSR intervention. More severe cognitive decline (PVLT≤36) was associated with the lower adherence to home practice. Conclusion: MBSR is well-accepted potentially promising intervention with positive effect on cognition, depressive symptoms and immunological profile.

Around half of people with severe COVID‐19 requiring intensive care unit (ICU) treatment will survive, but it is unclear how the immune response to SARS‐CoV‐2 differs between ICU patients that recover and those that do not. We conducted whole‐blood immunophenotyping of COVID‐19 patients upon admission to ICU and during their treatment and uncovered marked differences in their circulating immune cell subsets. At admission, patients who later succumbed to COVID‐19 had significantly lower frequencies of all memory CD8+ T cell subsets, resulting in increased CD4‐to‐CD8 T cell and neutrophil‐to‐CD8 T cell ratios. ROC and Kaplan‐Meier analyses demonstrated that both CD4‐to‐CD8 and neutrophil‐to‐CD8 ratios at admission were strong predictors of in‐ICU mortality. Therefore, we propose the use of the CD4‐to‐CD8 T cell ratio as a marker for the early identification of those individuals likely to require enhanced monitoring and/or pro‐active intervention in ICU.

Immune cells are highly dynamic in their response to the tissue environment. Most immune cells rapidly change their metabolic profile to obtain sufficient energy to engage in defensive or homeostatic processes. Such “immunometabolism” is governed through intermediate metabolites, and has a vital role in regulating immune‐cell function. The underlying metabolic reactions are shaped by the abundance and accessibility of specific nutrients, as well as the overall metabolic status of the host. Here, we discuss how different immune‐cell types gain a sufficient energy supply. We then explain how immune cells perform various functions under challenged conditions and expend energy to sustain homeostasis. Finally, we speculate on how the immune‐cell metabolic profile might be modulated in health and disease, by manipulating nutrient availability. By such intervention, the recovery of patient with dysregulated immune system responses might be sped up and the fitness of an individual efficiently restored.