Circulating interleukin-15 in dementia disorders

The objective of this study was to assess the role of interleukin-15 (IL-15) as a potential marker of immune reactions in patients with Alzheimer’s disease and vascular dementia. The authors measured by immunoassay serum IL-15 levels in 20 patients with Alzheimer’s disease and 15 patients with vascular dementia and compared them with serum IL-15 levels in 15 healthy subjects. The authors also studied the effect of treatment with acetylcholinesterase inhibitors (AChEI) on serum IL-15 levels. Patients with Alzheimer’s disease were found to have significantly lower serum IL-15 levels compared with healthy subjects and patients with vascular dementia. Healthy subjects and patients with vascular dementia did not differ between each other. Age, sex, disease duration, and Mini-Mental State Examination score did not affect IL-15 levels in any of the groups. Treatment with AChEI had no influence on IL-15 concentrations. The findings suggest that IL-15 is not implicated in the pathogenetic mechanisms of Alzheimer’s disease and vascular dementia. An immune hyporesponsiveness at some point during disease development may be responsible for the lower levels of IL-15 and other cytokines in Alzheimer’s disease patients

Serum oxidized low-density lipoprotein is inversely correlated to telomerase activity in peripheral blood mononuclear cells of haemodialysis patients

Background. Telomerase preserves telomeres’ function and structure preventing cellular senescence. Its activity is reduced in peripheral blood mononuclear cells (PBMC) of haemodialysis (HD) patients. The purpose of this study is to investigate the potential correlation between increased oxidative stress/inflammation and telomerase activity in PBMC of HD patients. Methods: Telomerase activity was measured by PCR-ELISA in PBMC isolated from a group of 42 HD patients and 39 subjects with estimated glomerular filtration rate >= 80 mL/min (control group). Serum oxidized low-density lipoprotein (ox-LDL), tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) were also measured in both groups by ELISA. Results: Ox-LDL was negatively correlated to percentage telomerase activity in PBMC (r = -0.506, P = 0.000 in the whole group of 81 HD and normal subjects and r = -0.559, P < 0.001 in HD patients). TNF was also inversely associated with percentage telomerase activity in the whole group studied (r= -0.492, P= 0.000) while IL-10 was not. In stepwise multiple linear regression, taking into consideration the most important characteristics of the HD patients and control group, the only significant predictors for percentage telomerase activity in PBMC were ox-LDL and TNF (beta = -0.421, t= -4.083, P= 0.000 and beta= -0.381, t= -3.691, P= 0.000, respectively) while examining separately HD patients, the predictors for the same parameter were ox-LDL and HD duration (beta = -0.671, t = -4.709, P = 0.000 and beta= -0.349, t = -2.447, P = 0.023, respectively). Conclusion: Ox-LDL serum level is inversely correlated to telomerase activity in PBMC of HD patients. Our study proposes a new consequence of increased oxidative stress in HD patients: the premature cellular senescence potentially related to atherosclerosis through LDL oxidation