Age‐dependent decreases in mitogen‐stimulation level and RNA content in peripheral blood mononuclear cells of down syndrome patients

Abstract

Objective: The aim of the present study was to determine whether or not the phytohemagglutinin (PHA)-activated proliferation and average RNA content in peripheral blood mononuclear cells (PBMC) of Down syndrome (DS) patients change with age.Method: Stimulated portion of PBMC and total RNA levels in these cells after 72 h of PHA stimulation from 38 DS patients were compared with 28 age-matched healthy controls using flow cytometric measurement.Results: Decreased ratio of PBMC from DS patients undergoes mitogenic stimulation with age (r = À0.84, P = 0.000). This decrease is not observed in the cells of control individuals (r = 0.03, P = 0.869). Stimulated PBMC in infants with DS have higher level of RNA contents compared to controls (Z = 2.227, P = 0.026). While RNA content in mitogen-stimulated PBMC of DS decreased progressively and significantly with age (r = À0.70, P = 0.000), no significant age-related change in RNA content was found among the cells of healthy individuals in the range of 0-27 year old (r = 0.275, P = 0.157, P > 0.05).Conclusion: Age-dependent decreases in mitogen-activated proliferation ratio and average RNA content of PBMC from DS patients appear as regular events. These results may contribute to the explanation of the immune deficiency seen in DS patients since the PHA-stimulated cells are principally T-lymphocytes. This is the first report on the decrease in PHA-stimulated proliferation ratio (stimulability) and RNA level in PBMC of DS patients in relation to age. q 2006 Clinical Cytometry Society

Nuclear protein contents in peripheral blood mononuclear cells of trisomy 21 infants

“…The challenge (8) and highly variable phenotype (4,8) of DS patients appear also in this area. The age-dependent decrease in protein content in PBMC nuclei of DS patients is similar to the age-dependent decrease in RNA content in PBMC of DS patients (24,25).…”

“…Present report shows that average nuclear protein content of PBMC measured by flow cytometry (FC) from DS infants is statistically higher than that of controls. The average nuclear protein levels of PBMC from DS patients decrease, however, with the age of the patients similar as seen in the case of RNA levels (24,25) in PBMC of these patients.…”

“…This in vivo (24) and in vitro RNA levels (25) decline, however, with the ages of the patients, to become finally lesser than that of controls as early as in the age of 15-20s.…”

NOR expression increases on metaphase chromosomes of down syndrome lymphocytes in concordance with mitogen concentration in culture medium

“…Could this observation serve in a new approach on the bases of wasted energy in DS cells due to overexpression of rDNA, NOR, or other protein synthesis? Our preliminary results on the comparison of total RNA levels in cells from DS infants/ children with those of controls were in favor of this hypothesis (19).…”

Pulmonary Botryomycosis in a Patient With Down Syndrome

“…It is the first case reported in a Down syndrome patient, which might be related to the already described immune dysfunction in these patients. [9] Unlike the other reported cases of pulmonary botryomycosis that usually presented with discrete lung masses, this patient presented with empyema and clinical sepsis. Other less common radiological variations include cavitatory lesions, consolidations or diffuse infiltrations.…”