Table 1.
T lymphocyte compartment in subjects with Down syndrome
| Author | Year | Number of subjects | Age | Main result |
|---|---|---|---|---|
| Burgio et al. [62] | 1975 | 83 DS subjects | Age groups: 0–5 years: 21 subjects | Correlation between PHA responsiveness and age (normal response before 11 years old) |
| 76 age-matched controls | 6–10 years: 8 subjects. 11–15 years: 10 subjects. 16–20 years: 18 subjects. 21–25 years: 18 subjects. 26–30 years: 8 subjects | |||
| Franceschi et al. [59] | 1981 | 28 DS subjects | DS subjects: age range: 6–23 years | No difference in lymphocyte counts |
| 28 age-matched controls | Controls: age range: 10–27 years | Impairment in the PHA and autologous mixed lymphocyte reaction responses | ||
| Karttunen et al. [61] | 1984 | 18 DS subjects | DS subjects: mean age = 20 years | Low response to PHA-induced stimulation in half of the DS subjects. Strong negative correlation between the age and the response. Normal IL-2 production |
| Controls (n = NA) | Controls: adults, mean age NA | Inversion of CD4+/CD8+ ratio | ||
| Lockitch et al. [51] | 1987 | 64 DS subjects | DS subjects: age range: 1–19 years | Lower lymphocytes, T lymphocytes, T helper, and suppressor cell counts |
| 30 age-matched controls | Controls: age range: 1–19 years | Reduced response to PHA in vitro | ||
| Cossarizza et al. [47] | 1990 | 15 DS children | NA | Decrease of the absolute number of circulating lymphocytes and of the absolute number of CD4+ cells |
| 16 age-matched controls | Increase in the percentages of CD8+ cells | |||
| Murphy et al. [54] | 1992 | 13 DS subjects | NA | Lower naïve T cells in peripheral blood |
| 13 age-matched controls | ||||
| Barrena et al. [45] | 1993 | 89 DS subjects | 30 children with DS (mean age = 7.9 years) and 59 adults with DS (mean age = 34 years) | Decrease in CD4+CD45RA+ cells. Inversion of CD45RA/CD29 ratio |
| 59 age-matched controls | ||||
| Park et al. [60] | 2000 | 43 DS subjects | DS subjects: mean age = 45 years | Lower PHA-stimulated proliferation and IL-2 production in aged individuals (> 30 years old) |
| 43 age-matched controls | Controls: NA | |||
| Cocchi et al. [46] | 2007 | 30 DS subjects | Children born from 1999 to 2004 | In the five first years of life, progressive decrease in the medium values of lymphocytes and CD4+ levels, with a concomitant increase in CD8+ cells. Lower values of lymphocyte and CD4+ cell counts. Lower CD4+/CD8+ ratio |
| Guazzarotti et al. [52] | 2009 | 25 DS subjects | DS subjects: mean age = 12.2 years | Reduction of percentages and absolute numbers of CD4+ T cells. Reduction of CD4+/CD8+ ratio |
| 42 age-matched controls | Controls: mean age = 11.7 years | Reduction of naïve CD4+ and CD8+ T cells. Increase in central memory and terminally differentiated CD4+ lymphocytes | ||
| Cetiner et al. [63] | 2010 | 32 DS subjects | DS subjects: mean age = 3.9 years | Higher percentage of CD8+ T cells. Similar percentage of CD4+ T cells and similar CD4+/CD8+ ratio |
| 32 age-matched controls | Controls: mean age = 4.5 years | |||
| Joshi et al. [48] | 2011 | 12 DS subjects | DS subjects: mean age = 9.4 years | Lower percentages of CD3+ T cells and CD8+ T cells, lower absolute numbers of CD4+ T cells. Lower CD4+/CD8+ ratio |
| 12 age-matched controls | Controls: mean age = 9.4 years | |||
| Trotta et al. [50] | 2011 | 24 DS subjects | DS subjects: mean age = 38 years | Similar percentages of CD3+ T cells. Higher percentages of CD8+ T cells |
| 21 age-matched controls | Controls: mean age = 43 years | |||
| Pellegrini et al. [53] | 2012 | 29 DS subjects | DS subjects: mean age = 11.4 years | Decrease in CD4+ T cells. Increase in CD8+ T cells. Decrease of CD4+/CD8+ ratio |
| 29 age-matched controls | Controls: mean age = 9.3 years | Increase in the number of circulating Treg (CD4+CD25+FoxP3+) cells, with impaired function in vitro | ||
| Schoch et al. [49] | 2017 | 40 DS subjects | DS subjects: mean age = 7.4 years | Lower levels of CD4+ T cells, no differences in CD8+ T cells |
| 51 age-matched controls | Controls: mean age = 8.8 years | Higher Th1/Th2 ratio and higher percentages of regulatory T cells | ||
| Higher expression of the inhibitory receptor PD-1 in all T cell subpopulations | ||||
| Farroni et al. [55] | 2018 | 12 DS subjects | NA | Reduction of Tfh cells in peripheral blood and tonsils. Impairment of the germinal center reaction |
| 11 age-matched controls | ||||
| Mitwalli et al. [23] | 2018 | 150 DS subjects | DS subjects: mean age = 5.56 years | Reduction in total lymphocyte count. Decrease in CD4+ T cells |
| 100 age-matched controls | Controls: mean age = 6.11 years | |||
| Waugh et al. [56] | 2019 | 18 DS subjects | DS subjects: median age = 29.5 years | No difference in total CD4+ T cells. Decrease in naïve CD4+ T cells. Enrichment in CD27+ CD4+ memory T cells |
| 18 age-matched controls | Controls: median age = 28.0 years | |||
| Araya et al. [57] | 2019 | 31 DS subjects | DS subjects: median age (cohort 1) = 26.4 years, median age (cohort 2) = 28.3 years, median age (cohort 3) = 29.6 years | Higher percentage of CD8+ T cells. Decreased frequency of CD4+ T cells. Lower CD4/CD8 ratio. Enrichment in differentiated and senescent CD8+ subsets |
| 40 age-matched controls | Controls: median age (cohort 1) = 33.1 years, median age (cohort 2) = 27.9 years, median age (cohort 3) = 30.2 years |
DS, Down syndrome; NA, not available; PHA, phytohemagglutinin