T Lymphocyte Subpopulations in Anorexia Nervosa and Refeeding
Several studies have addressed the question of the effects of starvation on immune function and changes in lymphocyte subsets. Patients with anorexia nervosa are severely malnourished, but there have been few studies of immune parameters in this group. For this reason, phenotypic markers of T cell function and activation were studied in 20 severely underweight patients with anorexia nervosa and again after a period of refeeding. The most significant finding was a reduction in the percentage and absolute number of CD8+ T cells in patients with anorexia, the result of a marked reduction in memory (CD45RO+RA-) CD8 cells. A tendency for recovery in numbers of this subset was seen after refeeding. A decreased memory:maive cell ratio was also seen among CD4 cells, but was less marked. Subtle abnormalities in activated CD4 and CD8 cells were also found in the patient group at the initial sampling, but did not follow any clear pattern. These findings indicate that starvation in anorexic patients is accompanied by a large change in memory CD8 T cells. It may be speculated that this relates to the perceived lack of symptomatic common viral infections in underweight anorexic patients and their return with the recovery of weight.
Available from: Samuel James Oliver
- "For example, it is not yet clear whether a deficit in energy intake per se or deficit in an individual macronutrient (e.g., protein; Norris et al., 1990) or micronutrient (e.g., zinc; Hosea, Rector, & Taylor, 2004) is responsible. A role for raised circulating cortisol has been proposed to account for decreased circulating T-lymphocyte populations in anorexia nervosa patients during starvation (Mustafa et al., 1997) and low lymphoid-organ cell numbers in rats during energy restriction (Fraker, King, Laakko, & Vollmer, 2000). Indeed, lower CD4 + CD8 + pre-T cells in the thymus of zinc-deficient and energy-deficient mice has been attributed to greater apoptosis resulting from elevated circulating cortisol (Hosea et al.; King et al., 2002). "
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ABSTRACT: The aim was to investigate the effects of 48 hr of fluid, energy, or combined fluid and energy restriction on circulating leukocyte and lymphocyte subset counts (CD3+, CD4+, and CD8+) and bacterially stimulated neutrophil degranulation at rest and after exercise. Thirteen healthy men (M +/- SEM age 21 +/- 1 yr) participated in 4 randomized 48-hr trials. During control (CON) participants received their estimated energy (2,903 +/- 17 kcal/day) and fluid (3,912 +/- 140 ml/day) requirements. During fluid restriction (FR) they received their energy requirements and 193 +/- 19 ml/day water to drink. During energy restriction (ER) they received their fluid requirements and 290 +/- 6 kcal/day. Fluid and energy restriction (F+ER) was a combination of FR and ER. After 48 hr, participants performed a 30-min treadmill time trial (TT) followed by rehydration (0-2 hr) and refeeding (2-6 hr). Circulating leukocyte and lymphocyte counts remained unchanged for CON and FR. Circulating leukocyte, lymphocyte, CD3+, and CD4+ counts decreased by ~20% in ER and ~30% in F+ER by 48 hr (p < .01), returning to within 0-hr values by 6 hr post-TT. Circulating neutrophil count and degranulation were unaltered by dietary restriction at rest and after TT. In conclusion, a 48-hr period of ER and F+ER, but not FR, decreased circulating leukocyte, lymphocyte, CD3+, and CD4+ counts but not neutrophil count or degranulation. Circulating leukocyte and lymphocyte counts normalized on refeeding. Finally, dietary restriction did not alter circulating leukocyte, lymphocyte, and neutrophil responses to 30 min of maximal exercise.
Available from: Tivadar L Tulassay
- "Interestingly, AN patients are well protected against infections for a long time (Marcos et al., 2003). Several data support that during the initial and mid-phase of AN only CD8 þ lymphocytes (cell type responsible for cell-mediated immunity) are affected, whereas the function of CD4 þ lymphocytes (conductors of the immune response) are maintained for a long time (Mustafa et al., 1997). From this point of view, immune system in AN is strikingly different from that in other forms of starvation (Marcos, 2000). "
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ABSTRACT: The aim of our study was to determine, how severe calorie restriction in anorexia nervosa (AN) may influence regulatory T (Treg) cells and their cellular networks, that is, their main inducers (dendritic cells (DC) and monocytes) and their target cells, CD4+ lymphocytes.
We measured the prevalence of Tregs, myeloid and plasmocytoid DC. The prevalence of tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-12-positive monocytes, IL-2, IL-4 and interferon (IFN)-gamma positive CD4+ cells was determined by intracellular staining after activation.
In total, 21 AN patients and 19 healthy age-matched controls (body mass index values, median (range): 14.9 (11.1-17.4) vs 23.2 (19.5-27.4) kg/m(2)) have been recruited.
Prevalence of Tregs, DCs, TNF-alpha and IL-12-positive monocytes, IL-4 and IFN-gamma-producing CD4+ cells were similar in AN and controls. The prevalence of IL-2-positive CD4+ cells was somewhat lower in AN (% value, median (range): 12.05 (7.50-16.70) vs 14.40 (12.00-22.00), P<0.05). None of these parameters correlated with the patients' clinical characteristics.
Our results suggest that the antigen presenting cell - regulatory T cell - CD4+ lymphocyte axis is not affected by calorie and nutritional deficiency.
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ABSTRACT: The purpose of this study was to assess anthropometry and immune responses in three groups of young females age 13–17 years: 24 anorexia nervosa patients (ANP), 10 elite gymnasts (GYM) who exercised for at least 48 hours per week, and 50 sedentary students who exercised for less than 12 hours per week and were assessed as controls (C). BMI, IBW, total leukocyte and lymphocyte counts, CD2, CD3, CD$ and CD8 subset counts were lower in GYM and ANP groups compared with controls. Leukocyte count was higher and lymphocyte count was lower in GYM than in ANP. CD56 counts were the lowest in ANP and were similar in GYM and C groups. The response to delayed hypersensitivity tests was lower in GYM compared to than in C group. None of the ANP subjects showed any response, thereby demonstrating complete anergy. It may be concluded that both anthropometry and immunological tests are consistent with the presence of subclinical malnutrition in GYM and ANP groups, particularly the latter. These findings should form the basis of strategies for prevention of overt malnutrition and its consequences in young elite sportswomen.
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