Alterations in B cell subsets correlate with body composition parameters in female adolescents with anorexia nervosa.

Anorexia nervosa (AN) is a severe eating disorder and often associated with altered humoral immune responses. However, distinct B cell maturation stages in peripheral blood in adolescents with AN have not been characterized. Treatment effects and the relationship between clinical and B cell parameters are also not fully understood. Here we investigated the phenotype of circulating B cell subsets and the relationship with body composition in adolescents with AN before (T0, n = 24) and after 6 weeks (T1, n = 20) of treatment. Using multi-parameter flow cytometry, we found increased percentages of antigen-experienced B cells and plasmablasts in patients with AN compared to healthy controls (n = 20). In contrast, percentages of CD1d+CD5+ B cells and transitional B cells with immunoregulatory roles were reduced at T0 and T1. These B cell frequencies correlated positively with fat mass, fat mass index (FMI), free fat mass index, and body mass index standard deviation score. In addition, scavenger-like receptor CD5 expression levels were downregulated on transitional B cells and correlated with fat mass and FMI in AN. Our findings that regulatory B cell subgroups were reduced in AN and their strong relationship with body composition parameters point toward an impact of immunoregulatory B cells in the pathogenesis of AN.

Brain-Behavior-Immune Interaction: Serum Cytokines and Growth Factors in Patients with Eating Disorders at Extremes of the Body Mass Index (BMI) Spectrum.

Alterations of the immune system are known in eating disorders (EDs), however the importance of cytokine balance in this context has not been clarified. We compared cytokines and growth factors at opposite ends of BMI ranges, in 90 patients classified in relation to BMI, depressive and EDs comorbidities. Serum concentrations of interleukin (IL)-1α, IL-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF) were determined by a biochip analyzer (Randox Labs). Differences were calculated through ANOVA. Possible predictors of higher cytokine levels were evaluated through regression analysis. IL-1α, IL-10, EGF, and IFN-γ were altered individuals with anorexia nervosa (AN) and binge eating disorder (BED). Night-eating was associated with IL-8 and EGF levels, IL-10 concentrations with post-dinner eating and negatively with sweet-eating, long fasting with higher IFN-γ levels. IL-2 increase was not linked to EDs, but to the interaction of depression and BMI. Altogether, for the first time, IL-1α, IL-10, EGF, and IFN-γ were shown to differ between AN and HCs, and between AN and individuals with obesity with or without BED. Only IL-2 was influenced by depression. Dysfunctional eating behaviors predicted abnormal concentrations of IL-10, EGF, IL-8 and IFN-γ.

Changes of endocrine function of adipose tissue in anorexia nervosa: comparison of circulating levels versus subcutaneous mRNA expression.

OBJECTIVE: To study the influence of chronic malnutrition in patients with anorexia nervosa on endocrine function of adipose tissue on both circulating and subcutaneous fat mRNA expression level. PATIENTS AND DESIGN: A total of 12 patients with anorexia nervosa and 18 normal weight age-matched women underwent anthropometric examination, single blood drawing and subcutaneous adipose tissue biopsy. MEASUREMENTS: Serum concentrations of high-sensitive CRP (hsCRP), leptin, soluble leptin receptor, adiponectin, resistin, interleukin-6 and insulin were measured by Luminex, enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA) kits. Subcutaneous adipose tissue mRNA expression of the same adipokines, adiponectin receptors 1 and 2 and immunocompetent cells marker CD68 was measured by real-time polymerase chain reaction (PCR). RESULTS: Decreased body fat content of patients with anorexia nervosa was accompanied by reduced hsCRP, leptin and increased adiponectin and soluble leptin receptor. Resistin, interleukin-6 and insulin levels did not differ from those of the control group. Fat mRNA adiponectin, leptin, interleukin-6 and CD68 expression was reduced, resistin mRNA expression was increased and adiponectin receptor 1 and 2 expression were unchanged as compared to the control group. CONCLUSIONS: Local perturbations in resistin, adiponectin and interleukin-6 mRNA expression in subcutaneous adipose tissue are not reflected by its circulating levels. These changes could be involved in some local metabolic disturbances in subcutaneous adipose tissue of anorexia nervosa patients.

Investigation of regulatory T cells in anorexia nervosa.

OBJECTIVE: 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. DESIGN: 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. SETTING AND SUBJECTS: 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. RESULTS: 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. CONCLUSIONS: Our results suggest that the antigen presenting cell - regulatory T cell - CD4+ lymphocyte axis is not affected by calorie and nutritional deficiency.

Disseminated tuberculosis with multiple intracerebral tuberculomas in a patient with anorexia nervosa.

OBJECTIVE: Multiple tuberculous mycobacterial infections infrequently occur in immunocompromised patients. The malnutrition resulted from anorexia nervosa may contribute to the significant impairment of immunity. The authors present a 23-year-old female patient initially diagnosed with anorexia nervosa. METHOD: Immunological study revealed that helper T-cell (CD4) and cytotoxic T-cell (CD8) comprised 25 and 32%, respectively, with a CD4 to CD8 ratio of 0.78. Brain magnetic resonance imaging revealed various multiple rings enhancing lesions with edematous change in both cerebral and cerebellar hemispheres. RESULTS: Open biopsy disclosed palisading epithelioid granuloma surrounded by inflamed granulation tissue. After anti-tuberculous therapy for 12 months, her weight was completely restored, but multiple intracranial tuberculomas were not completely disappeared. CONCLUSION: Disseminated tuberculous mycobacterial infections including multiple intracranial tuberculomas may be attributed to immunocompromised status in anorexia nervosa.

Chronic ACTH autoantibodies are a significant pathological factor in the disruption of the hypothalamic-pituitary-adrenal axis in chronic fatigue syndrome, anorexia nervosa and major depression.

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is a commonly recognized feature of many pathological conditions. Abnormal adrenal responses to experimental manipulation have been well documented in patients suffering from chronic fatigue syndrome, anorexia nervosa and major depression. Yet no defect of any single organ, gland or brain region has been identified as a cause of these abnormalities. The disruption of the HPA axis that occurs in these conditions can be understood if an interfering factor is present in these patients. Evidence indicates that this interfering factor is adrenocorticotropin hormone (ACTH) autoantibodies. Chronic high levels of ACTH autoantibodies will significantly disrupt the HPA axis and force the body to compensate for an impaired cortisol response. The resulting effect of chronic ACTH autoantibody interference is the manifestation of adrenocortical insufficient symptoms and psychological disturbances. Some symptoms of chronic fatigue syndrome, anorexia nervosa and major depression, such as anxiety, are the adverse effects of mechanisms compensating for less effective ACTH due to autoantibodies. Furthermore, these patients engage in extraordinary behaviors, such as self-injury, to increase their cortisol levels. When this compensation is inadequate, symptoms of adrenocortical insufficiency appear. Corticosteroid supplements have been demonstrated to be an effective treatment for chronic fatigue syndrome, anorexia nervosa and major depression. It allows the patients to have the corticosteroids they require for daily functioning and daily stressors. This therapy will relieve the patients of their symptoms of adrenocortical insufficiency and permit their cortisol-stimulating mechanisms to operate at levels that will not cause pathological problems.

Cytokine production by blood mononuclear cells from in-patients with anorexia nervosa.

Although protein-energy malnutrition is a common cause of immunodeficiency, the immune function in underweight anorexia nervosa (AN) patients usually seems to be better preserved than would be expected. However, a deranged cytokine production and its consequences are currently being investigated in these patients. This study was aimed at measuring, over time, the capacity of peripheral blood mononuclear cells (PBMC) from AN in-patients to produce several cytokines involved in the regulation of immune responses. The in vitro production of interferon (IFN)-gamma, interleukin (IL)-2, tumour necrosis factor (TNF)-alpha, IL-6 and IL-1 beta by phytohaemagglutinin-stimulated PBMC were assessed on forty female adolescents with AN. These measures were carried out twice, upon hospital admission and at discharge, which occurred on average after 1 month. Thirty-five control subjects were also studied. Cytokines were measured by ELISA kits. The production of TNF-alpha and IL-6 was lower and production of IL-1 beta higher in AN patients than in the control group at both time points of assessment. Refeeding for 1 month was not enough time to reverse these differences and patients still had a low body weight at discharge. IFN-gamma production was lower in the patients than in control subjects only at discharge and no differences were found in IL-2 production between both groups. The results suggest that a mechanism involving modifications in the secretion pattern of proinflammatory cytokines could explain some immune function findings in underweight AN patients.

Plasma concentrations of interleukin-1-beta, interleukin-6 and tumor necrosis factor-alpha, and of their soluble receptors and receptor antagonist in anorexia nervosa.

Interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) induce anorexia, and multiple behavioral and biochemical alterations that mimic those of anorexia nervosa. Reports in the literature, however, contain contrasting data on the pattern of secretion of the three cytokines and on the downstream activities of their receptors and receptor antagonists in anorexia nervosa. We measured plasma concentrations of IL-1beta, IL-6, TNF-alpha, soluble IL-6 receptor (sIL-6-R), soluble TNF-alpha receptors I and II (s-TNF-alpha-R-I and II), and soluble IL-1beta receptor antagonist (s-IL-1beta-R-A) in 14 female patients with anorexia nervosa (nine restricters, five binge/purgers) and in 13 age- and sex-matched healthy control subjects to see whether the circulating cytokine concentrations and the downstream steps of cytokine activity were impaired, and if these alterations were correlated with some aspects of the disease. Concentrations of IL-1beta, IL-6, TNF-alpha, s-TNF-alpha-R-I and -II and sIL-1beta-RA in plasma did not differ significantly in patients with anorexia nervosa compared with control subjects. Concentrations of sIL-6-R were significantly lower in the patients than in the control subjects, but there were no differences between the two sub-types of anorexia nervosa. The etiopathogenetic significance of the sIL-6-R alteration is not clear, but together with recent data in the literature on cytokine function, the finding suggests that an impairment of the pro-inflammatory cytokine pathway might be involved in the development of anorexia nervosa.

Eating disorders: a role for dipeptidyl peptidase IV in nutritional control.

Dipeptidyl peptidase IV (DPP IV), a serine protease with broad tissue distribution and known activity in serum, has been postulated to modulate nutrition control by modification or inactivation of peptide hormones operating in the enteroinsular axis. We hypothesized that changes of DPP IV activity in serum are related to the nutrition status of patients with eating disorders. Serum DPP IV activity was measured in 52 patients (28 with anorexia nervosa and 24 with bulimia nervosa) in four consecutive weekly analyses. Simultaneously, the number of CD26 (DPP IV)-positive peripheral blood lymphocytes was counted. The same analyses were carried out in 28 healthy female volunteers. In week 1 and throughout the observation period, DPP IV activity in the sera of patients with anorexia nervosa and, to a lesser extent, those with bulimia nervosa was elevated in comparison to that of healthy controls (week 1: means = 92.8 U/L for anorexia-nervosa patients and 89.3 U/L for bulimia-nervosa patients versus 74.7 U/L for healthy control subjects, P = 0.014; weeks 1-4: 91.8 U/L for anorexia-nervosa patients and 86.2 U/L for bulimia-nervosa patients versus 77.6 U/L for healthy controls, P < 0.001). We assume that the increase in DPP IV serum activity will increase the turnover of distinct peptide hormones with known effects on nutrition control and susceptibility to degradation by DPP IV. The potential impact of an increase in DPP IV activity in serum on satiety and nutrition control contributes to previously reported implications for immune function.

Evidence for a positive correlation between serum cortisol levels and IL-1beta production by peripheral mononuclear cells in anorexia nervosa.

A hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis has been reported in anorexia nervosa (AN), together with some immunological abnormalities, involving citokine - and particularly Tumor Necrosis-Factor-alpha (TNF-alpha) - production by polymorphonuclear cells. The ability of pro-inflammatory cytokines to activate the HPA axis is well known; however, there are no data demonstrating an interdependence between immunological and endocrine response in AN. To investigate the presence of a correlation between immune response and pituitary-adrenal function, plasma ACTH and serum cortisol concentrations were measured in 13 AN patients and in the same number of controls. TNF-alpha and interleukin (IL)-1beta production by ex-vivo unstimulated and LPS-stimulated peripheral mononuclear cells was also assessed. Circulating cortisol concentrations were higher (p<0.01) in AN (156.7 +/- 45.1 microg/l, mean +/- SD) than in controls (105.9 +/- 25.7 microg/l). Unstimulated IL-1beta release in supernatants of mononuclear cell cultures was slightly but not significantly higher in AN than in controls, while TNF-alpha release was similar in the two groups. A positive correlation was found between IL-1beta concentrations in unstimulated culture supranatants and serum cortisol levels in AN (r=0.782, p=0.002), while in normal subjects there was a trend toward a negative correlation; a slight positive correlation, while not significant, between IL-1beta and plasma ACTH, as well as between TNF-alpha and serum cortisol was also found in AN. These data suggest that the normal relationship between pro-inflammatory cytokines release, particularly IL-1beta, and cortisol secretion is deranged in AN.

Cytokine production in patients with anorexia nervosa, bulimia nervosa, and obesity.

OBJECTIVE: We previously reported elevated serum levels of the cytokines interleukin-6 (IL-6) and transforming growth factor-beta (TGF-beta) in patients with anorexia nervosa (AN). We investigated the cellular production of these two cytokines and of interferon-gamma (IFN-gamma), interleukin-1alpha (IL-1alpha), and tumor necrosis factor-alpha (TNF-alpha) in subjects with AN, bulimia nervosa (BN), and obesity as well as in normal-weight control subjects. METHODS: Supernatant fluids from isolated peripheral blood mononuclear cells (PBMC) incubated with and without concanavalin A (ConA) were assayed for cytokine concentrations by enzyme-linked immunosorbent assay (ELISA). RESULTS: Significant differences across the four groups were found in the stimulated cellular production of IFN-gamma and IL-6. Stimulated IFN-gamma production was elevated in the AN group compared to controls. IL-6 production was significantly elevated in obese subjects relative to the two normal-weight groups, BN and controls, and tended to be higher in the AN group than in the controls, but not significantly so. IL-1alpha production was greater in obese subjects. CONCLUSION: The findings of increased IFN-gamma production and a tendency toward increased IL-6 production (both of which suppress food intake in animals) in individuals who severely restrict food intake suggest a potential role for these cytokines in the pathogenesis of AN. Elevated IL-6 and IL-1alpha production by PBMC in obese individuals requires further investigation to determine if these cytokines contribute to the development or perpetuation of obesity.

Dipeptidyl peptidase IV (DPP IV, CD26) in patients with mental eating disorders.

The notion that patients with eating disorders maintain a functional immunosurveillance in spite of severe malnutrition has attracted researchers for years. Dipeptidyl Peptidase IV (DPP IV), a serine protease with broad tissue distribution and known activity in serum, operates in the cascade of immune responses. Membrane-bound DPP IV expressed on lymphocytes, also known as the leukocyte antigen CD26, is considered to participate in T cell activation. We hypothesized that the activity of DPP IV in serum and expression of CD26 in lymphocytes may be altered in patients with eating disorders. Serum DPP IV activity and the number of CD26 (DPP IV)-positive peripheral blood lymphocytes were measured in 44 patients (anorexia nervosa (AN): n = 21, bulimia (B): n = 23) in four consecutive weekly analyses. The analysis of CD26-positive cells included the characterization of CD26-bright and CD26-dim positive subsets. Additionally, the expression of CD25 (IL-2 Receptor alpha chain) was evaluated to estimate the degree of T cell activation. The same analyses were carried out in healthy female volunteers (HC, n = 20). CD26-positive cells were reduced in patients as compared to healthy controls (mean 40.2% (AN) and 41.1% (B) vs. 47.4% (HC), p < 0.01), while the DPP IV activity in serum was elevated (mean 108.4 U/l (AN) and 91.1 U/l (B) vs. 80.3 U/l (HC), p < 0.01). The potential implications of changes in DPP IV expression and serum activity on--and beyond--immune function are discussed.

Alterations in expression and in serum activity of dipeptidyl peptidase IV (DPP IV, CD26) in patients with hyporectic eating disorders.

The notion that patients with eating disorders maintain a functional immunosurveillance in spite of severe malnutrition has attracted researchers for years. Dipeptidyl peptidase IV (DPP IV), a serine protease with broad tissue distribution and known activity in serum, operates in the cascade of immune responses. Membrane-bound DPP IV expressed on lymphocytes, also known as the leucocyte antigen CD26, is considered to participate in T-cell activation. We hypothesized that the activity of DPP IV in serum and expression of CD26 in lymphocytes may be altered in patients with eating disorders. Serum DPP IV activity and the number of CD26 (DPP IV)-positive peripheral blood lymphocytes were measured in 34 patients [anorexia nervosa (AN): n = 11, bulimia (B): n = 23] in four consecutive weekly analyses. In addition, the expression of CD25 (interleukin-2 receptor alpha chain) was evaluated to estimate the degree of T-cell activation. The same analyses were carried out in healthy female volunteers (HC, n = 20). CD2-CD26-positive cells were reduced in patients compared with healthy controls [mean 40.2% (AN) and 41.1% (B) versus 47.4% (HC), P < 0.01], while the DPP IV activity in serum was elevated [mean 108.4 U/l (AN) versus 91.1 U/l (B) and 80.3 U/l (HC), P < 0.01]. The potential implications of our observations on, and beyond, immune function are discussed.

Immunoendocrine findings in patients with eating disorders.

Immune changes may occur in patients with anorexia nervosa (AN) or bulimia nervosa (BN), and a role for proinflammatory cytokines has been proposed in the pathogenesis of both disorders. We measured plasma levels of interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha (TNF-alpha), soluble forms of the cytokine receptor proteins gp130 and leukemia inhibitory factor receptor (LIF-R), the anti-inflammatory Clara cell 16-kD protein (CC16), prolactin (PRL), cortisol and 17beta-estradiol in 21 anorexic women, 21 bulimic women and 21 healthy females. As compared to healthy subjects, anorexics exhibited significantly increased plasma levels of gp130 and LIF-R, whereas bulimics had significantly decreased blood concentrations of CC16. No significant differences emerged in the blood levels of the remaining immune parameters. Both patient groups manifested higher plasma levels of cortisol and reduced plasma concentrations of PRL and 17beta-estradiol. In anorexics, a significant negative correlation was found between plasma levels of gp130 or LIF-R and the body mass index. These findings do not support the hypothesis that proinflammatory cytokines may play a pathogenetic role in eating disorders.

Capacity to produce cytokines during weight restoration in patients with anorexia nervosa.

OBJECTIVE: Anorexic patients are surprisingly free of infectious complications despite their seriously undernourished state. To study this phenomenon, we longitudinally measured the capacity to produce cytokines in restricting-type anorexic patients. METHODS: Lymphoproliferative responses with phytohemagglutinin (PHA) and the capacity of whole blood to produce cytokines, such as interleukin-1 (IL-1), IL-6, tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), and granulocyte-colony stimulating factor (G-CSF), were longitudinally measured before and after weight gain, that is, at admission and at less than 60, 65, and 75% of standard body weight (SBW), in 17 patients with restricting-type anorexia nervosa and in 17 control subjects. RESULTS: Cytokine production of IL-1, IL-6, and TNF-alpha per monocyte in the anorexic patients recovered only with the start of refeeding, whereas IFN-gamma production per lymphocyte was similar to that in control subjects and did not change during weight restoration. Only G-CSF production, even at 75% SBW, did not improve during weight restoration. Between the weight at admission and 65% SBW, the increase in the percentage of SBW and improvement of the total protein level were significantly correlated with improvement of the lymphocyte proliferative response with PHA. CONCLUSIONS: The capacity to produce most cytokines recovered with the start of weight gain; however, recovery was not correlated with weight gain. The results suggest that the capacity to produce cytokines in these anorexic patients was dependent on something other than the absolute value of body weight, such as the start of refeeding, the neuroendocrine system, or the autonomic nervous system.

Tumor necrosis factor-alpha: is there a continuum of liability between stress, anxiety states and anorexia nervosa?

Since the time of Freud, psychiatry has embraced the proposition that physiological and/or psychological stress precipitates various psychiatric disorders. To this effect, we propose that a continuum of liability obtains between stress, anxiety states and anorexia nervosa--a continuum which is grounded on a cytokine profile common to each of these conditions. For example, the biological response to stress, anxiety states and anorexia nervosa includes the elevation of interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha), and downregulation of interferon-gamma (IFN-gamma). Sustained elevation of IL-1 beta and TNF-alpha dysregulates both somatostatin and insulin secretion, the latter of which influences regional cerebral blood flow (rCBF) and brain energy metabolism. In addition, IL-1 beta and TNF-alpha influence the expression of certain crucial neuropeptides, which are known to be associated with anxiety states and anorexia nervosa. These neuropeptides include: beta-endorphin, cholecystokinin (CCK), neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP). beta-endorphin effects glucose metabolism in the limbic system, CCK increases the release of beta-endorphin from the anterior pituitary, NPY is a powerful anxiolytic that regulates beta-endorphin and insulin, while VIP indirectly regulates the expression of TNF-alpha through the inhibition of interleukin-4 (IL-4).

Lymphocyte subset, lymphocyte proliferative response, and soluble interleukin-2 receptor in anorexic patients.

BACKGROUND: Despite a prominent malnourished state, anorexics are unexpectedly free from infection. Several studies have shown that the cell-mediated immunity of anorexics might be well preserved, but results are conflicting. METHODS: Lymphocyte subsets, lymphoproliferative response to phytohemagglutinin, and soluble interleukin-2 receptor (sIL-2R) were measured in 7 patients with anorexia nervosa restricting type (RAN), 6 with anorexia nervosa binge-eating/purging type (ANBP), and 8 controls (C). RESULTS: Compared with controls, significantly elevated percentage of CD4 and CD4/CD8 ratio in ANBP was found. Although there was no significant difference in lymphoproliferative response among the three groups, sIL-2R in RAN was significantly lower than that in the C group, but not in ANBP. CONCLUSIONS: Although detail mechanism still remains to be unknown, some kinds of compensatory mechanism for cell-mediated immunity is working, especially in chronic underweight anorexic patients.