Autoantibodies against neuropeptides are associated with psychological traits in eating disorders

Previously, we identified that a majority of patients with anorexia nervosa (AN) and bulimia nervosa (BN) as well as some control subjects display autoantibodies (autoAbs) reacting with alpha-melanocyte-stimulating hormone (alpha-MSH) or adrenocorticotropic hormone, melanocortin peptides involved in appetite control and the stress response. In this work, we studied the relevance of such autoAbs to AN and BN. In addition to previously identified neuropeptide autoAbs, the current study revealed the presence of autoAbs reacting with oxytocin (OT) or vasopressin (VP) in both patients and controls. Analysis of serum levels of identified autoAbs showed an increase of IgM autoAbs against alpha-MSH, OT, and VP as well as of IgG autoAbs against VP in AN patients when compared with BN patients and controls. Further, we investigated whether levels of these autoAbs correlated with psychological traits characteristic for eating disorders. We found significantly altered correlations between alpha-MSH autoAb levels and the total Eating Disorder Inventory-2 score, as well as most of its subscale dimensions in AN and BN patients vs. controls. Remarkably, these correlations were opposite in AN vs. BN patients. In contrast, levels of autoAbs reacting with adrenocorticotropic hormone, OT, or VP had only few altered correlations with the Eating Disorder Inventory-2 subscale dimensions in AN and BN patients. Thus, our data reveal that core psychobehavioral abnormalities characteristic for eating disorders correlate with the levels of autoAbs against alpha-MSH, suggesting that AN and BN may be associated with autoAb-mediated dysfunctions of primarily the melanocortin system.

Stress, immunity and illness--a review

Psychological factors have long been thought to play a contributing role in either the predisposition, onset or course of various physical illnesses. Recently, rapid advances in immunology have created interest in the interaction between psychosocial factors, behaviour and the immune system. This paper reviews some of the models proposed to explain the relationship between psychological variables and physical illness and presents evidence for a contribution of psychological factors to certain illnesses in which abnormalities in immunologic state are thought to be important. From a somewhat different perspective, animal studies have demonstrated complex effects of stress, on disease susceptibility. Recent human studies have demonstrated consistent immunologic changes in people undergoing acute naturally occurring psychological stress such as bereavement or an important examination. In humans, the effects of chronic stress may be different from acute stress, corresponding to the findings in animals. Abnormalities in immunologic functioning and physical illness are reviewed for different psychiatric disorders--depression, anorexia nervosa and schizophrenia; depression is the only disorder which consistently demonstrated immunologic changes. Possible mechanisms for the stress/immune-change relationship are suggested.

Immunodeficiency associated with anorexia nervosa is secondary and improves after refeeding

Several studies have addressed the question of starvation effects on immune function by means of changes in lymphocyte subsets, cytokine induction or lymphocyte activation. Anorexia nervosa (AN) patients are severely malnourished and contradictory results have been obtained regarding the accompanying immunodeficiency, including its assignation as a part of the primary nervous disorder. In the present work, an extensive immunological function examination was carried out on 40 AN patients who were compared with a control group of 14 healthy girls. The AN patients were also classified according to their nutritional status (by the Body Mass Index: BMI), this being critical for a better understanding of these secondary immunodeficiency bases. Moreover, another immune system study was performed on five patients after refeeding. Lymphocyte subsets and function, cytokine induction and peripheral blood concentrations, and innate as well as humoral immunity were evaluated. Deregulation in the cytokine network, owing to the interaction of the central nervous (CNS) and immune systems, seems to be the initial immune alteration in AN immunodeficiency but it has not been disproved that the immunodeficiency is a direct consequence of the original psychiatric perturbation. Spontaneous high levels of circulating interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) have been observed; this is probably one of the causes of the anomalies found in the T-cell subpopulations (mainly the naive CD4+CD45RA+ reduction and the cytotoxic CD8+ increase) and T-cell activation status (mainly the down-regulation of the CD2 and CD69 activation pathways). This finally leads to an impairment, not only in T-cell function but also in T-cell to B-cell co-operation. The AN specificity of these results is confirmed by the fact that these immune alterations improve after refeeding and when nutritional status becomes less critical, which also suggests that AN immunodeficiency is indeed secondary to malnutrition.

Effect of body weight and caloric restriction on serum complement proteins, including Factor D/adipsin: studies in anorexia nervosa and obesity

Complement plays important roles in host immune defences, and recent studies suggest that adipose tissue is an important site of production for some complement proteins. Starvation has been associated with low complement levels, but studied populations have usually had concomitant opportunistic infections or other conditions which might affect complement levels. To determine the impact of body weight and changes in body weight on serum complement, we investigated levels of complement proteins in otherwise healthy patients with a wide range of body weights, including patients with anorexia nervosa before and after treatment, obese dieters before and after weight loss, and normal weight controls. We found that complement proteins of the alternative pathway (C3, B, and D), alternative pathway haemolytic activity (AP50) and the inhibitors H and I were low in starving anorectics and normalized with weight gain. C3a levels were comparable in anorectics at low weight and after weight gain, indicating that low serum complement levels were attributable to hypoproduction and not complement cascade activation with consumption. Further, levels of C3, B, AP50, H and I, but not D, were higher than controls in obese patients and decreased toward normal after weight loss. Overall, percentage of ideal body weight, changes in body weight, and serum transferrin were each highly correlated with serum levels of complement proteins. We conclude that levels of alternative pathway complement components are determined in part by factors that influence body weight and by weight changes, possibly due to changes in production in adipose tissue or at other sites.

The adaptive response of the immune system to the particular malnutrition of eating disorders

Despite the seriously undernourished state of patients with anorexia nervosa (AN) and bulimia nervosa (BN), controversial findings have been published regarding some aspects of the immune system that are otherwise impaired in more typical types of malnutrition, such as protein-energy malnutrition. In general, adaptation processes seem to occur enabling immune function to be preserved during long periods of the illness. However, cell-mediated immunity is usually altered in AN and BN as reflected by lymphocyte subset counts and the response to delayed hypersensitivity tests. Regarding the helper/cytotoxic T cell ratio (CD4:CD8), an immunological marker of the nutritional status, the results of our studies on AN and BN patients showed that the duration of the eating disorder and the time when appropriate treatment is achieved are likely contributors to the alteration of this ratio. Despite these findings, it has been repeatedly pointed out that anorexic patients seem to be free of common viral infections at least until the most advanced stages of debilitation. Some hypotheses that could explain the lack of infection symptoms are reviewed. Cytokines and the altered acute phase response to infection, as well as cortisol and leptin, are considered to be potential factors involved in the adaptation processes occurring in these syndromes. Further progress in the knowledge of the psychoneuroendocrine-immune interactions established in AN and BN will be relevant to the understanding of the aetiology and maintenance mechanisms of these pathologies.

An immunological assessment of patients with anorexia nervosa

Patients with most forms of protein-calorie malnutrition are typically more susceptible to infection. We studied the immunological consequences of a subgroup of malnourished subjects--nine patients with anorexia nervosa, who typically have a lower incidence of infection. The profiles of the patients with anorexia nervosa deviated from the reported typical profile of significantly depressed cell-mediated immunity in subjects with more common forms of protein-calorie malnutrition, demonstrating normal T-lymphocyte populations and unimpaired proliferative lymphocyte responsiveness to mitogenic stimulation with phytohemagglutinin and concanavalin A. In fact, mitogen responsiveness was significantly elevated above that of controls, and with nutritional repletion, this enhanced responsiveness regressed toward control values. Since impaired cell-mediated immunity has been consistently documented in other malnourished populations, and presumably contributes to their increased propensity toward infection, the maintenance of a relatively intact cell-mediated immune system may be an important factor separating the malnourished anorexia nervosa patient from other protein-calorie malnourished patients.

The role of tumor necrosis factor-alpha in the pathogenesis of anorexia and bulimia nervosa, cancer cachexia and obesity

In this paper a new immunological model of anorexia and bulimia nervosa will be presented in which the inflammatory cytokines are conceived as the fundamental regulators of body metabolism. This conception differs from the conventional view in which the inflammatory cytokines are perceived primarily as peptide molecules utilized by the immune system to control infection, inflammation and tissue or neuronal damage. Given that the inflammatory cytokines are also fundamental regulators of body metabolism, when they become dysregulated they create physiological chaos which results in the development of a number of autoimmune, metabolic and psychiatric disorders. In this proposed immunological model of anorexia and bulimia nervosa, elevated tumor necrosis factor-alpha features as the primary cause of these conditions. Pathophysiological parallels are drawn between anorexia nervosa and cancer cachexia in terms of the causal role the cytokines, neuropeptides and neurotransmitters play in the manifestation of shared symptoms. These shared symptoms include elevated tumour necrosis factor-alpha, down-regulated interleukin-2 and interleukin-4 and depletion of lean body mass. Furthermore, the following neuropeptides are dysregulated in both anorexia nervosa and cancer cachexia: vasoactive intestinal peptide, cholecystokinin, corticotropin-releasing factor, neuropeptide Y, peptide YY and beta-endorphin. In addition, in anorexia and bulimia nervosa, secretion of the neurotransmitter serotonin is inhibited while norepinephrine is enhanced. It will be argued that the causal interplay between the cytokines, neuropeptides and neurotransmitters initiates a cascade of biochemical events which may result in either anorexia or bulimia nervosa, or cancer cachexia. The extent to which these inflammatory cytokines, neuropeptides and neurotransmitters are causally efficacious in the pathogenesis of other autoimmune disorders, such as diabetes mellitus and rheumatoid arthritis, will also be addressed.

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.

Tumour necrosis factor production and cell-mediated immunity in anorexia nervosa

Fourteen patients with anorexia nervosa (AN) were studied for the production of tumour necrosis factor (TNF), the activation of the interferon (IFN) system and cell-mediated cytotoxicity (CMC) and the results were compared with 16 age-matched healthy women. AN patients had significantly increased spontaneous TNF production by peripheral blood mononuclear cells (PBMC) in vitro (16 +/- 5 U/ml versus 4 +/- 3 U/ml in the control group; P less than 0.05), although no TNF was detectable in the plasma from either group. TNF production in vitro, following stimulation of PBMC by phytohaemagglutinin (PHA) or tumour cells, was similar in AN patients and controls; however, lipopolysaccharide (LPS) induced TNF production was found to be lower in AN (P less than 0.1). CMC was significantly lower in AN patients (4 +/- 2 versus 10 +/- 3 in controls, expressed as lytic units/10(6) cells; P less than 0.05), but no difference could be found between AN and controls in IFN activity as reflected by the level of the IFN-induced enzyme 2'-5' oligoadenylate synthetase (2-5A) in PBMC. Beta-endorphins in the plasma were higher in the AN group (P less than 0.05) but these levels could not be correlated to those of IFN, CMC or TNF. Defective CMC and increased TNF production by PBMC in patients with anorexia nervosa may possibly result from the nutritional deficiencies and neuroendocrine abnormalities associated with the disease, and may contribute to the pathophysiology of AN.

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.

The immune system in eating disorders: an overview

Eating disorders, such as anorexia nervosa and bulimia nervosa, are becoming more and more common in our society. Although they are psychiatric illnesses, there are many factors involved, including abnormal food behavior. Nutrients play an important role in the development and functionality of immunocompetent cells. An impaired immunocompetence has been shown to be an important causal factor in the increased susceptibility of malnourished individuals to infectious disease. Therefore, studies on the immune system are of great interest when assessing the extent to which the nutritional status of these patients could be affected. However, the literature in this field is controversial, and the mechanisms are not yet completely defined, although some hypotheses try to clarify the disturbances caused in the organism under these bizarre circumstances. In spite of the fact that the immune system is altered by distorted food behaviors, such as in eating disorders, the awareness of characteristics of other systems involved, and therefore altered, by these pathologies would be very helpful for understanding the mechanisms triggered in these syndromes. In fact, the interactions among the immune and other systems in eating disorders are beginning to be studied. Finally, the main goals are to limit the evolution of these illnesses through early diagnosis, and to devise a long-lasting, definitive cure for these patients through appropriate therapy.

An investigation of the immune response of patients suffering from anorexia nervosa

Patients suffering from anorexia nervosa rarely appear to develop the common cold or influenza. This study examines the immunological response of fifteen female anorexia nervosa patients of both the vomiting and carbohydrate-abstaining type and compares them with a control population matched for age and occupation. Both anorectics and control populations received the admune influenza vaccine. Initially both groups had similar haemagglutination inhibition titres against the three different viral antigens: A/HK; A/PC; A/Eng. However, the anorectics showed over a 2-month period a higher titre of antibody especially to the Hong Kong virus: this was sigignificant. Cellular immune responses were measured using a tuberculin and a macrophage inhibition test, no significant difference between the two groups was obderved. These results which support the clinical findings are discussed.

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.

Immunocompetency in anorexia nervosa

Twenty-two consecutively admitted patients diagnosed for anorexia nervosa were evaluated for cellular immune functioning by means of an anergy panel to test delayed hypersensitivity. The panel included candida, streptokinase-streptodornase, and mumps antigen administered by a standard protocol. A standard nutritional profile including current weight, usual weight, total protein, albumin, total iron-binding capacity, white blood cell count, total lymphocyte count, triceps skinfold, and arm muscle circumference was concurrently compiled on these subjects. Six of 22 patients studied were anergic. Visceral protein measures were generally within normal limits even in the most depleted patients. Malnutrition as measured by severity of weight loss and triceps skinfolds was significantly related to anergy, whereas visceral protein indicators (serum albumin, total iron binding capacity, transferrin) were not correlated with anergy. Anergy appeared to be related more strongly to anthropometric indices of malnutrition than to visceral protein values. Cellular immunity was generally preserved until weight loss was far advanced.

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.

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-1β, 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.

T-lymphocyte subsets in patients with abnormal body weight: longitudinal studies. in anorexia nervosa and obesity

OBJECTIVE

In contrast to other types of starvation which are characterized by low CD4+ counts and increased susceptibility to infection, anorexia nervosa is not associated with an increase in infectious complications. To determine why infection risk of anorectics differs from that of other starving populations, we studied T-lymphocytes, including CD4+ and CD8+ phenotypes, in patients with anorexia nervosa, and for comparison, in dieting obese subjects.

METHODS

T-lymphocyte phenotypes were determined by flow cytometric analysis of monoclonal antibody-labeled cells obtained from patients with anorexia nervosa before and after successful therapy and weight gain, and in obese subjects before and after weight loss on a very-low-calorie diet.

RESULTS

Weight loss in anorectics and obese dieters was associated with normal CD4+ counts. Unexpectedly, CD8+ counts were low in anorectics, both before and after weight gain, and in obese subjects after (but not before) dieting.

DISCUSSION

Normal CD4+ counts in anorectics and obese dieters, despite marked weight loss, may explain the lack of increased infection risk in these eating-disordered patients, in contrast to other starving populations. The observation that CD8+ counts are low in anorectics with low and restored body weight and in obese patients after dieting has not been previously reported. The persistence of low CD8+ counts in anorectics even after weight gain suggests that some factors other than weight loss per se may be involved, possibly including effects due to stress, comorbid psychiatric conditions, or unidentified aspects of dysregulated pathophysiology secondary to disordered eating.

Low lymphocyte interferon-gamma production and variable proliferative response in anorexia nervosa patients

Interferon-gamma (IFN-gamma) production by peripheral blood mononuclear cells (PBMC) in 14 patients with anorexia nervosa (AN) was significantly lower than in 14 age-matched healthy controls. Follow-up samples in four patients displayed low levels, except in two when they recovered the IFN-gamma production as the hormonal cycles were restored. A large interindividual variation for the lymphocyte proliferative response was observed in 30 AN patients. DNA synthesis of PBMC was normal in 8 patients (27%), significantly increased in 6 (20%) (P < 0.001), and significantly decreased in 16 (53%) (P < 0.001). IFN-gamma inhibition was reversed by culturing a control lymphocyte population with monocytes from patients with AN. This was not observed in cultures of control monocytes and AN lymphocytes. IL-2 receptor (TAC subunit) was assessed and no difference was found in the number of TAC-positive cells between patients and controls. These results point out impaired production of the immunomodulator cytokine IFN-gamma as a major functional defect of AN peripheral lymphocytes.

Cytokine production in anorexia nervosa

The capacity of peripheral blood mononuclear cells (PBMCs) of anorexia nervosa (AN) patients to produce interleukin-1 (IL-1), interleukin-2 (IL-2), and interleukin-3-like activity (IL-3-LA) was studied. A significantly lower (-49%, p < 0.005) capacity to synthesize IL-2 and an almost significantly impaired ability (-35%, p = 0.058) to release IL-3-LA by PBMCs of AN patients was found, as compared with cells of the control group. IL-1 production, either spontaneous or after stimulation with lipopolysaccharide (LPS), did not differ significantly between AN patients and healthy subjects. The lessened capacity to produce IL-2 was accompanied by an enhanced stimulatory activity of the patient sera on the production of this cytokine by PBMCs of healthy subjects. It is therefore suggested that the serum of AN patients contains a stimulatory factor or factors for cytokine production that compensates for the lower production of cytokines by AN PBMCs. Such a compensatory mechanism may explain why AN patients do not have an higher susceptibility to infections.

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.

Reduced febrile response to bacterial infection in anorexia nervosa patients

OBJECTIVE

To report a reduced febrile response to bacterial infections in anorexia nervosa (AN) patients.

METHOD

Four cases were obtained from a retrospective review of charts from the St. Paul's Hospital Eating Disorders Program (Vancouver, Canada). The patients had died or had been admitted to the hospital for treatment of a bacterial infection. In addition, one case was obtained from the Royal Prince Alfred Hospital (Sydney, Australia).

RESULTS

All patients suffered a bacterial infection during the course of AN. None of the patients had a temperature higher than 37 degrees C during the infectious illness.

DISCUSSION

The absence of fever in AN may delay the diagnosis of bacterial infection and may be a marker of an impaired immune response. Therefore, alternative methods of investigation are necessary in patients with AN suspected of having a bacterial infection.

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).

D8/17 expression on B lymphocytes in anorexia nervosa

OBJECTIVE

The authors' goal was to determine whether D8/17, a rheumatic fever susceptibility trait marker, identifies a possible type of anorexia nervosa: pediatric autoimmune neuropsychiatric disorders associated with streptococcus (PANDAS) anorexia nervosa.

METHOD

Using immunofluorescence, the authors measured the percentage of D8/17-positive B lymphocytes in the peripheral blood of 16 subjects 7-21 years old who had not had rheumatic fever but who had possible PANDAS anorexia nervosa. The comparison subjects were 17 psychiatric patients with no eating disorder and no PANDAS characteristics. Subjects were considered D8/17 positive if they had 12% or more D8/17+ cells.

RESULTS

There were more D8/17-positive individuals among those with PANDAS anorexia nervosa (81%) than among the comparison subjects (12%). The subjects with PANDAS anorexia nervosa had a higher percentage of D8/17+ cells (mean=27.1%, SD=17%) than the comparison subjects (mean=5.3%, SD=7.4%).

CONCLUSIONS

A larger study is needed to determine whether D8/17 serves as a marker for susceptibility to a type of anorexia nervosa.

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.

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.