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

Clinical and Peripheral Biomarkers in Female Patients Affected by Anorexia: Does the Neutrophil/Lymphocyte Ratio (NLR) Affect Severity?

Anorexia Nervosa (AN) is a disabling disorder characterized by extreme weight loss and frequent chronicization, especially in its most severe forms. This condition is associated with a pro-inflammatory state; however, the role of immunity in symptom severity remains unclear. Total cholesterol, white blood cells, neutrophils, lymphocytes, platelets, iron, folate, vitamin D and B12 were dosed in 84 female AN outpatients. Mildly severe (Body Mass Index-BMI ≥ 17) versus severe (BMI < 17) patients were compared using one-way ANOVAs or χ² tests. A binary logistic regression model was run to investigate the potential association between demographic/clinical variables or biochemical markers and the severity of AN. Patients with severe anorexia (compared to mild forms) were older (F = 5.33; p = 0.02), engaged in more frequent substance misuse (χ² = 3.75; OR = 3.86; p = 0.05) and had a lower NLR (F = 4.12; p = 0.05). Only a lower NLR was predictive of severe manifestations of AN (OR = 0.007; p = 0.031). Overall, our study suggests that immune alterations may be predictive of AN severity. In more severe forms of AN, the response of the adaptive immunity is preserved, while the activation of the innate immunity may be reduced. Further studies with larger samples and a wider panel of biochemical markers are needed to confirm the present results.

The Role of the Gut Microbiome, Immunity, and Neuroinflammation in the Pathophysiology of Eating Disorders

There is a growing recognition that both the gut microbiome and the immune system are involved in a number of psychiatric illnesses, including eating disorders. This should come as no surprise, given the important roles of diet composition, eating patterns, and daily caloric intake in modulating both biological systems. Here, we review the evidence that alterations in the gut microbiome and immune system may serve not only to maintain and exacerbate dysregulated eating behavior, characterized by caloric restriction in anorexia nervosa and binge eating in bulimia nervosa and binge eating disorder, but may also serve as biomarkers of increased risk for developing an eating disorder. We focus on studies examining gut dysbiosis, peripheral inflammation, and neuroinflammation in each of these eating disorders, and explore the available data from preclinical rodent models of anorexia and binge-like eating that may be useful in providing a better understanding of the biological mechanisms underlying eating disorders. Such knowledge is critical to developing novel, highly effective treatments for these often intractable and unremitting eating disorders.

Combination of lymphocyte number and function in evaluating host immunity

Accurate monitoring of host immunity is hampered by the flaws of conventional tests. The relationship between lymphocyte number and function is unknown. The function of lymphocytes was analyzed based on IFN-γ secretion assay. Lymphocyte number and function was investigated in individuals under various states. The number of CD4⁺ and CD8⁺ T cells was gradually decreased, whereas the function of them was gradually increased with increasing age. A significantly negative correlation existed between the number and function of both CD4⁺ and CD8⁺ T cells. Differently, both the number and function of NK cells are maintained at a high level after birth. Staying up all night was found to impair the function of CD4⁺, CD8⁺ T cells, or NK cells. Lymphocyte number and function were both decreased in patients with immunosuppressive conditions or opportunistic infections, while the opposite phenomenon was observed in patients with some autoimmune diseases (except for NK cells). In kidney transplant recipients, the number and function of CD4⁺ and CD8⁺ T cells were increased or decreased when rejection or infection occurred. We demonstrated that evaluation of host immunity based on combination of lymphocyte number and function plays an important role in the diagnosis, treatment, and prognosis of diseases.

Anorexia Nervosa and the Immune System-A Narrative Review

The pathogenesis of an increasing number of chronic diseases is being attributed to effects of the immune system. However, its role in the development and maintenance of anorexia nervosa is seemingly under-appreciated. Yet, in examining the available research on the immune system and genetic studies in anorexia nervosa, one becomes increasingly suspicious of the immune system’s potential role in the pathophysiology of anorexia nervosa. Specifically, research is suggestive of increased levels of various pro-inflammatory cytokines as well as the spontaneous production of tumor necrosis factor in anorexia nervosa; genetic studies further support a dysregulated immune system in this disorder. Potential contributors to this dysregulated immune system are discussed including increased oxidative stress, chronic physiological/psychological stress, changes in the intestinal microbiota, and an abnormal bone marrow microenvironment, all of which are present in anorexia nervosa.

Decline of Plasma Concentrations of Interleukin-18 in Severely Malnourished Patients with Anorexia Nervosa: Exploratory Analysis

Multiple studies on the dynamics of inflammatory cytokines in patients with anorexia nervosa (AN) have been published, although results are not consistent among reports. Thus the pathophysiologic roles of these cytokines are not clear. We performed an exploratory analysis that included (1) comparisons of plasma interleukin-18 (IL-18) concentrations between patients with AN (n = 21) and healthy controls (n = 39), and (2) correlations between body mass index (BMI) and IL-18 concentrations in both groups, exploring the relationship between malnourishment and IL-18. Plasma IL-18 levels were significantly decreased in patients with AN compared with controls. Plasma IL-18 levels correlated to BMI in controls, but not in patients with AN. These results suggest that a decline in plasma IL-18 levels in patients with AN is not only due to malnourishment, but other pathophysiologic changes as well. IL-18 has a role in the brain’s reaction to sadness and chronic stress. Therefore, decreased levels of IL-18 may commonly occur in patients with chronic AN.

Immune disorders in anorexia

Anorexia nervosa is a disease involving eating disorders. It mainly affects young people, especially teenage women. The disease is often latent and occurs in many sub-clinical and partial forms. Approximately from 0.3% to 1% of the population suffers from anorexia. It has been shown that patients with anorexia develop neurotransmitter-related disorders, leading to uncontrolled changes in the immune and endocrine systems. Interactions between cytokines, neuropeptides, and neurotransmitters play an important role in disease development. Significant malnutrition induces disorders and alterations in T-cell populations. The cellular response in patients with anorexia nervosa has been shown to be normal, although opinions on this issue are controversial. Laboratory studies on neutrophils in anorexia patients showed decreased adhesion and reduced bactericidal and cell activities. Despite such unfavourable results, patients with anorexia are resistant to infections, which are very rare in this group. Glutamine improves the performance of the human immune system. The administration of glutamine to anorexia patients, as a supplement to parenteral nutrition, has resulted in significant improvements in immune system parameters. The results of previous studies on the causes and risk factors in the development of anorexia nervosa are still ambiguous. One can hope that the differences and similarities between patients with anorexia nervosa and those with other forms of protein-calorie malnutrition may be helpful in determining the relationship between nutritional status and body defences and susceptibility to infection, and can help to broaden the knowledge about the aetiopathogenesis of anorexia nervosa.

[Hematological changes in adolescent anorexia nervosa]

OBJECTIVE

Hematological changes often occur in patients with acute anorexia nervosa (AN). However, the relationship between these disturbances and other clinical parameters remains unclear.

METHOD

Leucocyte, erythrocyte, and thrombocyte counts as well as hematocrit, hemoglobin, and differential blood counts were collected at admission and after weight restoration in 88 female adolescent patients with the diagnosis of AN according to DSM-IV. These were then compared to clinical parameters.

RESULTS

At admission, there were mild changes in the blood count, most of which, however, were reversible after weight gain. Patients with a greater weight loss, a lower age-adjusted BMI, and a history of taking psychotropic drugs were more likely to develop hematological abnormalities.

CONCLUSIONS

Although most of the hematological changes in adolescent patients with AN were mild, patients with high weight loss and/or low age-adjusted BMI as well as those on psychotropic medication should be monitored carefully in order to avoid severe medical complications. An altered immune function in adult patients with chronic AN might contribute to a higher rate of infections and thus to an increased mortality.

Delayed diagnoses: nonspecific findings and diagnostic challenges in eating disorders

Objective. Eating disorders commonly present with nonspecific findings, masquerading as other, more common etiologies of malnutrition and wasting. In low-prevalence populations, these ambiguities can complicate clinicians' diagnostic reasoning, resulting in delayed or missed diagnoses. Method. We report the atypical case of a 51-year-old male with a five-year history of unexplained weight loss despite extensive past medical evaluation. Previous documentation of profound lymphopenia and bone marrow atrophy had not been linked to a known association with eating disorders. Results. Evaluation for medical etiologies of wasting was negative. Following psychiatric evaluation, the patient was diagnosed with an eating disorder, not otherwise specified, and admitted to a specialized nutritional rehabilitation program. Conclusion. The nonspecific clinical history, physical exam, and laboratory abnormalities of eating disorders can make these diagnoses challenging and delay appropriate treatment. Clinicians should consider eating disorders in patients with malnutrition, severe lymphopenias, and gelatinous marrow transformation early in their workup, so as to avoid potentially negative outcomes.

The hematology of anorexia nervosa

OBJECTIVE

Changes of the peripheral blood cell count in patients with anorexia nervosa (AN) are frequent. Anemia and leukopenia are observed in one-third of these patients. Examination of the bone marrow reveals in almost 50% of the patients with AN signs of bone marrow atrophy and can additionally suffer from a gelatinous bone marrow transformation.

METHOD

Published studies and investigations concerning hematological changes in patients with AN were reviewed.

RESULTS

Anemia and mild neutropenia are detectable in almost one-third of these patients, whereas thrombocytopenia is rather uncommon. The exact mechanism for these findings is still unclear, but 50% of AN-patients with hematological changes display morphological signs of partial bone marrow atrophy.

DISCUSSION

Changes of the peripheral blood cell count in patients with AN is a frequent observation but the peripheral blood cell count cannot predict the severity of bone marrow atrophy. All hematological and morphological alterations disappear completely and rapidly after sufficient refeeding.

Low lymphocyte count in underweight Japanese women

OBJECTIVE

Young women being underweight is a public health problem in Japan. The aim of this study was to investigate this problem by measuring lymphocyte count as an indicator of nutritional status.

METHODS

The subjects were 114 women aged 20-39 who participated in an annual health checkup for residents in a city in Aichi, Japan. Data from a questionnaire, physical examination, and blood tests were analyzed in relation to women who were severely underweight [body mass index (BMI) </= 17.5 kg/m(2)], slightly underweight (17.5 < BMI < 18.5 kg/m(2)), of normal weight (18.5 </= BMI < 25 kg/m(2)), and obese (BMI >/= 25 kg/m(2)).

RESULTS

Lymphocyte count tended to be lower with a decrease in BMI. The prevalence of low lymphocyte count of <1,500/mm(3) increased in underweight women. In women who had restricted food intake for weight loss, leukocyte count, and total serum protein, and lymphocyte count were lower. A multivariate logistic regression analysis showed the association of low lymphocyte count to being severely underweight [odds ratio (OR): 1.95; 95% confidence interval (CI): 1.07-3.56] and to restricted food intake for weight loss (OR: 3.73; 95% CI: 0.91-15.30).

CONCLUSION

This study suggests that being severely underweight and on restricted food intake for weight loss in adult women can be risk factors for low lymphocyte count, an indicator of malnutrition. It is important for young women to maintain BMI >17.5 kg/m(2) and not to restrict food intake when of normal weight or underweight in order to prevent malnutrition.

Immunological disturbance and infectious disease in anorexia nervosa: a review

OBJECTIVE

Severely malnourished patients with anorexia nervosa (AN) are reported to show fewer symptomatic viral infections and a poorer response to bacterial infection than controls. They are also reported to show mild immune system changes, although the relevance of these to altered infection disease presentation in AN and AN pathophysiology is unknown. Thus, in this paper, we suggest a range of immune system changes that might underpin these altered responses to common pathogens, and review a number of recent infectious disease findings for their utility in explaining the pathophysiology of AN.

METHODS

A systematic review of the literature pertaining to immunity and infectious disease in AN was performed.

RESULTS

AN is associated with leucopenia, and the increased spontaneous and stimulated levels of proinflammatory cytokines [i.e. interleukin (IL)-1β, IL-6 and tumour necrosis factor α). A range of less consistent findings are also reviewed. Most of these data were not controlled for length of illness, degree of malnutrition, micronutrient or vitamin deficiencies or recent refeeding and starvation.

CONCLUSION

Cytokine disturbances have been suggested to be causally related to AN symptomatology and pathophysiology of AN, although the evidence supporting this assertion is lacking. Immune and cytokine changes in AN do, however, occur in association with a decreased incidence of symptomatic viral infection, decreased clinical response to bacterial infection leading to delayed diagnosis and increased morbidity and mortality associated with the infections.

Malnutrition induces dissociated changes in lymphocyte count and subset proportion in patients with anorexia nervosa

OBJECTIVE

The effect of nutritional state on lymphocytes in patients with anorexia nervosa (AN) was studied.

METHOD

We studied total lymphocyte count (TLC), lymphocyte subsets, and nutritional markers [body mass index (BMI), insulin-like growth factor-1 (IGF-I)], and serum zinc concentration) in 33 patients with AN and 10 healthy controls.

RESULTS

TLC positively correlated with BMI (r = .680, p < .001), IGF-I (r = .609 p < .001), and zinc (r = .589, p < .001). The CD4+ T-lymphocyte (CD4) proportion correlated negatively with BMI (r = -.301, p = .05) and IGF-I (r = -.346, p = .023), counteracting the effect of malnutrition on TLC. However, because this increase in CD4 proportion was weak, patients with very severe malnutrition (indicated by serum zinc less than 40 microg/dL) had critically low CD4 counts of less than 200 cells/microL.

CONCLUSION

Our findings suggest that lymphocyte counts and subset proportion change in an opposite manner in patients with AN, and that decrease in serum zinc levels is nutrition-related.

On the role of sIL-2R measurements in rheumatoid arthritis and cancers

A soluble IL-2 receptor (sIL-2R) is a circulating form of a membrane receptor localized on lymphoid and some cancer cells. The biological function of sIL-2R has not been completely understood. Substantially, it seems to reflect T-lymphocyte activation in diseases of different pathology. Moreover, the soluble receptor has been considered, at least in part, responsible for unsuccessful immunotherapy with IL-2 in cancers. Several lines of evidence indicate sIL-2R measurements to be useful in determining disease progress and prognosis. This review summarizes current knowledge on the sIL-2R behavior in RA and solid cancers of varied etiology.

Two young female patients with anorexia nervosa complicated by Mycobacterium tuberculosis infection

Patients with anorexia nervosa (AN) seldom present with infectious illness, despite malnutrition-induced immunodeficiency. We described two young women who had a long-standing history of severe emaciation and pulmonary or lymph node tuberculosis discovered during the treatment of AN. Both patients reported a positive history of BCG vaccination. Contact tracing failed to reveal sources of infection, although the tuberculosis was considered transferred. Since the decline of notification rates for tuberculosis have been stagnant and outbreaks in schools or hospitals have been increasing in Japan, special attention must be given to the possibility of opportunistic infections in AN patients.

Involvement of cytokines in eating disorders: a critical review of the human literature

A number of findings from clinical and animal studies indicate that pro-inflammatory cytokines may play roles in eating disorders. The measurement of pro-inflammatory cytokines (IL-1, IL-6, TNFalpha), which are known to decrease food intake, provides highly variable data from which firm conclusions cannot be drawn. In most of the longitudinal studies where pro-inflammatory cytokines have been shown to be impaired in anorexia or bulimia nervosa, a return to normal values was observed after renutrition. However these findings do not exclude the possibility that pro-inflammatory cytokines might be overproduced in specific brain areas and act locally without concomitantly increased serum or immune production. It was also pointed out that the production of the major type-1 cytokines (especially IL-2) was depressed in anorexia nervosa. It remains unclear whether this is due to undernutrition or to a specific underlying cause common to eating disorders. The impaired cytokine profile observed in eating disorders could be related to several factors including impaired nutrition, psychopathological and neuroendocrine factors. More particular attention should be devoted to the deregulation of the anti/pro-inflammatory balance. Deregulation of the cytokine network may be responsible for medical complications in eating disorder patients who are afflicted with chronic underweight.

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.

Social stress in anorexia nervosa: a review of immuno-endocrine relationships

Anorexia nervosa (AN) patients have difficulty in establishing social contacts, leading to tension, anxiety and full-blown stress reactions. Stress hormones are chronically increased in AN, while immune function, which is involved in physical and psychological coping capacities, is mostly unimpaired. We examined immune function in a group of anorexics by measuring the T-lymphocyte proliferative response to stimulation with phytohemagglutinin (PHA), before and after in vivo acute administration of corticotropin-releasing hormone (CRH), to mirror a stress reaction. The responses of anorexics, before and after CRH stimulation, did not differ from those of controls. In a second group of anorexics, we measured plasma concentrations of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) before and after psychopharmacological (fluoxetine, amineptine) therapy. Basal values of the cytokines were not different in patients and controls, and did not change during therapy. In the same patients, we measured basal concentrations of soluble IL-1 beta receptor antagonist (s-IL-1 beta-RA), soluble IL-6 receptor (sIL-6-R) and soluble TNF-alpha receptors I and II (sTNF-alpha-R-I and -II). S-IL-1 beta-RA and sTNF-alpha-R-I and -II levels were not different in patients and controls, while those of s-IL-6-R were lower than normal in anorexics. The normality of most of the immune parameters in our anorexics, in basal conditions, after a stressful stimulation and after pharmacological manipulation of neurotransmitters suggests that the well-known interrelation among immune, neuroendocrine and central nervous system functions is not maintained in AN, the immune system being somehow unresponsive to stimuli.

Effects of symptomatic severity on elevation of plasma soluble interleukin-2 receptor in bipolar mania

BACKGROUND

Circulating soluble interleukin-2 receptors (sIL-2Rs) and soluble interleukin-6 receptors (sIL-6Rs) are stable immune measures. Elevated plasma sIL-2R levels are present in patients with schizophrenia, major depression, and bipolar mania, but not with minor psychiatric disorders. The increased plasma sIL-2R levels are state-dependent in bipolar mania. However, altered production of plasma sIL-6R and the effects of clinical characteristics on plasma sIL-6R and sIL-2R levels in bipolar disorder remains uncertain.

METHODS

Plasma sIL-2R and sIL-6R levels were measured in 31 Taiwanese bipolar manic (DSM-IV) patients with Young Mania Rating Scale (YMRS) scores of > or =26 as well as during the subsequent remission (YMRS< or =12), and equal numbers of age- and gender-matched healthy controls. The relationships of clinical variables such as age, age of onset, smoking, medication status, coexisting psychotic features, number of prior episodes, duration of illness, presence of depression before or following the manic episode, and manic severity to plasma sIL-2R and sIL-6R levels in acute mania along with remission were examined.

RESULTS

Plasma sIL-2R but not sIL-6R levels were significantly higher in acute mania than in subsequent remission (P<0.05) and controls (P<0.0005). In acute mania, the plasma sIL-2R levels were significantly correlated to YMRS scores (r=0.34, P<0.05). The remaining clinical variables had no effect on plasma sIL-2R and sIL-6R levels in acute mania or remission. There was a significantly positive relationship between the reduction of plasma sIL-2R levels from the acute to follow-up measurements (DeltasIL-2R) and symptomatic improvement of acute mania (DeltaYMRS) (r=0.61, P<0.001).

LIMITATIONS

Our sample included medicated and unmedicated patients in acute mania. The psychotropic medication may have divergent effects on the plasma sIL-2R levels in acute mania and subsequent remission.

CONCLUSIONS

Elevation of plasma sIL-2R but not sIL-6R levels in bipolar mania supports the idea that the immunomodulatory mechanism may vary in different psychotic disorders. In contrast to being a trait marker in schizophrenia and depressive disorder, plasma sIL-2R levels may be considered a biological indicator of manic severity in a group of bipolar affective patients.

Cytokines and anorexia nervosa

OBJECTIVE

Recent studies have indicated that the inflammatory cytokines could be implicated in anorexia nervosa and in its complications. To determinate the potential role of interleukins (IL-1, IL-2, IL-4, IL-6, IL-10), interferon (IFN gamma), tumor necrosis factor (TNF-alpha), and transforming growth factor (TGF-beta2) in anorexia nervosa, serum concentrations of these cytokines were measured in patients suffering from anorexia nervosa in comparison to healthy subjects.

METHOD

Twenty-nine anorexic women according to DSM-IV criteria participated in the study. The control group consisted of 20 healthy women without eating disorders, mood disorders, and immunological disorders.

RESULTS

We find that serum IL-2 and TGF-beta2 concentrations were both significantly decreased in anorexic patients, although the other cytokines did not differ significantly between the two groups.

CONCLUSION

Our results show that in patients with anorexia nervosa, there are lower levels of specific cytokines (especially IL-2 and TGF-beta2). These levels may reflect the combination of impaired nutrition and weight loss, therefore, the dysregulation of these cytokines may contribute in anorexia's complications. Follow-up studies should examine the effects of parameters such as starvation, psychopathologic factors, and psychoneuroendocrinological perturbation which could affect interplay between cytokines, neuropeptides, and neurotransmitters.

Plasma concentrations of tumor necrosis factor-alpha (TNF-alpha) and soluble TNF receptors in patients with bulimia nervosa

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) is a cytokine with numerous immunological and metabolic activities. In addition, TNF-alpha can stimulate a variety of physiological, neuroendocrine and behavioural responses of the central nervous system. In experimental animals, TNF-alpha induces changes in physiological and behavioural parameters which have also been observed in eating disorders. The biological activities of TNF-alpha are mediated by two structurally related, but functionally distinct receptors, TNF-RI and TNF-RII. Since injection of TNF-alpha results in increased shedding of TNF-alpha receptors, it is likely that TNF-alpha release is reflected by soluble TNF-receptors (sTNF-Rs) levels.

AIMS

We studied plasma concentrations of TNF-alpha and two sTNF-Rs (sTNF-RI and sTNF-RII) in female patients with bulimia nervosa.

DESIGN AND PATIENTS

Twenty female patients with bulimia nervosa (BN) and 20 age-matched normal women (N) were studied.

MEASUREMENTS

Plasma TNF-alpha concentrations were measured by enzyme immunoassay kit and plasma concentrations of sTNF-RI and sTNF-RII were measured by enzyme-linked immunosorbent assay.

RESULTS

Plasma TNF-alpha concentrations in BN were significantly higher than those in N (4.7+/- 0.5 ng/l vs. 1.6+/-0.1 ng/l; P<0.01). Although no significant difference was observed in plasma sTNF-RI concentrations between the two groups, plasma sTNF-RII concentrations in BN were significantly higher than those in N (2080.0+/-107.5 ng/l vs. 1569.5 +/-84.0 ng/l; P<0.01). Plasma TNF-alpha concentrations were significantly related to plasma sTNF-RI concentrations (r = 0.511, P<0.05) and to plasma sTNF-RII concentrations (r = 0.532, P<0.05) in bulimic patients. However, plasma TNF-alpha concentrations were not related to body fat mass or to bulimic behaviours in these patients.

CONCLUSIONS

Our present findings suggest that the adipose tissue may not be the immediate source of TNF-alpha in bulimic patients but the increase in plasma TNF-alpha in these patients may be derived from the central nervous system sources. The elevated sTNF-RII may reflect different shedding kinetics compared with sTNF-RI in bulimic patients.

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.