Elevated Bioactivity of the Tolerogenic Cytokines, Interleukin-10 and Transforming Growth Factor-β, in the Blood of Acutely Malnourished Weanling Mice

The Tolerance Model of Non-Inflammatory Immune Competence in Acute Pediatric Malnutrition: Origins, Evidence, Test of Fitness and Growth Potential

The tolerance model rests on the thesis of a physiologically regulated, albeit unsustainable, systemic attempt to adapt to the catabolic challenge posed by acute prepubescent malnutrition even in its severe forms. The model centers on the immunological component of the attempt, positing reorientation toward a non-inflammatory form of competence in place of the classic paradigm of immunological attrition and exhaustion. The foundation of the model was laid in 1990, and sixteen years later it was articulated formally on the basis of a body of evidence centered on T cell cytokines and interventions with cytokine and hormonal mediators. The benefit originally suggested was a reduced risk of autoimmune pathologies consequent to the catabolic release of self-antigens, hence the designation highlighting immune tolerance. Herein, the emergence of the tolerance model is traced from its roots in the recognition that acute malnutrition elicits an endocrine-based systemic adaptive attempt. Thereafter, the growth of the evidence base supporting the model is outlined, and its potential to shed new light on existing information is tested by application to the findings of a published clinical study of acutely malnourished children. Finally, some knowledge gaps pertinent to the model are identified and its potential for growth consonant with evolving perceptions of immunobiology is illustrated.

Palmitoleic acid ameliorates palmitic acid-induced proinflammation in J774A.1 macrophages via TLR4-dependent and TNF-α-independent signallings

Adipose tissue resident macrophages play an important role in the regulation of the inflammatory response. Monounsaturated fatty acids assist in the prevention of cardiovascular diseases via an anti-inflammatory effect. However, the mechanisms by which monounsaturated fatty acids, such as palmitoleic acid, regulate the inflammatory response has not been well investigated. In this study, we found that a high concentration of palmitic acid induced J774A.1 murine macrophages toward a pro-inflammatory state, possibly through the activation of the TLR2 or TLR4 genes, and their downstream signaling pathways. In contrast, palmitoleic acid induced a protective effect against inflammation in macrophage of non-obese rodents by inducing an alternative activation pathway via reducing TLR2 or TLR4 signaling. This study indicates that the balance of palmitic acid (saturated fatty acid) and palmitoleic acid (monounsaturated fatty acid) effects macrophage activation. The potential therapeutic impact of palmitoleic acid to ameliorate non-obese-mediated inflammation warrants further investigation.

Low omega-6/omega-3 ratio in a maternal protein-deficient diet promotes histone-3 changes in progeny neural cells and favors leukemia inhibitory factor genetranscription

Omega-3 (n-3) fatty acids modulate epigenetic changes critical to genesis and differentiation of neural cells. Conversely, maternal protein-malnutrition can negatively modify these changes. This study investigated whether a low n-6/n-3 ratio in a maternal diet could favor histone-3 (H3) modifications, gene transcription and differentiation in the offspring neural cells even under protein-deficiency. Female rats fed a control (Ct), or 3 types of multideficient diets differing in protein levels or linoleic/alpha-linolenic fatty acid ratios (RBD, RBD-C, RBD-SO) from 30 days prior to mating and during pregnancy. Cerebral cortex tissue and cortical cultures of progeny embryonic neurons and postnatal astrocytes were analyzed. H3K9 acetylation and H3K27 or H3K4 di-methylation levels were assessed by flow cytometry and/or immunocytochemistry. In astrocyte cultures and cortical tissue, the GFAP protein levels were assessed. Glial derived neurotrophic factor (GDNF) and leukemia inhibitory factor (LIF) gene expression were evaluated in the cortical tissue. GFAP levels were similar in astrocytes of Ct, RBD and RBD-C, but 65% lower in RBD-SO group. Higher levels of H3K9Ac were found in the neurons and H3K4Me2 in the astrocytes of the RBD group. No intergroup difference in the cortical GDNF mRNA expression or the H3K27Me2 levels in astrocytes was detected. LIF mRNA levels were higher in the RDB (P=.002) or RBD-C (P=.004) groups than in the control. The findings indicate the importance of dietary n-3 availability for the brain, even under a protein-deficient condition, inducing Histone modifications and increasing LIF gene transcription, involved in neural cell differentiation and reactivity.

Dual Role of GM-CSF as a Pro-Inflammatory and a Regulatory Cytokine: Implications for Immune Therapy

Granulocyte macrophage colony stimulating factor (GM-CSF) is generally recognized as an inflammatory cytokine. Its inflammatory activity is primarily due its role as a growth and differentiation factor for granulocyte and macrophage populations. In this capacity, among other clinical applications, it has been used to bolster anti-tumor immune responses. GM-CSF-mediated inflammation has also been implicated in certain types of autoimmune diseases, including rheumatoid arthritis and multiple sclerosis. Thus, agents that can block GM-CSF or its receptor have been used as anti-inflammatory therapies. However, a review of literature reveals that in many situations GM-CSF can act as an anti-inflammatory/regulatory cytokine. We and others have shown that GM-CSF can modulate dendritic cell differentiation to render them "tolerogenic," which, in turn, can increase regulatory T-cell numbers and function. Therefore, the pro-inflammatory and regulatory effects of GM-CSF appear to depend on the dose and the presence of other relevant cytokines in the context of an immune response. A thorough understanding of the various immunomodulatory effects of GM-CSF will facilitate more appropriate use and thus further enhance its clinical utility.

A non-inflammatory form of immune competence prevails in acute pre-pubescent malnutrition: new evidence based on critical mRNA transcripts in the mouse

The declining inflammatory immune competence of acute (i.e. wasting) pre-pubescent protein-energy malnutrition has been regarded as reflecting an unregulated immunological disintegration. Recent evidence, however, suggests that malnutrition stimulates a regulated immunological reconfiguration to achieve a non-inflammatory form of competence, perhaps offering protection against autoimmune reactions - the 'Tolerance Model'. Our objective was to determine the influence of acute pre-pubescent malnutrition on the expression of genes critical to tolerogenic regulation. Male and female C57BL/6J mice, initially 19 d old, consumed a complete purified diet either ad libitum (age-matched controls) or in restricted daily quantities (mimicking marasmus), or consumed an isoenergetic low-protein diet ad libitum (mimicking incipient kwashiorkor) for 14 d (six animals per dietary group). Gene expression in the spleen, typically an inflammatory organ, and in the small intestine, a site designed for non-inflammatory defence, was assessed by real-time quantitative RT-PCR, and normalised to β-actin. In the spleen of the malnourished groups, both IL-10 and transforming growth factor-β1 mRNA expression increased compared with controls (P < 0.05), whereas mRNA expression of IL-12p40 decreased (P < 0.05). Conversely, malnutrition exerted no influence on the expression of mRNA for these cytokines in the small intestine (P>0.05). Moreover, forkhead box P3 mRNA expression, indicative of cell-based tolerogenic potential, was sustained in both the spleen and intestine of the malnourished groups (P>0.05). Thus, despite limited supplies of energy and substrates, the spleen shifted towards a non-inflammatory character and the intestine was sustained in this mode in advanced pre-pubescent weight loss. These findings provide the first support for the Tolerance Model at the level of mRNA transcript expression.

Distinct clinical and immunologic profiles in severe malarial anemia and cerebral malaria in Zambia

BACKGROUND

The mechanisms of severe malarial anemia and cerebral malaria, which are extreme manifestations of Plasmodium falciparum malaria, are not fully understood.

METHODS

Children aged <6 years from southern Zambia presenting to the hospital with severe malarial anemia (n = 72), cerebral malaria (n = 28), or uncomplicated malaria (n = 66) were studied prospectively. Children with overlapping severe anemia and cerebral malaria were excluded.

RESULTS

Low interleukin 10 concentrations had the strongest association with severe anemia (standard β = .61; P < .001) followed by high tumor necrosis factor α and sFas concentrations, low weight-for-age z scores, presence of stool parasites, and splenomegaly (standard β = .15-.25; P ≤ .031); most of these factors were also associated with lower reticulocytes. Greater parasitemia was associated with higher interleukin 10 and tumor necrosis factor α concentrations, whereas sulfadoxizole/pyrimethamine therapy and lower weight-for-age z scores were associated with lower interleukin 10 levels. Thrombocytopenia and elevated tissue plasminogen activator inhibitor 1 levels had the strongest associations with cerebral malaria (standard β = .37 or .36; P < .0001), followed by exposure to traditional herbal medicine and hemoglobinuria (standard β = .21-.31; P ≤ .006).

CONCLUSIONS

Predictors of severe malarial anemia (altered immune responses, poor nutrition, intestinal parasites, and impaired erythropoiesis) differed from those of cerebral malaria (thrombocytopenia, herbal medicine, and intravascular hemolysis). Improved preventive and therapeutic measures may need to consider these differences.

Constitutive, but not challenge-induced, interleukin-10 production is robust in acute pre-pubescent protein and energy deficits: new support for the tolerance hypothesis of malnutrition-associated immune depression based on cytokine production in vivo

The tolerance model of acute (i.e., wasting) pre-pubescent protein and energy deficits proposes that the immune depression characteristic of these pathologies reflects an intact anti-inflammatory form of immune competence that reduces the risk of autoimmune reactions to catabolically released self antigens. A cornerstone of this proposition is the finding that constitutive (first-tier) interleukin(IL)-10 production is sustained even into the advanced stages of acute malnutrition. The IL-10 response to inflammatory challenge constitutes a second tier of anti-inflammatory regulation and was the focus of this investigation. Weanling mice consumed a complete diet ad libitum, a low-protein diet ad libitum (mimicking incipient kwashiorkor), or the complete diet in restricted daily quantities (mimicking marasmus), and their second-tier IL-10 production was determined both in vitro and in vivo using lipopolysaccharide (LPS) and anti-CD3 as stimulants of innate and adaptive defences, respectively. Both early (3 days) and advanced (14 days) stages of wasting pathology were examined and three main outcomes emerged. First, classic in vitro systems are unreliable for discerning cytokine production in vivo. Secondly, in diverse forms of acute malnutrition declining challenge-induced IL-10 production may provide an early sign that anti-inflammatory control over immune competence is failing. Thirdly, and most fundamentally, the investigation provides new support for the tolerance model of malnutrition-associated inflammatory immune depression.

ITGAM Arg77His is associated with disease susceptibility, arthritis, and renal symptoms in systemic lupus erythematosus patients from a sample of the Polish population

The ITGAM Arg77His (rs1143679) and Ala858Val (rs1143683) polymorphisms have been found to be strong contributors to systemic lupus erythematosus (SLE) development. There are evident population distinctions in terms of SLE distribution and manifestations; therefore, we investigated the distribution of the ITGAM Arg77His and Ala858Val polymorphisms in patients with SLE (n = 154) and control subjects (n = 276) in a sample of the Polish population. We observed that patients with the ITGAM His/His and Arg/His genotypes displayed a 1.811-fold increased risk of SLE incidence (95% confidence intervals [95% CI] = 1.171-2.802, p = 0.0089). Odds ratio (OR) for the homozygous ITGAM His/His genotype was 7.333 (95% CI = 0.8119-66.241, p = 0.0576). We also found that the ITGAM 858Val variant might be a risk factor in the occurrence of SLE; the OR for this allele amounted to 1.458 (95% CI = 1.021-2.080, p = 0.0372). There was an association of the ITGAM His/His and Arg/His genotypes with the occurrence of arthritis OR = 3.486 (95% CI = 1.619-7.508, p = 0.0015). We also observed an association between the ITGAM His/His and Arg/His genotypes and renal symptoms in the course of SLE OR = 2.975 (95% CI = 1.478-5.988; p = 0.0023). Our findings confirmed that there is an association of the ITGAM 77His or 858Val variants with SLE incidence and some clinical manifestation of this autoimmune disorder.

Recent advances in understanding of interactions between genes and diet in the etiology of colorectal cancer

At an international level, colorectal cancer (CRC) is a major cause of morbidity and mortality. Diet plays a major etiologic role, and a range of putative dietary carcinogens have been identified. The probability with which these lead to mutations, and thereby cause cancer, is strongly impacted by variants in genes coding for xenobiotic metabolizing or DNA repair enzymes. Nutrient deficiencies also play a role, which will be exacerbated by variants in metabolic genes. However, many of the causal genes in sporadic CRC have hitherto proved elusive. The power of large international collaborations, coupled with genome-wide association studies, has implicated a major functional role of the tumour growth factor-β pathway in CRC susceptibility. Nutrient regulation of gene expression may be especially important here. Future large collaborative studies must consider gene-gene and gene-diet interactions, coupled with high throughput genomic technologies, in order to uncover the relative roles of genetic variants, mutagenic xenobiotics, nutrient imbalance and gene expression in the etiology of CRC.

Enhancement of IL-10 bioactivity using an IL-10 peptide-based vaccine exacerbates Leishmania major infection and improves airway inflammation in mice

IL-10 is a regulatory cytokine that plays important roles in promoting disease progression in cutaneous leishmaniasis and suppressing allergic responses in asthma. We sought to develop an IL-10 peptide-based vaccine for the control of IL-10-related diseases. To break self-tolerance, hepatitis B core antigen (HBcAg) was used as a carrier. The vaccine was prepared by inserting a peptide derived from mouse IL-10 into the carrier using gene recombination methods. This vaccine presented as virus-like particles, bound to polyclonal anti-IL-10 antibodies, and induced high titers of IL-10-specific IgG. The in vivo effects of the vaccine were investigated in a murine model of cutaneous leishmaniasis. Unexpectedly, vaccinated mice developed larger cutaneous lesions, harbored significantly more parasites, and cells from lymph nodes produced higher amounts of parasite-specific IL-4, IL-10 and IFN-gamma in cultures. Further in vitro studies showed that serum IL-10-specific IgG from vaccinated mice significantly enhanced IL-10 bioactivity dose-dependently. This enhancing effect was confirmed in OVA-induced asthmatic mice. Vaccinated mice exhibited a significant decrease in airway eosinophils, lung inflammation, goblet hyperplasia, and levels of serum OVA-specific IgE, compared to control mice. We concluded that the IL-10 vaccine enhances the bioactivity of IL-10 in vitro and in vivo, providing a potential therapeutic approach in diseases associated with insufficient IL-10 production.

The blood level of transforming growth factor-β rises in the early stages of acute protein and energy deficit in the weanling mouse

Plasma transforming growth factor (TGF)-β levels are high in the advanced stages of acute (wasting) pre-pubescent deficits of protein and energy. Consequently, this potently anti-inflammatory cytokine may help to sustain the depression of inflammatory immune competence in acute malnutrition. Our objective was to determine if plasma TGF-β levels rise during the early stages of acute malnutrition and, secondarily, to confirm the elevation reported previously in advanced weight loss. In two experiments, male and female C57BL/6J mice, initially 19 d old, consumedad libituma complete purified diet (group C), or in restricted daily quantities (group R) or had free access to an isoenergetic low-protein diet (group LP). TGF-β bioactivity in platelet-poor plasma was determined via inhibition of Mv1Lu mink lung cell proliferation after 3 d (Expt 1, early stage) or 14 d (Expt 2, advanced stage) of dietary intervention. At 3 d, mean plasma TGF-β bioactivities were 802 (C), 2952 (R) and 4678 (LP) pg/ml, and after 14 d mean bioactivities were 1786 (C), 5360 (R) and 5735 (LP) pg/ml. At both time points, the malnourished groups differed from age-matched controls (P ≤ 0·05). Thus, metabolically distinct weanling systems mimicking paediatric marasmus (group R) and kwashiorkor (group LP) exhibit an early rise in blood TGF-β concentration, and this cytokine joins corticosterone and IL-10 as a third anti-inflammatory hormone temporally positioned to contribute to the initiation (and maintenance) of malnutrition-associated immune depression. This investigation contributes new insight into the active anti-inflammatory form of immune competence that appears to prevail in acute pre-pubescent malnutrition.

Elevated blood interleukin-10 levels and undiminished systemic interleukin-10 production rate prevail throughout acute protein-energy malnutrition in the weanling mouse

The objectives were to determine if blood IL-10 levels rise during the early stages of acute (wasting) pre-pubescent malnutrition in metabolically distinct murine models known to depress inflammatory immune competence and whether systemic IL-10 production is affected in these pathologies. Weanling C57BL/6J mice were assigned to dietary protocols that elicited wasting pathologies mimicking the human diseases of marasmus (restricted-intake group) or incipient kwashiorkor (low-protein group). An age-matched control group also was included. Serum IL-10 bioactivities were assessed in the early (day 3) and advanced (day 14) stages of weight loss, and net systemic IL-10 production was assessed at the same stages of pathology by in vivo cytokine capture. Blood IL-10 levels were elevated in both malnourished groups relative to controls at days 3 and 14 (range of P values: 0.03-0.0001). Further, despite a limited supply of energy and nitrogenous substrates, the systemic IL-10 production rate was at least sustained in the malnourished groups and, in fact, was elevated in the marasmic group (P=0.05) throughout the progression of weight loss. IL-10 emerges as an anti-inflammatory mediator positioned to participate in initiating and upholding the depressed immune competence that accompanies acute pre-pubescent deficits of protein and energy.

Cancer cachexia is associated with the IL10 -1082 gene promoter polymorphism in patients with gastroesophageal malignancy

BACKGROUND

The genetic predisposition of the host to local or systemic inflammation may contribute to the effect of cancer cachexia.

OBJECTIVE

We investigated the relation between cytokine polymorphisms (IL1B -511, IL6 -174, IL10 -1082, TNFA -308, and LTA +252) and markers of nutritional status among patients with gastroesophageal cancer to determine whether any such association was reflected by cytokine concentrations in the tumor or plasma compartments.

DESIGN

Patients (n = 203) with a diagnosis of gastroesophageal cancer underwent nutritional assessment (body mass index, anthropometric measures, dysphagia scoring, and estimation of dietary intake). Single nucleotide polymorphism genotyping was performed by TaqMan allelic discrimination genotyping. Serum cytokine and C-reactive protein concentrations were determined by enzyme-linked immunosorbent assay. Tumor tissue cytokine protein concentrations (n = 56) were determined by using the Cytometric Bead Array System.

RESULTS

IL10 GG and IL6 CC polymorphisms were associated with elevated serum C-reactive protein concentrations, and the IL6 CC genotype was also associated with elevated tumor tissue cytokine concentrations. At diagnosis, the IL10 GG, but not the IL6, genotype was linked with increased total weight loss: 4.9% for AA, 7.1% for AG, and 12.0% for GG (P = 0.007). Serum C-reactive protein concentrations correlated with increased weight loss (r = 0.24, P < 0.001). Compared with other genotypes, the IL10 GG genotype retained an independent association in determining the extent of weight loss on multivariate analysis (95% CI: 0.52, 3.43; P = 0.008). Possession of the GG allele was associated with a 2.3 times increased risk of developing cachexia (95% CI: 1.2, 4.3; P = 0.014).

CONCLUSION

These data suggest that the IL10 genotype of the host can influence the development of cachexia among patients with gastroesophageal malignancy.

CD11c+CD11b+ dendritic cells play an important role in intravenous tolerance and the suppression of experimental autoimmune encephalomyelitis

The central role of T cells in the induction of immunological tolerance against i.v. Ags has been well documented. However, the role of dendritic cells (DCs), the most potent APCs, in this process is not clear. In the present study, we addressed this issue by examining the involvement of two different DC subsets, CD11c(+)CD11b(+) and CD11c(+)CD8(+) DCs, in the induction of i.v. tolerance. We found that mice injected i.v. with an autoantigen peptide of myelin oligodendrocyte glycoprotein (MOG) developed less severe experimental autoimmune encephalomyelitis (EAE) following immunization with MOG peptide but presented with more CD11c(+)CD11b(+) DCs in the CNS and spleen. Upon coculturing with T cells or LPS, these DCs exhibited immunoregulatory characteristics, including increased production of IL-10 and TGF-beta but reduced IL-12 and NO; they were also capable of inhibiting the proliferation of MOG-specific T cells and enhancing the generation of Th2 cells and CD4(+)CD25(+)Foxp3(+) regulatory T cells. Furthermore, these DCs significantly suppressed ongoing EAE upon adoptive transfer. These results indicate that CD11c(+)CD11b(+) DCs, which are abundant in the CNS of tolerized animals, play a crucial role in i.v. tolerance and EAE and may be a candidate cell population for immunotherapy of autoimmune diseases.

Adoptively transferred dendritic cells restore primary cell-mediated inflammatory competence to acutely malnourished weanling mice

Immune depression associated with prepubescent malnutrition underlies a staggering burden of infection-related morbidity. This investigation centered on dendritic cells as potentially decisive in this phenomenon. C57BL/6J mice, initially 19 days old, had free access for 14 days to a complete diet or to a low-protein formulation that induced wasting deficits of protein and energy. Mice were sensitized by i.p. injection of sheep red blood cells on day 9, at which time one-half of the animals in each dietary group received a simultaneous injection of 10(6) syngeneic dendritic cells (JAWS II). All mice were challenged with the immunizing antigen in the right hind footpad on day 13, and the 24-hour delayed hypersensitivity response was assessed as percentage increase in footpad thickness. The low-protein diet reduced the inflammatory immune response, but JAWS cells, which exhibited immature phenotypic and functional characteristics, increased the response of both the malnourished group and the controls. By contrast, i.p. injection of 10(6) syngeneic T cells did not influence the inflammatory immune response of mice subjected to the low-protein protocol. Antigen-presenting cell numbers limited primary inflammatory cell-mediated competence in this model of wasting malnutrition, an outcome that challenges the prevailing multifactorial model of malnutrition-associated immune depression. Thus, a new dendritic cell-centered perspective emerges regarding the cellular mechanism underlying immune depression in acute pediatric protein and energy deficit.

Transforming growth factor-beta1 null mutation causes infertility in male mice associated with testosterone deficiency and sexual dysfunction

TGFbeta1 is a multifunctional cytokine implicated in gonad and secondary sex organ development, steroidogenesis, and spermatogenesis. To determine the physiological requirement for TGFbeta1 in male reproduction, Tgfb1 null mutant mice on a Prkdc(scid) immunodeficient background were studied. TGFbeta1-deficient males did not deposit sperm or induce pseudopregnancy in females, despite an intact reproductive tract with morphologically normal penis, seminal vesicles, and testes. Serum and intratesticular testosterone and serum androstenedione were severely diminished in TGFbeta1-deficient males. Testosterone deficiency was secondary to disrupted pituitary gonadotropin secretion because serum LH and to a lesser extent serum FSH were reduced, and exogenous LH replacement with human chorionic gonadotropin (hCG) induced serum testosterone to control levels. In the majority of TGFbeta1-deficient males, spermatogenesis was normal and sperm were developmentally competent as assessed by in vitro fertilization. Analysis of sexual behavior revealed that although TGFbeta1 null males showed avid interest in females and engaged in mounting activity, intromission was infrequent and brief, and ejaculation was not attained. Administration of testosterone to adult males, even after neonatal androgenization, was ineffective in restoring sexual function; however, erectile reflexes and ejaculation could be induced by electrical stimulation. These studies demonstrate the profound effect of genetic deficiency in TGFbeta1 on male fertility, implicating this cytokine in essential roles in the hypothalamic-pituitary-gonadal axis and in testosterone-independent regulation of mating competence.

Blood serum interferon-gamma bioactivity is low in weanling mice subjected to acute deficits of energy or both protein and energy

The main objective of the present study was to determine the influence of acute deficits of protein and energy on the blood serum level of interferon-gamma, a signature type 1 polarising inflammatory cytokine. In two 14 d experiments, male and female C57BL/6J mice, initial age 19 d, consumed a complete purified diet ad libitum or in restricted daily quantities, or had free access to an isoenergetic purified low-protein diet. A zero-time control group (age 19 d) was included in the second experiment. Serum interferon-gamma was assessed in both experiments by sandwich ELISA and, in the second experiment, also by a bioassay based on inhibition of proliferation by WEHI-279 B lymphoma cells. The immunoassay detected interferon-gamma inconsistently in all groups (range 0-14 pg/ml; detection limits 1 x 5 and 0 x 7 pg/ml in experiments 1 and 2, respectively). By contrast, interferon-gamma bioactivity was found in all animals of each group (means 339, 499, 124 and 200 pg/ml in zero-time controls, age-matched controls, low-protein and restricted intake groups, respectively; detection limit, 12 pg/ml), and the mean serum bioactivity of each malnourished group was low compared with the age-matched control (P <or=0 x 05). The present study defines the physiological serum interferon-gamma bioactivity of the adolescent mouse. Moreover, to the extent achievable by way of the blood, the results reflect the influence of metabolically diverse forms of acute malnutrition on the polarising type 1 cytokine profile within lymphoid microenvironments wherein immune responses arise. Therefore, the results suggest a mechanism underlying the cell-mediated inflammatory incompetence that characterises acute, prepubescent malnutrition.