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.

Intestinal disturbances associated with mortality of children with complicated severe malnutrition

BACKGROUND

Children admitted to hospital with complicated severe malnutrition (CSM) have high mortality despite compliance with standard WHO management guidelines. Limited data suggests a relationship between intestinal dysfunction and poor prognosis in CSM, but this has not been explicitly studied. This study aimed to evaluate the role of intestinal disturbances in CSM mortality.

METHODS

A case-control study nested within a randomized control trial was conducted among children hospitalized with CSM in Kenya and Malawi. Children who died (cases, n = 68) were compared with those who were discharged, propensity matched to the cases on age, HIV and nutritional status (controls, n = 68) on fecal metabolomics that targeted about 70 commonly measured metabolites, and enteropathy markers: fecal myeloperoxidase (MPO), fecal calprotectin, and circulating intestinal fatty acid binding protein (I-FABP).

RESULTS

The fecal metabolomes of cases show specific reductions in amino acids, monosaccharides, and microbial fermentation products, when compared to controls. SCFA levels did not differ between groups. The overall fecal metabolomics signature moderately differentiates cases from controls (AUC = 0.72). Enteropathy markers do not differ between groups overall, although serum I-FABP is elevated in cases in a sensitivity analysis among non-edematous children. Integrative analysis with systemic data suggests an indirect role of intestinal inflammation in the causal path of mortality.

CONCLUSIONS

Intestinal disturbances appear to have an indirect association with acute mortality. Findings of the study improve our understanding of pathophysiological pathways underlying mortality of children with CSM.

Reactive nitrogen compounds and their influence on human health: an overview

Nitrogen (N) is a critical component of food security, economy and planetary health. Human production of reactive nitrogen (Nr) via Haber-Bosch process and cultivation-induced biological N₂ fixation (BNF) has doubled global N cycling over the last century. The most important beneficial effect of Nr is augmenting global food supplies due to increased crop yields. However, increased circulation of Nr in the environment is responsible for serious human health effects such as methemoglobinemia ("blue baby syndrome") and eutrophication of coastal and inland waters. Furthermore, ammonia (NH₃) emission mainly from farming and animal husbandary impacts not only human health causing chronic lung disease, inflammation of human airways and irritation of eyes, sinuses and skin but is also involved in the formation of secondary particulate matter (PM) that plays a critical role in environment and human health. Nr also affects human health via global warming, depletion of stratospheric ozone layer resulting in greater intensity of ultra violet B rays (UVB) on the Earth's surface, and creation of ground-level ozone (through reaction of NO₂ with O₂). The consequential indirect human health effects of Nr include the spread of vector-borne pathogens, increased incidence of skin cancer, development of cataracts, and serious respiratory diseases, besides land degradation. Evidently, the strategies to reduce Nr and mitigate adverse environmental and human health impacts include plugging pathways of nitrogen transport and loss through runoff, leaching and emissions of NH₃, nitrogen oxides (NO _x ), and other N compounds; improving fertilizer N use efficiency; reducing regional disparity in access to N fertilizers; enhancing BNF to decrease dependence on chemical fertilizers; replacing animal-based proteins with plant-based proteins; adopting improved methods of livestock raising and manure management; reducing air pollution and secondary PM formation; and subjecting industrial and vehicular NO _x emission to pollution control laws. Strategic implementation of all these presents a major challenge across the fields of agriculture, ecology and public health. Recent observations on the reduction of air pollution in the COVID-19 lockdown period in several world regions provide an insight into the achievability of long-term air quality improvement. In this review, we focus on complex relationships between Nr and human health, highlighting a wide range of beneficial and detrimental effects.

Mechanisms of Kwashiorkor-Associated Immune Suppression: Insights From Human, Mouse, and Pig Studies

Malnutrition refers to inadequate energy and/or nutrient intake. Malnutrition exhibits a bidirectional relationship with infections whereby malnutrition increases risk of infections that further aggravates malnutrition. Severe malnutrition (SM) is the main cause of secondary immune deficiency and mortality among children in developing countries. SM can manifest as marasmus (non-edematous), observed most often (68.6% of all malnutrition cases), kwashiorkor (edematous), detected in 23.8% of cases, and marasmic kwashiorkor, identified in ~7.6% of SM cases. Marasmus and kwashiorkor occur due to calorie-energy and protein-calorie deficiency (PCD), respectively. Kwashiorkor and marasmic kwashiorkor present with reduced protein levels, protein catabolism rates, and altered levels of micronutrients leading to uncontrolled oxidative stress, exhaustion of anaerobic commensals, and proliferation of pathobionts. Due to these alterations, kwashiorkor children present with profoundly impaired immune function, compromised intestinal barrier, and secondary micronutrient deficiencies. Kwashiorkor-induced alterations contribute to growth stunting and reduced efficacy of oral vaccines. SM is treated with antibiotics and ready-to-use therapeutic foods with variable efficacy. Kwashiorkor has been extensively investigated in gnotobiotic (Gn) mice and piglet models to understand its multiple immediate and long-term effects on children health. Due to numerous physiological and immunological similarities between pigs and humans, pig represents a highly relevant model to study kwashiorkor pathophysiology and immunology. Here we summarize the impact of kwashiorkor on children's health, immunity, and gut functions and review the relevant findings from human and animal studies. We also discuss the reciprocal interactions between PCD and rotavirus-a highly prevalent enteric childhood pathogen due to which pathogenesis and immunity are affected by childhood SM.

Systemic inflammation and metabolic disturbances underlie inpatient mortality among ill children with severe malnutrition

Children admitted to hospital with an acute illness and concurrent severe malnutrition [complicated severe malnutrition (CSM)] have a high risk of dying. The biological processes underlying their mortality are poorly understood. In this case-control study nested within a multicenter randomized controlled trial among children with CSM in Kenya and Malawi, we found that blood metabolomic and proteomic profiles robustly differentiated children who died (n = 92) from those who survived (n = 92). Fatalities were characterized by increased energetic substrates (tricarboxylic acid cycle metabolites), microbial metabolites (e.g., propionate and isobutyrate), acute phase proteins (e.g., calprotectin and C-reactive protein), and inflammatory markers (e.g., interleukin-8 and tumor necrosis factor-α). These perturbations indicated disruptions in mitochondria-related bioenergetic pathways and sepsis-like responses. This study identified specific biomolecular disturbances associated with CSM mortality, revealing that systemic inflammation and bioenergetic deficits are targetable pathophysiological processes for improving survival of this vulnerable population.

Aminoacid Profiling of Children with Severe Acute Malnutrition Pre and Post Nutritional Rehabilitation

Malnutrition is a significant comorbidity in nearly one-third of the 8 million deaths in children under five years of age worldwide. Children with severe acute malnutrition have severely disturbed physiology and metabolism. Considering the vital importance of amino acids and the likely changes with the therapeutic diet, we aimed at evaluating these changes in children with SAM at baseline and after rehabilitation with a therapeutic diet at 14 days. Severe acute malnutrition defined as per WHO, for children between 6 months and 5 years with weight for height/length < -3SD of WHO charts, bilateral pitting edema, and mid-upper arm circumference (MUAC) < 1.5 cm. A total of 38 children were enrolled as cases, whereas the control group comprised of 37 children. Anthropometric measurement and estimation of amino acids in the blood were done at the baseline and after dietary rehabilitation. The individual levels of the essential and non-essential amino acids were significantly lower in the cases as compared to the controls, except for Aspartate and Threonine. The levels of amino acids increased significantly after dietary rehabilitation except for arginine, however not to the levels of those in controls. Most of the metabolites were reflective of maladaptation in SAM. Though nutritional rehabilitation of children with SAM improved the levels of amino acids, these levels were still low when compared to the controls, stipulating that complete metabolic recovery may take a longer duration of time. This necessitates the continuation of nutritional rehabilitation for a longer time and regular follow up of these children to ensure better compliance.

Liver disease in obesity and underweight: the two sides of the coin. A narrative review

PURPOSE

Malnutrition, whether characterized by not enough or too much nutrient intake, is detrimental to the liver. We herein provide a narrative literature revision relative to hepatic disease occurrence in over or undernourished subjects, to shed light on the paradox where both sides of malnutrition lead to similar liver dysfunction and fat accumulation.

METHODS

Medline, EMBASE, and Cochrane Library were searched for publications up to July 2020. Articles discussing the association between both chronic and acute liver pathology and malnutrition were evaluated together with studies reporting the dietary intake in subjects affected by malnutrition.

RESULTS

The association between overnutrition and non-alcoholic fatty liver disease (NAFLD) is well recognized, as the beneficial effects of calorie restriction and very low carbohydrate diets. Conversely, the link between undernutrition and liver injury is more complex and less understood. In developing countries, early exposure to nutrient deficiency leads to marasmus and kwashiorkor, accompanied by fatty liver, whereas in developed countries anorexia nervosa is a more common form of undernutrition, associated with liver injury. Weight gain in undernutrition is associated with liver function improvement, whereas no study on the impact of macronutrient distribution is available. We hypothesized a role for very low carbohydrate diets in the management of undernutrition derived liver pathology, in addition to the established one in overnutrition-related NAFLD.

CONCLUSIONS

Further studies are warranted to update the knowledge regarding undernutrition-related liver disease, and a specific interest should be paid to macronutrient distribution both in the context of refeeding and relative to its role in the development of hepatic complications of anorexia nervosa.

LEVEL OF EVIDENCE

Narrative review, Level V.

Plasma and Urinary Amino Acid Profile in Children with Infantile Tremor Syndrome

BACKGROUND

Infantile Tremor Syndrome (ITS) is a disorder of infancy, and characterized by developmental delay and/or regression, pallor, skin hyperpigmentation and hypopigmented hair. It is commonly seen in infants in whom exclusive breastfeeding is given inappropriately for longer durations than recommended. ITS is predominantly reported from the Indian subcontinent and in children from a lower socioeconomic background. It is a clinical diagnosis and vitamin B12 deficiency is the most commonly accepted etiology of this entity.

OBJECTIVES

The primary objectives of study were to compare the plasma and urine amino acid levels among children with ITS spectrum with those of healthy children. The secondary objectives were to compare the plasma and urine amino acid levels among children with ITS and Pre-ITS.

STUDY DESIGN

This cross-sectional, observational study was carried out at a tertiary care hospital in North India.

PARTICIPANTS

A total of 50 children aged < 36 months with ITS/Pre-ITS were enrolled. Children with Pre-ITS and ITS were compared with healthy age-matched study subjects.

RESULTS

Thirty-nine (78%) cases and twelve (24%) healthy children had low serum vitamin B12 levels. Folate levels were normal in all the controls, while only one case had folate deficiency. There were significant differences (p < 0.05) in the values of 32 amino acids in plasma. Among 44 urinary amino acids, levels of 30 amino acids were significantly different in the cases compared with the controls (p < 0.05).

CONCLUSIONS

Several changes in amino acids in the children suffering from ITS were observed. These changes may be a reflection of the metabolic derangements in ITS.

Intestinal interplay of quorum sensing molecules and human receptors

Human gut is in permanent contact with microorganisms that play an important role in many physiological processes including metabolism and immunologic activity. These microorganisms communicate and manage themself by the quorum sensing system (QS) that helps to coordinate optimal growth and subsistence by activating signaling pathways that regulate bacterial gene expression. Diverse QS molecules produced by pathogenic as well as resident microbiota have been found throughout the human gut. However, even a host can by affected by these molecules. Intestinal and immune cells possess a range of molecular targets for QS. Our present knowledge on bacteria-cell communication encompasses G-protein-coupled receptors, nuclear receptors and receptors for bacterial cell-wall components. The QS of commensal bacteria has been approved as a protective factor with favourable effects on intestinal homeostasis and immunity. Signaling molecules of QS interacting with above-mentioned receptors thus parcipitate on maintaining of barrier functions, control of inflammation processes and increase of resistance to pathogen colonization in host organisms. Pathogens QS molecules can have a dual function. Host cells are able to detect the ongoing infection by monitoring the presence and changes in concentrations of QS molecules. Such information can help to set the most effective immune defence to prevent or overcome the infection. Contrary, pathogens QS signals can target the host receptors to deceive the immune system to get the best conditions for growth. However, our knowledge about communication mediated by QS is still limited and detailed understanding of molecular mechanisms of QS signaling is desired.

Amino acid-enriched plant-based RUTF treatment was not inferior to peanut-milk RUTF treatment in restoring plasma amino acid levels among patients with oedematous or non-oedematous malnutrition

Ready-to-use therapeutic food (RUTF) with adequate quality protein is used to treat children with oedematous and non-oedematous severe acute malnutrition (SAM). The plasma amino acid (AA) profile reflects the protein nutritional status; hence, its assessment during SAM treatment is useful in evaluating AA delivery from RUTFs. The objective was to evaluate the plasma AAs during the treatment of oedematous and non-oedematous SAM in community-based management of acute malnutrition (CMAM) using amino acid-enriched plant-based RUTFs with 10% milk (MSMS-RUTF) or without milk (FSMS-RUTF) compared to peanut milk RUTF (PM-RUTF). Plasma AA was measured in a non-blinded, 3-arm, parallel-group, simple randomized controlled trial conducted in Malawi. The RUTFs used for SAM were FSMS-RUTF, MSMS-RUTF or PM-RUTF. A non-inferiority hypothesis was tested to compare plasma AA levels from patients treated with FSMS-RUTF or MSMS-RUTF with those from patients treated with PM-RUTF at discharge. For both types of SAM, FSMS-RUTF and MSMS-RUTF treatments were non-inferior to the PM-RUTF treatment in restoration of the EAA and cystine except that for FSMS-RUTF, methionine and tryptophan partially satisfied the non-inferiority criteria in the oedematous group. Amino-acid-enriched milk-free plant-source-protein RUTF has the potential to restore all the EAA, but it is possible that enrichment with amino acids may require more methionine and tryptophan for oedematous children.

Weaning and stunting affect nitrogen and carbon stable isotope natural abundances in the hair of young children

Natural abundances of stable nitrogen and carbon isotopes (δ¹⁵N and δ¹³C) can vary with both dietary intake and metabolic (specifically catabolic) state. In low-income countries, weaning is a period of dietary transition from milk to plant-based foods and a high-risk period for malnutrition. We explored how diet and malnutrition impact hair δ¹⁵N and δ¹³C in young children by an observational, cross-sectional study in Cox’s Bazar District, Bangladesh [255 children, 6–59 months with 19.6% wasted (7.1% severely) and 36% stunted (9.8% severely)]. Hair δ¹⁵N and δ¹³C exhibited exponential decreases with age, with the loss of one trophic level (3.3‰ and 0.8‰, respectively) from 6 to 48 months, which we associate with the shift from exclusive breastfeeding to complete weaning. After adjustment for age and breastfeeding status, hair isotopic values were unaffected by wasting but lower in severe stunting (−0.45‰ to −0.6‰, P < 0.01). In this population of young children, whose isotopic values in hair primarily depended on age, we failed to observe any effect of wasting, likely due to opposite, compensating effects between dietary and metabolic changes involved. In contrast, we evidenced low δ¹⁵N and δ¹³C values in severely stunted children that likely indicate chronic exposure to diets low in animal products.

Edematous severe acute malnutrition is characterized by hypomethylation of DNA

Edematous severe acute childhood malnutrition (edematous SAM or ESAM), which includes kwashiorkor, presents with more overt multi-organ dysfunction than non-edematous SAM (NESAM). Reduced concentrations and methyl-flux of methionine in 1-carbon metabolism have been reported in acute, but not recovered, ESAM, suggesting downstream DNA methylation changes could be relevant to differences in SAM pathogenesis. Here, we assess genome-wide DNA methylation in buccal cells of 309 SAM children using the 450 K microarray. Relative to NESAM, ESAM is characterized by multiple significantly hypomethylated loci, which is not observed among SAM-recovered adults. Gene expression and methylation show both positive and negative correlation, suggesting a complex transcriptional response to SAM. Hypomethylated loci link to disorders of nutrition and metabolism, including fatty liver and diabetes, and appear to be influenced by genetic variation. Our epigenetic findings provide a potential molecular link to reported aberrant 1-carbon metabolism in ESAM and support consideration of methyl-group supplementation in ESAM.

Urinary Organic Acids Increase After Clinical Stabilization of Hospitalized Children With Severe Acute Malnutrition

BACKGROUND

Despite a reduction of child mortality in low-income countries, acutely ill undernourished children still have an elevated risk of death. Those at highest risk are children with severe acute malnutrition (SAM) who often show metabolic dysregulation that remains poorly understood.

OBJECTIVE

We performed a pilot study to examine changes in urinary organic acids during nutritional rehabilitation of children with SAM, and to identify metabolites associated with the presence of edema or with mortality.

METHODS

This study included 76 children aged between 6 and 60 months, hospitalized for SAM at the Moyo Nutritional Rehabilitation and Research Unit in Blantyre, Malawi. Urine was collected at admission and 3 days after clinical stabilization and metabolomics were performed using gas chromatography-mass spectrometry. Metabolite concentrations were evaluated with both uni- and multivariate approaches.

RESULTS

Most metabolites increased 3 days after clinical stabilization, and total urinary concentration changed from 1.2 mM (interquartile range [IQR], 0.78-1.7) at admission to 3.8 mM (IQR, 2.1-6.6) after stabilization (P < .0001). In particular, 6 metabolites showed increases: 3-hydroxybutyric, 4-hydroxyhippuric, p-hydroxyphenylacetic, oxoglutaric, succinic, and lactic acids. Urinary creatinine was low at both time points, but levels did increase from 0.63 mM (IQR, 0.2-1.2) to 2.6 mM (IQR,1.6-4.4; P < .0001). No differences in urinary profiles were found between children who died versus those who survived, nor between children with severe wasting or edematous SAM.

CONCLUSIONS

Total urinary metabolites and creatinine increase after stabilization and may reflect partial recovery of overall metabolism linked to refeeding. The use of urinary metabolites for risk assessment should be furthered explored.

TRIAL REGISTRATION

TranSAM study (ISRCTN13916953).

Evolutionary and developmental mismatches are consequences of adaptive developmental plasticity in humans and have implications for later disease risk

A discrepancy between the phenotype of an individual and that which would confer optimal responses in terms of fitness in an environment is termed 'mismatch'. Phenotype results from developmental plasticity, conditioned partly by evolutionary history of the species and partly by aspects of the developmental environment. We discuss two categories of such mismatch with reference primarily to nutrition and in the context of evolutionary medicine. The categories operate over very different timescales. A developmental mismatch occurs when the phenotype induced during development encounters a different environment post-development. This may be the result of wider environmental changes, such as nutritional transition between generations, or because maternal malnutrition or placental dysfunction give inaccurate information about the organism's likely future environment. An evolutionary mismatch occurs when there is an evolutionarily novel environment. Developmental plasticity may involve immediate adaptive responses (IARs) to preserve survival if an environmental challenge is severe, and/or predictive adaptive responses (PARs) if the challenge does not threaten survival, but there is a fitness advantage in developing a phenotype that will be better adapted later. PARs can have long-term adverse health consequences if there is a developmental mismatch. For contemporary humans, maternal constraint of fetal growth makes PARs likely even if there is no obvious IAR, and this, coupled with the pervasive nutritionally dense modern environment, can explain the widespread observations of developmental mismatch, particularly in populations undergoing nutritional transition. Both developmental and evolutionary mismatch have important public health consequences and implications for where policy interventions may be most effective. This article is part of the theme issue 'Developing differences: early-life effects and evolutionary medicine'.

Benefit of feeding tube placement for refractory malnutrition after bariatric surgery

BACKGROUND

Bariatric surgery provides durable weight loss and decreases the incidence of co-morbid conditions for people with obesity. Most patients benefit from resultant weight loss, but some are at risk for postoperative refractory malnutrition, a serious but poorly understood complication.

OBJECTIVE

To evaluate differences in bariatric surgery patients who received a feeding tube postoperatively for malnutrition compared with other indications.

SETTING

Retrospective cohort study at an academic bariatric surgery center (1985-2015).

METHODS

All bariatric surgery patients that received a feeding tube postoperatively over a 30-year period were identified. Data abstraction from the medical record was performed to assess demographic characteristics, operative details, tube indication, and resultant body mass index (BMI) changes.

RESULTS

From a total of 3487 patients who underwent bariatric surgery during the study period, 139 (3.9%) required placement of a feeding tube postoperatively. Refractory malnutrition was the indication in 24 patients, all after Roux-en-Y gastric bypass. There were no significant differences between these patients and other bariatric surgery patients in terms of mean age (40.6±9.9 versus 43.1±13.4 years, P = .4) and preoperative BMI (47.5±10.5 versus 51.0±9.6 kg/m2, P = .1). The median time from surgery to tube placement for malnutrition patients was 4 years. Compared with other feeding tube indications, malnutrition patients had higher percent excess BMI lost after surgery (126.2±31.9 versus 52.5±44.3%, P<.0001). After tube placement, malnutrition patients had a significant increase in mean BMI compared with other indications (14.5±20.9 versus-13.0±14.0%, P< .001).

CONCLUSION

Patients with refractory malnutrition benefit from feeding tube placement, which results in a significant increase in BMI.

Impact of Childhood Malnutrition on Host Defense and Infection

The global impact of childhood malnutrition is staggering. The synergism between malnutrition and infection contributes substantially to childhood morbidity and mortality. Anthropometric indicators of malnutrition are associated with the increased risk and severity of infections caused by many pathogens, including viruses, bacteria, protozoa, and helminths. Since childhood malnutrition commonly involves the inadequate intake of protein and calories, with superimposed micronutrient deficiencies, the causal factors involved in impaired host defense are usually not defined. This review focuses on literature related to impaired host defense and the risk of infection in primary childhood malnutrition. Particular attention is given to longitudinal and prospective cohort human studies and studies of experimental animal models that address causal, mechanistic relationships between malnutrition and host defense. Protein and micronutrient deficiencies impact the hematopoietic and lymphoid organs and compromise both innate and adaptive immune functions. Malnutrition-related changes in intestinal microbiota contribute to growth faltering and dysregulated inflammation and immune function. Although substantial progress has been made in understanding the malnutrition-infection synergism, critical gaps in our understanding remain. We highlight the need for mechanistic studies that can lead to targeted interventions to improve host defense and reduce the morbidity and mortality of infectious diseases in this vulnerable population.

Severe childhood malnutrition

The main forms of childhood malnutrition occur predominantly in children <5 years of age living in low-income and middle-income countries and include stunting, wasting and kwashiorkor, of which severe wasting and kwashiorkor are commonly referred to as severe acute malnutrition. Here, we use the term 'severe malnutrition' to describe these conditions to better reflect the contributions of chronic poverty, poor living conditions with pervasive deficits in sanitation and hygiene, a high prevalence of infectious diseases and environmental insults, food insecurity, poor maternal and fetal nutritional status and suboptimal nutritional intake in infancy and early childhood. Children with severe malnutrition have an increased risk of serious illness and death, primarily from acute infectious diseases. International growth standards are used for the diagnosis of severe malnutrition and provide therapeutic end points. The early detection of severe wasting and kwashiorkor and outpatient therapy for these conditions using ready-to-use therapeutic foods form the cornerstone of modern therapy, and only a small percentage of children require inpatient care. However, the normalization of physiological and metabolic functions in children with malnutrition is challenging, and children remain at high risk of relapse and death. Further research is urgently needed to improve our understanding of the pathophysiology of severe malnutrition, especially the mechanisms causing kwashiorkor, and to develop new interventions for prevention and treatment.

Protein Malnutrition Alters Tryptophan and Angiotensin-Converting Enzyme 2 Homeostasis and Adaptive Immune Responses in Human Rotavirus-Infected Gnotobiotic Pigs with Human Infant Fecal Microbiota Transplant

Malnutrition leads to increased morbidity and is evident in almost half of all deaths in children under the age of 5 years. Mortality due to rotavirus diarrhea is common in developing countries where malnutrition is prevalent; however, the relationship between malnutrition and rotavirus infection remains unclear. In this study, gnotobiotic pigs transplanted with the fecal microbiota of a healthy 2-month-old infant were fed protein-sufficient or -deficient diets and infected with virulent human rotavirus (HRV). After human rotavirus infection, protein-deficient pigs had decreased human rotavirus antibody titers and total IgA concentrations, systemic T helper (CD3⁺ CD4⁺) and cytotoxic T (CD3⁺ CD8⁺) lymphocyte frequencies, and serum tryptophan and angiotensin I-converting enzyme 2. Additionally, deficient-diet pigs had impaired tryptophan catabolism postinfection compared with sufficient-diet pigs. Tryptophan supplementation was tested as an intervention in additional groups of fecal microbiota-transplanted, rotavirus-infected, sufficient- and deficient-diet pigs. Tryptophan supplementation increased the frequencies of regulatory (CD4⁺ or CD8⁺ CD25⁺ FoxP3⁺) T cells in pigs on both the sufficient and the deficient diets. These results suggest that a protein-deficient diet impairs activation of the adaptive immune response following HRV infection and alters tryptophan homeostasis.

Molecular Evidence for Differential Long-term Outcomes of Early Life Severe Acute Malnutrition

BACKGROUND

Severe acute malnutrition (SAM) in infants may present as one of two distinct syndromic forms: non-edematous (marasmus), with severe wasting and no nutritional edema; or edematous (kwashiorkor) with moderately severe wasting. These differences may be related to developmental changes prior to the exposure to SAM and phenotypic changes appear to persist into adulthood with differences between the two groups. We examined whether the different response to SAM and subsequent trajectories may be explained by developmentally-induced epigenetic differences.

METHODS

We extracted genomic DNA from muscle biopsies obtained from adult survivors of kwashiorkor (n=21) or marasmus (n=23) and compared epigenetic profiles (CpG methylation) between the two groups using the Infinium® 450K BeadChip array.

FINDINGS

We found significant differences in methylation of CpG sites from 63 genes in skeletal muscle DNA. Gene ontology studies showed significant differential methylation of genes in immune, body composition, metabolic, musculoskeletal growth, neuronal function and cardiovascular pathways, pathways compatible with the differences in the pathophysiology of adult survivors of SAM.

INTERPRETATION

These findings suggest persistent developmental influences on adult physiology in survivors of SAM. Since children who develop marasmus have lower birth weights and after rehabilitation have different intermediary metabolism, these studies provide further support for persistent developmentally-induced phenomena mediated by epigenetic processes affecting both the infant response to acute malnutrition and later life consequences.

FUNDING

Supported by a Grant from the Bill and Melinda Gates Foundation (Global Health OPP1066846), Grand Challenge "Discover New Ways to Achieve Healthy Growth."

EVIDENCE BEFORE THIS STUDY

Previous research has shown that infants who develop either kwashiorkor or marasmus in response to SAM differ in birth weight and subsequently have different metabolic patterns in both infancy and adulthood.

ADDED VALUE OF THIS STUDY

This study demonstrates epigenetic differences in the skeletal muscle of adult survivors of marasmus versus kwashiorkor and these differences are in genes that may underlie the longer-term consequences.

IMPLICATIONS OF ALL THE AVAILABLE EVIDENCE

These data are compatible with the different clinical responses to SAM arising from developmentally-induced epigenetic changes laid down largely before birth and provide evidence for the predictive adaptive response model operating in human development.

Colitis, independent of macronutrient intake, compromises bone structure and strength in growing piglets

BACKGROUND

Deterioration in bone health is a concern in managing pediatric inflammatory bowel diseases, but clear understanding of the independent contributions of disease and nutrition is lacking. This study aimed to ascertain whether bone health could be conserved during colitis by maintaining adequate nutritional intake in growing piglets.

METHODS

The effect of colitis on bone structure and strength was determined in piglets with dextran sulphate sodium-induced colitis. Piglets received either 100% macro/micronutrient requirements or 50% macro/100% micronutrient requirements. Femurs were analyzed for dual-energy x-ray absorptiometry, peripheral quantitative computed tomography, microcomputed tomography, and 3-point bending tests.

RESULTS

Colitis, regardless of a well-nourished or malnourished diet, compromised areal bone mineral density (-17%) and volumetric bone mineral density (-20%) in cortical and trabecular bone. Structural integrity at mid-diaphysis was maintained during colitis; however, lower cortical area, trabecular area, and bone mineral content resulted in lower energy to break.

CONCLUSION

Colitis compromises both bone structure and strength of long bones in piglets, independent of macronutrient intakes. Although confirmation of these findings in pediatric cohorts is needed, these data identify aspects of bone health that may be affected by inflammatory bowel disease.

Developmental contributions to macronutrient selection: a randomized controlled trial in adult survivors of malnutrition

Background and objectives: Birthweight differences between kwashiorkor and marasmus suggest that intrauterine factors influence the development of these syndromes of malnutrition and may modulate risk of obesity through dietary intake. We tested the hypotheses that the target protein intake in adulthood is associated with birthweight, and that protein leveraging to maintain this target protein intake would influence energy intake (EI) and body weight in adult survivors of malnutrition.

Methodology: Sixty-three adult survivors of marasmus and kwashiorkor could freely compose a diet from foods containing 10, 15 and 25 percentage energy from protein (percentage of energy derived from protein (PEP); Phase 1) for 3 days. Participants were then randomized in Phase 2 (5 days) to diets with PEP fixed at 10%, 15% or 25%.

Results: Self-selected PEP was similar in both groups. In the groups combined, selected PEP was 14.7, which differed significantly (P < 0.0001) from the null expectation (16.7%) of no selection. Self-selected PEP was inversely related to birthweight, the effect disappearing after adjusting for sex and current body weight. In Phase 2, PEP correlated inversely with EI (P = 0.002) and weight change from Phase 1 to 2 (P = 0.002). Protein intake increased with increasing PEP, but to a lesser extent than energy increased with decreasing PEP.

Conclusions and implications: Macronutrient intakes were not independently related to birthweight or diagnosis. In a free-choice situation (Phase 1), subjects selected a dietary PEP significantly lower than random. Lower PEP diets induce increased energy and decreased protein intake, and are associated with weight gain.

Progressive Changes in the Plasma Metabolome during Malnutrition in Juvenile Pigs

Severe acute malnutrition (SAM) is one of the leading nutrition-related causes of death in children under five years of age. The clinical features of SAM are well documented, but a comprehensive understanding of the development from a normal physiological state to SAM is lacking. Characterizing the temporal metabolomic change may help to understand the disease progression and to define nutritional rehabilitation strategies. Using a piglet model we hypothesized that a progressing degree of malnutrition induces marked plasma metabolite changes. Four-week-old weaned pigs were fed a nutrient-deficient maize diet (MAL) or nutritionally optimized reference diet (REF) for 7 weeks. Plasma collected weekly was subjected to LC-MS for a nontargeted profiling of metabolites with abundance differentiation. The MAL pigs showed markedly reduced body-weight gain and lean-mass proportion relative to the REF pigs. Levels of eight essential and four nonessential amino acids showed a time-dependent deviation in the MAL pigs from that in the REF. Choline metabolites and gut microbiomic metabolites generally showed higher abundance in the MAL pigs. The results demonstrated that young malnourished pigs had a profoundly perturbed metabolism, and this provides basic knowledge about metabolic changes during malnourishment, which may be of help in designing targeted therapeutic foods for refeeding malnourished children.

Metabolomics in Nutrition Research: Biomarkers Predicting Mortality in Children with Severe Acute Malnutrition

Background

Millions of the world's children suffer from malnutrition, which predisposes to death from diarrhea and a variety of infectious diseases. Mortality rates among infants and toddlers remain staggeringly high, in part because the pathogenesis of acute malnutrition and its complications remains poorly understood.

Objective

We used metabolomic analysis to characterize the metabolic status of Ugandan children with severe acute malnutrition (SAM) and to delineate changes in hormones, metabolites, growth factors, and cytokines during nutritional therapy. We hypothesized that hormonal and metabolic factors measured at presentation would associate with, or predict, subsequent mortality during treatment

Methods

This was a prospective cohort study of 75 severely malnourished children 6 months to 5 years of age treated as inpatients with F-75 and F-100 and supplemental micronutrients; after discharge, they received ready-to-use therapeutic food (RUTF). This increased the mean weight-for-height z-score (WHZ) from −4.27 to −1.75 SD. Blood samples were obtained at presentation, after 2 weeks of inpatient therapy, and after 4 to 10 weeks of RUTF. Plasma samples were analyzed by tandem mass spectrometry and microassays.

Results

At presentation there were high levels of non-esterified fatty acids (NEFA), ketones, and even-chain acylcarnitines, indicating active lipolysis and fatty acid oxidation. In contrast, albumin, amino acids, and C3 carnitine, a by-product of branched-chain amino acids, were low. Levels of insulin, insulin-like growth factor 1 (IGF-1), adiponectin, and leptin were low, while levels of ghrelin, growth hormone, cortisol, interleukin 6 (IL-6), peptide YY (PYY), and glucagon-like peptide 1 (GLP-1) were high. The metabolic and hormonal changes were reversed by formula feeding and RUTF. Biomarkers associated with mortality included HIV, WHZ, and mid-upper-arm circumference (MUAC); the biochemical factor associated most strongly with mortality was low leptin, a marker of adipose reserve and modulator of immune function.

Conclusions

Low leptin predicts mortality in edematous and nonedematous patients with SAM. Leptin assays might be used to identify malnourished children at highest risk for death.

The immune system in children with malnutrition--a systematic review

Background

Malnourished children have increased risk of dying, with most deaths caused by infectious diseases. One mechanism behind this may be impaired immune function. However, this immune deficiency of malnutrition has not previously been systematically reviewed.

Objectives

To review the scientific literature about immune function in children with malnutrition.

Methods

A systematic literature search was done in PubMed, and additional articles identified in reference lists and by correspondence with experts in the field. The inclusion criteria were studies investigating immune parameters in children aged 1–60 months, in relation to malnutrition, defined as wasting, underweight, stunting, or oedematous malnutrition.

Results

The literature search yielded 3402 articles, of which 245 met the inclusion criteria. Most were published between 1970 and 1990, and only 33 after 2003. Malnutrition is associated with impaired gut-barrier function, reduced exocrine secretion of protective substances, and low levels of plasma complement. Lymphatic tissue, particularly the thymus, undergoes atrophy, and delayed-type hypersensitivity responses are reduced. Levels of antibodies produced after vaccination are reduced in severely malnourished children, but intact in moderate malnutrition. Cytokine patterns are skewed towards a Th2-response. Other immune parameters seem intact or elevated: leukocyte and lymphocyte counts are unaffected, and levels of immunoglobulins, particularly immunoglobulin A, are high. The acute phase response appears intact, and sometimes present in the absence of clinical infection. Limitations to the studies include their observational and often cross-sectional design and frequent confounding by infections in the children studied.

Conclusion

The immunological alterations associated with malnutrition in children may contribute to increased mortality. However, the underlying mechanisms are still inadequately understood, as well as why different types of malnutrition are associated with different immunological alterations. Better designed prospective studies are needed, based on current understanding of immunology and with state-of-the-art methods.

Severe acute malnutrition in childhood: hormonal and metabolic status at presentation, response to treatment, and predictors of mortality

OBJECTIVE

Malnutrition is a major cause of childhood morbidity and mortality. To identify and target those at highest risk, there is a critical need to characterize biomarkers that predict complications prior to and during treatment.

METHODS

We used targeted and nontargeted metabolomic analysis to characterize changes in a broad array of hormones, cytokines, growth factors, and metabolites during treatment of severe childhood malnutrition. Children aged 6 months to 5 years were studied at presentation to Mulago Hospital and during inpatient therapy with milk-based formulas and outpatient supplementation with ready-to-use food. We assessed the relationship between baseline hormone and metabolite levels and subsequent mortality.

RESULTS

Seventy-seven patients were enrolled in the study; a subset was followed up from inpatient treatment to the outpatient clinic. Inpatient and outpatient therapies increased weight/height z scores and induced striking changes in the levels of fatty acids, amino acids, acylcarnitines, inflammatory cytokines, and various hormones including leptin, insulin, GH, ghrelin, cortisol, IGF-I, glucagon-like peptide-1, and peptide YY. A total of 12.2% of the patients died during hospitalization; the major biochemical factor predicting mortality was a low level of leptin (P = .0002), a marker of adipose tissue reserve and a critical modulator of immune function.

CONCLUSIONS

We have used metabolomic analysis to provide a comprehensive hormonal and metabolic profile of severely malnourished children at presentation and during nutritional rehabilitation. Our findings suggest that fatty acid metabolism plays a central role in the adaptation to acute malnutrition and that low levels of the adipose tissue hormone leptin associate with, and may predict, mortality prior to and during treatment.

Diet and kwashiorkor: a prospective study from rural DR Congo

The etiology of kwashiorkor remains enigmatic and longitudinal studies examining potential causes of kwashiorkor are scarce. Using historical, longitudinal study data from the rural area of Bwamanda, Democratic Republic of Congo, we investigated the potential causal association between diet and the development of kwashiorkor in 5 657 preschool children followed 3-monthly during 15 months. We compared dietary risk factors for kwashiorkor with those of marasmus. Kwashiorkor was diagnosed as pitting oedema of the ankles; marasmus as abnormal visibility of skeletal structures and palpable wasting of the gluteus muscle. A 24-h recall was administered 3-monthly to record the consumption of the 41 locally most frequent food items. We specified Hanley–Miettinen smooth-in-time risk models containing potential causal factors, including food items, special meals prepared for the child, breastfeeding, disease status, nutritional status, birth rank, age, season and number of meals. Bayesian Information Criteria identified the most plausible causal model of why some children developed kwashiorkor. In a descriptive analysis of the diet at the last dietary assessment prior to development of kwashiorkor, the diet of children who developed kwashiorkor was characterized by low consumption of sweet potatoes, papaya and “other vegetables” [0.0% , 2.3% (95% CI [0.4, 12.1]) and 2.3% (95% CI [0.4, 12.1])] in comparison with children who did not develop kwashiorkor [6.8% (95% CI [6.4, 7.2]), 15.5% (95% CI [15, 16.1]) and 15.1% (95% CI [14.6, 15.7])] or children who developed marasmus [4.5% (95% CI [2.6, 7.5]) 11.8% (95% CI [8.5, 16.0]) and 17.6% (95% CI [13.7, 22.5])]. Sweet potatoes and papayas have high β-carotene content and so may some of “the other vegetables”. We found that a risk model containing an age function, length/height-for age Z-score, consumption of sweet potatoes, papaya or other vegetables, duration of this consumption and its interaction term, was the most plausible model. Among children aged 10–42 months, the risk of developing kwashiorkor increased with longer non-consumption of these foods. The analysis was repeated with only children who developed marasmus as the reference series, yielding similar results. Our study supports that β-carotene may play an important role in the protection against kwashiorkor development.

Risk factors for acute pancreatitis in patients with severe motor and intellectual disabilities

BACKGROUND

Acute pancreatitis in patients with severe motor and intellectual disability (SMID) is a rare but life-threatening condition. Possible causes of acute pancreatitis in these patients including valproic acid therapy, hypothermia and nasoduodenal tube feeding, have not yet been investigated in detail. The aim of this study was therefore to investigate the risk factors for acute pancreatitis in patients with SMID.

METHODS

Five SMID patients with acute pancreatitis and 15 SMID patients without acute pancreatitis were reviewed. Age; serum total cholesterol, triglyceride, total protein, and albumin; height; bodyweight; body surface area; body mass index; daily calorie intake; daily calorie intake per unit of body mass surface area; daily calorie intake per kilogram bodyweight; and valproic acid usage were examined.

RESULTS

A statistically significant difference was observed in serum albumin level between the two groups (P = 0.026).

CONCLUSION

The mechanism of acute pancreatitis in these patients was considered as pancreatic morphological change, acinar damage, and elevated serum trypsinogen level caused by malnutrition. It is likely that acute pancreatitis in patients with SMID occurs due to the same mechanism as in anorexia nervosa and malnourished patients. To prevent acute pancreatitis in these patients, it is important to maintain adequate nutritional status.

Dermatosis in children with oedematous malnutrition (Kwashiorkor): a review of the literature

Children with oedematous malnutrition, known as kwashiorkor, may develop a characteristic skin lesion, named 'Dermatosis of Kwashiorkor' (DoK). Only a few studies have been concerned with this condition, and the reason for the development of DoK remains unexplained. This study review the existing studies concerning DoK, including its clinical manifestations, histopathology, suggested pathophysiology, current treatment and prognosis for children of the age of 6 months to 5 years. Standardized clinical studies are needed to further understand the implications of DoK. Such studies would suffer from the lack of consistency concerning the terminology and scoring of the lesions in DoK. We therefore stress the need for a standardized scoring of the degree of DoK. This would facilitate valid and comparable studies and the development of better treatment for this vulnerable group of patients.

Diagnostic and prognostic value of procalcitonin and C-reactive protein in malnourished children

BACKGROUND

Early recognition of bacterial infections is crucial for their proper management, but is particularly difficult in children with severe acute malnutrition (SAM). The objectives of this study were to evaluate the accuracy of C-reactive protein (CRP) and procalcitonin (PCT) for diagnosing bacterial infections and assessing the prognosis of hospitalized children with SAM, and to determine the reliability of CRP and PCT rapid tests suitable for remote settings.

METHODS

From November 2007 to July 2008, we prospectively recruited 311 children aged 6 to 59 months hospitalized with SAM plus a medical complication in Maradi, Niger. Blood, urine, and stool cultures and chest radiography were performed systematically on admission. CRP and PCT were measured by rapid tests and by reference quantitative methods using frozen serum sent to a reference laboratory.

RESULTS

Median CRP and PCT levels were higher in children with bacteremia or pneumonia than in those with no proven bacterial infection (P < .002). However, both markers performed poorly in identifying invasive bacterial infection, with areas under the curve of 0.64 and 0.67 before and after excluding children with malaria, respectively. At a threshold of 40 mg/L, CRP was the best predictor of death (81% sensitivity, 58% specificity). Rapid test results were consistent with those from reference methods.

CONCLUSIONS

CRP and PCT are not sufficiently accurate for diagnosing invasive bacterial infections in this population of hospitalized children with complicated SAM. However, a rapid CRP test could be useful in these settings to identify children most at risk for dying.

Unter- und Mangelernährung

Unter- und Mangelernährung bezeichnen Krankheitszustände, die daraus resultieren, dass dem Organismus über einen längeren Zeitraum zu wenig Nährstoffe und Nahrungsenergie zugeführt werden. Obwohl dies die Ursache der Krankheitszustände ist, müssen in der klinischen Praxis die pathophysiologischen Veränderungen beachtet werden, um eine vitale Gefährdung der Patienten zu vermeiden.

Sentinel site community surveillance of mortality and nutritional status in southwestern Central African Republic, 2010

Background

During 2010, a community-based, sentinel site prospective surveillance system measured mortality, acute malnutrition prevalence, and the coverage of a Médecins Sans Frontières (MSF) intervention in four sous-préfectures of Lobaye prefecture in southwestern Central African Republic. We describe this surveillance system and its evaluation.

Methods

Within 24 randomly selected sentinel sites, home visitors performed a census, weekly demographic surveillance of births, deaths, and in- or out-migration, and weekly anthropometry on a sample of children. We evaluated the system through various methods including capture-recapture analysis and repeat census.

Results

The system included 18,081 people at baseline. Over 32 weeks, the crude death rate was 1.0 (95% confidence interval [CI]: 0.8-1.2) deaths per 10,000 person-days (35 deaths per 1,000 person-years), with higher values during the rainy season. The under-5 death rate was approximately double. The prevalence of severe acute malnutrition (SAM) was 3.0% (95% CI: 2.3-4.0), almost half featuring kwashiorkor signs. The coverage of SAM treatment was 29.1%. The system detected >90% of deaths, and >90% of death reports appeared valid. However, demographic surveillance yielded discrepancies with the census and an implausible rate of population growth, while the predictive value of SAM classification was around 60%.

Discussion

We found evidence of a chronic health crisis in this remote region. MSF's intervention coverage improved progressively. Mortality data appeared valid, but inaccuracies in population denominators and anthropometric measurements were noted. Similar systems could be implemented in other remote settings and acute emergencies, but with certain technical improvements.

Prenatal factors contribute to the emergence of kwashiorkor or marasmus in severe undernutrition: evidence for the predictive adaptation model

Background

Severe acute malnutrition in childhood manifests as oedematous (kwashiorkor, marasmic kwashiorkor) and non-oedematous (marasmus) syndromes with very different prognoses. Kwashiorkor differs from marasmus in the patterns of protein, amino acid and lipid metabolism when patients are acutely ill as well as after rehabilitation to ideal weight for height. Metabolic patterns among marasmic patients define them as metabolically thrifty, while kwashiorkor patients function as metabolically profligate. Such differences might underlie syndromic presentation and prognosis. However, no fundamental explanation exists for these differences in metabolism, nor clinical pictures, given similar exposures to undernutrition. We hypothesized that different developmental trajectories underlie these clinical-metabolic phenotypes: if so this would be strong evidence in support of predictive adaptation model of developmental plasticity.

Methodology/Principal Findings

We reviewed the records of all children admitted with severe acute malnutrition to the Tropical Metabolism Research Unit Ward of the University Hospital of the West Indies, Kingston, Jamaica during 1962–1992. We used Wellcome criteria to establish the diagnoses of kwashiorkor (n = 391), marasmus (n = 383), and marasmic-kwashiorkor (n = 375). We recorded participants' birth weights, as determined from maternal recall at the time of admission. Those who developed kwashiorkor had 333 g (95% confidence interval 217 to 449, p<0.001) higher mean birthweight than those who developed marasmus.

Conclusions/Significance

These data are consistent with a model suggesting that plastic mechanisms operative in utero induce potential marasmics to develop with a metabolic physiology more able to adapt to postnatal undernutrition than those of higher birthweight. Given the different mortality risks of these different syndromes, this observation is supportive of the predictive adaptive response hypothesis and is the first empirical demonstration of the advantageous effects of such a response in humans. The study has implications for understanding pathways to obesity and its cardio-metabolic co-morbidities in poor countries and for famine intervention programs.

Comparative proteomic analysis of human whole saliva of children with protein-energy undernutrition

OBJECTIVE

The aim of the present study was to investigate the protein profile of children with different levels of protein-energy undernutrition (PEU) through a proteomic approach of human whole saliva.

METHODS

Initially, saliva samples of children with mild, moderate, and severe PEU were collected and lyophilized. Saliva samples of healthy children were used as controls. Samples were analyzed for total protein using the Bradford method. Saliva samples were analyzed by two-dimensional electrophoresis according to their isoelectric point (pI) and their molecular weights (MWs).

RESULTS

Comparisons of protein bands among the healthy and mildly, moderately, and severely undernourished children showed significant differences in the MWs (P = 0.001) and pI values (P = 0.03). In total 159 spots were identified in the healthy children; 156, 168, and 221 spots were observed in mildly, moderately, and severely undernourished children, respectively. Mildly undernourished children presented with the spot with the highest MW of 293 kDa (pI = 7.77) and the lowest MW of 5 kDa (pI = 4.83). Moderately undernourished children were the only ones who did not present with a protein band with an MW of 30 kDa. The presence of a protein band with an MW of 123 kDa (pI = 516), possibly a cyclin-dependent protein kinase, was also observed only in this group.

CONCLUSION

The protein profile in saliva varies according to the presence or absence of PEU, and these variations are specifically expressed in different grades of undernutrition. Thus, saliva may be an important diagnostic tool for the assessment of PEU.

A comparison of the heart and muscle total lipid and fatty acid profiles of nine large shark species from the east coast of South Africa

We have assessed the fatty acid profiles of the hearts and different muscle tissues from nine large shark species (Carcharhinus limbatus (blacktip), Carcharhinus obscurus (dusky), Carcharhinus brevipinna (spinner), Carcharhinus leucas (Zambezi/bull), Galeocerdo cuvier (tiger), Sphyrna lewini (scalloped hammerhead), Sphyrna zygaena (smooth hammerhead), Carcharodon carcharias (great white) and Carcharias taurus (raggedtooth/grey nurse/sand tiger)) found off the east coast of South Africa. While there was generally little variation between the species, all species showed profiles rich in both n6 and n3 polyunsaturated fatty acids compared to terrestrial commercial meats that have low n3. Thus, utilizing skeletal muscle tissues from sharks caught as part of the bycatch when fishing for teleosts would avoid unnecessary wastage of a potentially valuable resource, with all the possible health benefits of high quality protein combined with balanced polyunsaturates, although contamination with high levels of metabolic wastes, such as urea, may be a negative consideration.

An unusual cause of extensive edema

Edema of nutritional origin is quite rare in industrialized countries. We report the case of an 8-month-old boy with a history of kwashiorkor. Even if the diagnosis is not obvious, there is a need to perform a proper diagnosis at admission to avoid inappropriate management.

Pathophysiological changes that affect drug disposition in protein-energy malnourished children

Protein-energy malnutrition (PEM) is a major public health problem affecting a high proportion of infants and older children world-wide and accounts for a high childhood morbidity and mortality in the developing countries. The epidemiology of PEM has been extensively studied globally and management guidelines formulated by the World Health Organization (WHO). A wide spectrum of infections such as measles, malaria, acute respiratory tract infection, intestinal parasitosis, tuberculosis and HIV/AIDS may complicate PEM with two or more infections co-existing. Thus, numerous drugs may be required to treat the patients. In-spite of abundant literature on the epidemiology and management of PEM, focus on metabolism and therapeutic drug monitoring is lacking. A sound knowledge of pathophysiology of PEM and pharmacology of the drugs frequently used for their treatment is required for safe and rational treatment. In this review, we discuss the pathophysiological changes in children with PEM that may affect the disposition of drugs frequently used for their treatment. This review has established abnormal disposition of drugs in children with PEM that may require dosage modification. However, the relevance of these abnormalities to the clinical management of PEM remains inconclusive. At present, there are no good indications for drug dosage modification in PEM; but for drug safety purposes, further studies are required to accurately determine dosages of drugs frequently used for children with PEM.

Reduced production of sulfated glycosaminoglycans occurs in Zambian children with kwashiorkor but not marasmus

BACKGROUND

Kwashiorkor, a form of severe malnutrition with high mortality, is characterized by edema and systemic abnormalities. Although extremely common, its pathophysiology remains poorly understood, and its characteristic physical signs are unexplained.

OBJECTIVE

Because kwashiorkor can develop in protein-losing enteropathy, which is caused by a loss of enterocyte heparan sulfate proteoglycan (HSPG), and previous observations suggest abnormal sulfated glycosaminoglycan (GAG) metabolism, we examined whether intestinal GAG and HSPG are abnormal in children with kwashiorkor.

DESIGN

Duodenal biopsy samples collected from Zambian children with marasmus (n = 18), marasmic kwashiorkor (n = 8), and kwashiorkor (n = 15) were examined for expression of HSPG, GAGs, and immunologic markers and compared against reference samples from healthy UK control children. GAG and HSPG expression density and inflammatory cell populations were quantitated by computerized analysis.

RESULTS

The kwashiorkor group was less wasted and had a lower HIV incidence than did the other groups. All duodenal biopsy samples showed inflammation compared with the histologically uninflamed control samples. Biopsy samples from marasmic children had greater inflammation and greater CD3+ and HLA-DR (human leukocyte antigen DR)-positive cell densities than did samples from children with kwashiorkor. Expression of both HSPG and GAGs was similar between marasmic and well-nourished UK children but was markedly lower in children with kwashiorkor in both the epithelium and lamina propria. Although underglycosylated and undersulfated, epithelial syndecan-1 protein was normally expressed in kwashiorkor, which confirmed that abnormalities arise after core protein synthesis.

CONCLUSIONS

Intestinal HSPG loss occurs in kwashiorkor, which may precipitate protein-losing enteropathy to cause edema. If occurring systemically, impaired HSPG expression could cause several previously unexplained features of kwashiorkor. We speculate that a genetic predisposition to reduced HSPG biosynthesis may offer a contrasting selective advantage, by both diminishing protein catabolism during transient undernutrition and protecting against specific infectious diseases.