Immunostimulation and growth faltering in UK infants

Detection of interferon alpha and beta receptor subunit 1 (IFNAR1) loss-of-function Glu386∗ variant by tri-allelic genotyping

Mutations of the human interferon alpha and beta receptor subunit 1 (IFNAR1) gene are associated with severe viral infections. Individuals homozygous for the Glu386∗ variant have impaired type I interferon signalling and can suffer severe illness when exposed to certain viruses and live attenuated virus vaccines. Glu386∗ heterozygotes are clinically unaffected, but can pass the variant allele to their descendants. We aimed to develop an assay that can identify IFNAR1 Glu386∗ homozygotes and heterozygotes to support urgent clinical diagnosis, and that can use dried blood spots (DBS) sent at ambient temperature to overcome geographical logistical challenges in the South Pacific region. The tri-allelic genotyping assay interrogates a single nucleotide polymorphism (rs201609461) located in IFNAR1. The reference allele G encodes for wild-type IFNAR1. Minor alleles A (c.1156G>A) and T (c.1156G>T) encode for Glu386Lys and a truncated IFNAR1 protein (p.Glu386∗), respectively. Synthetic oligonucleotides were mixed in equal molar ratio to create six different genotypes which were randomly assigned to 960 genotyping reactions by R software. Three different fluorescence probes were designed to discriminate the three alleles (G, T and A) within a pair of flanking primers in a single genotyping reaction. The assay discriminated all three alleles using DBS from Guthrie cards randomly spiked with synthetic oligonucleotides. We correctly identified all the different genotypes in 960 reactions in these blinded experiments. These findings validate the genotyping assay for rapidly identifying the IFNAR1 Glu386∗ variant from DBS.

Balancing growth, reproduction, maintenance, and activity in evolved energy economies

Economic models predominate in life history research, which investigates the allocation of an organism's resources to growth, reproduction, and maintenance. These approaches typically employ a heuristic Y model of resource allocation, which predicts trade-offs among tasks within a fixed budget. The common currency among tasks is not always specified, but most models imply that metabolic energy, either from food or body stores, is the critical resource. Here, we review the evidence for metabolic energy as the common currency of growth, reproduction, and maintenance, focusing on studies in humans and other vertebrates. We then discuss the flow of energy to competing physiological tasks (physical activity, maintenance, and reproduction or growth) and its effect on life history traits. We propose a Ψ model of energy flow to these tasks, which provides an integrative framework for examining the influence of environmental factors and the expansion and contraction of energy budgets in the evolution of life history strategies.

Nutritional status and its correlates among tribal children of Melghat, central India

OBJECTIVE

To find out the magnitude and epidemiological determinants of malnutrition among 0-6 y tribal children.

METHODS

A community based cross sectional study was done in the villages of Melghat in central India. The information of 540 children in the age group 0-6 y was collected. The newly developed WHO growth standards were used to calculate conventional indices of malnutrition (underweight, stunting and wasting) and composite index of anthropometric failure (CIAF). Univariate and multiple logistic regression analysis were used to find out the correlates of malnutrition.

RESULTS

The prevalence of malnutrition among these tribal children in terms of underweight, stunting, and wasting were 60.9 %, 66.4 % and 18.8 % respectively. Malnutrition in terms of composite index of anthropometric failure (CIAF) was 76.3 %. The important correlates of malnutrition that emerged out of this study were the age of child, age of mother less than 20 y at her first pregnancy, practice of not feeding colostrum, calorie deficit diet, anemia and morbidities like diarrhea and acute respiratory illnesses.

CONCLUSIONS

The prevalence of malnutrition was high in tribal children. The health care delivery at village level should be strengthened for early diagnosis and prompt treatment of anemia and other morbidities in children. The strategies are needed to delay the child bearing age in this community and improve breast feeding practices.

Fecal calprotectin levels are higher in rural than in urban Chinese infants and negatively associated with growth

BACKGROUND

Fecal calprotectin (FC) is an established simple biomarker of gut inflammation. To examine a possible relationship between linear growth and gut inflammation, we compared fecal calprotectin levels in 6 month old infants from poor rural vs affluent urban families.

METHODS

The project was a cross-sectional comparison of FC from rural and urban populations in China. The relationship between length-for-age Z-score (LAZ) and FC concentrations were also compared. Single fecal samples were assayed for FC using EK-CAL ELISA kits.

RESULTS

The age of subjects for both locations was 6.1 ± 0.2 mo; all were apparently healthy. The mean ± SD of the LAZ for the rural and urban infants were -0.6 ± 0.9 and 0.4 ± 0.9, respectively. FC had a non-normal distribution. The median FC of 420.9 and 140.1 μg/g for rural and urban infants, respectively, were significantly different (P < 0.0001). For the rural group, linear regression analysis showed that an increase in FC of 100 μg/g was associated with a decrease of 0.06 in LAZ.

CONCLUSION

FC levels were significantly elevated in the rural infants and high concentrations accounted for approximately one-third of the low LAZ scores of these infants.

Incidence and correlates of "growth faltering" among 0-6 y children: a panel study from rural Wardha

OBJECTIVES

To study the magnitude and determinants of growth faltering among 0-6 y children in adopted villages of medical college.

METHODS

A total 305 children of less than 6 y were followed monthly for 1 y to assess the growth faltering. At each visit, the mothers/caretakers of children were interviewed and information regarding immunization, morbidity profile, dietary history and child feeding practices collected using a pre-tested interview schedule. Monthly anthropometric measurements of child were taken. Growth faltering has been defined as failure to gain weight or actual loss of weight, and weight gain less than 300 g over a period of three consecutive months.

RESULTS

The cumulative incidence of growth faltering among 0-6 y children was 930 per 1,000 children per year (95% CI 900.8-959.2).The number of growth faltering episodes per child per year was 3.1 (95% CI 2.9-3.3). In the multivariate analysis, the authors found presence of anemia, presence of any illness and improper household ventilation as significant predictors of growth faltering.

CONCLUSIONS

The present finding suggests more focus should be given on early detection and timely correction of growth faltering rather than just identification and treatment of severely malnourished children.

Impact of intestinal permeability, inflammation status and parasitic infections on infant growth faltering in rural Bangladesh

A longitudinal study of 298 rural Bangladeshi infants found evidence of growth faltering starting at 3 months of age. Anthropometric status declined substantially in the first 2 years of life, with weight-for-height (WHZ) falling from - 0.49 to - 1.75, weight-for-age (WAZ) from - 1.18 to - 2.87 and height-for-age (HAZ) from - 1.00 to - 1.88. Higher concentrations of the acute-phase protein alpha-1-acid glycoprotein (AGP) and higher gut mucosal damage (as signified by raised lactulose:mannitol (L:M) ratios) were both associated with chronic malnutrition as indicated by poorer HAZ and WAZ scores (P = 0.011 and 0.005 for AGP and 0.039 and 0.019 for L:M ratio, respectively). Higher Hb levels were related to improved z-scores, while elevation of Giardia-specific IgM titre (GSIgM) was associated with poor WAZ and WHZ (P = 0.015 and 0.039, respectively). IgG did not show any significant association with z-scores and the L:M ratio did not correlate with any of the inflammation markers or Giardia infection. The prevalence of geohelminth infections was low (only 4 % in the total study period). However, the level of GSIgM indicated high endemicity of Giardia infection from early in life, although very few cysts were detected from stool samples. These findings suggest that rural Bangladeshi infants are being exposed to high levels of infection with concomitant gut damage and growth faltering.

Impact of anti-Giardia and anthelminthic treatment on infant growth and intestinal permeability in rural Bangladesh: a randomised double-blind controlled study

In order to test the impact of Giardia and geohelminthic infection on infant growth faltering in Bangladesh, a randomised double-blind placebo controlled intervention of 36 weeks' duration was conducted in a rural community located 40 km northwest of Dhaka. Infants aged between 3 and 15 months were randomly assigned to either anti-Giardia and anthelminthic treatment, anti-Giardia treatment only, or a control. Weight and supine length were recorded every 4 weeks. Every 12 weeks intestinal permeability (lactulose/mannitol ratio), haemoglobin, plasma albumin, alpha-1-acid glycoprotein, IgG and Giardia-specific IgM (GSIgM) and eggs of the three common geohelminths and G. intestinalis cysts were determined. Data on 222 fully compliant infants were analysed. No significant differences in intestinal permeability, biochemical or anthropometric variables were found between the intervention groups, although there were associations between improvement in small intestinal mucosal function and better weight-for-age and weight-for-height (length) Z-scores. GSIgM titres indicated high endemicity with rapid re-infection of Giardia among infants; over 95% of infants were positive throughout the study, whereas the stool examination showed very few infants with either geohelminth eggs or Giardia cysts.

Childhood conditions influence adult progesterone levels

BACKGROUND

Average profiles of salivary progesterone in women vary significantly at the inter- and intrapopulation level as a function of age and acute energetic conditions related to energy intake, energy expenditure, or a combination of both. In addition to acute stressors, baseline progesterone levels differ among populations. The causes of such chronic differences are not well understood, but it has been hypothesised that they may result from varying tempos of growth and maturation and, by implication, from diverse environmental conditions encountered during childhood and adolescence.

METHODS AND FINDINGS

To test this hypothesis, we conducted a migrant study among first- and second-generation Bangladeshi women aged 19-39 who migrated to London, UK at different points in the life-course, women still resident in Bangladesh, and women of European descent living in neighbourhoods similar to those of the migrants in London (total n = 227). Data collected included saliva samples for radioimmunoassay of progesterone, anthropometrics, and information from questionnaires on diet, lifestyle, and health. Results from multiple linear regression, controlled for anthropometric and reproductive variables, show that women who spend their childhood in conditions of low energy expenditure, stable energy intake, good sanitation, low immune challenges, and good health care in the UK have up to 103% higher levels of salivary progesterone and an earlier maturation than women who develop in less optimal conditions in Sylhet, Bangladesh (F9,178 = 5.05, p < 0.001, standard error of the mean = 0.32; adjusted R(2) = 0.16). Our results point to the period prior to puberty as a sensitive phase when changes in environmental conditions positively impact developmental tempos such as menarcheal age (F2,81 = 3.21, p = 0.03) and patterns of ovarian function as measured using salivary progesterone (F2,81 = 3.14, p = 0.04).

CONCLUSIONS

This research demonstrates that human females use an extended period of the life cycle prior to reproductive maturation to monitor their environment and to modulate reproductive steroid levels in accordance with projected conditions they might encounter as adults. Given the prolonged investment of human pregnancy and lactation, such plasticity (extending beyond any intrauterine programming) enables a more flexible and finely tuned adjustment to the potential constraints or opportunities of the later adult environment. This research is the first, to our knowledge, to demonstrate a postuterine developmental component to variation in reproductive steroid levels in women.

THE ECOLOGIES OF HUMAN IMMUNE FUNCTION

Immune function is notoriously complex, and current biomedical research elaborates this complexity by focusing on the cellular and molecular mechanisms that characterize immune defenses. However, the human immune system is a product of natural selection that develops and functions in whole organisms that are integral parts of their surrounding environments. A population-level, cross-cultural, adaptationist perspective is therefore a necessary complement to the micro levels of analysis currently favored by biomedical immunology. Prior field-based research on human immunity is reviewed to demonstrate the relevance of cultural ecological factors, with an emphasis on the ecologies of nutrition, infectious disease, reproduction, and psychosocial stress. Common themes and anthropological contributions are identified in an attempt to promote future research in human ecological immunology that integrates theory and method for a more contextualized understanding of this important physiological system.