Severe neonatal anemia increases intestinal permeability by disrupting epithelial adherens junctions

Posttranscriptional Regulation of Intestinal Mucosal Growth and Adaptation by Noncoding RNAs in Critical Surgical Disorders

The human intestinal epithelium has an impressive ability to respond to insults and its homeostasis is maintained by well-regulated mechanisms under various pathophysiological conditions. Nonetheless, acute injury and inhibited regeneration of the intestinal epithelium occur commonly in critically ill surgical patients, leading to the translocation of luminal toxic substances and bacteria to the bloodstream. Effective therapies for the preservation of intestinal epithelial integrity and for the prevention of mucosal hemorrhage and gut barrier dysfunction are limited, primarily because of a poor understanding of the mechanisms underlying mucosal disruption. Noncoding RNAs (ncRNAs), which include microRNAs (miRNAs), long ncRNAs (lncRNAs), circular RNAs (circRNAs), and small vault RNAs (vtRNAs), modulate a wide array of biological functions and have been identified as orchestrators of intestinal epithelial homeostasis. Here, we feature the roles of many important ncRNAs in controlling intestinal mucosal growth, barrier function, and repair after injury-particularly in the context of postoperative recovery from bowel surgery. We review recent literature surrounding the relationships between lncRNAs, microRNAs, and RNA-binding proteins and how their interactions impact cell survival, proliferation, migration, and cell-to-cell interactions in the intestinal epithelium. With advancing knowledge of ncRNA biology and growing recognition of the importance of ncRNAs in maintaining the intestinal epithelial integrity, ncRNAs provide novel therapeutic targets for treatments to preserve the gut epithelium in individuals suffering from critical surgical disorders.

A Detailed Protocol for the Induction of Anemia and RBC Transfusion-associated Necrotizing Enterocolitis in Neonatal Mice

Anemia is a common and serious health problem, nearly universally diagnosed in preterm infants, and is associated with increased morbidity and mortality worldwide. Red blood cell (RBC) transfusion is a lifesaving and mainstay therapy; however, it has critical adverse effects. One consequence is necrotizing enterocolitis (NEC), an inflammatory bowel necrosis disease in preterm infants. The murine model of phlebotomy-induced anemia and RBC transfusion-associated NEC enables a detailed study of the molecular mechanisms underlying these morbidities and the evaluation of potential new therapeutic strategies. This protocol describes a detailed procedure for obtaining murine pups with phlebotomy-induced anemia and delivering an RBC transfusion that develops NEC.

Biology of Anemia: A Public Health Perspective

Our goal is to present recent progress in understanding the biological mechanisms underlying anemia from a public health perspective. We describe important advances in understanding common causes of anemia and their interactions, including iron deficiency (ID), lack of other micronutrients, infection, inflammation, and genetic conditions. ID develops if the iron circulating in the blood cannot provide the amounts required for red blood cell production and tissue needs. ID anemia develops as iron-limited red blood cell production fails to maintain the hemoglobin concentration above the threshold used to define anemia. Globally, absolute ID (absent or reduced body iron stores that do not meet the need for iron of an individual but may respond to iron supplementation) contributes to only a limited proportion of anemia. Functional ID (adequate or increased iron stores that cannot meet the need for iron because of the effects of infection or inflammation and does not respond to iron supplementation) is frequently responsible for anemia in low- and middle-income countries. Absolute and functional ID may coexist. We highlight continued improvement in understanding the roles of infections and inflammation in causing a large proportion of anemia. Deficiencies of nutrients other than iron are less common but important in some settings. The importance of genetic conditions as causes of anemia depends upon the specific inherited red blood cell abnormalities and their prevalence in the settings examined. From a public health perspective, each setting has a distinctive composition of components underlying the common causes of anemia. We emphasize the coincidence between regions with a high prevalence of anemia attributed to ID (both absolute and functional), those with endemic infections, and those with widespread genetic conditions affecting red blood cells, especially in sub-Saharan Africa and regions in Asia and Oceania.

Red Blood Cell Transfusion, Anemia, Feeding, and the Risk of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in preterm infants. Severe anemia and red blood cell (RBC) transfusion are associated with gut inflammation and injury in preclinical models and observational studies. However, there is uncertainty about the causal role of these factors in the pathogenesis of NEC. Observational studies have shown that withholding feeding during RBC transfusion may reduce the risk of NEC, although confirmatory data from randomized trials are lacking. In this review, we summarize data on feeding during RBC transfusion and its role in NEC and highlight ongoing randomized trials.

Severe anaemia, iron deficiency, and susceptibility to invasive bacterial infections

Severe anaemia and invasive bacterial infections remain important causes of hospitalization and death among young African children. The emergence and spread of antimicrobial resistance demand better understanding of bacteraemia risk factors to inform prevention strategies. Epidemiological studies have reported an association between severe anaemia and bacteraemia. In this review, we explore evidence that severe anaemia is associated with increased risk of invasive bacterial infections in young children. We describe mechanisms of iron dysregulation in severe anaemia that might contribute to increased risk and pathogenesis of invasive bacteria, recent advances in knowledge of how iron deficiency and severe anaemia impair immune responses to bacterial infections and vaccines, and the gaps in our understanding of mechanisms underlying severe anaemia, iron deficiency, and the risk of invasive bacterial infections.

Periorbital edema as the presenting sign of protein-losing enteropathy from excessive cow's milk intake

We report the case of a 15-month-old girl who presented with bilateral, positional periorbital edema, systemic hypoalbuminemia, and profound iron deficiency caused by excessive cow's milk intake. Her symptoms rapidly improved with reduction of cow's milk intake and iron supplementation.

Analysis of clinical presentations, lip transepidermal water loss and associated dermatological conditions in patients with chronic cheilitis

Chronic cheilitis (CC) is a spectrum of inflammatory changes of unknown etiology that affect the vermilion of the lips. This study aimed to describe the epidemiology, clinical presentations and risk factors of CC. Patients with CC were recruited from the National Clinical Research Center for Oral Disease of China. A convenience sample of inhabitants who live in the same geographical region were recruited as the control group. The lip skin transepidermal water loss (TEWL) and capacitance of CC patients were compared with that of age- and gender-matched controls. Our results demonstrated that of the 109 patients with CC, 72 (66.1%; 95% CI: 57.0-75.1%) were female. The common clinical presentations of CC consisted of desquamation (n = 99; 90.8%), and/or chapping (n = 81; 74.3%), and/or pruritus (n = 64; 58.7%). Multivariable analysis showed that allergic dermatologic diseases (P < 0.001; OR: 4.5; 95% CI: 2.4-8.4), anemia (P = 0.001; OR: 3.3; 95% CI: 1.5-7.5), and indoor/outdoor alternate working environment (P < 0.001; OR: 2.1; 95% CI: 1.5-2.8) were the significant risk factors for CC. The mean lip skin TEWL was found to be significantly higher, while the capacitance was lower in CC patients compared to that of control individuals. This study provides insights into the etiopathogenesis of CC and may help clinicians to identify the most effective management strategies.

Hematological changes in neonatal mice with phlebotomy-induced anemia

BACKGROUND

Anemia is a nearly universal diagnosis in preterm infants, caused by phlebotomy, and exacerbated by the underlying erythropoietic immaturity. Newborn infants are exposed to the unique stressor of fetal-to-neonatal transition, which requires significant adaptation ex utero. Accordingly, the preterm infant's response to anemia may alter the ability to confront underlying illness. This study utilized our preclinical mouse model of phlebotomy-induced anemia (PIA) to comprehensively investigate associated hematological changes.

METHODS

C57BL/6 mice were subjected to timed phlebotomy between postnatal days 2--10 to induce severe anemia. Complete blood counts were determined by the Sysmex XT-2000iV analyzer.

RESULTS

Anemic pups showed a gradual reduction of RBC and hemoglobin (Hb) and increased reticulocyte (RET) counts and red cell distribution width (RDW), however, with reduced RET-Hb from postnatal day (P) of 4 onwards. Elevated levels of high fluorescent RET and immature reticulocyte fraction (IRF) were noted in anemic mouse pups, but low and medium fluorescent RET were reduced. Also, the reduction of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were noted in anemic pups. No changes were seen in lymphocytes, but monocytes and neutrophils were significantly elevated from P4-P6.

CONCLUSIONS

PIA in mouse pups is associated with hematological changes that may be exacerbating factors in neonatal diseases.

IMPACT

Anemia is common and often severe in premature infants. Investigation of hematological parameters in settings of preclinical anemia may be an index of therapeutic strategies. Preclinical model evaluating the effects of neonatal anemia on the remainder of complete blood count. Detailed time kinetic phlebotomy-induced anemic mice enable us to study the impact on developmental delays in erythropoiesis and possible strategic intervention. Hematological effects of severe anemia in mice might provide insight on how best to investigate anemia in preterm infants.

The long-term clinical course of protein-losing enteropathy combined with iron deficiency anemia in Korean toddlers: Possible association with cow's milk protein

BACKGROUND

Protein-losing enteropathy (PLE), a rare condition with excessive gastrointestinal protein loss, presents with hypoalbuminemia, edema, or ascites. Several cases of PLE combined with severe iron deficiency anemia (IDA) have been reported in infants and toddlers that were considered to result from excessive cow's milk consumption, although the mechanism has not been clearly established.

METHODS

We retrospectively reviewed the clinical, laboratory, endoscopic, and radiologic characteristics of patients diagnosed and treated for PLE with IDA between 2015 and 2021. Long-term outcomes were analyzed according to dietary intervention during the follow-up period.

RESULTS

A total of 10 patients aged 7.0-26.7 months were enrolled in the study and the median follow-up duration of them was 9.4 months (range, 1.3-18.0). Six of them were fed powdered formula, while two were fed whole cow's milk, and their median daily intake was 700 mL (range, 300-900). The times to normalization of hemoglobin, albumin, and eosinophil count were shorter in patients with dietary elimination of cow's milk protein immediately after diagnosis compared to those with reduced intake or no dietary change.

CONCLUSION

Early complete elimination of cow's milk protein should be considered, especially if the laboratory parameters are not normalized with adequate iron supplementation even though the clinical symptoms show improvement. We would like to draw attention to the possibility of the cow's milk protein in the pathogenesis of the condition through the non-IgE-mediated immune reactions.

Unusual Gram-negative bacteria cause more severe bacterial meningitis than the three classical agents in children

Aim

To compare the characteristics, mortality and sequelae at hospital discharge of childhood bacterial meningitis (BM) caused by the three “classical” agents Neisseria meningitidis, Haemophilus influenzae or Streptococcus pneumoniae versus BM due to other aetiology in Finland, Latin America and Angola.

Methods

This observational study is a secondary analysis of data from five prospective treatment trials on non‐neonatal BM in Finland, Latin America and Angola in 1984–2017.

Results

Of the 1568 cases, 1459 (93%) were caused by the classics, 80 (5%) by other Gram‐negative and 29 (2%) by other Gram‐positive bacteria. Nonclassical Gram‐negative disease was encountered especially in Angola (p < 0.0001). Overall, children in the nonclassical group presented later for treatment and were more often underweight and anaemic (p < 0.001). In multivariate analysis, even if the area was strongest predictor of poor outcome, nonclassical Gram‐negative BM increased the odds for death twofold and the odds for death or severe sequelae 2.5‐fold.

Conclusion

BM of a nonclassical aetiology is a particularly severe disease affecting especially Angolan children poorly armoured to fight infections. Since vaccinations are diminishing the role of classical agents, that of nonclassical agents is growing.

Early erythropoietin for preventing necrotizing enterocolitis in preterm neonates - an updated meta-analysis

Previous systematic reviews suggest reduction in necrotizing enterocolitis (NEC) among preterm infants supplemented with erythropoietin (EPO). We aimed to update our 2018 systematic review in this field considering the evidence accumulated over the last 3 years. Randomized controlled trials (RCTs) reporting the effect of early EPO supplementation vs placebo/no EPO supplementation on any stage NEC in preterm infants were included. Fixed effect model was used for meta-analysis. Trial sequential analysis (TSA) was conducted to verify the effects of EPO on NEC after accounting for repeated significance testing. A total of 22 RCTs (n = 5359) were included, of which six were new (n = 2541 additional preterm infants) in comparison to our previous systematic review. EPO significantly decreased the risk of any stage NEC (232/2669 (8.7%) vs 313/2690 (11.6%); RR: 0·76; TSA adjusted 95% CI (0·64, 0·90); p = 0·0008, number needed to treat (NNT) = 34). The risk of definite NEC (≥ Stage II) was also significantly reduced by EPO administration (105/2219 (4.7%) vs 141/2246 (6.3%); RR: 0.77; 95% CI (0.61, 0.98); p = 0.03, NNT: 62). However, the results for definite NEC were no longer significant on sensitivity analyses that included (a) only double-blind RCTs and (b) only prospectively registered trials. The quality of evidence was deemed moderate-to-low for the reported outcomes.

CONCLUSION

There is moderate to low-quality evidence that early prophylactic EPO reduces any stage and ≥ Stage II NEC in preterm neonates. Prospectively registered, adequately powered, double-blind RCTs are required to confirm these findings.

WHAT IS KNOWN

• Experimental studies have shown that erythropoietin (EPO) has gastrointestinal trophic effects. • Systematic reviews have shown that early treatment with EPO may decrease the risk of gut injury in preterm or low birth weight infants.

WHAT IS NEW

• Early EPO supplementation significantly reduced the incidence of any stage NEC and definite NEC in preterm infants < 34 weeks of gestation. • EPO had no significant effect on definite NEC in the analyses that included only double-blinded and prospectively registered RCTs. How might it impact clinical practice in the foreseeable future? • Early prophylactic EPO can be recommended for NEC prevention if its benefits are consistently demonstrated in adequately powered randomized trials with a low risk of bias.

Neonatal anemia relates to intestinal injury in preterm infants

BACKGROUND

Anemia is associated with decreased tissue oxygenation in preterm infants and may contribute to developing necrotizing enterocolitis (NEC). We aimed to investigate whether hemoglobin level is associated with intestinal injury, by comparing anemic infants 10 days prior to red blood cell (RBC) transfusion with non-anemic controls.

METHODS

A nested case-control study in which we matched anemic preterms (gestational age (GA) < 32 weeks) with non-anemic controls (1:1), based on GA, birth weight (BW), and postnatal age. We measured urinary intestinal fatty acid-binding protein, I-FABP, marker for intestinal injury, twice weekly. Simultaneously, we assessed splanchnic oxygen saturation (r_sSO₂) and r_sSO₂ variability.

RESULTS

Thirty-six cases and 36 controls were included (median GA 27.6 weeks, BW 1020 grams). Median I-FABP level was higher in cases from 6 days to 24-h before transfusion (median ranging: 4749-8064 pg/ml versus 2194-3751 pg/ml). R_sSO₂ and r_sSO₂ variability were lower in cases than controls shortly before transfusion. Hemoglobin levels correlated negatively with r_sSO₂ and r_sSO₂ variability in cases, and negatively with I-FABP in cases and controls together.

CONCLUSIONS

Urinary I-FABP levels were higher in anemic infants before RBC transfusion than in non-anemic matched controls, suggesting intestinal injury associated with anemia. This may predispose to NEC in some anemic preterm infants.

IMPACT

Anemia is a common comorbidity in preterm infants and may lead to impaired splanchnic oxygen saturation and intestinal tissue hypoxia, a proposed mechanism for NEC. Lower hemoglobin level is associated with higher urinary I-FABP levels, a marker for intestinal injury, both in anemic preterm infants and in cases and controls together. Lower splanchnic oxygen saturation and reduction of its variability are associated with higher urinary I-FABP levels in anemic preterm infants before their first RBC transfusion. These results support the hypothesis that anemia in very preterm infants results in intestinal cell injury, which may precede NEC development in some.

let-7e downregulation characterizes early phase colonic adenoma in APCMin/+ mice and human FAP subjects

The crypt-villus axis represents the essential unit of the small intestine, which integrity and functions are fundamental to assure tissue and whole-body homeostasis. Disruption of pathways regulating the fine balance between proliferation and differentiation results in diseases development. Nowadays, it is well established that microRNAs (miRNAs) play a crucial role in the homeostasis maintenance and perturbation of their levels may promote tumor development. Here, by using microarray technology, we analysed the miRNAs differentially expressed between the crypt and the villus in mice ileum. The emerged miRNAs were further validated by Real Time qPCR in mouse model (ApcMin/+), human cell lines and human tissue samples (FAP) of colorectal cancer (CRC). Our results indicated that miRNAs more expressed in the villi compartment are negatively regulated in tumor specimens, thus suggesting a close association between these microRNAs and the differentiation process. Particularly, from our analysis let-7e appeared to be a promising target for possible future therapies and a valuable marker for tumor staging, being upregulated in differentiated cells and downregulated in early-stage colonic adenoma samples.

The Consequence of Excessive Consumption of Cow's Milk: Protein-Losing Enteropathy with Anasarca in the Course of Iron Deficiency Anemia-Case Reports and a Literature Review

Cow's milk is a key component of a child's diet. While the consumption of even trace amounts can result in allergy to its proteins and/or hypolactasia, excessive cow's milk consumption can result in numerous health complications, including iron deficiency, due to the diet being improperly balanced. Although the incidence of iron deficiency has declined, it remains the most widespread nutritional deficiency globally and the most common cause of anemia. One rare consequence of anemia caused by iron deficiency is protein-losing enteropathy; however, the mechanisms of its development are unclear. The following manuscript, based on a literature review, presents two rare cases of children, a 16-month-old boy and a 2.5-year-old girl, who developed severe microcytic anemia, enteropathy with hypoalbuminemia, and anasarca as a result of excessive cow's milk consumption. It highlights the possible relationship between excessive consumption of cow's milk in children and severe iron deficiency anemia with accompanying hypoalbuminemia; it may also result in serious clinical conditions, even in children that do not demonstrate food hypersensitivity.

Protein-Losing Enteropathy in the Setting of Iron Deficiency Anemia: A Case Series

Protein-losing enteropathy (PLE) in the setting of severe iron deficiency anemia (IDA) and excessive cow milk intake is an uncommonly recognized phenomenon. Here, we describe a series of 7 toddlers who presented for evaluation of edema in the setting of excessive cow milk intake between November 2016 and January 2019. Laboratory studies in each patient were consistent with IDA and hypoalbuminemia with evidence of PLE. Diagnostic evaluation and treatment of each patient differed, although all were instructed to restrict cow milk and provided with oral iron supplementation. The edema had resolved, and the IDA had improved in all 7 patients by the time of their follow-up outpatient appointments. Iron deficiency and PLE should be considered in patients who present with anasarca.

How Severe Anaemia Might Influence the Risk of Invasive Bacterial Infections in African Children

Severe anaemia and invasive bacterial infections are common causes of childhood sickness and death in sub-Saharan Africa. Accumulating evidence suggests that severely anaemic African children may have a higher risk of invasive bacterial infections. However, the mechanisms underlying this association remain poorly described. Severe anaemia is characterized by increased haemolysis, erythropoietic drive, gut permeability, and disruption of immune regulatory systems. These pathways are associated with dysregulation of iron homeostasis, including the downregulation of the hepatic hormone hepcidin. Increased haemolysis and low hepcidin levels potentially increase plasma, tissue and intracellular iron levels. Pathogenic bacteria require iron and/or haem to proliferate and have evolved numerous strategies to acquire labile and protein-bound iron/haem. In this review, we discuss how severe anaemia may mediate the risk of invasive bacterial infections through dysregulation of hepcidin and/or iron homeostasis, and potential studies that could be conducted to test this hypothesis.