Red Blood Cell Enzymopathies

Fava Bean- Versus Non-Fava Bean-Induced Acute Hemolytic Crisis in Children With Glucose-6-Phosphate Dehydrogenase Deficiency: A Prospective Comparative Study

BACKGROUND

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a red cell enzymopathy in which exposure to oxidative stressors, such as drugs or fava bean ingestion, can trigger acute hemolytic episodes (AHEs). This study aimed to compare the clinical characteristics of fava bean-induced hemolysis (FBIH) with non-fava bean-induced hemolysis (NFBIH) in children with G6PD deficiency in a high-prevalence setting.

METHODS

A prospective cohort study was conducted at a region referral hospital in Oman. Hospital records of children hospitalized for AHE due to G6PD deficiency over a 3-year period were analyzed. Participants were categorized into FBIH and NFBIH groups based on the documented precipitating factor.

RESULTS

Among the 236 recruited cases, 51.6% AHEs were attributed to FBIH. Children with FIBH were younger, more likely to present with abdominal pain, and had greater severity of hemolysis upon admission (hemoglobin: 4.8 vs. 6.7 g/dL; p < 0.001). Lab markers such as serum ferritin, blood urea, lactate dehydrogenase, and alkaline phosphatase were significantly elevated in FBIH. The least squares regression model demonstrated a strong link between various predictor variables and hemoglobin levels, explaining about 76.6% of the variance in the study cohort.

CONCLUSION

Children with FBIH experience more severe hemolytic episodes compared to those with NFBIH. Our statistical model identified clinical and laboratory parameters potentially useful in early risk stratification during AHEs. Culturally sensitive dietary education of patients and caregivers is necessary, particularly in regions where fava beans are a dietary staple. The potential influence of specific G6PD genotypes within the NFBIH group merits future investigation.

Beyond ATP: Metabolite Networks as Regulators of Physiological and Pathological Erythroid Differentiation

Hematopoietic stem cells (HSCs) possess the capacity for self-renewal and the sustained production of all mature blood cell lineages. It has been well established that a metabolic rewiring controls the switch of HSCs from a self-renewal state to a more differentiated state, but it is only recently that we have appreciated the importance of metabolic pathways in regulating the commitment of progenitors to distinct hematopoietic lineages. In the context of erythroid differentiation, an extensive network of metabolites, including amino acids, sugars, nucleotides, fatty acids, vitamins, and iron, is required for red blood cell (RBC) maturation. In this review, we highlight the multifaceted roles via which metabolites regulate physiological erythropoiesis as well as the effects of metabolic perturbations on erythroid lineage commitment and differentiation. Of note, the erythroid differentiation process is associated with an exceptional breadth of solute carrier (SLC) metabolite transporter upregulation. Finally, we discuss how recent research, revealing the critical impact of metabolic reprogramming in diseases of disordered and ineffective erythropoiesis, has created opportunities for the development of novel metabolic-centered therapeutic strategies.

Holistic assessment of dimethoate toxicity in Carcinus aestuarii's muscle tissues

Dimethoate (DMT) is one of the most harmful and commonly used organophosphate pesticides in agricultural lands to control different groups of parasitic insects. However, this pesticide is considered a dangerous pollutant for aquatic organisms following its infiltration in coastal ecosystems through leaching. Yet, our investigation aimed to gain new insights into the toxicity mechanism of DMT in the muscles of the green crab Carcinus aestuarii, regarding oxidative stress, neurotransmission impairment, histological aspects, and changes in lipid composition, assessed for the first time on the green crab's muscle. Specimens of C. aestuarii were exposed to 50, 100, and 200 µg DMT L-1 for 24 h. Compared to the negative control group, the higher the DMT concentration, the lower the saturated fatty acids (SFA), and the higher the monounsaturated fatty acids (MUFA). The significant increase in polyunsaturated fatty acid n-6 (PUFA n-6) was related to the high release, mainly, of linoleic acid (LA, C18: 2n6) and arachidonic acid (ARA, C20: 4n6) levels. Biochemical biomarkers showed that DMT exposure promoted oxidative stress, highlighted by increased levels of hydrogen peroxide (H2O2), malondialdehyde (MDA), advanced oxidation protein product levels (AOPP), and protein carbonyl (PCO). Furthermore, the antioxidant defense system was activated, as demonstrated by the significant changes in the enzymatic activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH) levels associated with an adaptation process of C. aestuarii to cope with the DMT exposure. This pesticide significantly impairs the neurotransmission process, as evidenced by the inhibition of acetylcholinesterase (AChE) activity. Finally, several histopathological changes were revealed in DMT-treated crabs, including vacuolation, and muscle bundle loss.This research offered new insights into the toxic mechanism of DMT, pointing to the usefulness of fatty acid (FA) composition as a sensitive biomarker in littoral crabs.

Identification of potential biomarkers related to mesenchymal stem cell response in patients with Alzheimer's disease

BACKGROUND

Preclinical studies showed that mesenchymal stem cells (MSCs) ameliorate tau phosphorylation, amyloid-beta accumulation, and inflammation in Alzheimer's disease (AD) mouse models via secretion of neurotrophic factors and cytokines. We aimed to identify CSF biomarkers that can be used to predict or monitor the response to MSCs in patients with AD.

METHODS

AD patients were injected with human umbilical cord blood-MSCs (n = 22) or placebo (n = 12). The cerebrospinal fluid (CSF) samples were collected at baseline, one day after the first injection, and one day after the third injection. The patients injected with MSCs were classified into good responder (GR) or poor responder (PR) groups based on the rate of changes in the ratio of total-tau and phosphorylated-tau in the CSF. We selected three typical participants in each group, and their CSF protein levels were analyzed using liquid chromatography/tandem mass spectrometry (LC-MS/MS).

RESULTS

In the LC-MS/MS analysis, 1,667 proteins were identified. Eleven proteins showed significant differences between the typical GR and PR at baseline. Based on their significance level and known functions, two proteins, reticulocalbin-3 (RCN3) and follistatin-related protein 3 (FSTL3), were selected as potential biomarkers to predict MSC response. A total of 173 proteins showed significant change one day after the third injection compared to the baseline in typical GR. We excluded 45 proteins that showed significant change after the third injection compared to the baseline in the typical PR. Based on their significance level and known function, four proteins, scrapie-responsive protein 1 (SCRG1), neural proliferation differentiation and control protein (NPDC1), apolipoprotein E (ApoE), and cystatin C (CysC), were selected as potential biomarker to monitor MSC response. Additionally, functional analysis revealed that the increased CSF proteins after the third injection compared to the baseline in the typical GR were associated with synaptogenesis.

CONCLUSIONS

This study identified two proteins (RCN3 and FSTL3) that may be potential biomarkers for predicting MSC response and four proteins (SCRG1, NPDC1, ApoE, CysC) that may be potential biomarkers for monitoring MSC response in patients with AD. Further studies are needed to validate our results. Trial registration Clinical Trials.gov, NCT02054208. Registered on 4 February 2014. Samsung Medical Center IRB File No.2017-04-025. Registered on 20 June 2017.

Severe Hyperbilirubinemia Secondary to Henna Application in a Neonate With G6PD Deficiency: A Case Report and Literature Review

Henna is a natural product commonly used for cosmetics, healing, and social occasions in the Middle East and South Asian countries. It usually carries no significant medical complications in a healthy individual. However, henna in a patient with G6PD deficiency can cause serious medical complications, including severe hyperbilirubinemia and hemolytic anemia, due to its oxidative stress on the erythrocyte. This paper reports a previously undiagnosed G6PD deficient neonate who presented with severe hyperbilirubinemia without the classical laboratory findings of hemolytic anemia. In addition, we reviewed the literature and summarized the clinical and laboratory findings of 31 G6PD-deficient pediatric patients with henna-induced hemolytic anemia (HIHA). The reported adverse effects of HIHA included death (N: 2), kernicterus (N: 3), life-threatening hemolytic anemia that required blood transfusion (N: 9), and severe hyperbilirubinemia requiring exchange transfusion (N: 7). Although HIHA in G6PD deficiency is a well-known fact in the literature, we believe it is still under-reported. Given the high prevalence of G6PD deficiency and the widespread practice of henna application, we recommend avoiding it, especially in infancy, until the G6PD status is known. Society awareness should be raised about it.

Regulation of Eukaryote Metabolism: An Abstract Model Explaining the Warburg/Crabtree Effect

Adaptation of metabolism is a response of many eukaryotic cells to nutrient heterogeneity in the cell microenvironment. One of these adaptations is the shift from respiratory to fermentative metabolism, also called the Warburg/Crabtree effect. It is a response to a very high nutrient increase in the cell microenvironment, even in the presence of oxygen. Understanding whether this metabolic transition can result from basic regulation signals between components of the central carbon metabolism are the the core question of this work. We use an extension of the René Thomas modeling framework for representing the regulations between the main catabolic and anabolic pathways of eukaryotic cells, and formal methods for confronting models with known biological properties in different microenvironments. The formal model of the regulation of eukaryote metabolism defined and validated here reveals the conditions under which this metabolic phenotype switch occurs. It clearly proves that currently known regulating signals within the main components of central carbon metabolism can be sufficient to bring out the Warburg/Crabtree effect. Moreover, this model offers a general perspective of the regulation of the central carbon metabolism that can be used to study other biological questions.

Interpreting sulfhemoglobin and methemoglobin in patients with cyanosis: An overview of patients with M-hemoglobin variants

INTRODUCTION

Methemoglobin (MetHb) and sulfhemoglobin (SHb) measurements are useful in the evaluation of cyanosis. When one or both values are elevated, additional analysis is important to establish the etiology of the disorder. Methemoglobinemia occurs from acquired or hereditary causes with diverse treatment considerations, while true sulfhemoglobinemia is only acquired and treatment is restricted to toxin removal. Some toxic exposures can result in a dual increase in MetHb and SHb. Hereditary conditions, such as M-Hemoglobin variants (M-Hbs), can result in increased MetHb and/or SHb values but are clinically compensated and do not require treatment if they are cyanotic but otherwise clinically well.

METHODS

Herein, we report 53 hemoglobin variant cases that have associated MetHb and SHb levels measured by an adapted Evelyn-Malloy laboratory assay method.

RESULTS

Our data indicate M-Hbs cause variable patterns of MetHb and SHb elevation in a fairly reproducible pattern for the particular variant. In particular, α globin chain M-Hbs can mimic acquired sulfhemoglobinemia due to an isolated increased SHb value.

CONCLUSION

If the patient appears clinically well other than cyanosis, M-Hbs should be considered early in the evaluation process to differentiate from acquired conditions to avoid unnecessary testing and treatment regimens and prompt genetic counseling.