The global prevalence of glucose-6-phosphate dehydrogenase deficiency: A systematic review and meta-analysis

Rapid and reliable detection of G6PD mutations using recombinase polymerase amplification coupled with lateral flow strip

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy, affecting approximately 500 million people worldwide. It results from inherited mutations in the G6PD gene, causing increased susceptibility to drug-induced hemolytic anemia and severe neonatal jaundice. While phenotypic tests are commonly used, genetic testing is increasingly recognized for its value in the accurate diagnosis of G6PD deficiency, especially in heterozygous females and newborns. This study aimed to develop and evaluate a rapid, field-deployable genetic test for the detection of four common G6PD variants in Thailand: G6PD Gaohe (c.95A > G), G6PD Mahidol (c.487G > A), G6PD Viangchan (c.871G > A), and G6PD Canton (c.1376G > T). The assays utilize recombinase polymerase amplification with allele-specific primers incorporating locked nucleic acids to enhance specificity, followed by lateral flow strip detection for visual readout. The assays deliver results within 45 min at 37 ˚C. Singleplex detection demonstrated 100 % diagnostic sensitivity (Confidence interval (CI): 95.01-100.0 %) and specificity (CI: 95.49-100.0 %). Duplex assays (Gaohe + Canton and Mahidol + Viangchan) also demonstrated 100 % diagnostic sensitivity (CI: 94.87-100.0 %) and specificity (CI: 91.19-100.0 %). Limits of detection (LOD) for singleplex assays were 0.25, 1.00, 0.50, and 0.50 ng/µL, for Gaohe, Mahidol, Viangchan, and Canton, respectively. Duplex assays showed LODs of 0.10 ng/μL for Mahidol + Viangchan and 10.00  ng/μL for Gaohe + Canton. Band intensity differences ranged from 5.25 to 19.61 pixels between mutant, wild-type, and nontarget alleles, enabling clear allele discrimination. This innovative diagnostic tool offers a rapid, reliable, and accessible solution for point-of-care genetic testing, with the potential to improve clinical management and healthcare outcomes in regions with a high burden of G6PD deficiency.

Blood storage effect of G6PD on RBC quality

BACKGROUND

The most prevalent metabolic condition of red blood cells, glucose-6-phosphate dehydrogenase (G6PD) deficiency, affects around 35 million people globally. The highest prevalence is seen in tropical and subtropical areas of the eastern hemisphere, where it can affect up to 35 % of the population. G6PD deficiency, the most prevalent enzyme deficit, is not currently tested for in blood products. G6PD deficiency is a genetic factor that influences the quality of stored red blood cells impacting their ability to respond to oxidative stress. This hospital-based cross-sectional study aimed at assessing the prevalence of G6PD deficiency in donor blood and the impact of the enzyme deficiency on red cell indices during storage.

METHOD

A total of 57 blood bags were screened for G6PD deficiency. Red cell indices and blood film comments were investigated on Day 0, Day 7 and Day 14 of storage.

RESULTS

Eight out of 57 (14 %) had the G6PD full defect and 86 % (49/57) had no defect. Over the course of 14 days storage, the hemoglobin and red blood cell count significantly decreased in G6PD-deficient blood units with a corresponding significant increase in mean corpuscular volume and red cell distribution width-standard deviation compared to baseline and normal G6PD activity. The blood film comment showed 85.7 % normocytic normochromic, 2.0 % microcytic hypochromic and 12.2 % macrocytic hyperchromic from G6PD-non-deficient donors whereas G6PD-deficient donors had 75 % normocytic normochromic with 12.5 % microcytic hypochromic and 12.5 % macrocytic hypochromic after 2 wk in storage.

CONCLUSION

Red blood cell count and hemoglobin reduce significantly in G6PD-deficient donor units during storage with an associated increased mean corpuscular volume indicating progressive loss of the cellular membrane homeostatic mechanism that could potentially result in further hemolysis during long term storage.

DSP-1, the major fibronectin type-II protein of donkey seminal plasma is a small heat-shock protein and exhibits chaperone-like activity against thermal and oxidative stress

Fibronectin type-II (FnII) proteins are major constituents in the seminal plasma of many mammals and play a crucial role in sperm capacitation. Additionally, the seminal FnII proteins from bull and horse exhibit chaperone-like activity (CLA), by acting as small heat shock proteins (shsps). The present work demonstrates that the major FnII protein of donkey seminal plasma, DSP-1 exhibits CLA with broad specificity and protects various client proteins such as alcohol dehydrogenase, lactate dehydrogenase and enolase against thermal and oxidative stress. Binding of phosphorylcholine (PrC) - the head group moiety of choline phospholipids, which are the physiological ligands of DSP-1 - decreased the CLA whereas binding of 1,2-dioleoyl-sn-glycero-3-phospholcholine (DOPC) increased the CLA. Biophysical studies suggested that these contrasting effects on the CLA by phosphorylcholine and diacyl phosphatidylcholine could be attributed to changes in the surface hydrophobicity of DSP-1 upon binding to these ligands. Interestingly, binding of PrC reduced DSP-1 tetramers to monomers with lower surface hydrophobicity, whereas binding to DOPC liposomes increased its surface hydrophobicity. These results, which demonstrate that DSP-1 exhibits CLA and functions as a molecular chaperone, expand the family of mammalian seminal FnII proteins that function as shsps.

A live bacteria enzyme assay for identification of human disease mutations and drug screening

Advances in high-throughput sequencing have enabled the identification of genetic variations associated with human disease. However, deciphering the functional significance of these variations remains challenging. Here we propose an alternative approach that uses humanized Escherichia coli to study human genetic enzymopathies and to screen candidate drug effects on metabolic targets. By replacing selected E. coli metabolic enzymes with their human orthologues and their sequence variants, we demonstrate that the growth rate of E. coli reflects the in vivo activity of heterologously expressed human enzymes. This approach accurately reflected enzyme activities of known sequence variants, enabling rapid screening of causal sequence variations associated with human diseases. This approach bridges the gap between in vitro assays and cell-based assays. Our findings suggest that the proposed approach using a humanized E. coli strain holds promise for drug discovery, offering a high-throughput and cost-effective platform for identifying new compounds targeting human enzymes. Continued research and innovation in this field have the potential to impact the development and practice of precision medicine.

Building capacity for pediatric hematological diseases in Sub-Saharan Africa

ABSTRACT

The spectrum of hematological diseases in African children includes anemias, bleeding disorders, thromboses, and oncological diseases such as leukemias. Although data are limited, outcomes for these diseases are poorer in Africa. The dearth of specialists, and lack of infrastructure that supports diagnosis and management, have been identified as key barriers to improving outcomes for childhood hematological disorders in Sub-Saharan Africa (SSA). To address these, intentional capacity building efforts addressing education and training, diagnostic capacity, and access to blood products and medicines are needed. This article explores some ongoing efforts in the region aimed at fostering the capacity to identify and treat childhood hematological disorders across a breadth of initiatives targeting the critical themes of education, diagnostic support, and treatment. We also identify existing opportunities through international partnerships, to build sustainable programs that can support children with hematological diseases in SSA.

Ozone-Oxygen Therapy to Prevent HPV-Related Cancers of the Lower Gynecological Tract in Infected Patients: The Rationale for Further Developments

BACKGROUND

O3-O2 therapy is an alternative medical treatment that introduces a mixture of O3-O2 into the body for therapeutic purposes. The objective of this study is to evaluate its margins of applicability in the eradication of HPV infection from the lower gynecological tract by means of vaginal insufflation.

METHODS

An in-depth review of the international literature on this topic is carried out; in addition, O3-O2 therapy is compared with other treatments currently available in terms of its advantages, disadvantages, and exploited technologies.

RESULTS

The possible benefits and limitations of O3-O2 vaginal insufflation are explained in detail; overall, it appears to be an interesting tool as part of complex management to prevent HPV-related cancers of the lower gynecological tract in infected patients.

CONCLUSIONS

The rationale and guidelines of this innovative procedure have been successfully illustrated, providing the technical specifications for further developments.

Scrub Typhus Infection Precipitating Hemolysis in a Patient With G6PD Deficiency: A Case Report

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a well-known red blood cell enzymopathy and a cause of intravascular hemolysis. This case report presents a child with underlying G6PD deficiency who experienced an acute episode of extensive intravascular hemolysis induced by a scrub typhus infection. The key takeaway from this report is that scrub typhus infection can trigger extensive hemolysis in patients with even "mild" G6PD deficiency, and normal G6PD levels found during the acute phase of hemolysis do not rule out the possibility of underlying G6PD deficiency.

Human immune system: Exploring diversity across individuals and populations

The immune response is an intricate system that involves the complex connection of cellular and molecular components, each with distinct functional specialisations. It has a distinct capacity to adjust and mould the immune response in accordance with specific stimuli, influenced by both genetic and environmental factors. The presence of genetic diversity, particularly across different ethnic and racial groups, significantly contributes to the impact of incidence of diseases, disease susceptibility, autoimmune disorders, and cancer risks in specific regions and certain populations. Environmental factors, including geography and socioeconomic status, further modulate the variety of the immune system responses. These, in turn, affect the susceptibility to infectious diseases and development of autoimmune disorders. Despite the complexity of the relationship, there remains a gap in understanding the specificity of immune indices across races, immune reference ranges among populations, highlighting the need for deeper understanding of immune diversity for personalized approaches in diagnostics and therapeutics. This review systematically organizes these findings, with the goal of emphasizing the potential of targeted interventions to address health disparities and advance translational research, enabling a more comprehensive strategy. This approach promises significant advancements in identifying specific immunological conditions, focusing on personalized interventions, through both genetic and environmental factors.

Revealing the secrets of Blue Zones

Aging is influenced by cellular senescence mechanisms that are associated with oxidative stress. Oxidative stress is the imbalance between antioxidants and free radicals. This imbalance affects enzyme activities and causes mitochondrial dysfunction. It also slows down cellular energy production and disrupts cellular homeostasis. Additionally, oxidative stress stimulates inflammation, increases the number of point mutations, and alters intercellular communication. It can lead to epigenetic alterations, genomic instability, telomere attrition, and loss of proteostasis. Ultimately, these factors contribute to aging and the development of chronic diseases. Glucose-6-phosphate dehydrogenase (G6PD) is an antioxidant enzyme that protects cells from oxidative and nitrosative damage. It helps restore redox balance, preserve macromolecule function, and rescue cells from cellular senescence, autophagy, and stress-induced apoptosis. G6PD is considered an anti-senescence enzyme. The World Health Organization classifies G6PD variants into five groups based on the enzyme's residual activity. The first four classes are categorized according to the degree of G6PD deficiency, while the fifth class includes variants with enzyme activities greater than normal. Increased G6PD activity does not exhibit clinical manifestations. Consequently, the full spectrum of mutations and the prevalence of increased G6PD activity in the population remain unknown. The world's oldest and healthiest people live in Blue Zones. These comprise isolated populations, and there may be a geographic prevalence of high-activity G6PD variants that protect against oxidative stress-induced senescence. To uncover the secret of centenarians' longevity, additional research is needed to determine whether the hidden factor is the increased activity of the G6PD enzyme.

Medications and Acute Hemolysis in G6PD-Deficient Patients - A Real-World Study

Many drug labels contain precautions of use in G6PD-deficient patients due to hemolytic concerns, but much of this is based on scarce clinical, epidemiological, or structural data. In this real-world study, we aimed to examine if the administration of presumably risky medications for G6PD-deficient patients was followed by hemolysis. The study is based on data from Clalit Health Services database that provides inclusive health care for more than half of the Israeli population (~ 4.7 million). Within the database, we identified all G6PD-deficient patients by G6PD <6 U/g Hb. Within the G6PD-deficient cohort, we identified all hospitalizations with a discharge diagnosis of hemolysis (January 1, 2010 to December 31, 2022), validated the cases, and identified the culprit event. For the rest of the G6PD-deficient patients with no-hemolysis, we recorded filled prescriptions of medications listed as presumably risky. We identified 31,962 G6PD-deficient patients. Within the cohort, there were 71 cases of major hemolysis requiring hospitalization (0.2% of the cohort), of whom 51 (71.8%) had been caused by ingestion of fava beans, six (8.5%) were associated with an infection, and three (4.2%) suggested to be associated with medications (nitrofurantoin, phenazopyridine, and a "pain killer"). Within the 31,875 patients with no major hemolysis, nitrofurantoin has been prescribed safely to 1,366 G6PD-deficient males and females; hundreds/thousands of G6PD-deficient patients had been prescribed safely ciprofloxacin, glibenclamide, ofloxacin, phenazopyridine, sulfamethoxazole/cotrimoxazole, sulfasalazine, hydroxychloroquine, glimepiride, mesalazine, and sulfacetamide. In this real-world study, we are showing that a list of medications, suspected previously as carrying risks for hemolysis in G6PD-deficient patients, have been prescribed safely to G6PD-deficient patients, providing reassurance to patients, prescribers, and regulators.

Hydroxocobalamin Versus Methylene Blue for Treatment of Vasoplegic Shock Following Cardiopulmonary Bypass: A Systematic Review and Meta-analysis

OBJECTIVES

To summarize the evidence of the hemodynamic effects and vasopressor requirements of adult cardiac surgery patients with vasoplegic shock treated with hydroxocobalamin or methylene blue.

DESIGN

Systematic review and meta-analysis.

SETTING

Multi-institutional.

PARTICIPANTS

Adult cardiac surgery patients with vasoplegic shock.

INTERVENTIONS

Administration of hydroxocobalamin or methylene blue.

MEASUREMENTS AND MAIN RESULTS

A total of 263 patients in four retrospective observational studies were included in a pooled analysis. There was no significant difference in the primary outcome, vasopressor requirement at 1 hour (mean difference [MD]: 0.00 mcg/kg/min norepinephrine equivalent [NEE], 95% confidence interval [CI]: -0.09 to 0.08). Hydroxocobalamin was associated with a significant improvement in mean arterial pressure at 1 hour (MD: 5.30 mmHg, 95% CI: 2.98 to 7.62), total vasopressor dose at 1 hour (MD: -0.13 mcg/kg/min NEE, 95% CI: -0.25 to -0.01), total vasopressor at 6 hours (MD: -0.15 mcg/kg/min NEE, 95% CI: -0.21 to -0.08). No differences were observed in systemic vascular resistance or mortality between groups. Three studies were deemed at moderate risk of bias and one at serious risk.

CONCLUSIONS

Hydroxocobalamin has been shown to have a beneficial effect on hemodynamics and vasopressor requirements in vasoplegic cardiac surgery patients compared with methylene blue, although evidence is limited, and further well-powered randomized controlled trials are required.

Functional analysis of G6PD variants associated with low G6PD activity in the All of Us Research Program

The glucose-6-phosphate dehydrogenase (G6PD) enzyme protects red blood cells against oxidative damage. Individuals with G6PD-impairing polymorphisms are at risk of hemolytic anemia from oxidative stressors. Prevention of G6PD deficiency-related hemolytic anemia is achievable by identifying affected individuals through G6PD genetic testing. However, accurately predicting the clinical consequence of G6PD variants is limited by over 800 G6PD variants which remain of uncertain significance (VUS). There also remains inconsistency in which deficiency-causing variants are included in genetic testing arrays: many institutions only test c.202G > A, though dozens of other variants can cause G6PD deficiency. Here, we improve G6PD genotype interpretations using the All of Us Research Program data and a yeast functional assay. We confirm that G6PD coding variants are the main contributor to decreased G6PD activity and that 13% of individuals in the All of Us data with deficiency-causing variants would be missed by only genotyping for c.202G > A. We expand clinical interpretation for G6PD VUS, reporting that c.595A > G ("Dagua" or "Açores") and the novel variant c.430C > G reduce activity sufficiently to lead to G6PD deficiency. We also provide evidence that 5 missense VUS are unlikely to lead to G6PD deficiency, and we applied the new World Health Organization (WHO) guidelines to recommend classifying 2 synonymous variants as WHO Class C. In total, we provide new or updated clinical interpretations for 9 G6PD variants. We anticipate these results will improve the accuracy, and prompt increased use, of G6PD genetic tests through a more complete clinical interpretation of G6PD variants.

Diagnostic accuracy of the point-of-care standard G6PD test™ (SD Biosensor) for glucose-6-phosphate dehydrogenase deficiency: a systematic review and meta-analysis

BACKGROUND

Glucose-6-Phosphate Dehydrogenase deficiency (G6PDd) is a common genetic enzymopathy that can induce haemolysis triggered by various factors, including some anti-malarial drugs. Although many Point-of-Care (PoC) tests, such as Standard G6PD™ are available to detect G6PDd, its pooled diagnostic test accuracy (DTA) remains unknown.

METHODS

To estimate the DTA of StandG6PD-BS at various thresholds of G6PDd, a systematic review with a DTA meta-analysis were conducted, searching EMBASE, MEDLINE, and SciELO databases up to April 4, 2024.The included studies were those that measured G6PD activity using StandG6PD-BS (reference test) and spectrophotometry (gold standard) in patients suspected of having G6PDd. The risk of bias (RoB) of the studies was assessed using the QUADAS-2 tool and the certainty of evidence (CoE) with the GRADE approach. For the estimation of within-study DTA, a random-effect bivariate meta-analysis was performed to determine the pooled sensitivity and specificity for 30%, 70%, and 80% enzyme levels' thresholds, and a graphical analysis of the heterogeneity using crosshair and Confidence Regions on receiver operating characteristic (ROC) space plots.

RESULTS

After screening 2496 reports, four studies were included with 7864 participants covering all thresholds. Two studies had high RoB in QUADAS-2 domains 2 and 3, and the others had low RoB, with low, moderate, and high heterogeneity at the 30%, 70%, and 80% thresholds, respectively. The pooled sensitivity was 99.1%, 95.7%, and 90% for 30%, 70%, and 80% thresholds, respectively. The pooled specificity was 97.4%; 92.9%; and 89.0% for 30%, 70%, and 80% thresholds, respectively.

CONCLUSION

StandG6PD-BS is a PoC test with high sensitivity and specificity to detect G6PDd at different thresholds.

Risky Remedy: Rasburicase-Induced Methemoglobinemia in Tumor Lysis Syndrome Complicated by G6PD Deficiency

Tumor lysis syndrome (TLS) is a critical oncologic emergency characterized by metabolic disturbances resulting from rapid cancer cell lysis. Rasburicase, a recombinant urate oxidase, is the primary treatment for hyperuricemia in TLS but poses a risk for methemoglobinemia in patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency. We present the case of a 59-year-old male with diffuse large B-cell lymphoma (DLBCL) who developed spontaneous TLS. Rasburicase was administered, successfully reducing uric acid levels, but the patient subsequently experienced cyanosis, hypoxia, and hemolytic anemia. Methemoglobinemia and G6PD deficiency were confirmed, highlighting the need for early identification of G6PD deficiency before rasburicase use. This case emphasizes the importance of prompt recognition and management of rasburicase-induced methemoglobinemia, especially in high-risk populations.

Controversies in our understanding of extreme hyperbilirubinemia in glucose-6-phosphate dehydrogenase-deficient neonates

Despite declarations that kernicterus should be a "never-event", the condition continues to occur, glucose-6-phosphate dehydrogenase (G6PD)-deficiency being a leading cause. In this paper, we address some controversies regarding the pathophysiology and the potential for extreme hyperbilirubinemia associated with G6PD-deficiency. We present evidence to demonstrate that G6PD-deficiency-associated neonatal hyperbilirubinemia is no longer limited to countries and geographic regions to which the condition was indigenous, but is also encountered in North America and other Western countries with a low inherent G6PD-deficiency frequency. Pathophysiologically, while a diminished bilirubin conjugative component is undoubtedly present, we present evidence that there is a component of increased hemolysis as well, contributing to the extreme, exponential hyperbilirubinemia associated with G6PD-deficiency. Extreme hyperbilirubinemia in G6PD heterozygotes, while less frequent than in male hemizygotes or female deficient homozygotes, has been reported, suggesting previous underestimation of the risks of heterozygosity. Universal neonatal screening for G6PD-deficiency, while not expected to prevent acute, episodic hyperbilirubinemia, should increase awareness, thereby facilitating earlier referral for treatment, prior to the onset of bilirubin encephalopathy. Finally, we speculate as to what the future looks like for babies with G6PD-deficiency, potential therapeutic stratagems, and the effect of G6PD-deficiency on medical conditions beyond the realm of neonatal hyperbilirubinemia. IMPACT STATEMENTS: G6PD-deficiency is encountered in North America and Western countries previously thought to have a low frequency of the condition. Extreme, sudden neonatal hyperbilirubinemia is due, in the main, to increased hemolysis, an independent risk factor for neurotoxicity. Extreme hyperbilirubinemia may follow apparently resolved neonatal hyperbilirubinemia which had been treated by phototherapy. Female G6PD heterozygotes, previously thought to be unaffected clinically by G6PD-deficiency, while at low risk, may, nevertheless, develop extreme hyperbilirubinemia. Universal neonatal G6PD screening should be aimed towards increasing caretaker awareness and facilitating referral for treatment prior to the onset of bilirubin encephalopathy.

G6PD Potenza: A Novel Pathogenic Variant Broadening the Mutational Landscape in the Italian Population

Background: Glucose 6 phosphate dehydrogenase (G6PD) is a rate-limiting enzyme of the pentose phosphate pathway. The loss of G6PD activity in red blood cells increases the risk of acute haemolytic anaemia under oxidative stress induced by infections, some medications, or fava beans. More than 200 single missense mutations are known in the G6PD gene. A 41-year-old woman with a family history of favism coming from the Basilicata region (Italy) was evaluated at our hospital for G6PD abnormalities. Methods: DNA was extracted from a peripheral blood sample and genotyped for the most common G6PD pathogenic variants (PVs). Positive results obtained by Restriction Fragment Length Polymorphism (RFLP), as per practice in our laboratory, were then reconfirmed in Sanger sequencing. Results:RFLP analysis highlighted a variant compatible with the G6PD Cassano variant. Confirmatory testing by Sanger unexpectedly identified a novel variant: c.1357G>A, p.(Val453Met) (NM_001360016.2); the same variant was found in the patient's mother. In silico models predicted a deleterious effect of this variant at the protein level. The novel G6PD variant was named "G6PD Potenza" on the basis of the patient's regional origin. Conclusions: This case describes a novel G6PD variant. It also highlights how the Sanger sequencing technique still represents an indispensable confirmatory standard method for variants that could be misinterpreted by only using a "first-level" approach, such as the RFLP. We stress that the evaluation of clinical manifestations in G6PD-deficient patients is of primary importance for the classification of each new G6PD mutation, in agreement with the new WHO guidelines.

Real-world use of the CarestartTM glucose-6-phosphate dehydrogenase rapid diagnostic test to determine G6PD deficiency in Nigerian neonates

G6PD deficiency (G6PDd) is the most common X-linked genetic disease worldwide and the most common cause of severe neonatal hyperbilirubinemia (NH) in Nigeria. Screening for G6PDd has been recommended for over thirty years but is still not routinely done in Nigeria. We sought to investigate a low-cost rapid diagnostic test to determine G6PDd in Nigerian neonates. Enrolled neonates were screened using the CareStartTM G6PD point-of-care rapid diagnostic test; and mothers/caregivers of neonates with G6PDd were asked about their cord care product(s); transcutaneous bilirubin levels were done on neonates with G6PDd using the JM 103 meter. One hundred and forty neonates were enrolled between 15 January and 1 July 2022. Eighteen (12.8%) of all neonates enrolled and 13.9% of enrolled males (0% of females) were G6PDd. Seventeen of the mothers/caregivers of the G6PDd neonates were asked about cord care. The majority of mothers/caregivers (15/17, 88%%) reported including methylated spirits in their neonate's cord care; seven of these used chlorohexidine plus methylated spirits (41.2%) while only one mother/caregiver used chlorohexidine alone. One mother/caregiver used mentholatum alone and another used mentholatum, chlorhexidine gel, and methylated spirits. Maximum bilirubin levels for those infants with G6PDd ranged from 3.2 to 18.8 mg/dl with 16/17 (94.1%) of bilirubin levels exceeding 5.5 mg/dl. This study again highlights the need for large-scale G6PDd screening. Additionally, it highlights the need to correlate the type of cord care with the risk of NH in future studies.

G6pdN126D Variant Increases the Risk of Developing VEGFR (Vascular Endothelial Growth Factor Receptor) Blocker-Induced Pulmonary Vascular Disease

BACKGROUND

G6PD (glucose-6-phosphate-dehydrogenase) is a key enzyme in the glycolytic pathway and has been implicated in the pathogenesis of cancer and pulmonary hypertension-associated vascular remodeling. Here, we investigated the role of an X-linked G6pd mutation (N126D polymorphism), which is known to increase the risk of cardiovascular disease in individuals from sub-Saharan Africa and many others with African ancestry, in the pathogenesis of pulmonary hypertension induced by a vascular endothelial cell growth factor receptor blocker used for treating cancer.

METHODS AND RESULTS

CRISPR-Cas9 genome editing was used to generate the G6pd variant (N126D; G6pdN126D) in rats. A single dose of the vascular endothelial cell growth factor receptor blocker sugen-5416 (SU; 20 mg/kg in DMSO), which is currently in a Phase 2/3 clinical trial for cancer treatment, was subcutaneously injected into G6pdN126D rats and their wild-type littermates. After 8 weeks of normoxic conditions, right ventricular pressure and hypertrophy, pulmonary artery remodeling, the metabolic profile, and cytokine expression were assessed. Right ventricular pressure and pulmonary arterial wall thickness were increased in G6PDN126D+SU/normoxic rats. Simultaneously, levels of oxidized glutathione, inositol triphosphate, and intracellular Ca2+ were increased in the lungs of G6PDN126D+SU/normoxic rats, whereas nitric oxide was decreased. Also increased in G6PDN126D+SU/normoxic rats were pulmonary levels of plasminogen activator inhibitor-1, thrombin-antithrombin complex, and expression of proinflammatory cytokines CCL3 (chemokine [C-C motif] ligand), CCL5, and CCL7.

CONCLUSIONS

Our results suggest G6PDN126D increases inositol triphosphate-Ca2+ signaling, inflammation, thrombosis, and hypertrophic pulmonary artery remodeling in SU-treated rats. This suggests an increased risk of vascular endothelial cell growth factor receptor blocker-induced pulmonary hypertension in those carrying this G6PD variant.

Hemolytic Anemia Secondary to Rasburicase Treatment in the Setting of Glucose-6-Phosphate-Dehydrogenase Deficiency: A Case Report

Rasburicase is a recombinant form of urate oxidase, a medication used to treat hyperuricemia by metabolizing uric acid into an inactive and more soluble metabolite, allantoin. An oxidizing agent, hydrogen peroxide, is produced during the conversion of uric acid to allantoin. We present here a case of hemolytic anemia secondary to rasburicase treatment which was later confirmed to have glucose-6-phosphate dehydrogenase deficiency (G6PDD). Treatment was stopped after one dose and the patient received a transfusion of packed red blood cells to correct the anemia. The patient's hyperuricemia was subsequently managed with allopurinol and febuxostat.

Glucose-6-phosphate dehydrogenase and its 3D structures from crystallography and electron cryo-microscopy

Glucose-6-phosphate dehydrogenase (G6PD) is the first enzyme in the pentose phosphate pathway. It has been extensively studied by biochemical and structural techniques. 13 X-ray crystal structures and five electron cryo-microscopy structures in the PDB are focused on in this topical review. Two F420-dependent glucose-6-phosphate dehydrogenase (FGD) structures are also reported. The significant differences between human and parasite G6PDs can be exploited to find selective drugs against infections such as malaria and leishmaniasis. Furthermore, G6PD is a prognostic marker in several cancer types and is also considered to be a tumour target. On the other hand, FGD is considered to be a target against Mycobacterium tuberculosis and possesses a high biotechnological potential in biocatalysis and bioremediation.

A Multi-Center Retrospective Database Evaluation of Pediatric Subjects Diagnosed With Methemoglobinemia

Background

Methemoglobinemia requires early identification and treatment, but limited knowledge exists regarding the current therapeutic approach taken by clinicians as well as the outcomes that occur in children.

Objectives

To determine the current prevalence of this rare disease in the pediatric population, evaluate the impact of methemoglobin and functional hemoglobin levels, and assess how this disease is approached by clinicians. We hypothesize that methemoglobinemia prevalence is low and more methylene blue use would be observed in subjects with functional hemoglobin levels less than 7 g/dL.

Design

This was a retrospective observational cohort study utilizing deidentified TriNetX® electronic health record (EHR) data.

Methods

Using a multicenter EHR database, we evaluated subjective characteristics, diagnostic, laboratory results, medication, and procedural codes.

Results

Ninety-eight children (mean age 5.3 ± 5.3 years) from 53 healthcare organizations were included. Methemoglobinemia prevalence was 0.0015% with an overall 30-day mortality of 6.1%. Subjects with methemoglobin percentages greater than 20% had a higher frequency of methylene blue administration (70.6% versus 24.7%, P = .0005). Critical care service requirements and methylene blue administration were similar in the subjects with functional hemoglobin less than 7 g/dL and more than 7 g/dL groups. Overall, 13 (13.2%) subjects underwent glucose-6-phosphate dehydrogenase deficiency (G6PD) testing.

Conclusion

In our study, we found methemoglobinemia prevalence in children is low, there is a low frequency of G6PD testing despite methylene blue hemolysis risk, and subjects appeared to be treated similarly despite a low functional hemoglobin. These findings highlight the continued critical nature of this disease and may highlight opportunities for education aimed at improving care in children diagnosed with methemoglobinemia, particularly related to G6PD testing.

The 50th anniversary of Blood Cells, Molecules and Diseases, 1975-2024

The journal Blood Cells was initiated in 1975 by Marcel Bessis, a French hematologist and cell biologist, as a vehicle for the publication of papers and discussions presented at an international blood club meeting he convened at L' Institut de Pathologie Cellulaire on the campus of Hôpital Bicétre in Kremlin Bicétre, France, a commune on the southern border of Paris. The group met at the Institute for the first time in October 1972. After the first meeting, Bessis published the articles describing the presentations in the Nouvelle Revue d'Hématologie Française, France's principal journal for articles on the science and practice of hematology of which he was the editor. The refusal of the Nouvelle Revue d'Hématologie Française to continue publishing the papers from the meeting of the blood club in English prompted Bessis to start a new journal, Blood Cells, in 1975. Blood Cells, also, began to accept individual submitted papers unrelated to the blood club meeting and, thus, it evolved into a standard journal. A decade later, when Bessis became ill, he asked Brian Bull, a hematopathologist and professor at Loma Linda University School of Medicine in California to assume the position as the second editor-in-chief. He and Bessis had become scientific collaborators and good friends in the preceding years. In 1995, Ernest Beutler, Chair of Molecular and Experimental Medicine at Scripps Research Institute, assumed the editor-in-chief position and transformed the Journal by making three consequential changes. He expanded its title to Blood Cells, Molecules and Diseases, converted its editorial board to past presidents of the American Society of Hematology plus a few additional experimental hematologists of note, a few from abroad, and he converted the Journal to a digital format, hosted on the Scripps Research Institute server. The Journal was the first published solely in a digital format. It, subsequently, was bought by Academic Press, then Harcourt and, then, by Elsevier. The next three editors-in-chief were (i) Marshall A. Lichtman, then Professor of Medicine (Hematology) and of Biochemistry and Biophysics and former Dean of the School of Medicine and Dentistry at the University of Rochester Medical Center, editor from 2000 to 2013, (ii) Mohandas Narla, then Vice President for Research and Director of The Laboratory of Red Cell Physiology at the New York Blood Center, editor from 2014 to 2021 and (iii) Lionel Blanc, Professor of Molecular Medicine and Pediatrics, Center for Autoimmune, Musculoskeletal and Hematopoietic Diseases, Institute of Molecular Medicine, The Feinstein Institutes for Medical Research and the Les Nelkin Professor of Pediatric Oncology Donald and Barbara Zucker School of Medicine at Hofstra-Northwell from 2022 to the present. Although the Journal publishes papers on any aspect of hematology, it has developed a focus on disorders of red cells, erythropoiesis and hematopoiesis. In October 2024, it celebrates its 50th anniversary as a vehicle for the publication of papers in the discipline of hematology.

Rasburicase-induced hemolytic anemia and methemoglobinemia: a systematic review of current reports

Since the FDA's approval of rasburicase use for treatment of tumor lysis syndrome (TLS), multiple cases of rasburicase-induced methemoglobinemia and hemolytic anemia have been reported among patients with G6PD deficiency. This study aims to provide a systematic review of cases reporting such adverse reactions to rasburicase. A literature review of published cases in PubMed, Embase, Cochrane, and Web of Science was conducted. Descriptive studies reporting cases of rasburicase-induced methemoglobinemia and/or hemolytic anemia in English were analyzed and summarized in this study. Forty-three cases, including a case from our institution, were included in this study. Most cases (60.5%) received rasburicase for TLS treatment. Almost all patients (93.8%) were tested for G6PD after rasburicase administration. The median time to symptom onset was 24 h. The median methemoglobin level was 10%, peaking after a median of 24 h. The median hemoglobin nadir was 6.1 g/dL, and most patients (n = 32) required blood transfusion. Out of 39 cases with reported outcomes, 35 patients (89.7%) recovered, while four patients (three females and one male) died. The median time to recovery was 4.5 days while the median time to death was 8 days. Screening for G6PD deficiency among high-risk patients is important but not practical in acutely severe settings. When prior screening for G6PD deficiency is not feasible, close monitoring for methemoglobinemia and hemolytic anemia is recommended. Exchange transfusion is increasingly reported as a potentially successful therapeutic modality. Ascorbic acid may provide limited benefits. Methylene blue should be avoided as it may exacerbate hemolysis among these patients.

The Impact of the G6PD Gene Mutations in Patients with Chronic Hepatitis C Infection Treated with Direct-Acting Antivirals: A Multicenter Observational Study

Following the advent of direct-acting antivirals (DAAs), the treatment of hepatitis C virus (HCV) infection is now rarely challenging. However, data are still limited concerning DAA use in patients affected by glucose-6-phosphate dehydrogenase deficiency (G6PDd). Based on these considerations, the goal of this study was to evaluate the effectiveness and safety of DAAs in this subpopulation. A retrospective multicenter observational study (2015-2023) was conducted on all 2754 consecutive HCV-positive patients treated with first- and second-generation all-oral DAAs, and with a G6PDd diagnosis confirmed by quantitative testing (n = 38). At the treating clinician's discretion, an enhanced clinical and laboratory follow-up was performed, generally on a monthly basis both during treatment and up to six months after the end of it. Concerning hematochemical parameters, no significant differences were found between any considered time point. In all cases, no treatment-related adverse events were reported, and virologic response rates were as expected without G6PDd. In conclusion, in a large experience which, to the best of our knowledge, is unprecedented in the literature, the treatment of HCV hepatitis with nearly all available DAAs in patients with G6PDd as a comorbidity-a common occurrence in countries such as Italy-proved to be highly effective and safe.

Study of the antigenic characteristics of red blood cells units and their sickle cell disease recipients and the G6PD activity of transfused red blood cells units

INTRODUCTION

Transfusion has a central place in the treatment of patients with sickle cell disease (SCD). Matching blood groups of red blood cell (RBC) units with the blood groups of the patient is essential to prevent alloimmunization and delayed hemolytic transfusion reaction. African ancestry donors have the best phenocompatibility with patients of the same origin, however their RBCs may present characteristic that can alter quality of the unit such as glucose-6-phosphate dehydrogenase (G6PD) deficiency. The objective is to analyze transfusion protocol, immunization rate and mismatch situations of SCD recipients and to evaluate the frequency of G6PD deficiency in RBCs units from African ancestry donors.

METHODS

Samples of units transfused to SCD patients were analyzed. Transfusion data were collected from institutional databases. The activity of G6PD was measured in the segment of the RBC units.

RESULTS

A total of 98 segments of units transfused to 37 SCD recipients in 41 transfusions episodes was collected. Among patients, 35.1% (n = 13) had no antibodies; 10.8% (n = 4) had antibodies against Fya/Fyb, Jka/Jkb, M/N, S/s; 21.6% (n = 8) against RH/K antigens. In all cases, the protocols were in line with the recommendations. G6PD deficiency was observed in 9 units, that were all collected from Afro-Caribbean donors.

CONCLUSION

The transfusion protocol is established to prevent immunological reactions due to disparities in blood group antigens between donors and SCD recipients. However, the units of African ancestry donors, which allowed the best compatibility, displayed a high rate of G6PD deficiency. The storage and recovery impact of this deficiency must be evaluated.

Screening and the analysis of genotypic and phenotypic characterization of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Fujian province, China

Introduction

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common X-linked hereditary disorder in southern China. However, the incidence rate of G6PD deficiency and the frequency of the most common G6PD gene variants vary widely. The purpose of this study was to investigate the prevalence, genotype, and phenotypic features of G6PD deficiency in neonates in Fujian province, southeastern China.

Methods

This retrospective cohort study enrolled 2,789,002 newborns (1,521,431 males and 1,267,571 females) based on the newborn screening program for G6PD deficiency in Fujian Province between January 2010 and December 2021.

Results

Of the 2,789,002 newborns enrolled, 26,437 cases were diagnosed (22,939 males and 3,498 females), and the estimated prevalence of G6PD deficiency in Fujian province was 0.95%. The prevalence was significantly higher among males (1.51%) than in females (0.28%) (p < 0.00001). Among the 3,198 patients with G6PD deficiency, 3,092 cases (2,145 males and 947 females) were detected to have G6PD gene variants. The top six prevalent genotypes identified represented 90.84% (2095/3,198) of the total and included c.1376G > T (44.93%), c.1388G > A (18.42%), c.1024C > T (9.32%), c.95A > G (8.69%), c.392G > T (5.25%), and c.871G > A (4.22%). The frequency of genotypes with c.1388G > A, c.1024C > T, and c.871G > A was higher in males in the Fujian province than in females, while the frequency of genotypes with c.1376G > T was lower. Furthermore, when comparing the enzyme activities of the top six prevalent genotypes, there were significant differences in the enzyme activities among the genotypes of male hemizygotes and female heterozygotes. According to the new classification of G6PD variants proposed by the World Health Organization (WHO), the variants with c.1376G > T, c.95A > G, and c.871G > A were recognized as Class A, while the c.392G > T, c.1388G > A, and c.1024C > T were recognized as Class B.

Discussion

To the best of our knowledge, this study is the first to systematically describe the overview of epidemiological characteristics of newborn G6PD deficiency in Fujian province, China, including the screening rate, incidence rate, and variant spectrum. Additionally, we elucidated the relationship between the distribution of enzyme activity with specific mutations and their WHO classification patterns. Our results could provide strategies for screening, diagnosis, and genetic counseling of G6PD deficiency in this area.

Glucose-6-phosphate dehydrogenase deficiency and neonatal indirect hyperbilirubinemia: a retrospective cohort study among 40,305 consecutively born babies

BACKGROUND AND OBJECTIVE

Glucose-6-phosphate dehydrogenase deficiency (G6PDD) being highly prevalent in the Middle East, the primary objective was to estimate the incidence of neonatal jaundice among G6PD-deficient neonates and to explore its association with various risk factors.

METHODS

This retrospective cohort study includes 7 years data of neonates diagnosed with G6PDD between 1st January 2015, and 30 September 2022, from Al Wakra Hospital, HMC Qatar.

RESULTS

Among the 40,305 total births, 1013 had G6PDD with an incidence of 2.51%. Of all the G6PDD babies, 24.6% (249/1013) received phototherapy and three babies required exchange transfusion. Statistically significant associations were noted between the need for phototherapy and gestational age, gestational age groups, birth weight, and birth weight groups, but logistic regression analysis showed significant association for phototherapy only with the gestational age group.

CONCLUSION

Universal screening and proper follow-up is essential for G6PDD as it plays crucial role in neonatal jaundice.

Syncope in the Emergency Department: A Case Report of a Rare Presentation of Favism

Consumption of fava beans in a patient with glucose-6-phosphate dehydrogenase (G6PD) deficiency, also called favism, can lead to a haemolytic crisis. We report the case of a 69-year-old patient of Iranian origin admitted to the emergency department following syncope. The patient's comprehensive interview and blood analysis revealed that the patient presented a haemolytic crisis triggered by fava beans consumption, due to previously undiagnosed G6PD deficiency. The pathophysiology of favism is complex and clinical presentations of G6PD deficiency are numerous due to multiple genetic variants. Indirect signs, such as the presence of methemoglobinaemia and hemighosts on the blood smear, can aid in the diagnosis. This case highlights the importance of considering G6PD deficiency as a potential diagnosis in case of haemolytic crisis, even in elderly patients.

Detection of Duffy blood group genotypes and submicroscopic Plasmodium infections using molecular diagnostic assays in febrile malaria patients

BACKGROUND

Malaria remains a severe parasitic disease, posing a significant threat to public health and hindering economic development in sub-Saharan Africa. Ethiopia, a malaria endemic country, is facing a resurgence of the disease with a steadily rising incidence. Conventional diagnostic methods, such as microscopy, have become less effective due to low parasite density, particularly among Duffy-negative human populations in Africa. To develop comprehensive control strategies, it is crucial to generate data on the distribution and clinical occurrence of Plasmodium vivax and Plasmodium falciparum infections in regions where the disease is prevalent. This study assessed Plasmodium infections and Duffy antigen genotypes in febrile patients in Ethiopia.

METHODS

Three hundred febrile patients visiting four health facilities in Jimma town of southwestern Ethiopia were randomly selected during the malaria transmission season (Apr-Oct). Sociodemographic information was collected, and microscopic examination was performed for all study participants. Plasmodium species and parasitaemia as well as the Duffy genotype were assessed by quantitative polymerase chain reaction (qPCR) for all samples. Data were analysed using Fisher's exact test and kappa statistics.

RESULTS

The Plasmodium infection rate by qPCR was 16% (48/300) among febrile patients, of which 19 (39.6%) were P. vivax, 25 (52.1%) were P. falciparum, and 4 (8.3%) were mixed (P. vivax and P. falciparum) infections. Among the 48 qPCR-positive samples, 39 (13%) were negative by microscopy. The results of bivariate logistic regression analysis showed that agriculture-related occupation, relapse and recurrence were significantly associated with Plasmodium infection (P < 0.001). Of the 300 febrile patients, 85 (28.3%) were Duffy negative, of whom two had P. vivax, six had P. falciparum, and one had mixed infections. Except for one patient with P. falciparum infection, Plasmodium infections in Duffy-negative individuals were all submicroscopic with low parasitaemia.

CONCLUSIONS

The present study revealed a high prevalence of submicroscopic malaria infections. Plasmodium vivax infections in Duffy-negative individuals were not detected due to low parasitaemia. In this study, an improved molecular diagnostic tool was used to detect and characterize Plasmodium infections, with the goal of quantifying P. vivax infection in Duffy-negative individuals. Advanced molecular diagnostic techniques, such as multiplex real-time PCR, loop-mediated isothermal amplification (LAMP), and CRISPR-based diagnostic methods. These techniques offer increased sensitivity, specificity, and the ability to detect low-parasite-density infections compared to the employed methodologies.

Hemolysis attributed to high dose vitamin C: Two case reports

BACKGROUND

High-dose vitamin C treatment (HVCT) can reduce the adverse effect of chemotherapy and enhance the effect of antitumor therapy, which has been considered one of the safest alternative treatments. However, the severity of its adverse effects may have been underestimated. The most serious adverse effect is hemolysis, which may result in acute kidney injury or death. Although glucose-6-phosphate dehydrogenase (G6PD) deficiency is considered to be the main cause, the probability and pathological mechanism are not completely understood, leading to a lack of effective and standardized treatment methods.

CASE SUMMARY

Two patients with colorectal cancer developed hemolytic anemia after using 1 g/kg HVCT. In contrast to previous cases, the lowest hemoglobin level in the two cases was < 50 g/L, which was lower than previously reported. This may be because Case 1 had chronic hepatitis B for many years, which caused abnormal liver reserve function, and Case 2 had grade II bone marrow suppression. Both patients improved and were discharged after blood replacement therapy. Our cases had the most severe degree of hemolysis but the best prognosis, suggesting that our treatment may be helpful for rescue of drug-induced hemolysis. This is the first review of the literature on hemolysis caused by HVCT, and we found that all patients with G6PD deficiency developed hemolysis after HVCT.

CONCLUSION

G6PD deficiency should be considered as a contraindication to HVCT, and it is not recommended for patients with bone marrow suppression, moderate-to-severe anemia, hematopoietic abnormalities, or abnormal liver and kidney function. Early blood purification and steroid therapy may avoid acute kidney injury or death caused by HVCT-related hemolytic anemia.

Risk of diabetes mellitus based on the interactive association between G6PD rs72554664 polymorphism and sex in Taiwan Biobank individuals

The presence of glucose-6-phosphate dehydrogenase (G6PD) deficiency may increase the risk of type 2 diabetes mellitus (T2DM), with differing prevalence between males and females. Although G6PD deficiency is an X-linked genetic condition, its interaction with sex regarding T2DM risk among the Taiwanese population has not been fully explored. This study aimed to investigate the association between G6PD deficiency and T2DM risk in the Taiwanese population, focusing on the potential influence of sex. Data were obtained from the Taiwan Biobank (TWB) database, involving 85,334 participants aged 30 to 70 years. We used multiple logistic regression analysis to assess the interaction between G6PD rs72554664 and sex in relation to T2DM risk. The T2DM cohort comprised 55.35% females and 44.65% males (p < 0.001). The TC + TT genotype of rs72554664 was associated with an increased risk of T2DM, with an odds ratio (OR) of 1.95 (95% CI: 1.39-2.75), and males showed an OR of 1.31 (95% CI: 1.19-1.44). Notably, the G6PD rs72554664-T allelic variant in hemizygous males significantly elevated the T2DM risk (OR), 4.57; p < 0.001) compared to females with the CC genotype. Our findings suggest that the G6PD rs72554664 variant, in conjunction with sex, significantly affects T2DM risk, particularly increasing susceptibility in males. The association of the G6PD rs72554664-T allelic variant with a higher risk of T2DM highlights the importance of sex-specific mechanisms in the interplay between G6PD deficiency and T2DM.

Effectiveness of an Unsupervised Primaquine Regimen for Preventing Plasmodium vivax Malaria Relapses in Northeast Myanmar: A Single-Arm Nonrandomized Observational Study

BACKGROUND

Plasmodium vivax presents a significant challenge for malaria elimination in the Greater Mekong Subregion. We evaluated the effectiveness of primaquine for reducing relapses of vivax malaria.

METHODS

Patients with uncomplicated P vivax malaria from eastern Myanmar received chloroquine (25-mg base/kg given in 3 days) plus unsupervised PQ (0.25 mg/kg/d for 14 days) without screening for glucose-6-phosphate dehydrogenase deficiency and were followed for a year.

RESULTS

A total of 556 patients were enrolled to receive the chloroquine/primaquine treatment from February 2012 to August 2013. During the follow-up, 38 recurrences were detected, presenting a cumulative recurrence rate of 9.1% (95% CI, 4.1%-14.1%). Genotyping at the pvmsp1 and pvmsp3α loci by amplicon deep sequencing and model prediction indicated that 13 of the 27 recurrences with genotyping data were likely due to relapses. Notably, all confirmed relapses occurred within the first 6 months.

CONCLUSIONS

The unsupervised standard dose of primaquine was highly effective as a radical cure for P vivax malaria in eastern Myanmar. The high presumed effectiveness might have benefited from the health messages delivered during the enrollment and follow-up activities. Six-month follow-ups in the Greater Mekong Subregion are sufficient for detecting most relapses.

Current Status of Molecular Diagnosis of Hereditary Hemolytic Anemia in Korea

Hereditary hemolytic anemia (HHA) is considered a group of rare hematological diseases in Korea, primarily because of its unique ethnic characteristics and diagnostic challenges. Recently, the prevalence of HHA has increased in Korea, reflecting the increasing number of international marriages and increased awareness of the disease. In particular, the diagnosis of red blood cell (RBC) enzymopathy experienced a resurgence, given the advances in diagnostic techniques. In 2007, the RBC Disorder Working Party of the Korean Society of Hematology developed the Korean Standard Operating Procedure for the Diagnosis of Hereditary Hemolytic Anemia, which has been continuously updated since then. The latest Korean clinical practice guidelines for diagnosing HHA recommends performing next-generation sequencing as a preliminary step before analyzing RBC membrane proteins and enzymes. Recent breakthroughs in molecular genetic testing methods, particularly next-generation sequencing, are proving critical in identifying and providing insight into cases of HHA with previously unknown diagnoses. These innovative molecular genetic testing methods have now become important tools for the management and care planning of patients with HHA. This review aims to provide a comprehensive overview of recent advances in molecular genetic testing for the diagnosis of HHA, with particular emphasis on the Korean context.

Prevalence of Glucose-6-Phosphate Dehydrogenase Deficiency in Male Newborn Infants and Its Relationship with Neonatal Jaundice in Thailand

OBJECTIVE

The study aimed to explore the prevalence of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency among male newborn infants in northeastern Thailand and its relationship with neonatal jaundice (NJ).

STUDY DESIGN

This prospective cohort study included male newborn infants with gestational age (GA) ≥35 weeks born between July 1, 2019, and March 1, 2021. Cord blood was sent for G-6-PD fluorescent spot test (FST) and results were reported as normal, partial, or complete deficiency. Infants with NJ would have blood tested for total serum bilirubin (TSB) level and other possible causes of NJ. Duration of phototherapy, length of hospital stays, and complications were documented.

RESULTS

There were 922 male infants included in this study with 854 (93.1%) term and 63 (6.9%) preterm infants. FST showed 132 infants (14.4%) had G-6-PD deficiency. Incidence of NJ was significantly higher among infants with G-6-PD deficiency compared with infants with normal G-6-PD level (47.7 vs. 25.8%; relative risk [RR]: 2.62, 95% confidence interval [CI]: 1.79-3.82; p < 0.001). Regardless of G-6-PD level, preterm infants had significantly higher incidence of NJ than term infants (52.4 vs. 27.3%; RR: 2.93, 95% CI: 1.75-4.92; p < 0.001). Duration of phototherapy was significantly longer in infants with G-6-PD deficiency with NJ but hospital stays were similar. Infants with combined G-6-PD deficiency and other causes of hemolysis did not have higher TSB level than infants with isolated G-6-PD deficiency. Risk factors associated with NJ were G-6-PD deficiency and preterm infants, whereas more advance GA was associated with reduced risk for NJ.

CONCLUSION

G-6-PD deficiency and preterm infants were important risk factors for NJ. Routine G-6-PD screening, close monitoring for signs of NJ in infant with risks, and appropriate parental counseling should be implemented.

KEY POINTS

· G-6-PD deficiency increases risk of neonatal jaundice.. · Preterm infants have higher risk for neonatal jaundice.. · G-6-PD deficiency does not link with severe jaundice..

Liver-targeted polymeric prodrugs delivered subcutaneously improve tafenoquine therapeutic window for malaria radical cure

Approximately 3.3 billion people live with the threat of Plasmodium vivax malaria. Infection can result in liver-localized hypnozoites, which when reactivated cause relapsing malaria. This work demonstrates that an enzyme-cleavable polymeric prodrug of tafenoquine addresses key requirements for a mass administration, eradication campaign: excellent subcutaneous bioavailability, complete parasite control after a single dose, improved therapeutic window compared to the parent oral drug, and low cost of goods sold (COGS) at less than $1.50 per dose. Liver targeting and subcutaneous dosing resulted in improved liver:plasma exposure profiles, with increased efficacy and reduced glucose 6-phosphate dehydrogenase-dependent hemotoxicity in validated preclinical models. A COGS and manufacturability analysis demonstrated global scalability, affordability, and the ability to redesign this fully synthetic polymeric prodrug specifically to increase global equity and access. Together, this polymer prodrug platform is a candidate for evaluation in human patients and shows potential for P. vivax eradication campaigns.

Functional Analysis of G6PD Variants Associated With Low G6PD Activity in the All of Us Research Program

Glucose-6-phosphate dehydrogenase (G6PD) protects red blood cells against oxidative damage through regeneration of NADPH. Individuals with G6PD polymorphisms (variants) that produce an impaired G6PD enzyme are usually asymptomatic, but at risk of hemolytic anemia from oxidative stressors, including certain drugs and foods. Prevention of G6PD deficiency-related hemolytic anemia is achievable through G6PD genetic testing or whole-genome sequencing (WGS) to identify affected individuals who should avoid hemolytic triggers. However, accurately predicting the clinical consequence of G6PD variants is limited by over 800 G6PD variants which remain of uncertain significance. There also remains significant variability in which deficiency-causing variants are included in pharmacogenomic testing arrays across institutions: many panels only include c.202G>A, even though dozens of other variants can also cause G6PD deficiency. Here, we seek to improve G6PD genotype interpretation using data available in the All of Us Research Program and using a yeast functional assay. We confirm that G6PD coding variants are the main contributor to decreased G6PD activity, and that 13% of individuals in the All of Us data with deficiency-causing variants would be missed if only the c.202G>A variant were tested for. We expand clinical interpretation for G6PD variants of uncertain significance; reporting that c.595A>G, known as G6PD Dagua or G6PD Açores, and the newly identified variant c.430C>G, reduce activity sufficiently to lead to G6PD deficiency. We also provide evidence that five missense variants of uncertain significance are unlikely to lead to G6PD deficiency, since they were seen in hemi- or homozygous individuals without a reduction in G6PD activity. We also applied the new WHO guidelines and were able to classify two synonymous variants as WHO class C. We anticipate these results will improve the accuracy, and prompt increased use, of G6PD genetic tests through a more complete clinical interpretation of G6PD variants. As the All of Us data increases from 245,000 to 1 million participants, and additional functional assays are carried out, we expect this research to serve as a template to enable complete characterization of G6PD deficiency genotypes. With an increased number of interpreted variants, genetic testing of G6PD will be more informative for preemptively identifying individuals at risk for drug- or food-induced hemolytic anemia.

Alzheimer's Disease: A Review of Pathology, Current Treatments, and the Potential Therapeutic Effect of Decreasing Oxidative Stress by Combined Vitamin D and l-Cysteine Supplementation

Significance: Excess oxidative stress and neuroinflammation are risk factors in the onset and progression of Alzheimer's disease (AD) and its association with amyloid-β plaque accumulation. Oxidative stress impairs acetylcholine (ACH) and N-methyl-d-aspartate receptor signaling in brain areas that function in memory and learning. Glutathione (GSH) antioxidant depletion positively correlates with the cognitive decline in AD subjects. Treatments that upregulate GSH and ACH levels, which simultaneously decrease oxidative stress and inflammation, may be beneficial for AD. Recent Advances: Some clinical trials have shown a benefit of monotherapy with vitamin D (VD), whose deficiency is linked to AD or with l-cysteine (LC), a precursor of GSH biosynthesis, in reducing mild cognitive impairment. Animal studies have shown a simultaneous decrease in ACH esterase (AChE) and increase in GSH; combined supplementation with VD and LC results in a greater decrease in oxidative stress and inflammation, and increase in GSH levels compared with monotherapy with VD or LC. Therefore, cosupplementation with VD and LC has the potential of increasing GSH, downregulation of oxidative stress, and decreased inflammation and AChE levels. Future Directions: Clinical trials are needed to determine whether safe low-cost dietary supplements, using combined VD+LC, have the potential to alleviate elevated AChE, oxidative stress, and inflammation levels, thereby halting the onset of AD. Goal of Review: The goal of this review is to highlight the pathological hallmarks and current Food and Drug Administration-approved treatments for AD, and discuss the potential therapeutic effect that cosupplementation with VD+LC could manifest by increasing GSH levels in patients. Antioxid. Redox Signal. 40, 663-678.

Ancient genomes illuminate Eastern Arabian population history and adaptation against malaria

The harsh climate of Arabia has posed challenges in generating ancient DNA from the region, hindering the direct examination of ancient genomes for understanding the demographic processes that shaped Arabian populations. In this study, we report whole-genome sequence data obtained from four Tylos-period individuals from Bahrain. Their genetic ancestry can be modeled as a mixture of sources from ancient Anatolia, Levant, and Iran/Caucasus, with variation between individuals suggesting population heterogeneity in Bahrain before the onset of Islam. We identify the G6PD Mediterranean mutation associated with malaria resistance in three out of four ancient Bahraini samples and estimate that it rose in frequency in Eastern Arabia from 5 to 6 kya onward, around the time agriculture appeared in the region. Our study characterizes the genetic composition of ancient Arabians, shedding light on the population history of Bahrain and demonstrating the feasibility of studies of ancient DNA in the region.

Factors predicting mortality in hospitalised HIV-negative children with lower-chest-wall indrawing pneumonia and implications for management

INTRODUCTION

In 2012, the World Health Organization revised treatment guidelines for childhood pneumonia with lower chest wall indrawing (LCWI) but no 'danger signs', to recommend home-based treatment. We analysed data from children hospitalized with LCWI pneumonia in the Pneumonia Etiology Research for Child Health (PERCH) study to identify sub-groups with high odds of mortality, who might continue to benefit from hospital management but may not be admitted by staff implementing the 2012 guidelines. We compare the proportion of deaths identified using the criteria in the 2012 guidelines, and the proportion of deaths identified using an alternative set of criteria from our model.

METHODS

PERCH enrolled a cohort of 2189 HIV-negative children aged 2-59 months who were admitted to hospital with LCWI pneumonia (without obvious cyanosis, inability to feed, vomiting, convulsions, lethargy or head nodding) between 2011-2014 in Kenya, Zambia, South Africa, Mali, The Gambia, Bangladesh, and Thailand. We analysed risk factors for mortality among these cases using predictive logistic regression. Malnutrition was defined as mid-upper-arm circumference <125mm or weight-for-age z-score <-2.

RESULTS

Among 2189 cases, 76 (3·6%) died. Mortality was associated with oxygen saturation <92% (aOR 3·33, 1·99-5·99), HIV negative but exposed status (4·59, 1·81-11·7), moderate or severe malnutrition (6·85, 3·22-14·6) and younger age (infants compared to children 12-59 months old, OR 2·03, 95%CI 1·05-3·93). At least one of three risk factors: hypoxaemia, HIV exposure, or malnutrition identified 807 children in this population, 40% of LCWI pneumonia cases and identified 86% of the children who died in hospital (65/76). Risk factors identified using the 2012 WHO treatment guidelines identified 66% of the children who died in hospital (n = 50/76).

CONCLUSIONS

Although it focuses on treatment failure in hospital, this study supports the proposal for better risk stratification of children with LCWI pneumonia. Those who have hypoxaemia, any malnutrition or those who were born to HIV positive mothers, experience poorer outcomes than other children with LCWI pneumonia. Consistent identification of these risk factors should be prioritised and children with at least one of these risk factors should not be managed in the community.

Glucose-6-phosphate dehydrogenase deficiency and psychotic disorders: A systematic review

OBJECTIVES

Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD) is the most common enzymopathy globally. Early studies suggested an association with severe psychotic illness; however, changes to laboratory testing and diagnostic classification renders the association unclear. This study aims to explore the interaction between G6PD deficiency and psychotic symptoms, in particular to identify specific patterns of presentation or impact on outcomes.

METHODS

Pubmed, Embase, and PsycInfo databases were searched from inception to May 2023. Descriptive statistics and narrative review of were used to synthesise data on demographics, mental and physical health diagnoses, investigations, treatment, and outcomes.

RESULTS

No clear link was found in published data (eight case reports, case series of n = 29) with a high rate (63%) of haemolytic crisis at the time of psychiatric presentation suggested delirium as an alternative diagnosis. Four case control studies found no significant difference in the prevalence of G6PD deficiency. However, catatonic presentation was reported in 40% of the case series and a higher prevalence of G6PD deficiency in catatonic schizophrenia was noted in case control studies.

CONCLUSIONS

Based on the information available there was no clear association between G6PD deficiency and psychotic illness or treatment resistance, although paucity of studies and risk of bias limit strong conclusions.

Propensity score matched analysis and risk stratification of donors with G6PD deficiency in living donor liver transplantation

INTRODUCTION

Glucose 6 phosphate dehydrogenase (G6PD) deficiency (G6PDd) can trigger hemolysis following surgical stress. Differentiating G6PDd-related post-operative hemolytic episodes (PHE) and post-hepatectomy liver failure may be challenging especially in living donors where donor safety is paramount. We analysed outcomes of our cohort of G6PDd liver donors.

METHODS

G6PDd individuals with no evidence of hemolysis were considered as living donors if there was no alternative family donor. Outcomes of G6PDd donors undergoing left lateral/left lobe donation (Group LL) and right lobe donation (Group RL) were compared with non-G6PDd donors matched in a 1:3 ratio using propensity score matching.

RESULTS

59 G6PDd donors (5.8% of 1011) underwent living donor hepatectomy (LiDH) during the study period. LL-G6PDd donors (22.37%) had higher post-operative peak bilirubin level compared to matched controls, but no difference in morbidity or need for post-operative blood transfusion.RL-G6PDd donors (37.63%) had higher peak bilirubin level, morbidity (16.2% vs. 3.6%, p = 0.017) and more post-operative blood transfusion (21.6% vs. 6.4%, p = 0.023) as compared to matched non-G6PDd cohort. Four RL-G6PDd donors (10.8%) developed PHE. Low G6PD activity (15% vs. 40%, p = 0.034) and lower future liver remnant (FLR) (34.3% vs. 37.8%, p = 0.05) were identified as risk factors for PHE.

CONCLUSION

We report the largest to-date series of G6PDd individuals undergoing LiDH and confirm the safety of LL donation in G6PDd. Our analysis identifies specific risk factors for PHE and suggests that right lobe LiDH be avoided in individuals with less than 25% G6PD activity when the FLR is less than 36%.

Late-onset aspirin-related hemolysis and subsequent subdural hemorrhage in patient with glucose-6-phosphate dehydrogenase deficiency

Key Clinical Message

Aspirin-related hemolysis in G6PD deficiency could be late-onset during long-term administration. Hemolytic anemia could continue for a relatively long time in elder patient with G6PD deficiency, which might be related to other adverse events.

Abstract

Aspirin-related hemolysis in G6PD-deficient individuals was generally reported among patients who received high-dose supplements within several days after ingestion. The safety of long-term and low-dose (50-325 mg/day) aspirin in patients coexist G6PD deficiency and cardiovascular disease is neglected in clinical practice. In this case, we observed a late-onset hemolysis and subsequent fatal subdural hemorrhage in one G6PD-deficient individual who had received long-term and low-dose aspirin. An 83-year-old male was diagnosed with acute ischemic stroke and treated with 100 mg/day aspirin at the emergency room. After admission, the patient was diagnosed with severe G6PD deficiency based on enzyme activity, but no hemolysis occurred within 10-day aspirin therapy in the hospital. Hence, 100 mg/day aspirin was continued on discharge. Two months later, the patient presented acute hemolysis manifested as fatigue, dark urine, and moderate jaundice. Although hemolysis was self-limit in a few days, hemoglobin decline continued for 20 days until a fatal subdural hemorrhage occurred. Our study indicated aspirin-related hemolysis could be late-onset in G6PD-deficient individual even receiving low-dose treatment and is probably linked to subsequent major bleeding events.

Mining local exome and HLA data to characterize pharmacogenetic variants in Saudi Arabia

Pharmacogenomics (PGx) is a promising field of precision medicine where efficacy of drugs is maximized while side effects are minimized for individual patients. Knowledge of the frequency of PGx-relevant variants (pharmacovariants) in the local population is a pre-requisite to informed policy making. Unfortunately, such knowledge is largely lacking from the Middle East. Here, we describe the use of a large clinical exome database (n = 13,473) and HLA haplotypes (n = 64,737) from Saudi Arabia, one of the largest countries in the Middle East, along with previously published data from the local population to ascertain allele frequencies of known pharmacovariants. In addition, we queried another exome database (n = 816) of well-phenotyped research subjects from Saudi Arabia to discover novel candidate variants in known PGx genes (pharmacogenes). Although our results show that only 26% (63/242) of class 1A/1B PharmGKB variants were identified, we estimate that 99.57% of the local population have at least one such variant. This translates to a minimum estimated impact of 9% of medications dispensed by our medical center annually. We also highlight the contribution of rare variants where 71% of the pharmacogenes devoid of common pharmacovariants had at least one potentially deleterious rare variant. Thus, we show that approaches that go beyond the use of commercial PGx kits that have been optimized for other populations should be implemented to ensure universal and equitable access of all members of the local population to personalized prescription practices.

Successful management of delayed-onset adenosine deaminase deficiency with novel mutation

A 4-year-old boy presented with acute-onset autoimmune cytopenia with severe, persistent lymphopenia, autoimmune thyroiditis, elevated IgE and glucose 6-phosphate dehydrogenase enzyme deficiency. In immunologic evaluation, lower T, B and natural killer cells and higher levels of adenosine deaminase (ADA) metabolites were observed. The compound heterozygous novel ADA gene mutations causing ADA deficiency were detected. Successful immunologic and metabolic cure was achieved with enzyme replacement therapy, followed by reduced intensity conditioning hematopoietic stem cell transplantation from a matched unrelated donor. An interesting aspect of this patient is the detection of novel compound heterozygous mutations without consanguinity and a secondary outcome is the recovery of glucose 6-phosphate dehydrogenase deficiency after hematopoietic stem cell transplantation.

The Emerging Roles of γ-Glutamyl Peptides Produced by γ-Glutamyltransferase and the Glutathione Synthesis System

L-γ-Glutamyl-L-cysteinyl-glycine is commonly referred to as glutathione (GSH); this ubiquitous thiol plays essential roles in animal life. Conjugation and electron donation to enzymes such as glutathione peroxidase (GPX) are prominent functions of GSH. Cellular glutathione balance is robustly maintained via regulated synthesis, which is catalyzed via the coordination of γ-glutamyl-cysteine synthetase (γ-GCS) and glutathione synthetase, as well as by reductive recycling by glutathione reductase. A prevailing short supply of L-cysteine (Cys) tends to limit glutathione synthesis, which leads to the production of various other γ-glutamyl peptides due to the unique enzymatic properties of γ-GCS. Extracellular degradation of glutathione by γ-glutamyltransferase (GGT) is a dominant source of Cys for some cells. GGT catalyzes the hydrolytic removal of the γ-glutamyl group of glutathione or transfers it to amino acids or to dipeptides outside cells. Such processes depend on an abundance of acceptor substrates. However, the physiological roles of extracellularly preserved γ-glutamyl peptides have long been unclear. The identification of γ-glutamyl peptides, such as glutathione, as allosteric modulators of calcium-sensing receptors (CaSRs) could provide insights into the significance of the preservation of γ-glutamyl peptides. It is conceivable that GGT could generate a new class of intercellular messaging molecules in response to extracellular microenvironments.

Prevalence of G6PD deficiency and submicroscopic malaria parasites carriage in malaria hotspot area in Northwest, Tanzania

BACKGROUND

The use of primaquine for mass drug administration (MDA) is being considered as a key strategy for malaria elimination. In addition to being the only drug active against the dormant and relapsing forms of Plasmodium vivax, primaquine is the sole potent drug against mature/infectious Plasmodium falciparum gametocytes. It may prevent onward transmission and help contain the spread of artemisinin resistance. However, higher dose of primaquine is associated with the risk of acute haemolytic anaemia in individuals with a deficiency in glucose-6-phosphate dehydrogenase. In many P. falciparum endemic areas there is paucity of information about the distribution of individuals at risk of primaquine-induced haemolysis at higher dose 45 mg of primaquine.

METHODS

A retrospective cross-sectional study was carried out using archived samples to establish the prevalence of G6PD deficiency in a malaria hotspot area in Misungwi district, located in Mwanza region, Tanzania. Blood samples collected from individuals recruited between August and November 2010 were genotyped for G6PD deficiency and submicroscopic parasites carriage using polymerase chain reaction.

RESULTS

A total of 263 individuals aged between 0 and 87 were recruited. The overall prevalence of the X-linked G6PD A- mutation was 83.7% (220/263) wild type, 8% (21/263) heterozygous and 8.4% (22/263) homozygous or hemizygous. Although, assessment of the enzymatic activity to assign the phenotypes according to severity and clinical manifestation as per WHO was not carried out, the overall genotype and allele frequency for the G6PD deficiency was 16.4% and 13. 2%, respectively. There was no statistically significant difference in among the different G6PD genotypes (p > 0.05). Out of 248 samples analysed for submicroscopic parasites carriage, 58.1% (144/248) were P. falciparum positive by PCR. G6PD heterozygous deficiency were associated with carriage of submicroscopic P. falciparum (p = 0.029).

CONCLUSIONS

This study showed that 16.4% of the population in this part of North-western Tanzania carry the G6PD A- mutation, within the range of 15-32% seen in other parts of Africa. G6PD gene mutation is widespread and heterogeneous across the study area where primaquine would be valuable for malaria control and elimination. The maps and population estimates presented here reflect potential risk of higher dose of primaquine being associated with the risk of acute haemolytic anaemia (AHA) in individuals with a deficiency in glucose-6-phosphate dehydrogenase and call further research on mapping of G6PD deficiency in Tanzania. Therefore, screening and education programmes for G6PD deficiency is warranted in a programme of malaria elimination using a higher primaquine dose.