The PreQuine Platform: A novel diagnostic tool for measuring glucose-6-phosphate dehydrogenase (G6PD) activity and hemoglobin concentration.

Quantitative diagnosis of glucose-6-phosphate dehydrogenase (G6PD) deficiency is essential for the safe administration of 8-aminoquinoline based radical cure for the treatment of Plasmodium vivax infections. Here, we present the PreQuine Platform (IVDS, USA), a quantitative biosensor that uses a dual-analyte assay for the simultaneous measurement of Hemoglobin (Hgb) levels and G6PD enzyme activity within the same sample. The platform relies on a downloadable mobile application. The device requires 10µl of whole blood and works with a reflectance-based meter. Comparing the G6PD measurement normalized by Hgb of 12 samples from the PreQuine Platform with reference measurements methods (spectrophotometry, Pointe Scientific, USA and hemoglobin meter, HemoCue, Sweden) showed a positive and significant agreement with a slope of 1.0091 and an intercept of -0.0379 under laboratory conditions. Next steps will be to conduct field trials in Bangladesh, Cambodia, and the USA to assess diagnostic performance, user friendliness and acceptance.

Kinetics of glucose-6-phosphate dehydrogenase (G6PD) activity during Plasmodium vivax infection: implications for early radical malaria treatment.

BACKGROUND: Plasmodium vivax relapses due to dormant liver hypnozoites can be prevented with primaquine. However, the dose must be adjusted in individuals with glucose-6-phosphate-dehydrogenase (G6PD) deficiency. In French Guiana, assessment of G6PD activity is typically delayed until day (D)14 to avoid the risk if misclassification. This study assessed the kinetics of G6PD activity throughout P. vivax infection to inform the timing of treatment. METHODS: For this retrospective monocentric study, data on G6PD activity between D1 and D28 after treatment initiation with chloroquine or artemisinin-based combination therapy were collected for patients followed at Cayenne Hospital, French Guiana, between January 2018 and December 2020. Patients were divided into three groups based on the number of available G6PD activity assessments: (i) at least two measurements during the P. vivax malaria infection; (ii) two measurements: one during the current infection and one previously; (iii) only one measurement during the malaria infection. RESULTS: In total, 210 patients were included (80, 20 and 110 in groups 1, 2 and 3, respectively). Data from group 1 showed that G6PD activity remained stable in each patient over time (D1, D3, D7, D14, D21, D28). None of the patients with normal G6PD activity during the initial phase (D1-D3) of the malaria episode (n = 44) was categorized as G6PD-deficient at D14. Patients with G6PD activity < 80% at D1 or D3 showed normal activity at D14. Sex and reticulocyte count were statistically associated with G6PD activity variation. In the whole sample (n = 210), no patient had severe G6PD deficiency (< 10%) and only three between 10 and 30%, giving a G6PD deficiency prevalence of 1.4%. Among the 100 patients from group 1 and 2, 30 patients (26.5%) were lost to follow-up before primaquine initiation. CONCLUSIONS: In patients treated for P. vivax infection, G6PD activity did not vary over time. Therefore, G6PD activity on D1 instead of D14 could be used for primaquine dose-adjustment. This could allow earlier radical treatment with primaquine, that could have a public health impact by decreasing early recurrences and patients lost to follow-up before primaquine initiation. This hypothesis needs to be confirmed in larger prospective studies.

[The effect of glucose-6-phosphate dehydrogenase deficiency on allogeneic hematopoietic stem cell transplantation in patients with hematological disorders].

Objectives: To determine the effect of glucose-6-phosphate-dehydrogenase (G6PD) deficiency on patients' complications and prognosis following allogeneic stem cell hematopoietic transplantation (allo-HSCT) . Methods: 7 patients with G6PD deficiency (study group) who underwent allo-HSCT at Peking University People's Hospital from March 2015 to January 2021 were selected as the study group, and thirty-five patients who underwent allo-HSCT during the same period but did not have G6PD deficiency were randomly selected as the control group in a 1∶5 ratio. Gender, age, underlying diseases, and donors were balanced between the two groups. Collect clinical data from two patient groups and perform a retrospective nested case-control study. Results: The study group consisted of six male patients and one female patient, with a median age of 37 (range, 2-45) years old. The underlying hematologic diseases included acute myeloid leukemia (n=3), acute lymphocytic leukemia (n=2), and severe aplastic anemia (n=2). All 7 G6PD deficiency patients achieved engraftment of neutrophils within 28 days of allo-HSCT, while the engraftment rate of neutrophils was 94.5% in the control group. The median days of platelet engraftment were 21 (6-64) d and 14 (7-70) d (P=0.113). The incidence rates of secondary poor graft function in the study group and control group were 42.9% (3/7) and 8.6% (3/35), respectively (P=0.036). The CMV infection rates were 71.4% (5/7) and 31.4% (11/35), respectively (P=0.049). The incidence rates of hemorrhagic cystitis were 57.1% (4/7) and 8.6% (3/35), respectively (P=0.005), while the bacterial infection rates were 100% (7/7) and 77.1% (27/35), respectively (P=0.070). The infection rates of EBV were 14.3% (1/7) and 14.3% (5/35), respectively (P=1.000), while the incidence of fungal infection was 14.3% (1/7) and 25.7% (9/35), respectively (P=0.497). The rates of post-transplant lymphoproliferative disease (PTLD) were 0% and 5.7%, respectively (P=0.387) . Conclusions: The findings of this study indicate that blood disease patients with G6PD deficiency can tolerate conventional allo-HSCT pretreatment regimens, and granulocytes and platelets can be implanted successfully. However, after transplantation, patients should exercise caution to avoid viral infection, complications of hemorrhagic cystitis, and secondary poor graft function.

Newborn screening in Colombia: The experience of a private program in Bogotá / Tamizaje neonatal en Colombia: la experiencia de un programa privado en Bogotá.

Introduction. The first neonatal screening program in Colombia ­ PREGEN ­ was set up in the medical private sector of Bogotá in 1988. We report the results from recent years that, given the scarcity of similar information in our country, may help estimate the frequency of the evaluated neonatal disorders and which ones should be included in the neonatal screening programs in our country. Objective. To describe the results of PREGEN´s newborn screening program between 2006 and 2019. Materials and methods. We analyzed databases and other informative documents preserved in PREGEN from the 2006-2019 period. Results. One in every 164 newborns screened in our program had an abnormal hemoglobin variant, and one in every 194 carried some hemoglobin S variant. Glucose-6- phosphate dehydrogenase deficiency and congenital hypothyroidism are next as the more common disorders. Conclusions. Abnormal hemoglobin causes the most frequent monogenic disorder in the world. Glucose-6-phosphate dehydrogenase deficiency is the most common enzymopathy affecting nearly 400 million individuals worldwide. Since both disorders are more common in people of African descent and confer some resistance to malaria, we believe that screening for both disorders may be more relevant in the areas with African ancestry in our country.

Introducción. En Colombia, el primer programa de tamizaje neonatal, PREGEN, inició labores en el sector privado de Bogotá en 1988. En este artículo se presentan los resultados obtenidos en los últimos años, que, dada la carencia de estos estudios en el país, pueden servir para evaluar la frecuencia de aparición de los trastornos congénitos evaluados y estimar cuáles de ellos deben ser objeto de tamizaje neonatal a nivel nacional. Objetivos. Reportar los resultados del programa de tamizaje PREGEN entre el 2006 y el 2019. Materiales y métodos. Para este análisis se examinaron las bases de datos y otros documentos informativos de PREGEN para el periodo 2006-2019. Resultados. Uno de cada 164 recién nacidos tamizados en el programa PREGEN en Bogotá presentó una variante anormal de la hemoglobina y uno de cada 194 es portador de hemoglobina S. Los siguientes dos trastornos más frecuentes encontrados fueron la deficiencia de la enzima glucosa-6-fosfato deshidrogenasa (frecuencia 1:2.231) y el hipotiroidismo congénito (frecuencia 1:3.915). Conclusiones. Las hemoglobinopatías mostraron ser uno de los desórdenes monogénicos más comunes, seguidos por la deficiencia de glucosa-6-fosfato deshidrogenasa y el hipotiroidismo congénito. Se calcula que cerca de 400 millones de personas en el mundo están afectadas por la deficiencia de glucosa-6-fosfato deshidrogenasa, por lo cual es la enzimopatía más común en el mundo. Como ambos desórdenes son más frecuentes en poblaciones de origen africano y confieren algún grado de resistencia a la malaria, es de prever que su tamizaje debe ser de mayor importancia en las zonas con ancestros africanos en Colombia.

Field evaluation of a novel semi-quantitative point-of-care diagnostic for G6PD deficiency in Indonesia.

BACKGROUND: The WHO recommends routine testing of G6PD activity to guide radical cure in patients with Plasmodium vivax malaria. Females may have intermediate G6PD enzyme activity and to date, only complex diagnostics are able to reliably identify them. The semi-quantitative G6PD diagnostic "One Step G6PD Test" (Humasis, RoK; "RDT") is a lateral flow assay that can distinguish deficient, intermediate, and normal G6PD status and offers a simpler diagnostic alternative. METHODS: G6PD status of participants enrolled in Malinau and Nunukan Regencies and the capital Jakarta was assessed with the RDT, and G6PD activity was measured in duplicate by reference spectrophotometry. The adjusted male median (AMM) of the spectrophotometry measurements was defined as 100% activity; 70% and 30% of the AMM were defined as thresholds for intermediate and deficient G6PD status, respectively. Results were compared to those derived from spectrophotometry at the clinically relevant G6PD activity thresholds of 30% and 70%. RESULTS: Of the 161 participants enrolled, 10 (6.2%) were G6PD deficient and 12 (7.5%) had intermediate G6PD activity by spectrophotometry. At the 30% threshold, the sensitivity of the RDT was 10.0% (95%CI: 0.3-44.5%) with a specificity of 99.3% (95%CI: 96.4-100.0%); the positive predictive value was 50.0% (95%CI: 1.3-98.7%) and the negative predictive value 94.3% (95%CI: 89.5-97.4%). The corresponding figures at the 70% threshold were 22.7% (95%CI: 7.8-45.4%), 100.0% (95%CI: 97.4-100.0%), 100.0% (95%CI: 47.8-100.0%) and 89.1% (95%CI: 83.1-93.5%), respectively. CONCLUSION: While there is a dire need for an easy-to-use, economical, semi-quantitative diagnostic for the point of care, the observed performance of the "One Step G6PD Test" in its current form was insufficient to guide antimalarial treatment.

Quantifying the effect of glucose 6-phosphate dehydrogenase deficiency on glycated hemoglobin values in children and adolescents with type 1 diabetes.

The primary objectives of the study were (a) to confirm that glucose 6-phosphate dehydrogenase (G6PD) deficiency affects HbA1c values in a sample of children and adolescents with type 1 diabetes (T1D) and (b) to quantify this effect so that a correction can be applied to the HbA1c values found in current clinical practice. The following data were collected: age, sex, G6PD, number of daily capillary blood glucose measurements, 90-day average blood glucose levels prior to the study, HbA1c, and glycated hemoglobin estimated (eA1c) obtained from blood glucose levels. Patients were divided into three groups based on G6PD values: deficient, intermediate, and nondeficient. In each group, a comparison between the average eA1C and HbA1c values was performed. Then, the difference between the eA1c and HbA1c values of each patient and the mean of the differences (MD) of all patients was calculated within the three groups. Finally, a comparison of the MD values between groups was performed. Seventy-four subjects with T1D were studied. Based on the G6PD value, 33 subjects were deficient, 8 were intermediate, and 33 subjects were nondeficient. In deficient patients, the eA1c values were significantly higher than the HbA1c values. In the other two groups, however, there were no differences. The MD values between the three groups were significantly different. In deficient patients, MD values were higher than those in intermediate and in nondeficient patients. No difference was found between intermediate and nondeficient subjects. Our study confirms that G6PD deficiency affects HbA1c values in children and adolescents with T1D, both in deficient subjects and, to a much lesser extent, in intermediate subjects. In deficient subjects, there is an average reduction in HbA1c attributable to enzyme deficiency of 1.3% (14 mmol/mol) and in intermediate subjects of 0.3% (3 mmol/mol).

Acalypha indica induced acute oxidative haemolysis and methaemoglobinaemia: two case reports.

BACKGROUND: Herbal products and traditional remedies are commonly used by individuals worldwide for the management of common ailments, even though most are not without risks. Acalypha indica is a popular medicinal plant consumed in some Asian countries. CASE PRESENTATION: This case report presents a 40-year-old previously unevaluated Sri Lankan female and her 8-year-old son who presented with severe glucose-6-phosphate dehydrogenase (G6PD) deficiency related acute intravascular oxidative haemolysis and methaemoglobinaemia precipitated by Acalypha indica consumption, successfully managed with supportive care and blood transfusion. CONCLUSIONS: This case highlights the potential hemolytic and methaemoglobinaemic effects of ingesting oxidant herbal products and the importance of considering such exposures in patients presenting with hemolysis and multiorgan involvement, particularly in communities where herbal product intake is popular. Healthcare providers should be aware of the risks associated with traditional remedies and maintain a high index of suspicion to ensure prompt recognition and appropriate management.

Functional effects of an African glucose-6-phosphate dehydrogenase (G6PD) polymorphism (Val68Met) on red blood cell hemolytic propensity and post-transfusion recovery.

BACKGROUND: Donor genetic variation is associated with red blood cell (RBC) storage integrity and post-transfusion recovery. Our previous large-scale genome-wide association study demonstrated that the African G6PD deficient A- variant (rs1050828, Val68Met) is associated with higher oxidative hemolysis after cold storage. Despite a high prevalence of X-linked G6PD mutation in African American population (>10%), blood donors are not routinely screened for G6PD status and its importance in transfusion medicine is relatively understudied. STUDY DESIGN AND METHODS: To further evaluate the functional effects of the G6PD A- mutation, we created a novel mouse model carrying this genetic variant using CRISPR-Cas9. We hypothesize that this humanized G6PD A- variant is associated with reduced G6PD activity with a consequent effect on RBC hemolytic propensity and post-transfusion recovery. RESULTS: G6PD A- RBCs had reduced G6PD protein with ~5% residual enzymatic activity. Significantly increased in vitro hemolysis induced by oxidative stressors was observed in fresh and stored G6PD A- RBCs, along with a lower GSH:GSSG ratio. However, no differences were observed in storage hemolysis, osmotic fragility, mechanical fragility, reticulocytes, and post-transfusion recovery. Interestingly, a 14% reduction of 24-h survival following irradiation was observed in G6PD A- RBCs compared to WT RBCs. Metabolomic assessment of stored G6PD A- RBCs revealed an impaired pentose phosphate pathway (PPP) with increased glycolytic flux, decreasing cellular antioxidant capacity. DISCUSSION: This novel mouse model of the common G6PD A- variant has impaired antioxidant capacity like humans and low G6PD activity may reduce survival of transfused RBCs when irradiation is performed.

Prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Gia Lai Province, Vietnam.

Glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) deficiency is one of the most common X-linked hereditary disorders worldwide. G6PD deficiency provides resistance against severe malaria, but paradoxically, G6PD deficiency is also a stumbling block in fighting against malaria. Primaquine (PQ), a drug for the radical cure of Plasmodium vivax, can cause lethal acute hemolytic anemia in malaria patients with inherited G6PD deficiency. In this study, we analyzed the phenotypic and genotypic G6PD deficiency status in 1721 individuals (963 males and 758 females) residing in three malaria-endemic areas within the Gia Lai province, Vietnam. The G6PD activity in individuals ranged from 3.04 to 47.82 U/g Hb, with the adjusted male median (AMM) of 7.89 U/g Hb. Based on the G6PD activity assay results, no phenotypic G6PD deficiency was detected. However, the multiplex polymerase chain reaction to detect G6PD variations in the gene level revealed that 26 individuals (7 males, 19 females) had Viangchan mutations (871 G > A). Sequencing analyses suggested that all the males were hemizygous Viangchan, whereas one was homozygous, and 18 were heterozygous Viangchan in females. These results suggested a relatively low prevalence of G6PD deficiency mutation rate (1.51%) in the minor ethnic populations residing in the Gia Lai province, Vietnam. However, considering these areas are high-risk malaria endemic, concern for proper and safe use of PQ as a radical cure of malaria is needed by combining a G6PD deficiency test before PQ prescription.

Primaquine in glucose-6-phosphate dehydrogenase deficiency: an adaptive pharmacometric assessment of ascending dose regimens in healthy volunteers.

Background: Primaquine is an 8-aminoquinoline antimalarial. It is the only widely available treatment to prevent relapses of Plasmodium vivax malaria. The 8-aminoquinolines cause dose-dependent haemolysis in glucose-6-phosphate dehydrogenase deficiency (G6PDd). G6PDd is common in malaria endemic areas but testing is often not available. As a consequence primaquine is underused. Methods: We conducted an adaptive pharmacometric study to characterise the relationship between primaquine dose and haemolysis in G6PDd. The aim was to explore shorter and safer primaquine radical cure regimens compared to the currently recommended 8-weekly regimen (0.75 mg/kg once weekly), potentially obviating the need for G6PD testing. Hemizygous G6PDd healthy adult Thai and Burmese male volunteers were admitted to the Hospital for Tropical Diseases in Bangkok. In Part 1, volunteers were given ascending dose primaquine regimens whereby daily doses were increased from 7.5 mg up to 45 mg over 15-20 days. In Part 2 conducted at least 6 months later, a single primaquine 45 mg dose was given. Results: 24 volunteers were enrolled in Part 1, and 16 in Part 2 (13 participated in both studies). In three volunteers, the ascending dose regimen was stopped because of haemolysis (n=1) and asymptomatic increases in transaminases (n=2; one was hepatitis E positive). Otherwise the ascending regimens were well tolerated with no drug-related serious adverse events. In Part 1, the median haemoglobin concentration decline was 3.7 g/dL (range: 2.1-5.9; relative decline of 26% [range: 15-40%]). Primaquine doses up to 0.87 mg/kg/day were tolerated subsequently without clinically significant further falls in haemoglobin. In Part 2, the median haemoglobin concentration decline was 1.7 g/dL (range 0.9-4.1; relative fall of 12% [range: 7-30% decrease]). The ascending dose primaquine regimens gave seven times more drug but resulted in only double the haemoglobin decline. Conclusions: In patients with Southeast Asian G6PDd variants, full radical cure treatment can be given in under 3 weeks compared with the current 8-week regimen. Funding: Medical Research Council of the United Kingdom (MR/R015252/1) and Wellcome (093956/Z/10/C, 223253/Z/21/Z). Clinical trial number: Thai Clinical Trial Registry: TCTR20170830002 and TCTR20220317004.

Radical cure for Plasmodium vivax malaria after G6PD qualitative testing in four provinces in Cambodia, results from Phase I implementation.

BACKGROUND: Cambodia aims to eliminate all forms of malaria by 2025. In 2020, 90% of all malaria cases were Plasmodium vivax. Thus, preventing P. vivax and relapse malaria is a top priority for elimination. 14-day primaquine, a World Health Organization-recommended radical cure treatment regimen, specifically targets dormant hypnozoites in the liver to prevent relapse. Cambodia introduced P. vivax radical cure with primaquine after glucose-6-phosphate dehydrogenase (G6PD) qualitative testing in 2019. This paper presents Cambodia's radical cure Phase I implementation results and assesses the safety, effectiveness, and feasibility of the programme prior to nationwide scale up. METHODS: Phase I implementation was carried out in 88 select health facilities (HFs) across four provinces. Males over 20kgs with confirmed P. vivax or mixed (P. vivax and Plasmodium falciparum) infections were enrolled. A descriptive analysis evaluated the following: successful referral to health facilities, G6PD testing results, and self-reported 14-day treatment adherence. P. vivax incidence was compared before and after radical cure rollout and a controlled interrupted time series analysis compared the estimated relapse rate between implementation and non-implementation provinces before and after radical cure. RESULTS: In the 4 provinces from November 2019 to December 2020, 3,239 P. vivax/mixed infections were reported, 1,282 patients underwent G6PD deficiency testing, and 959 patients received radical cure, achieving 29.6% radical cure coverage among all P. vivax/mixed cases and 98.8% coverage among G6PD normal patients. Among those who initiated radical cure, 747 patients (78%) completed treatment. Six patients reported side effects. In implementation provinces, an average 31.8 relapse cases per month were estimated signaling a 90% (286 cases) reduction in relapse compared to what would be expected if radical cure was not implemented. CONCLUSIONS: Plasmodium vivax radical cure is a crucial tool for malaria elimination in Cambodia. The high coverage of radical cure initiation and adherence among G6PD normal patients demonstrated the high feasibility of providing radical cure at point of care in Cambodia. Incomplete referral from community to HFs and limited capacity of HF staff to conduct G6PD testing in high burden areas led to lower coverage of G6PD testing. Phase I implementation informed approaches to improve referral completion and patient adherence during the nationwide expansion of radical cure in 2021.

Genetic analysis and molecular basis of G6PD deficiency among malaria patients in Thailand: implications for safe use of 8-aminoquinolines.

BACKGROUND: It was hypothesized that glucose-6-phosphate dehydrogenase (G6PD) deficiency confers a protective effect against malaria infection, however, safety concerns have been raised regarding haemolytic toxicity caused by radical cure with 8-aminoquinolines in G6PD-deficient individuals. Malaria elimination and control are also complicated by the high prevalence of G6PD deficiency in malaria-endemic areas. Hence, accurate identification of G6PD deficiency is required to identify those who are eligible for malaria treatment using 8-aminoquinolines. METHODS: The prevalence of G6PD deficiency among 408 Thai participants diagnosed with malaria by microscopy (71), and malaria-negative controls (337), was assessed using a phenotypic test based on water-soluble tetrazolium salts. High-resolution melting (HRM) curve analysis was developed from a previous study to enable the detection of 15 common missense, synonymous and intronic G6PD mutations in Asian populations. The identified mutations were subjected to biochemical and structural characterisation to understand the molecular mechanisms underlying enzyme deficiency. RESULTS: Based on phenotypic testing, the prevalence of G6PD deficiency (< 30% activity) was 6.13% (25/408) and intermediate deficiency (30-70% activity) was found in 15.20% (62/408) of participants. Several G6PD genotypes with newly discovered double missense variants were identified by HRM assays, including G6PD Gaohe + Viangchan, G6PD Valladolid + Viangchan and G6PD Canton + Viangchan. A significantly high frequency of synonymous (c.1311C>T) and intronic (c.1365-13T>C and c.486-34delT) mutations was detected with intermediate to normal enzyme activity. The double missense mutations were less catalytically active than their corresponding single missense mutations, resulting in severe enzyme deficiency. While the mutations had a minor effect on binding affinity, structural instability was a key contributor to the enzyme deficiency observed in G6PD-deficient individuals. CONCLUSIONS: With varying degrees of enzyme deficiency, G6PD genotyping can be used as a complement to phenotypic screening to identify those who are eligible for 8-aminoquinolines. The information gained from this study could be useful for management and treatment of malaria, as well as for the prevention of unanticipated reactions to certain medications and foods in the studied population.

Field assessment of the operating procedures of a semi-quantitative G6PD Biosensor to improve repeatability of routine testing.

In remote communities, diagnosis of G6PD deficiency is challenging. We assessed the impact of modified test procedures and delayed testing for the point-of-care diagnostic STANDARD G6PD (SDBiosensor, RoK), and evaluated recommended cut-offs. We tested capillary blood from fingerpricks (Standard Method) and a microtainer (BD, USA; Method 1), venous blood from a vacutainer (BD, USA; Method 2), varied sample application methods (Methods 3), and used micropipettes rather than the test's single-use pipette (Method 4). Repeatability was assessed by comparing median differences between paired measurements. All methods were tested 20 times under laboratory conditions on three volunteers. The Standard Method and the method with best repeatability were tested in Indonesia and Nepal. In Indonesia 60 participants were tested in duplicate by both methods, in Nepal 120 participants were tested in duplicate by either method. The adjusted male median (AMM) of the Biosensor Standard Method readings was defined as 100% activity. In Indonesia, the difference between paired readings of the Standard and modified methods was compared to assess the impact of delayed testing. In the pilot study repeatability didn't differ significantly (p = 0.381); Method 3 showed lowest variability. One Nepalese participant had <30% activity, one Indonesian and 10 Nepalese participants had intermediate activity (≥30% to <70% activity). Repeatability didn't differ significantly in Indonesia (Standard: 0.2U/gHb [IQR: 0.1-0.4]; Method 3: 0.3U/gHb [IQR: 0.1-0.5]; p = 0.425) or Nepal (Standard: 0.4U/gHb [IQR: 0.2-0.6]; Method 3: 0.3U/gHb [IQR: 0.1-0.6]; p = 0.330). Median G6PD measurements by Method 3 were 0.4U/gHb (IQR: -0.2 to 0.7, p = 0.005) higher after a 5-hour delay compared to the Standard Method. The definition of 100% activity by the Standard Method matched the manufacturer-recommended cut-off for 70% activity. We couldn't improve repeatability. Delays of up to 5 hours didn't result in a clinically relevant difference in measured G6PD activity. The manufacturer's recommended cut-off for intermediate deficiency is conservative.

Evaluating the relationship between Clinical G6PD enzyme activity and gene variants.

Glucose-6-phosphate dehydrogenase (G6PD) is a the first and rate-limiting enzyme that plays a critical role in G6PD deficiency, the most common enzyme disorder worldwide, is related to intravascular hemolysis. To determine the clinical enzyme activity level in different G6PD variants, we evaluated 15 variant from 424 clinical blood samples by using multicolor melting curve analysis and DNA sequencing. The results showed that the enzyme activities of the hemizygous deficient were 1.5-2.4 U/gHb, which was significantly lower than those of the heterozygous (P < 0.001) and the compound heterozygous variants (P < 0.05). Since the hemizygous of c.1024C > T (Chinese-5) mutation affects the kinetic parameters of G6PD and increase utilization of analogues, its enzyme activity is more than those of other mutations that mutated in the ß+α region of G6PD. The heterozygous enzyme levels ranged from 6.5-20.1 U/gHb; and there was no significant difference among different heterozygous variants (P > 0.05). The enzyme activity levels of the compound heterozygous mutation were mainly in the range of 1.7-3.8 U/gHb, which was much lower than that of the heterozygous mutation (P < 0.001). In summary, our findings revealed that the enzyme activity of G6PD in blood have a significant relationship with genotype of G6PD.

G6PD gene detection in neonatal hyperbilirubinemia and analysis of related risk factors.

BACKGROUND: Hyperbilirubinemia is a common disorder in neonates, with premature infants at higher risk of developing the disorder. OBJECTIVE: Glucose-6-phosphate dehydrogenase (G6PD) gene detection was used to determine the incidence of G6PD deficiency and analyze the etiologies of G6PD deficiency in neonates with hyperbilirubinemia in the Zunyi region with the aim of providing scientific evidence for the clinical diagnosis and treatment. METHODS: For the gene detection, 64 neonates with hyperbilirubinemia were selected as the observation group and 30 normal neonates were selected as the control group, and the risk factors for hyperbilirubinemia were investigated by using multivariate logistic regression analysis. RESULTS: Among the neonates in the observation group, 59 cases had the G1388A mutation (92.19%) and 5 cases had the G1376T mutation (7.81%). No mutation was detected in the control group. In the observation group, the proportion of neonates who were born prematurely, with artificial feeding, with the age of starting feeding of more than 24 h, the time of first bowel movement of more than 24 h, premature rupture of membranes, infection, scalp hematoma, and perinatal asphyxia was higher than that in the control group, and the difference was statistically significant (p< 0.05). Multivariate logistic regression analysis showed that prematurity, infection, scalp hematoma, perinatal asphyxia, the age of starting feeding of more than 24 h, and the time of first bowel movement over 24 h were risk factors for the development of neonatal hyperbilirubinemia (p< 0.05). CONCLUSION: The G1338A and G1376T mutations were important features of the genetics of neonatal hyperbilirubinemia, and genetic detection together with the prevention of prematurity, infection, scalp hematoma, perinatal asphyxia, the age of starting feeding, and the time of first bowel movement would help reduce the incidence of this disease.

Glucose-6-phosphate dehydrogenase deficiency accelerates arterial aging in diabetes.

AIMS: High glucose levels and Glucose-6-Phosphate Dehydrogenase deficiency (G6PDd) have both tissue inflammatory effects. Here we determined whether G6PDd accelerates arterial aging (information linked stiffening) in diabetes. METHODS: Plasma glucose, interleukin 6 (IL6), and arterial stiffness (indexed as carotid-femoral Pulse Wave Velocity, PWV) and red blood cell G6PD activity were assessed in a large (4448) Sardinian population. RESULTS: Although high plasma glucose in diabetics, did not differ by G6DP status (178.2 ± 55.1 vs 169.0 ± 50.1 mg/dl) in G6DPd versus non-G6PDd subjects, respectively, IL6, and PWV (adjusted for age and glucose) were significantly increased in G6PDd vs non-G6PDd subjects (PWV, 8.0 ± 0.4 vs 7.2 ± 0.2 m/sec) and (IL6, 6.9 ± 5.0 vs 4.2 ± 3.0 pg/ml). In non-diabetics, neither fasting plasma glucose, nor IL6, nor PWV were impacted by G6PDd. CONCLUSION: G6PDd in diabetics is associated with increased inflammatory markers and accelerated arterial aging.

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%.