Early neonatal bilirubin, hematocrit, and glucose-6-phosphate dehydrogenase status

Genetic spectrum and clinical early natural history of glucose-6-phosphate dehydrogenase deficiency in Mexican children detected through newborn screening

BACKGROUND

Glucose-6-phosphate dehydrogenase deficiency (G6PDd) newborn screening is still a matter of debate due to its highly heterogeneous birth prevalence and clinical expression, as well as, the lack of enough knowledge on its natural history. Herein, we describe the early natural clinical course and the underlying GDPD genotypes in infants with G6PDd detected by newborn screening and later studied in a single follow-up center. G6PDd newborns were categorized into three groups: group 1: hospitalized with or without neonatal jaundice (NNJ); group 2: non-hospitalized with NNJ; and group 3: asymptomatic. Frequencies of homozygous UGT1A1*28 (rs34983651) genotypes among G6PDd patients with or without NNJ were also explored.

RESULTS

A total of 81 newborns (80 males, one female) were included. Most individuals (46.9%) had NNJ without other symptoms, followed by asymptomatic (42.0%) and hospitalized (11.1%) patients, although the hospitalization of only 3 of these patients was related to G6PDd, including NNJ or acute hemolytic anemia (AHA). Nine different G6PDd genotypes were found; the G6PD A-202A/376G genotype was the most frequent (60.5%), followed by the G6PD A-376G/968C (22.2%) and the Union-Maewo (rs398123546, 7.4%) genotypes. These genotypes produce a wide range of clinical and biochemical phenotypes with significant overlapping residual enzymatic activity values among class I, II or III variants. Some G6PD A-202A/376G individuals had enzymatic values that were close to the cutoff value (5.3 U/g Hb, 4.6 and 4.8 U/g Hb in the groups with and without NNJ, respectively), while others showed extremely low enzymatic values (1.1 U/g Hb and 1.4 U/g Hb in the groups with and without NNJ, respectively). Homozygosity for UGT1A1*28 among G6PDd patients with (11.9%, N = 5/42) or without (10.3%, N = 4/39) NNJ did not shown significant statistical difference (p = 0.611).

CONCLUSION

Wide variability in residual enzymatic activity was noted in G6PDd individuals with the same G6PD genotype. This feature, along with a documented heterogeneous mutational spectrum, makes it difficult to categorize G6PD variants according to current WHO classification and precludes the prediction of complications such as AHA, which can occur even with > 10% of residual enzymatic activity and/or be associated with the common and mild G6PD A-376G/968C and G6PD A-202A/376G haplotypes.

Estimated disease burden and lost economic productivity due to glucose-6-phosphate dehydrogenase deficiency in Nigerian newborns

Glucose-6-phosphate dehydrogenase (G6PD) deficiency rarely manifests as extreme hyperbilirubinemia [EHB, total serum/plasma bilirubin > 25 mg/dL (428 µmol/L)]. It is a major preventable cause of newborn morbidity and mortality. In resource-constrained communities of Nigeria, experts have observed its significant clinical burden. We accessed a previously published pooled model of G6PD deficiency and determined its prevalence, subsequent risk of EHB, kernicterus, and death to be 26.4% [95% confidence interval (CI): 19.5, 33.2%]; 33.3% (95%CI: 16.6, 50%); and 22.7% (95% CI: 16.5, 28.9%), respectively. The total number of disability-adjusted life years (DALYs) lost to symptomatic G6PD deficiency was 54,251 (95% CI: 6,039, 189,149). Estimated national average economic deficits due to mortality and disability ranged from $309 to $584 million. G6PD deficiency, when symptomatic in Nigerian newborns, is a significant disease burden, placing 1% of annual births at increased risks of neonatal mortality and morbidity, which contribute to significant economic productivity losses.

Maternal Instruction About Jaundice and the Incidence of Acute Bilirubin Encephalopathy in Nigeria

OBJECTIVE

To evaluate whether teaching mothers about neonatal jaundice will decrease the incidence of acute bilirubin encephalopathy among infants admitted for jaundice.

STUDY DESIGN

This was a multicenter, before-after and cross-sectional study. Baseline incidences of encephalopathy were obtained at 4 collaborating medical centers between January 2014 and May 2015 (Phase 1). Structured jaundice instruction was then offered (May to November 2015; Phase 2) in antenatal clinics and postpartum. Descriptive statistics and logistic regression models compared 3 groups: 843 Phase 1 controls, 338 Phase 2 infants whose mothers received both antenatal and postnatal instruction (group A), and 215 Phase 2 infants whose mothers received no instruction (group B) either because the program was not offered to them or by choice.

RESULTS

Acute bilirubin encephalopathy occurred in 147 of 843 (17%) Phase 1 and 85 of 659 (13%) Phase 2 admissions, which included 63 of 215 (29%) group B and 5 of 338 (1.5%) group A infants. OR for having acute bilirubin encephalopathy, comparing group A and group B infants adjusted for confounding risk factors, was 0.12 (95% CI 0.03-0.60). Delayed care-seeking (defined as an admission total bilirubin ≥18 mg/dL at age ≥48 hours) was the strongest single predictor of acute bilirubin encephalopathy (OR 11.4; 6.6-19.5). Instruction decreased delay from 49% to 17%. Other major risk factors were home births (OR 2.67; 1.69-4.22) and hemolytic disease (hematocrit ≤35% plus bilirubin ≥20 mg/dL) (OR 3.03; 1.77-5.18). The greater rate of acute bilirubin encephalopathy with home vs hospital birth disappeared if mothers received jaundice instruction.

CONCLUSIONS

Providing information about jaundice to mothers was associated with a reduction in the incidence of bilirubin encephalopathy per hospital admission.

Prevalence of and mothers' knowledge, attitude and practice towards glucose-6-phosphate dehydrogenase deficiency among neonates with jaundice: a cross-sectional study

BACKGROUND

Neonatal jaundice (NNJ) is a frequent complication of glucose-6-phosphate dehydrogenase (G6PD) deficiency.

OBJECTIVES

To estimate the prevalence of G6PD deficiency among neonates with jaundice and to assess mothers' perception towards G6PD and NNJ.

METHODS

A cross-sectional study was carried out on 487 ethnic Egyptian neonates with indirect hyperbilirubinaemia from June 2018 to July 2019. The collected data included maternal and neonatal characteristics. Laboratory investigations included serum bilirubin, reticulocyte count, ABO grouping, Rh typing and neonatal serum G6PD test. Mothers were interviewed individually using a structured, researcher-administered questionnaire to assess their perceptions of G6PD deficiency and NNJ.

RESULTS

The prevalence of G6PD deficiency was 10.10%. Neonates with G6PD deficiency showed higher levels of serum bilirubin (p<0.001). Male gender, family history of G6PD deficiency and consanguinity were risk factors for G6PD deficiency (OR=4.27, 95% CI 1.66 - 10.99; OR=9.54, 95% CI 4.80- 18.95; OR=10.219, 95% CI 5.39 - 19.33, respectively). Mothers' perceptions of NNJ and G6PD were low, with only 30% having good knowledge on NNJ and 17.10% on G6PD deficiency, 46.8% with positive attitude towards NNJ and 45.0% towards G6PD deficiency, and 29.9% with good practice towards NNJ and 19.9% towards G6PD deficiency.

CONCLUSION

G6PD deficiency seems to be an important cause of NNJ. Mothers' perceptions of both NNJ and G6PD deficiency were low. A mass health education programme on both of these diseases is needed to ensure better and early detection, good timing of treatment, and better prevention of the triggering factors to ensure better health for children.

Prevalence of neonatal hyperbilirubinaemia and its association with glucose-6-phosphate dehydrogenase deficiency and blood-type incompatibility in sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND

Hyperbilirubinaemia is a silent cause of newborn disease and death worldwide. However, studies of the disease in sub-Saharan Africa are highly variable with respect to its prevalence. Hence, this study aimed to estimate the overall magnitude of neonatal hyperbilirubinaemia and its association with glucose-6-phosphate dehydrogenase (G6PD) deficiency and blood-type incompatibility in sub-Saharan Africa.

METHODS

PubMed, Scopus, Google Scholar and the Cochrane Review were systematically searched online to retrieve hyperbilirubinaemia-related articles. All observational studies reported the prevalence of hyperbilirubinaemia in sub-Saharan Africa were included for analysis and excluded if the study failed to determine the desired outcome. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Heterogeneity across the included studies was evaluated using the inconsistency index (I²). Subgroup and meta- regression analysis were also done. Publication bias was examined by funnel plot and the Egger's regression test. The random-effect model was fitted to estimate the pooled prevalence of neonatal hyperbilirubinaemia. The meta-analysis was performed using the STATA V.14 software.

RESULTS

A total of 30 486 studies were collected from the different databases and 10 articles were included for the final analysis. The overall magnitude of neonatal hyperbilirubinaemia was 28.08% (95% CI20.23 to 35.94, I²=83.2) in sub-Saharan Africa. Neonates with G6PD deficiency (OR 2.42, 95% CI 1.64 to 3.56, I²=37%) and neonates that had a blood type that was incompatible with their mother's (OR 3.3, (95% CI 1.96 to 5.72, I²=84%) were more likely to develop hyperbilirubinaemia.

CONCLUSION

The failure to prevent and screen G6PD deficiency and blood-type incompatibility with their mother's results in high burden of neonatal hyperbilirubinaemia in sub-Saharan Africa. Therefore, early identification and care strategies should be developed to the affected neonates with G6PD deficiency and blood-type incompatibility with their mother's to address long-term medical and scholastic damages among those exposed to hyperbilirubinaemia.

Prevalence of inherited blood disorders and associations with malaria and anemia in Malawian children

In sub-Saharan Africa, inherited causes of anemia are common, but data are limited regarding the geographical prevalence and coinheritance of these conditions and their overall contributions to childhood anemia. To address these questions in Malawi, we performed a secondary analysis of the 2015-2016 Malawi Micronutrient Survey, a nationally and regionally representative survey that estimated the prevalence of micronutrient deficiencies and evaluated both inherited and noninherited determinants of anemia. Children age 6 to 59 months were sampled from 105 clusters within the 2015-2016 Malawi Demographic Health Survey. Hemoglobin, ferritin, retinol binding protein, malaria, and inflammatory biomarkers were measured from venous blood. Molecular studies were performed using dried blood spots to determine the presence of sickle cell disease or trait, α-thalassemia trait, and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Of 1279 eligible children, 1071 were included in the final analysis. Anemia, iron deficiency, and malaria were common, affecting 30.9%, 21.5%, and 27.8% of the participating children, respectively. α-Thalassemia trait was common (>40% of children demonstrating deletion of 1 [33.1%] or 2 [10.0%] α-globin genes) and associated with higher prevalence of anemia (P < .001). Approximately 20% of males had G6PD deficiency, which was associated with a 1.0 g/dL protection in hemoglobin decline during malaria infection (P = .02). These data document that inherited blood disorders are common and likely play an important role in the prevalence of anemia and malaria in Malawian children.

Indirect neonatal hyperbilirubinemia in hospitalized neonates on the Thai-Myanmar border: a review of neonatal medical records from 2009 to 2014

BACKGROUND

Indirect neonatal hyperbilirubinemia (INH) is a common neonatal disorder worldwide which can remain benign if prompt management is available. However there is a higher morbidity and mortality risk in settings with limited access to diagnosis and care. The manuscript describes the characteristics of neonates with INH, the burden of severe INH and identifies factors associated with severity in a resource-constrained setting.

METHODS

We conducted a retrospective evaluation of anonymized records of neonates hospitalized on the Thai-Myanmar border. INH was defined according to the National Institute for Health and Care Excellence guidelines as 'moderate' if at least one serum bilirubin (SBR) value exceeded the phototherapy threshold and as 'severe' if above the exchange transfusion threshold.

RESULTS

Out of 2980 records reviewed, 1580 (53%) had INH within the first 14 days of life. INH was moderate in 87% (1368/1580) and severe in 13% (212/1580). From 2009 to 2011, the proportion of severe INH decreased from 37 to 15% and the mortality dropped from 10% (8/82) to 2% (7/449) coinciding with the implementation of standardized guidelines and light-emitting diode (LED) phototherapy. Severe INH was associated with: prematurity (< 32 weeks, Adjusted Odds Ratio (AOR) 3.3; 95% CI 1.6-6.6 and 32 to 37 weeks, AOR 2.2; 95% CI 1.6-3.1), Glucose-6-phosphate dehydrogenase deficiency (G6PD) (AOR 2.3; 95% CI 1.6-3.3), potential ABO incompatibility (AOR 1.5; 95% CI 1.0-2.2) and late presentation (AOR 1.8; 95% CI 1.3-2.6). The risk of developing severe INH and INH-related mortality significantly increased with each additional risk factor.

CONCLUSION

INH is an important cause of neonatal hospitalization on the Thai-Myanmar border. Risk factors for severity were similar to previous reports from Asia. Implementing standardized guidelines and appropriate treatment was successful in reducing mortality and severity. Accessing to basic neonatal care including SBR testing, LED phototherapy and G6PD screening can contribute to improve neonatal outcomes.

Diagnostic performances of the fluorescent spot test for G6PD deficiency in newborns along the Thailand-Myanmar border: A cohort study

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited enzymatic disorder associated with severe neonatal hyperbilirubinemia and acute haemolysis after exposure to certain drugs or infections. The disorder can be diagnosed phenotypically with a fluorescent spot test (FST), which is a simple test that requires training and basic laboratory equipment. This study aimed to assess the diagnostic performances of the FST used on umbilical cord blood by locally-trained staff and to compare test results of the neonates at birth with the results after one month of age.

Methods: We conducted a cohort study on newborns at the Shoklo Malaria Research Unit, along the Thai-Myanmar border between January 2015 and May 2016. The FST was performed at birth on the umbilical cord blood by locally-trained staff and quality controlled by specialised technicians at the central laboratory. The FST was repeated after one month of age. Genotyping for common local G6PD mutations was carried out for all discrepant results.

Results: FST was performed on 1521 umbilical cord blood samples. Quality control and genotyping revealed 10 misdiagnoses. After quality control, 10.7% of the males (84/786) and 1.2% of the females (9/735) were phenotypically G6PD deficient at birth. The FST repeated at one month of age or later diagnosed 8 additional G6PD deficient infants who were phenotypically normal at birth.

Conclusions: This study shows the short-comings of the G6PD FST in neonatal routine screening and highlights the importance of training and quality control. A more conservative interpretation of the FST in male newborns could increase the diagnostic performances. Quantitative point-of-care tests might show higher sensitivity and specificity for diagnosis of G6PD deficiency on umbilical cord blood and should be investigated.

Markers of oxidative stress in umbilical cord blood from G6PD deficient African newborns

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked disorder that affects as many as 400 million people worldwide, making it the most common enzymatic defect. Subjects with G6PD deficiency are more likely to develop neonatal hyperbilirubinemia potentially leading to kernicterus and are at increased risk for acute hemolytic anemia when exposed to pro-oxidant compounds such as anti-malarial drugs. We collected umbilical cord blood from 300 males born in Uganda to assess for novel markers of systemic oxidative stress. We determined that 10.7% of the samples collected were G6PD A- deficient (G202A/A376G) and when these were compared with unaffected controls, there was significantly higher 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentration, elevated ferritin, increased leukocyte count and higher small molecule antioxidant capacity. These data suggest increased baseline oxidative stress and an elevated antioxidant response in umbilical cord blood of patients with G6PD deficiency.

A Survey of Practice and Knowledge of Refugee and Migrant Pregnant Mothers Surrounding Neonatal Jaundice on the Thailand-Myanmar Border

BACKGROUND

In populations with a high prevalence of glucose-6-phosphate dehydrogenase deficiency, practices that can induce haemolysis need to be identified to raise awareness of preventable risks. The aim of this survey was to determine the proportion of prospective mothers using haemolytic agents and their knowledge and practice surrounding neonatal jaundice.

METHODS

Pregnant mothers were invited to participate in a cross-sectional survey conducted at Shoklo Malaria Research Unit on the Thailand-Myanmar border.

RESULTS

From 12 April 2015 to 12 June 2015, 522 pregnant women completed the survey. Mothball use in the household was reported by 41.4% (216 of 522) of prospective mothers and menthol containing products on baby skin by 46.7% (244 of 522).

CONCLUSION

Just over 40% of the households reported use of naphthalene-containing mothballs. Future health promotion activities that focus on reducing naphthalene mothball and menthol-containing products use have the potential to reduce rates of severe neonatal jaundice in this population.

Use of Transcutaneous Bilirubin to Determine the Need for Phototherapy in Resource-Limited Settings

BACKGROUND

Routine and timely determination of total serum bilirubin (TSB) remains a challenge in many resource-limited countries with substantial burden of severe neonatal hyperbilirubinemia. Limited evidence exists on the potential usefulness of transcutaneous bilirubin (TcB) to identify infants who may require phototherapy based on possible treatment criteria in such settings.

OBJECTIVE

To compare the number of infants requiring phototherapy across different TSB criteria and determine the predictive performance of TcB under each criterion.

METHODS

Infants with paired TcB and TSB measurements in a maternity hospital in Lagos, Nigeria, were assessed for phototherapy based on TSB criteria by the American Academy of Pediatrics (AAP), National Institute for Health and Clinical Excellence (NICE) UK, and World Health Organization (WHO), and an absolute threshold of ≥12 mg/dL. The predictive performance of TcB across treatment criteria was evaluated with receiver operating curve analysis.

RESULTS

A total of 1,011 infants with a mean TcB of 10.54 ± 3.19 (range: 2.7-19.9) mg/dL and TSB of 9.63 ± 2.61 (range: 0.3-19.5) mg/dL were assessed. Some 60 (5.9%) infants required phototherapy by 1 or more TSB criteria, with TSB ≥12 mg/dL identifying 55 (91.7%) and AAP 27 (45%) of these infants. All infants identified by the NICE and WHO criteria were equally detected by the AAP criterion. TcB showed negative predictive values of 99.0-99.9%, and positive predictive values of 7.7-15.5% across all criteria.

CONCLUSIONS

The number of infants requiring phototherapy varies significantly across treatment criteria. TcB may be useful in identifying infants who do not require phototherapy, but may also identify a high proportion of false positives that is burdensome in resource-limited settings.

National G6PD neonatal screening program in Gaza Strip of Palestine: rationale, challenges and recommendations

Congenital genetic disorders affecting neonates or young children can have serious clinical consequences if undiagnosed and left untreated. Early detection and an accurate diagnosis are, therefore, of major importance for preventing negative patient outcomes. Even though the occurrence of each specific metabolic disorder may be rare, their collective impact of preventable complications may be of considerable importance to the public health. Our previous studies showed that glucose-6-phosphate dehydrogenase (G6PD) deficiency is a problem of public health importance that has been shown to be a predominant cause of acute hemolytic anemia requiring hospitalization in Palestinian young children in Gaza Strip. Intriguingly, the majority of these children had one of the three variants, Mediterranean(c.) (563T) , African G6PD A-(c.) (202A) (/c.) (376G) and heretofore unrecognized as a common G6PD-deficient variant G6PD Cairo(c.) (404C) . The high prevalence of G6PD deficiency, as well as dietary factors in the region that precipitate anemia, argues for a need to protect the Palestinian children from a treatable and manageable genetic and metabolic disorder. This work reviews and discusses rationales and challenges of G6PD screening program in Gaza Strip. We advocate adopting a national neonatal G6PD screening program in Gaza Strip to identify children at risk and promote wellness and health for Palestine.