Prevalence and association of early onset severe hyperbilirubinemia in newborn in the East China region: Retrospective medical record analyses

Research on the prevalence and association of hyperbilirubinemia is controversial because of different cultures, demographics, and clinical conditions. The etiology of hyperbilirubinemia is affected by the environment and other factors in the newborn. The World Health Organization recommended a 1-day hospital stay after uncomplicated delivery, jaundice assessment before discharge, and screening on 3rd and 7th days after birth for hyperbilirubinemia. However, the implementation of these recommendations is difficult in China. The objective of this study was to evaluate the prevalence and association of early onset severe hyperbilirubinemia in newborns in East China. Retrospective medical record analyses for 250 cesarean sections or vaginal deliveries, ≥2 kg body weight, and negative for Hepatitis B surface antigen by birth newborns were performed. A biochemical analyzer, quantitative assay, and quantitative polymerase chain reaction were used to evaluate total serum bilirubin, glucose-6-phosphate dehydrogenase (G6PD) deficiency, and gene variant phenotyping, respectively. A total in 33 (13%) newborns were reported with early onset severe hyperbilirubinemia (according to the American Academy of Pediatrics, total serum bilirubin ≥ 342 μmol/L within 6 hours of birth). All newborns with severe hyperbilirubinemia were hospitalized and underwent phototherapy. The mothers of all newborns had a gestational age ≥ 35 weeks. Hospitalization included artificial feeding, and breastfeeding was rare (P < .0001). ABO incompatibility ("O" blood type for mother and either "A" or "AB" or "B" blood type for newborn, P = .0411), G6PD deficiency (G6PD/6-phosphogluconate dehydrogenase ≤ 1.0 in quantitative assay, P = .0422), Rh incompatibility (the mother's blood type was Rh negative and newborn blood type was Rh positive, P = .0416), fewer genotype rs4149056 frequencies (P = .0452), higher genotype rs2306283 frequencies (P = .0461), and higher genotype rs1805173 frequencies (P = .0471) were independent parameter for early onset severe hyperbilirubinemia of newborns. The prevalence of early onset severe hyperbilirubinemia in Chinese newborns is 13% in the East China region. Blood incompatibility, G6PD deficiency, fewer genotype rs4149056 frequencies, higher genotype rs2306283 frequencies, and higher genotype rs1805173 frequencies were independent predictors of early onset severe hyperbilirubinemia among newborns in the East China region (Level of Evidence: IV; Technical Efficacy: Stage 5).

Co-Occurring Hemolysis and Methemoglobinemia After COVID-19 Infection in Patient With G6PD Deficiency

Hemolytic anemia and methemoglobinemia are known complications in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. They can be elicited by various oxidative stressors. Here we report a case of an adult with the first episode of G6PD deficiency associated hemolysis and methemoglobinemia after acquiring COVID-19 infection, who had no recent exposure to oxidative drugs or fava beans. A 52-year-old gentleman known to have myocardial bridging on aspirin and beta-blocker, with no other medical illnesses, developed anemia symptoms, jaundice, and hypoxia after contracting COVID-19 infection. Further laboratory work revealed non-immune hemolytic anemia, methemoglobinemia, and a positive G6PD screen test. He was treated conservatively with a blood transfusion, and his oxygen saturation improved thereafter. With the widespread COVID-19 infection and its morbidity worldwide, it is crucial to consider methemoglobinemia in the differential diagnosis of hypoxia. Testing for G6PD is an essential next step in such cases, as starting methylene blue in G6PD deficiency can worsen hemolysis. Apart from COVID-19, there is no other identified trigger for the acute event in this patient. It is not known whether COVID-19 infection alone is enough to result in G6PD deficiency-associated hemolysis and methemoglobinemia simultaneously.

Update on pathogenesis, management, and control of Plasmodium vivax

PURPOSE OF REVIEW

This is a review of Plasmodium vivax epidemiology, pathogenesis, disease presentation, treatment and innovations in control and elimination. Here, we examine the recent literature and summarize new advances and ongoing challenges in the management of P. vivax .

RECENT FINDINGS

P. vivax has a complex life cycle in the human host which impacts disease severity and treatment regimens. There is increasing data for the presence of cryptic reservoirs in the spleen and bone marrow which may contribute to chronic vivax infections and possibly disease severity. Methods to map the geospatial epidemiology of P. vivax chloroquine resistance are advancing, and they will inform local treatment guidelines. P. vivax treatment requires an 8-aminoquinoline to eradicate the dormant liver stage. Evidence suggests that higher doses of 8-aminoquinolines may be needed for radical cure of tropical frequent-relapsing strains.

SUMMARY

P. vivax is a significant global health problem. There have been recent developments in understanding the complexity of P. vivax biology and optimization of antimalarial therapy. Studies toward the development of best practices for P. vivax control and elimination programs are ongoing.

New Diagnosis of G6PD Deficiency Presenting as Severe Rhabdomyolysis

A 24-year-old African-American man presented with malaise and low back pain and was found to have acute severe rhabdomyolysis followed by acute hemolysis. Glucose-6-phosphate dehydrogenase (G6PD) deficiency was suspected by the presence of blister cells on peripheral smear and was confirmed by a low enzyme activity assay. Our patient reported playing football, along with upper respiratory infection symptoms, prior to presentation. Extensive infectious and toxicology workup was negative; however, several inflammatory proteins were markedly elevated. We hypothesized the large inflammatory burden led to an increased reactive oxygen radical burden that overwhelmed muscle and erythrocyte reducing power. Severe rhabdomyolysis in G6PD deficiency is not a common presentation because skeletal muscles are more resistant to oxidative damage compared to red blood cells. Our case adds to the few existing reports of myolysis in the setting of G6PD deficiency.

Tafenoquine for travelers' malaria: evidence, rationale and recommendations

Background

Endemic malaria occurring across much of the globe threatens millions of exposed travelers. While unknown numbers of them suffer acute attacks while traveling, each year thousands return from travel and become stricken in the weeks and months following exposure. This represents perhaps the most serious, prevalent and complex problem faced by providers of travel medicine services. Since before World War II, travel medicine practice has relied on synthetic suppressive blood schizontocidal drugs to prevent malaria during exposure, and has applied primaquine for presumptive anti-relapse therapy (post-travel or post-diagnosis of Plasmodium vivax) since 1952. In 2018, the US Food and Drug Administration approved the uses of a new hepatic schizontocidal and hypnozoitocidal 8-aminoquinoline called tafenoquine for the respective prevention of all malarias and for the treatment of those that relapse (P. vivax and Plasmodium ovale).

Methods

The evidence and rationale for tafenoquine for the prevention and treatment of malaria was gathered by means of a standard search of the medical literature along with the package inserts for the tafenoquine products Arakoda™ and Krintafel™ for the prevention of all malarias and the treatment of relapsing malarias, respectively.

Results

The development of tafenoquine-an endeavor of 40 years-at last brings two powerful advantages to travel medicine practice against the malaria threat: (i) a weekly regimen of causal prophylaxis; and (ii) a single-dose radical cure for patients infected by vivax or ovale malarias.

Conclusions

Although broad clinical experience remains to be gathered, tafenoquine appears to promise more practical and effective prevention and treatment of malaria. Tafenoquine thus applied includes important biological and clinical complexities explained in this review, with particular regard to the problem of hemolytic toxicity in G6PD-deficient patients.

Prevalence and molecular characterization of G6PD deficiency in two Plasmodium vivax endemic areas in Venezuela: predominance of the African A-(202A/376G) variant

BACKGROUND

Glucose-6-phosphate dehydrogenase (G6PD) deficiency causes acute haemolytic anaemia triggered by oxidative drugs such as primaquine (PQ), used for Plasmodium vivax malaria radical cure. However, in many endemic areas of vivax malaria, patients are treated with PQ without any evaluation of their G6PD status.

METHODS

G6PD deficiency and its genetic heterogeneity were evaluated in northeastern and southeastern areas from Venezuela, Cajigal (Sucre state) and Sifontes (Bolívar state) municipalities, respectively. Blood samples from 664 randomly recruited unrelated individuals were screened for G6PD activity by a quantitative method. Mutation analysis for exons 4-8 of G6PD gen was performed on DNA isolated from G6PD-deficient (G6PDd) subjects through PCR-RFLP and direct DNA sequencing.

RESULTS

Quantitative biochemical characterization revealed that overall 24 (3.6%) subjects were G6PDd (average G6PD enzyme activity 4.5 ± 1.2 U/g Hb, moderately deficient, class III), while DNA analysis showed one or two mutated alleles in 19 of them (79.2%). The G6PD A-(202A/376G) variant was the only detected in 17 (70.8%) individuals, 13 of them hemizygous males and four heterozygous females. Two males carried only the 376A → G mutation. No other mutation was found in the analysed exons.

CONCLUSIONS

The G6PDd prevalence was as low as that one shown by nearby countries. This study contributes to the knowledge of the genetic background of Venezuelan population, especially of those living in malaria-endemic areas. Despite the high degree of genetic mixing described for Venezuelan population, a net predominance of the mild African G6PD A-(202A/376G) variant was observed among G6PDd subjects, suggesting a significant flow of G6PD genes from Africa to Americas, almost certainly introduced through African and/or Spanish immigrants during and after the colonization. The data suggest that 1:27 individuals of the studied population could be G6PDd and therefore at risk of haemolysis under precipitating factors. Information about PQ effect on G6PDd individuals carrying mild variant is limited, but since the regimen of 45 mg weekly dose for prevention of malaria relapse does not seem to be causing clinically significant haemolysis in people having the G6PD A-variant, a reasoned weighing of risk-benefit for its use in Venezuela should be done, when implementing public health strategies of control and elimination.

Point-of-care G6PD diagnostics for Plasmodium vivax malaria is a clinical and public health urgency

Malaria caused by Plasmodium vivax threatens over 2 billion people globally and sickens tens of millions annually. Recent clinical evidence discredits the long-held notion of this infection as intrinsically benign revealing an often threatening course associated with mortality. Most acute attacks by this species derive from latent forms in the human liver called hypnozoites. Radical cure for P. vivax malaria includes therapy aimed both at the acute attack (blood schizontocidal) and against future attacks (hypnozoitocidal). The only hypnozoitocide available is primaquine, a drug causing life-threatening acute hemolytic anemia in patients with the inherited blood disorder glucose-6-phosphate dehydrogenase (G6PD) deficiency. This disorder affects 400 million people worldwide, at an average prevalence of 8 % in malaria-endemic nations. In the absence of certain knowledge regarding the G6PD status of patients infected by P. vivax, providers must choose between the risk of harm caused by primaquine and that caused by the parasite by withholding therapy. Resolving this dilemma requires the availability of point-of-care G6PD diagnostics practical for use in the impoverished rural tropics where the vast majority of malaria patients seek care.

Submicroscopic carriage of Plasmodium falciparum and Plasmodium vivax in a low endemic area in Ethiopia where no parasitaemia was detected by microscopy or rapid diagnostic test

BACKGROUND

Motivated by the success in malaria control that was documented over the last decade Ethiopia is aiming at malaria elimination by 2020 in selected districts. It is currently unknown if asymptomatic, submicroscopic malaria parasite carriage may form a hurdle to achieve elimination. The elimination effort may further be complicated by possible glucose-6 phosphate dehydrogenase (G6PD) deficiency which would hinder the use of 8-aminoquinolines in the elimination efforts.

METHOD

In February 2014 a community-based cross-sectional survey was conducted in Malo, southwest Ethiopia. Finger-prick blood samples (n = 555) were tested for presence of Plasmodium falciparum and Plasmodium vivax with microscopy, rapid diagnostic test (RDT), and nested polymerase chain reaction (nPCR). Multiplicity of P. falciparum infections was determined based on genotyping the polymorphic merozoite surface protein-2 (MSP-2) gene. Individuals were also genotyped for mutations in the gene that produces G6PD.

RESULTS

All study participants were malaria infection negative by microscopy and RDT. Nested PCR revealed P. falciparum mono-infection in 5.2% (29/555), P. vivax mono-infection in 4.3% (24/555) and mixed infection in 0.2% (1/555) of individuals. All parasitemic individuals were afebrile (axillary temperature <37.5°C). None of the study participants carried mutations for the G6PD African A-(202GA) and Mediterranean (563CT) variants. All infections, except one, were single-clone infection by MSP-2 genotyping.

CONCLUSION

The detection of a substantial number of subpatent malaria infections in an apparently asymptomatic population without evidence for malaria transmission by conventional diagnostics raises questions about the path to malaria elimination. It is currently unknown how important these infections are for sustaining malaria transmission in the study sites. The absence of G6PD deficiency indicates that 8-aminoquinolines may be safely deployed to accelerate elimination initiatives.

Primaquine: the risks and the benefits

Primaquine is the only generally available anti-malarial that prevents relapse in vivax and ovale malaria, and the only potent gametocytocide in falciparum malaria. Primaquine becomes increasingly important as malaria-endemic countries move towards elimination, and although it is widely recommended, it is commonly not given to malaria patients because of haemolytic toxicity in subjects who are glucose-6-phosphate dehydrogenase (G6PD) deficient (gene frequency typically 3-30% in malaria endemic areas; >180 different genetic variants). In six decades of primaquine use in approximately 200 million people, 14 deaths have been reported. Confining the estimate to reports with known denominators gives an estimated mortality of one in 621,428 (upper 95% CI: one in 407,807). All but one death followed multiple dosing to prevent vivax malaria relapse. Review of dose-response relationships and clinical trials of primaquine in G6PD deficiency suggests that the currently recommended WHO single low dose (0.25 mg base/kg) to block falciparum malaria transmission confers a very low risk of haemolytic toxicity.

G6PD deficiency in Latin America: systematic review on prevalence and variants

Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts. The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region. A systematic search of the published literature was undertaken in August 2013. Bibliographies of manuscripts were also searched and additional references were identified. Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd. The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed. G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations. Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available.

PCR-based allelic discrimination for glucose-6-phosphate dehydrogenase (G6PD) deficiency in Ugandan umbilical cord blood

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common X-linked disorder in the world. G6PD deficiency puts children at risk for hyperbilirubinemia and kernicterus during the newborn period and an increased risk of severe hemolysis after exposure to many antimalarial medications. A laboratory diagnosis of G6PD deficiency is rare in the developing world due to limited resources. We developed a TaqMan-based allele-specific assay to rapidly determine rates of G6PD deficiency contributing alleles (G202A and A376G) in East Africa. We tested umbilical cord blood from 100 Ugandan newborns and found that the overall allele frequency of G202A was .13 and A376G was .32. The overall incidence of G6PD A- (G202A/A376G) was 6%; all A- variants were males. There was no correlation between G6PD deficiency and umbilical cord blood hemoglobin, white blood count, platelet count, or other hematologic parameters. Allele-specific PCR can serve as a rapid method to determine specific G6PD deficiency allele frequencies in a given population and as a diagnostic tool in a hospital setting in which laboratory resources are present.

Reinventing primaquine for endemic malaria

After sixty years of continuous use, primaquine remains the only therapy licensed for arresting transmission and relapse of malaria. The US Army developed primaquine for soldiers in a wartime crisis setting. Dosing strategies suited to that narrow population were adopted without modification or validation for the broader population of humans exposed to risk of malaria. The poor suitability of these strategies in populations exhibiting greater vulnerability to hemolytic toxicity among glucose-6-phosphate dehydrogenase deficient patients has not been addressed. Primaquine requires chemotherapeutic reinvention delivering less threatening doses by leveraging unexplored co-drug synergies.

Elimination therapy for the endemic malarias

Most malaria diagnosed outside endemic zones occurs in patients experiencing the consequences of what was likely a single infectious bite by an anopheline mosquito. A single species of parasite is nearly always involved and expert opinion on malaria chemotherapy uniformly prescribes species- and stage-specific treatments. However the vast majority of people experiencing malaria, those resident in endemic zones, do so repeatedly and very often with the involvement of two or more species and stages of parasite. Silent forms of these infections-asymptomatic and beyond the reach of diagnostics-may accumulate to form substantial and unchallenged reservoirs of infection. In such settings treating only the species and stage of malaria revealed by diagnosis and not others may not be sensible or appropriate. Developing therapeutic strategies that address all species and stages independently of diagnostic evidence may substantially improve the effectiveness of the control and elimination of endemic malaria.

Cooperating G6PD mutations associated with severe neonatal hyperbilirubinemia and cholestasis

We report a novel glucose-6-phosphate dehydrogenase (G6PD) mutation, which we propose to name G6PD Cincinnati (c.1037A > T, p.N346I), found in combination with G6PD Gastonia (c.637G > T, p.V213L) in an infant who presented with neonatal cholestasis. The G6PD Cincinnati mutation results in a non-conservative amino acid substitution at the tetramer interface disturbing its formation, as seen by native gel electrophoresis and immunoblotting. G6PD Gastonia disrupts dimerization of the enzyme and by itself causes chronic non-spherocytic hemolytic anemia. The G6PD Cincinnati mutation may have aggravated the clinical picture of G6PD Gastonia with the result of severe perinatal hemolysis causing cholestasis and associated liver injury.

A novel G6PD mutation leading to chronic hemolytic anemia

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an important cause of hemolytic anemia worldwide. Severely affected patients have chronic hemolysis with exacerbations following oxidative stress. Mutations causing severe chronic non-spherocytic hemolytic anemia (CNSHA) commonly cluster in Exon 10, a region important for protein dimerization. An African-American male presented at age 2 weeks with pallor and jaundice, and was found to have hemolytic anemia with G6PD deficiency. His severe clinical course was inconsistent with the expected G6PD A(-) variant. DNA sequencing revealed two common mutations (A(-)) and a third novel Exon 10 mutation. This inherited haplotype represents a novel triple G6PD coding mutation causing chronic hemolysis.

What is the role of the second "structural" NADP+-binding site in human glucose 6-phosphate dehydrogenase?

Human glucose 6-phosphate dehydrogenase, purified after overexpression in E. coli, was shown to contain one molecule/subunit of acid-extractable "structural" NADP+ and no NADPH. This tightly bound NADP+ was reduced by G6P, presumably following migration to the catalytic site. Gel-filtration yielded apoenzyme, devoid of bound NADP+ but, surprisingly, still fully active. Mr of the main component of "stripped" enzyme by gel filtration was approximately 100,000, suggesting a dimeric apoenzyme (subunit Mr = 59,000). Holoenzyme also contained tetramer molecules and, at high protein concentration, a dynamic equilibrium gave an apparent intermediate Mr of 150 kDa. Fluorescence titration of the stripped enzyme gave the K d for structural NADP+ as 37 nM, 200-fold lower than for "catalytic" NADP+. Structural NADP+ quenches 91% of protein fluorescence. At 37 degrees C, stripped enzyme, much less stable than holoenzyme, inactivated irreversibly within 2 d. Inactivation at 4 degrees C was partially reversed at room temperature, especially with added NADP+. Apoenzyme was immediately active, without any visible lag, in rapid-reaction studies. Human G6PD thus forms active dimer without structural NADP+. Apparently, the true role of the second, tightly bound NADP+ is to secure long-term stability. This fits the clinical pattern, G6PD deficiency affecting the long-lived non-nucleate erythrocyte. The Kd values for two class I mutants, G488S and G488V, were 273 nM and 480 nM, respectively (seven- and 13-fold elevated), matching the structural prediction of weakened structural NADP+ binding, which would explain decreased stability and consequent disease. Preparation of native apoenzyme and measurement of Kd constant for structural NADP+ will now allow quantitative assessment of this defect in clinical G6PD mutations.

Glucose-6-phosphate dehydrogenase deficiency does not result from mutations in the promoter region of the G6PD gene

In this study, we investigated whether glucose-6-phosphate dehydrogenase (G6PD) promoter mutations are responsible for G6PD deficiency. We analysed the G6PD proximal promoter and the 5' untranslated region (UTR) in 65 G6PD-deficient individuals, in which no mutations have been found in the G6PD gene coding sequences, using a nonradioactive polymerase chain reaction/single-strand conformation polymorphism (PCR/SSCP) analysis. We identified no sequence variations in the G6PD core promoter or in the 5' UTR of these G6PD-deficient individuals, which indicates that G6PD deficiency is not associated with promoter mutations in the G6PD locus.