Poor correlation between hemolysis and jaundice in glucose 6-phosphate dehydrogenase-deficient babies

BACKGROUND: The role of hemolysis in the pathophysiology of neonatal jaundice (NNJ) in patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency has been questioned recently. The aim of the present study was to determine the contribution of hemolysis to the pathophysiology of jaundice in Malay neonates with G6PD deficiency and NNJ. METHODS: Four groups of babies were included in the study: (i) G6PD deficient with NNJ; (ii) G6PD deficient without NNJ; (iii) G6PD normal with NNJ; and (iv) normal controls. Babies with other known causes of jaundice were excluded from the study. All subjects underwent the following investigations on day 3-5 after birth: hemoglobin level (Hb), serum bilirubin level, carboxyhemoglobin (CO-Hb) concentration, reticulocyte count and full blood picture. The results of the investigations were compared between the groups using SPSS version 11. RESULTS: Babies with G6PD and jaundice had a similar percentage of CO-Hb to babies with G6PD without NNJ or babies with normal G6PD and NNJ (1.76 +/- 0.40% vs 1.66 +/- 0.31% and 1.67 +/- 0.28%, respectively; P: 0.23 and 0.41, respectively). Total Hb levels and reticulocyte counts were not significantly different between the groups. The blood film showed more (even though not reaching significance) hemolysis in the G6PD patients but results of the blood film were very similar for G6PD patients with and those without NNJ. CONCLUSION: Hemolysis is not a main determinant of neonatal jaundice in G6PD-deficient babies.     

Relationship between Exposure to Icterogenic Agents, Glucose-6-Phosphate Dehydrogenase Deficiency and Neonatal Jaundice in Nigeria

ABSTRACT. In a study of the relationship between exposure to icterogenic agents, G-6-PD deficiency and severe neonatal jaundice (NNJ) (serum bilirubin 3±205 umol/I) in 234 Nigerian term male neonates, 106 infants with severe NNJ and 128 controls, it was found that 62.3 % of the jaundiced infants and 13.3 % of the infants without NNJ were G6PD deficient (p<0.01). The proportion of infants exposed to icterogenic agents in the two groups was very similar (p<0.5). There was a strong association between exposure to icterogenic agents and NNJ in 83 G6PD deficient infants (p<0.01), but there was no association between exposure to icterogenic agents and NNJ in the whole group of 234 infants or in 151 infants with normal G6PD status. It is concluded that there is an association between genetically determined G-6-PD deficiency and exogenous agents in causing severe NNJ in Nigerian infants.     

Relationship between exposure to icterogenic agents, glucose-6-phosphate dehydrogenase deficiency and neonatal jaundice in Nigeria

In a study of the relationship between exposure to icterogenic agents, G-6-PD deficiency and severe neonatal jaundice (NNJ) (serum bilirubin greater than or equal to 205 mumol/l) in 234 Nigerian term male neonates, 106 infants with severe NNJ and 128 controls, it was found that 62.3% of the jaundiced infants and 13.3% of the infants without NNJ were G6PD deficient (p less than 0.01). The proportion of infants exposed to icterogenic agents in the two groups was very similar (p greater than or equal to 0.5). There was a strong association between exposure to icterogenic agents and NNJ in 83 G6PD deficient infants (p less than 0.01), but there was no association between exposure to icterogenic agents and NNJ in the whole group of 234 infants or in 151 infants with normal G6PD status. It is concluded that there is an association between genetically determined G-6-PD deficiency and exogenous agents in causing severe NNJ in Nigerian infants.     

G6PD deficiency in neonates: A prospective study

One thousand consecutively born babies were screened for G6PD deficiency and observed for seven days for development of jaundice. Frequency of the deficiency was 3.9%, being 5% in males and 2.8% in females. Religion did not have any bearing on the frequency. Parental screening in cases of babies deficient in G6PD enzyme revealed deficiency of the enzyme in majority of the mothers. Hyperbilirubinemia developed in 48.7% of babies having G6PD deficiency : It is recommended that any neonate presenting with jaundice must be screened for G6PD deficiency not only to define the etiology of hyperbilirubinemia but also to prevent future hemolytic episodes.     

Efficacy of phototherapy in neonatal hyperbilirubinaemia associated with glucose-6-phosphate dehydrogenase deficient status

The efficacy of phototherapy in a group of 427 infants with hyperbilirubinaemia associated with glucose-6-phosphate dehydrogenase (G6PD) deficiency and a comparable group of 3924 G6PD normal infants with non-haemolhtic hyperbilirubinaemia was evaluated. Phototherapy was highly effective in reducing bilirubin levels in both groups of infants, being significantly more effective in the group with normal G6PD status. Failure rate was very low (2.03/1000) in the group with normal G6PD status and nil in the G6PD deficient group. Bilirubin rebound after phototherapy was unremarkable with very few infants requiring a second exposure —4.68/1000 in the G6PD deficient group and 6.37/1000 in the G6PD normal group. All the babies tolerated phototherapy well. Phototherapy would therefore seem to be a simple and effective method for the management of severe jaundice associated with G6PD deficiency.     

Why does the Iranian National Program of Screening Newborns for G6PD Enzyme Deficiency Miss a Large Number of Affected Infants?

Purpose: G6PD enzyme deficiency is one of the most prevalent genetic disorders worldwide and it has high incidence rate in Northern provinces of Iran. It was observed that national neonatal screening for G6PD enzyme deficiency fails to detect all affected infants. In order to clarify the cause, this study has been done in Thalassemia Research Center, Sari, Iran. Materials and Methods: This was a diagnostic study. The newborns with parents of Mazandarani origin were enrolled. Cord blood from the placental side was collected and used for decolorization test, quantitative enzyme assay (QEA) and DNA study. A heel-prick sample collected on day 3–5 after birth was used for fluorescent spot test (FST). In male cases, QEA was considered as the gold standard. For females, DNA study was considered as the gold standard. Based on QEA test results, neonates with <20% and 20–60% of mean normal enzyme activity were considered as total deficient and partial deficient, respectively. Results: A total of 365 neonates (52.3% females and 47.7% males) were studied. According to FST, 13 male newborns had G6PD deficiency. No deficient female was detected. Decolorization test diagnosed 18 male and one female as G6PD deficient newborns. QEA diagnosed 19 males and 28 females with G6PD enzyme deficiency (26 partial, 2 total deficient cases). DNA analysis detected 14 males as hemizygote and 34 females as heterozygote. Conclusion: FST does not have the required sensitivity for newborn screening and QEA is recommended as the preferred method.     

G6PD deficiency in newborn infants

Five hundred consecutive newborns were screened for erythrocytic G6PD deficiency in cord blood. The overall incidence of G6PD deficiency was found to be 2.80 percent. The incidence of G6PD deficiency was higher among males (3.77%) compared to females (1.44%). The incidence of erythrocytic G6PD deficiency was higher in Muslims (16.67%) compared to Hindus (2.63%). No definite relationship of erythrocytic G6PD deficiency was observed with consanguinity. Fifty per cent mothers of G6PD deficient newborns were also found to be G6PD deficient. Among brothers and sisters of G6PD deficient children the incidence of G6PD deficiency was 50.00 and 9.10 per cent respectively. There was no significant difference in the incidence of hyperbilirubinemia between erythrocytic G6PD deficient and non deficient newborns.     

Glucose-6-phosphate dehydrogenase deficiency: another risk factor for necrotizing enterocolitis?

We recently observed several babies in our neonatal intensive care unit (NICU) with necrotizing enterocolitis (NEC) who were subsequently found to have glucose-6-phosphate dehydrogenase (G6PD) deficiency. The aim of this study was to explore the association of NEC and G6PD deficiency. G6PD deficiency was significantly higher (27.8%) in infants with NEC compared with the 5.3% prevalence among NICU admissions (odds ratio = 6.9; 95% confidence interval = 2 to 23.5). G6PD deficiency also was found to be a marker for more severe NEC. G6PD deficiency should be considered a risk factor for NEC.     

Incidence and causes of sepsis in glucose-6-phosphate dehydrogenase-deficient newborn infants

To determine the susceptibility to sepsis in newborn infants deficient in glucose-6-phosphate dehydrogenase (G6PD), we screened 33,943 Saudi Arab infants. Deficiency of G6PD was found in 18%. Sepsis was determined by the presence of clinical signs of sepsis and confirmed by positive blood cultures. Sepsis was documented in 75 infants (2.2/1000). The incidence of sepsis was significantly higher in 6138 G6PD-deficient infants (3.4/1000) than in the 27,805 with normal G6PD activity (1.9/1000; p less than 0.02). The incidence of catalase-positive organism sepsis was higher in G6PD-deficient infants (2.9/1000) compared with those with normal G6PD activity (1/1000; p less than 0.0002), whereas the incidence of catalase-negative organism sepsis did not differ (p less than 0.2). Deficiency of G6PD was more common in infants with late sepsis (46%) than in those with early sepsis (21%) and in all infants screened (18%) (p less than 0.03 and p less than 0.001, respectively). We conclude that neonates with G6PD deficiency are more susceptible to late sepsis and to infection with catalase-positive organisms. The exact mechanism for the increased susceptibility is not clear, but a partial explanation could be lack of leukocyte bactericidal activity associated with G6PD deficiency, and an increased susceptibility to infection caused by hyperferremia resulting from lysis of G6PD-deficient erythrocytes.     

Why we are still doing so many exchange blood transfusion for neonatal jaundice in Nigeria

Background  Since exchange blood transfusion (EBT) is associated with serious complications, phototherapy has been made more powerful to reduce the need for EBT in the developed world. This study was undertaken to determine the indications for EBT in neonatal jaundice (NNJ) at our unit and what proportion of EBTs was possibly avoidable. Methods  All the babies who had EBT for hyperbilirubinemia over a three-year period were included. Age, sex, weight, place of delivery, blood group of baby and mother, other investigations, management, and the outcome of the babies were recorded. Results  Of the 1686 babies admitted to the neonatal unit, 90 (5.3%) had EBT. Fourteen (15.6%) were inborn while 76 (84.4%) were out-born babies. Fifty-six (62.2%) babies were admitted primarily for NNJ while 34 (37.8%) developed NNJ during admission. Thirty-six (40.0%) of the babies had phototherapy for more than 24 hours prior to EBT either because they were of very low birthweight or NNJ was detected very early and therapy was so commenced. Sixty-eight (75.6%) babies had single EBT while the remaining 22 (24.4%) had two sessions of EBT. Factors associated with severe NNJ in babies requiring EBT included low birthweight (<2500 g, 44.4%), ABO incompatibility (30.0%), glucose-6-phosphate dehydrogenase deficiency (34.4%) and septicemia (26.1%). Twenty-seven (30.0%) of the neonates developed features of kernicterus: 26 before admission while 1 during admission; all except one were delivered outside the hospital. Conclusions  The EBT rate in our center was high. With more effective phototherapy, EBT could be avoided in most of the babies who initially had phototherapy for more than 24 hours before EBT and repeated EBT sessions. Health education of the population at risk, especially pregnant women, and early referral at the primary health care level will reduce the burden of severe NNJ.     

广西地区葡萄糖-6-磷酸脱氢酶缺乏症与病毒性肝炎的关系

目的了解病毒性肝炎并葡萄糖-6磷-酸脱氢酶(G6PD)缺乏症患儿的基因突变类型,探讨G6PD缺乏基因突变与病毒性肝炎的关系。方法采用自然或错配引物介导的聚合酶链反应(PCR)限/制性内切酶分析,对病毒性肝炎并G6PD缺乏症18例患儿进行G6PD基因3种常见突变类型的分析,并对其临床表现进行分析。结果18例检测出8例G1388A突变,4例G1376T突变,1例A95G突变,突变率为72.22%,与单纯的G6PD缺乏症的基因突变型比较无显著差异。肝炎并G6PD缺乏症患儿急性溶血及急性肾衰竭的发生较单纯肝炎明显增加。结论肝炎患儿G6PD缺乏可能是原发性改变,而肝炎并G6PD缺乏症患儿较单纯肝炎病情重、并发症多。     

Neonatal Hyperbilirubinemia in infants with G6PD c.563C > T Variant

ABSTRACT: BACKGROUND: There is a strong correlation between glucose-6-phosphate dehydrogenase (G6PD) deficiency and neonatal hyperbilirubinemia with a rare but potential threat of devastating acute bilirubin encephalopathy. G6PD deficiency was observed in 4-14% of hospitalized icteric neonates in Pakistan. G6PD c.563C > T is the most frequently reported variant in this population. The present study was aimed at evaluating the time to onset of hyperbilirubinemia and the postnatal bilirubin trajectory in infants having G6PD c.563C > T. METHODS: This was a case-control study conducted at The Aga Khan University, Pakistan during the year 2008. We studied 216 icteric male neonates who were re-admitted for phototherapy during the study period. No selection was exercised. Medical records showed that 32 were G6PD deficient while 184 were G6PD normal. Each infant was studied for birth weight, gestational age, age at the time of presentation, presence of cephalhematoma, sepsis and neurological signs, peak bilirubin level, age at peak bilirubin level, days of hospitalization, whether phototherapy or exchange blood transfusion was initiated, and the outcome. During hospital stay, each baby was tested for complete blood count, reticulocyte count, ABO and Rh blood type, direct antiglobulin test and quantitative G6PD estimation [by kinetic determination of G6PDH]. G6PDgenotype was analyzed in 32 deficient infants through PCRRFLP analysis and gene sequencing. RESULTS: G6PD variants c.563C > T and c.131 C > G were observed in 21 (65%) and three (9%) of the 32 G6PD deficient infants, respectively. DNA of eight (25%) newborns remained uncharacterized. In contrast to G6PD normal neonates, infants with c.563C > T variant had significantly lower enzyme activity (mean +/- 1SD; 0.3 +/- 0.2 U/gHb vs. 14.0 +/- 4.5 U/gHb, p < 0.001) experienced higher peak levels of total serum bilirubin (mean +/- 1SD; 16.8 +/- 5.4 mg/dl vs. 13.8 +/- 4.6 mg/dl, p = 0.008) which peaked earlier after birth (mean +/- 1SD 2.9 +/- 1.6 vs. 4.3 +/- 2.3 days, p = 0.007). No statistically significant difference was observed in mean weight, age at presentation, hemoglobin, reticulocyte count, TSH level, hospital stay or in the frequency of initiation of phototherapy or blood exchange between the two groups. CONCLUSIONS: We concluded that infants with G6PD c.563C > T variant developed jaundice earlier than infants with normal G6PD enzyme levels. Compared to G6PD normal infants, G6PD c.563C > T carrying infants had significantly low G6PD activity.     

Neonatal jaundice and glucose-6-phosphate dehydrogenase deficiency in Basrah

In a study on a group of 186 newborn babies presenting with jaundice, erythrocyte glucose-6-phosphate dehydrogenase (G6PD) deficiency was detected in 95 (51%) of the patients. The incidence of severe hyperbilirubinaemia appeared to be much greater in G6PD-deficient infants (46%) than in infants who did not have the red cell defect (15%). No change was found in this association when ABO incompatibility was excluded. Phototherapy did not reduce the need for exchange transfusion, which was necessary in 27 babies. Eight babies developed kernicterus and one died. Early detection of G6PD deficiency and close surveillance of the affected newborns may be important in reducing the risk of severe neonatal jaundice and kernicterus associated with G6PD deficiency in Basrah.     

Glucose-6-phosphate dehydrogenase deficiency in neonates

Objective: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited deficiency that may be the cause of neonatal hyperbilirubinemia, as has been found in several countries and among widely different ethnic groups, especially in Mediterranean region. Our aim was to study the prevalence of G6PD deficiency in relation to neonatal jaundice.Methods : From March 1998 to April 2001 we studied 705 clinically icteric neonates who were admitted to Al-Zahra and Beheshti hospitals, two teaching hospitals in Isfahan, Iran. Laboratory investigations included determination of direct and indirect serum bilirubin concentrations, blood group typing, direct coomb’s test, hemoglobin, blood smear, reticulocyte count and G6PD level.Results: In only 53(7.5%) of cases G6PD deficiency was diagnosed. In all G6PD deficient neonates no evidence of other factors known to cause hyperbilirubinemia were detected. The sex distribution was 13(24.5%)females and 40(75.5%)males in the G6PD deficient group. The mean bilirubin level in G6PD deficient and G6PD normal groups were 22.26 +/-8.36 and 18.14 +/-3.85 mg/dl, respectively (p=0.001). Phototherapy was required in G6PD deficient and other icteric neonates with duration of 3.76 +/-1.93 and 3.13 +/-2.14 days, respectively (p=0.045). Twenty-seven of the 53(50.9%) G6PD deficient infants required exchange transfusion. None of them developed kernicterus.Conclusions: Since the prevalence of severe hyperbilirubinemia among our neonates was relatively high and about half of them required exchange transfusion, early detection of this enzymopathy regardless of sex and close surveillance of the affected newborns may be important in reducing the risk of severe hyperbilirubinemia and exchange transfusion.     

Increased incidence of hyperbilirubinaemia in 'unchallenged' glucose-6-phosphate dehydrogenase deficiency in term Saudi newborns.

The incidence of severe hyperbilirubinaemia was significantly higher among the G6PD-deficient Saudi infants born at term than in non-deficient babies (34% vs 9%) (p less than 0.005). No apparent offending factors were detected in either the babies or their mothers. All babies who developed hyperbilirubinaemia did so during the 1st week of life. The highest mean bilirubin level for all jaundiced G6PD-deficient babies was recorded on the 4th postnatal day. Although the incidence of severe hyperbilirubinaemia among our neonates was relatively high, only two of them (7%), a boy and a girl, required exchange transfusions. Five of 29 jaundiced babies with G6PD deficiency were readmitted after discharge because of significant jaundice. One required exchange transfusion. Since G6PD deficiency seems to be a relatively common cause of neonatal jaundice in Saudi newborns, early detection of this enzymopathy by cord blood screening is justified to avoid morbidity and deaths.     

Glucose-6-phosphate dehydrogenase activity in male premature and term neonates

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) activity is higher in term neonates than in adults. Some studies have suggested that activity may be even higher in preterm infants. OBJECTIVES: To determine if G6PD activity is higher in preterm than term neonates, and whether higher activity would interfere with diagnosis of G6PD deficiency in premature infants. METHODS: G6PD activity was determined in the first 48 hours after delivery in male premature, term, and near term infants. G6PD deficient neonates were separated, and the remaining premature infants compared with healthy, male, G6PD normal, near term and term neonates. RESULTS: Ninety four premature infants (mean (SD) gestational age 31.9 (3.8) weeks (range 23-36)) were studied. In four, G6PD activity was 0.8-1.8 U/g haemoglobin (Hb), which is clearly in the deficient range with no overlap into the normal range. G6PD activity in the remaining premature infants was significantly higher than in 24 near term and term neonates (gestational age > or = 37 weeks) (14.2 (4.6) v 12.0 (3.8) U/g Hb). Further analysis showed that significance was limited to those born between 29 and 32 weeks gestation, in which group G6PD activity was significantly higher than in those born before 29 weeks gestation, at 33-36 weeks gestation, and > or = 37 weeks gestation. CONCLUSIONS: G6PD activity is higher in premature infants born between 29 and 32 weeks gestation than in term neonates. This did not interfere with diagnosis of G6PD deficiency.     

葡萄糖-6-磷酸脱氢酶缺乏症研究现状

葡萄糖-6-磷酸脱氢酶（ glucose-6-phosphate dehydrogenase,G6PD）是磷酸戊糖途径的主要调节酶,对维持细胞内能量代谢和氧化还原反应的平衡起着重要作用。 G6PD缺乏症是最常见的遗传性红细胞酶缺陷病。目前尚无有效治疗方法,防治重点是尽早明确诊断,避免接触易导致发病的敏感性因素。目前应用于临床诊断的方法主要是G6PD酶活性的检测,该方法对女性杂合子检出率低。国内外研究表明, G6PD杂合子是新生儿高胆红素血症的危险因素。临床迫切需要可以同时检出G6PD缺乏症不同基因型的诊断方法。该文就G6PD缺乏症的研究现状作一综述。     

成都市54025例早产儿葡萄糖-6-磷酸脱氢酶缺乏症筛查结果及分子遗传学特征分析

目的 分析成都市早产儿葡萄糖-6-磷酸脱氢酶(glucose-6-phosphate dehydrogenase,G6PD)缺乏症筛查结果及基因突变分布情况,探讨早产儿人群G6PD筛查流程改进方案.方法 采用干血斑G6PD荧光分析法,对成都市2015年1月1日至2019年12月31日出生的54025例早产儿足跟血样本进...     

Hyperbilirubinemia in healthy neonates with glucose-6-phosphate dehydrogenase deficiency

A cohort study was carried out to assess the association between glucose-6-phosphate dehydrogenase (G6PD) deficiency, diagnosed by quantitative enzyme assay, and neonatal hyperbilirubinemia, defined as serum total bilirubin >/=15 mg/dl, in the well-baby nursery of Chang Gung Children's Hospital. Among 42,110 inborn infants, 757 male (3.54%) and 326 female (1.57%) newborns were G6PD-deficient. Compared to the occurrence of hyperbilirubinemia in G6PD-normal newborns (1.41% in male, 1.44% in female) in the well-baby nursery, a significantly higher incidence was observed in both G6PD-deficient male (11.36%) and female (7.06%) newborns. Further analyses demonstrated that the enzyme activity of G6PD in G6PD-deficient male newborns with hyperbilirubinemia (1.56+/-1.37 U/g Hb) were significantly lower than the subjects without hyperbilirubinemia (2.01+/-1.7 U/g Hb). No significant difference was observed in G6PD-deficient female newborns with hyperbilirubinemia (6.91+/-2.76 U/g Hb) compared to those without hyperbilirubinemia (7.81+/-2.84 U/g Hb). These data suggest that the G6PD-deficient neonates are at increased risk for hyperbilirubinemia even in the nursery free from agents that can potentially cause hemolysis to G6PD-deficient red cells. The lower G6PD enzyme activity was associated with the neonatal hyperbilirubinemia in G6PD-deficient male neonates.     

Leukocyte function and characterization of leukocyte glucose-6-phosphate dehydrogenase in Sicilian mutants.

Nine Sicilian children known to be deficient in glucose-6-phosphate dehyrdrogenase (G6PD) were studied to see if there were anomalies of bactericidal activity in peripheral blood phagocytes. The type of deficiency was established. The G6PD levels in the leukocyte were found to be 26% of the controls (0.094 +/- 0.03, normal controls 0.360 +/- 0.12). The Michaelis constant for NADP and glucose-6-phosphate (G6P) was lower than the control. Conversely, the utilization of the analogous 2-deoxyglucose-6-phosphate (2dG6P) and galactose-6-phosphate (Ga16P) was higher. The thermostability of the enzyme in the deficient subjects was lower and the pH optima (8 and 9.5) were different from the controls. An identical electrophoretic pattern was found in both normal and deficient subjects. The bactericidal activity in the deficient subjects was normal. There was no difference in the results of nitroblue tetrazolium (NBT) tests in either group.