Increased incidence of sepsis and altered monocyte functions in severely injured type A- glucose-6-phosphate dehydrogenase-deficient African American trauma patients

OBJECTIVE: To determine whether trauma patients with the common, type A- glucose-6-phosphate dehydrogenase (G6PD) deficiency have an aggravated inflammatory response, increased incidence of septic complications, and/or more profound alterations in leukocyte functions compared with nondeficient trauma patients. SETTINGS: Intensive and surgical care units of a trauma center and flow cytometry and experimental laboratories at a teaching university hospital. DESIGN: Prospective cohort clinical study with measurements on days 2 and 5 postinjury. Monocyte and neutrophil oxidant content, apoptosis, and CD11b expression and plasma cytokine levels were compared between G6PD-deficient and nondeficient patients. PATIENTS: A total of 467 male African American trauma patients were screened for the deficiency. Forty-four type A-202/376 G6PD-deficient patients were identified and enrolled in the study; 43 nondeficient patients were also enrolled and were matched by age, clinical criteria of injury severity, and type of trauma. MAIN RESULTS: After severe injury (Injury Severity Score, > or =16), 50% of the deficient and 6.2% of nondeficient patients developed sepsis with positive bacterial blood cultures. In deficient patients, the frequency of bronchial (75%) and wound infections (25%) was also increased compared with nondeficient patients (32% and 0%). The durations of systemic inflammatory response syndrome, Sepsis Syndrome, and days on antibiotics were three times longer in deficient than in nondeficient individuals. However, adult respiratory distress syndrome occurred in 37% of both groups. Anemia was more severe in the deficient than nondeficient patients from day 10 posttrauma. On day 5, the peroxide content was doubled, apoptosis was decreased, and CD11b expression was increased in monocytes from deficient patients compared with cells from nondeficient patients. On day 5, the plasma interleukin (IL)-10 concentration was significantly lower in deficient than nondeficient patients, whereas tumor necrosis factor-alpha, IL-6, and IL-8 levels were similar. After moderate injuries (Injury Severity Score, 9-16), the deficiency was not associated with adverse clinical effects, and the trauma-induced changes in leukocyte function were similar in deficient and nondeficient patients. CONCLUSIONS: The common type A- G6PD deficiency predisposes septic complications and anemia in trauma patients after severe injuries as defined by an Injury Severity Score of > or =16. This adverse clinical course is accompanied by altered monocyte functions manifested as augmented oxidative stress, a decreased apoptotic response, increased cell adhesion properties, and a diminished IL-10 response.     

Attenuated monocyte IL-10 production in glucose-6-phosphate dehydrogenase-deficient trauma patients

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the world's most common known human genetic polymorphisms, but the pathophysiology of the defect remains largely unknown. In the present study, we compared hematology parameters and ex vivo monocyte cytokine responses in non-deficient and G6PD-deficient trauma patients. Deficient and non-deficient, moderately injured, trauma patients exhibited similar hematology profiles at the time of hospital admission. In contrast to non-deficient patients, G6PD-deficient patients were anemic 2 days post-injury. Monocytes from deficient individuals produced 50% less interleukin 10 (IL-10) in response to LPS and >90% less IL-10 in response to PMA, compared with non-deficient patients, 2 days post-injury. The presence of phenylhydrazine-treated, opsonized, autologous RBC (OX-RBC), alone had no effect on IL-10 production by non-deficient or deficient monocytes, whereas IL-10 responses to lipopolysaccharide (LPS) were augmented by OX-RBC in both groups. However, IL-10 production was markedly lower by monocytes from G6PD-deficient than non-deficient patients after stimulation with LPS plus OX-RBC. TNF-alpha production following PMA was similar in deficient and non-deficient patients, and the differences following LPS or LPS plus OX-RBC stimulation were moderate between deficient and non-deficient samples. Interferon (IFN)-gamma production ex vivo was doubled by OX-RBC treatment alone, but it was not stimulated by LPS treatment. IFN-gamma production was similar in non-deficient and G6PD-deficient patients. These data suggest that the observed differences in IL-10 responses between G6PD-deficient and non-deficient patients are not attributable to differences in TNF-alpha or IFN-gamma production. Taken together, our data suggest that a reduction in the capacity to produce IL-10 may be an intrinsic characteristic of G6PD-deficient monocytes. An attenuated IL-10 production may be a contributing mechanism in the previously observed augmented inflammatory response in severely injured G6PD-deficient compared with non-deficient trauma patients.     

Glucose-6-phosphate dehydrogenase activity in term and near-term, male African American neonates

BACKGROUND: We determined values for glucose-6-phosphate dehydrogenase (G-6-PD) activity in African American neonates. METHODS: G-6-PD activity was measured on umbilical cord blood from term and near-term healthy, male neonates. Neonates were stratified according to the number of neonates for each numerical unit of G-6-PD activity. Corrected end tidal carbon monoxide (ETCOc), a non-invasive index of hemolysis, was performed on each neonate. At least one predischarge transcutaneous bilirubin determination was performed. RESULTS: Five hundred neonates were studied. Two subpopulations were apparent, with no overlap between the subgroups. Mean value for the 64 (12.8%) infants with the lower values (G-6-PD deficient) was 2.7+/-1.1 U/g Hb, range 0.4-6.6 U/g Hb, while that for the 436 neonates with the higher values (G-6-PD normal) was 21.8+/-2.9 U/g Hb, range 14.5-33.8 U/g Hb. No significant differences in activity were noted between those neonates <37 weeks gestational age and those >37 weeks. Enzyme activity in the lower range in both groups was not related to the development of hyperbilirubinemia. G-6-PD enzyme activity did not correlate with ETCOc values either for the entire cohort or for the individual subsets. CONCLUSIONS: G-6-PD-deficient neonates formed a separate subgroup from those with normal enzyme activity. The data supplied should facilitate interpretation of G-6-PD test results.     

Screening of jaundiced neonates for glucose-6-phosphate dehydrogenase deficiency

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is transmitted as an X-linked recessive disorder, and thus female infants are expected to be only rarely affected. Review of the records of 1,478 jaundiced newborn infants (728 boys and 750 girls) screened for G6PD deficiency at the Foothills Provincial Hospital in Calgary showed 41 (5.6%) boys and 17 (2.2%) girls with this disorder. In view of the unexpected and unexplained high frequency of G6PD deficiency in female infants, I recommend that screening for this disorder be done in selected jaundiced infants regardless of sex.     

海口地区新生儿G6PD基因突变分析

目的 了解海口地区新生儿葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症的发生率及基因突变特点. 方法 用荧光斑点法对2016年1月1日至2016年2月24日出生于海口的5 295例新生儿进行G6PD活性筛查,对173例初筛阳性的标本用多色探针荧光PCR熔解曲线法(MMCA)进行基因分型.结果 本次筛查发现海口地区新生儿群体的G6PD缺乏症发生率为3.87％ (205/5 295),其中男女发生率分别为4.99％(142/2 848)和2.57％ (63/2 447).173例初筛阳性标本中检出142例(82.08％)有基因突变,基因携带率为3.18％(142/5 295/84.39％).共检出6种基因突变类型,含74例(52.11％) c.1376 G＞T,33例(23.24％)c.1388 G＞A,13例(9.15％)c.95 A＞G,8例(5.63％)c.1024 C＞T,4例(2.82％) c.871 G＞A,5例(3.52％) c.392 G＞T,并检出3例(2.11％)c.1376 G＞T复合c.1388 G＞A突变、1例(0.71％) c.392 G＞T复合c.517 T＞C突变、1例(0.71％)c.95 A＞G复合c.1388 G＞A突变. 结论 海口地区是G6PD缺乏症高发地区,c.1376G＞T、c.1388G＞A和c.95 A＞G是主要的3种基因突变型.     

Dominance of high-producing interleukin 6 and low-producing interleukin 10 and interferon gamma alleles in glucose-6-phosphate dehydrogenase-deficient trauma patients

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, a condition associated with malaria resistance, is a common genetic polymorphism. Decreased interleukin (IL)-10 production was demonstrated in vivo and in vitro in the African and Mediterranean forms of G6PD deficiencies. We hypothesized that low-producing IL-10 alleles are more abundant in the G6PD-deficient than nondeficient population. One hundred eleven men with African American ancestry were tested for G6PD deficiency (Type A-202/376) and for the cytokine gene promoter polymorphisms of IL-10 (-1082 G/A, -819 T/C, and -592 A/C), tumor necrosis factor (TNF)-alpha (-308 G/A), transforming growth factor (TGF)-beta1 (C/T codon 10 and C/G codon 25), IL-6 (-174 G/C), and interferon (IFN)-gamma (+874 A/T). There were no differences in the allele frequencies for TNF-alpha, IL-6, or TGF-beta1 between the G6PD-deficient and nondeficient population. In contrast, the low-producing IL-10 alleles (-592A) and low-producing IFN-gamma (+874A) allele frequencies were greater in G6PD-deficient than nondeficient samples (P = 0.035 and 0.009). Seventy-one percent of G6PD-deficient and 50% of nondeficient samples carried the high-producing IL-6(G) allele with low-producing IL-10(A) allele (P = 0.03). Furthermore, 95% of deficient and 81% of nondeficient samples carried the IL-6(G) allele together with low-producing IFN-gamma(A) allele (P = 0.017). These investigations indicate a predominant presence of high-producing IL-6 alleles together with low-producing IL-10 and IFN-gamma alleles in individuals with ancestry from malaria-endemic regions. The frequency of low-producing IL-10 genotypes is greater in the G6PD-deficient compared with nondeficient patients. The fact that these genetic differences are preserved in the current African American G6PD-deficient population indicates their potential role in pathophysiological processes in the absence of the selective pressure caused by tropical diseases.     

Increased resistance to oxidative stress in normal and glucose-6-phosphate dehydrogenase-deficient hemolysates in the presence of enzyme substrates

Erythrocytes and hemolysates from 10 normal and 10 glucose-6-phosphate dehydrogenase-deficient individuals were incubated with cumene hydroperoxide, and free radical-induced lipid peroxidation was monitored by chemiluminescence. Chemiluminescence intensities in erythrocytes of normal and deficient subjects were similar in the presence or absence of glucose-6-phosphate dehydrogenase substrates. Hemolysates of normal and deficient subjects also showed similar chemiluminescence in the absence of substrates. However, with the addition of substrates to the incubation medium, deficient hemolysates reached maximum chemiluminescence intensity within a shorter period, and maximum values were higher than in normal hemolysates. We believe this offers a new means of detection of glucose-6-phosphate dehydrogenase-deficient patients.     

Ribose metabolism and nucleic acid synthesis in normal and glucose-6-phosphate dehydrogenase-deficient human erythrocytes infected with Plasmodium falciparum.

The metabolism of pentose-phosphate was investigated in Plasmodium falciparum-infected normal and glucose-6-phosphate dehydrogenase (G6PD)-deficient human red blood cells in vitro. 5'-Phosphoribosyl-1-pyrophosphate (PRPP) content of infected normal red blood cells was increased 50-60-fold at the parasite trophozoite growth stage over that of uninfected cells. The PRPP increment in infected G6PD-deficient cells at comparable stage and parasitemia was only 40% of the value in normal infected cells. Red blood cell PRPP synthetase activity did not change during the growth cycle of the parasite and was similar in both normal and G6PD-deficient cells. Reduced glutathione (GSH) content of G6PD-deficient cells under conditions of culture fell to low or undetectable levels. These low levels of GSH were shown to inhibit the function of red blood cell PRPP synthetase, which requires GSH for full activity. Measurements of the incorporation of 1-14C or 6-14C selectively labeled glucose into parasite nucleic acids revealed that in normal infected red cells, approximately 20% of the pentose was produced via the oxidation of glucose-6-phosphate, whereas in infected G6PD-deficient cells (Mediterranean type), none of the pentose was produced via the oxidative pathway. It is concluded that the low level of reduced GSH found in G6PD deficiency and the resultant partial inhibition of PRPP synthetase together with the missing oxidative pathway for ribose phosphate production can account fully for the reduced parasite growth rate in G6PD-deficient red blood cells described previously. Of these two mechanisms, the predominant one is the impaired PRPP synthetase activity due to low GSH levels in enzyme-deficient red blood cells. The contribution to the ribose-phosphate pool by the hexose monophosphate shunt is relatively minor. A co-existing oxidative stress (which is often hypothesized to mediate the destruction of parasitized red blood cells) is not required to explain growth inhibition in this scheme and does not represent the most straight-forward explanation of the data described in this report.     

Prevalence of glucose-6-phosphate dehydrogenase deficiency among neonates at a tertiary care centre in Lebanon

In this study we aimed to determine the prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency in a Lebanese population and the clinical outcomes and associated adverse events encountered amongst affected patients. Newborn screening in a tertiary care centre in North Lebanon showed a prevalence of 2.1% (62 out of 3009), significantly higher in males than females, and in Muslims than Christians. Among 45 infants followed for a median of 2.2 years from birth, 12 (27%) were admitted to hospital for severe haemolytic crises, despite a programme of early family education and close follow-up. A nationwide newborn screening program to identify afflicted individuals, and to augment vigilance about this disease, should be considered in countries where the disorder is prevalent.     

An update on the prevalence of glucose-6-phosphate dehydrogenase deficiency and neonatal jaundice in Tehran neonates

OBJECTIVES: The aim of this study was to screen newborns in Tehran for glucose-6-phosphate dehydrogenase (G6PD) deficiency in relation to hyperbilirubinemia and jaundice. DESIGN AND METHODS: We performed quantitative and qualitative red blood cell (RBC) G6PD assays in cord blood of 2000 male and female at-term neonates. Observations for jaundice and bilirubin determination were made in G6PD-deficient and normal groups. Those with severe jaundice were treated with phototherapy or exchange transfusion. RESULTS: Our results showed that 2.1% (3.6% of males and 0.6% of females) was G6PD-deficient. Those with severe jaundice and hyperbilirubinemia (160 normal and 17 G6PD-deficient) were hospitalized and treated with phototherapy or exchange transfusion. Bilirubin levels in G6PD-deficient neonates were somewhat higher compared to G6PD-normal babies (18.8 +/- 2.4 mg/dl [321.5 +/- 41 micromol/l] vs. 15.7 +/- 3.2 mg/dl [268.5 +/- 54.7 micromol/l]; P < 0.05). G6PD activity was significantly lower in G6PD-deficient group than in the normal group (2.1 +/- 0.7 vs. 12.5 +/- 5.0 U/g Hb; P < 0.001). CONCLUSION: This study shows that the incidence of G6PD deficiency in newborns of Tehran is 2.1%, which is relatively high, and also hyperbilirubinemia and jaundice are approximately 3-fold higher in G6PD-deficient group than in the G6PD-normal group (51% vs. 16%). This emphasizes the necessity of neonatal screening on cord blood samples of both sexes for G6PD deficiency and the need to watch closely for development of hyperbilirubinemia.     

Microheterogeneity of glucose-6-phosphate dehydrogenase phenotypes

Glucose-6-phosphate dehydrogenase (G-6-PD) is the first enzyme of the pentose phosphate pathway and has been extensively investigated. Several variants of G-6-PD were encountered in different regions of Saudi Arabia during an extensive screening programme. A modified rapid isoelectric focussing procedure using LKB Ampholine PAG plates (pH 5.5-8.5) was used to separate the isoenzymes of G-6-PD. G-6-PD-B+ (the normal enzyme) was separated into five major and three minor fractions. The pattern obtained for G-6-PD-A+, G-6-PD-A-, G-6-PD-Mediterranean and G-6-PD-Mediterranean-like showed that the variants differ significantly in their isoenzyme pattern. In this paper it is shown that isoelectric focussing is a sensitive, powerful and reproducible technique to study microheterogeneity of red cell enzymes.