Annotation

Adverse Clinical Effects Associated With Non-catecholamine Pharmacologic Agents for Treatment of Vasoplegic Syndrome in Adult Cardiac Surgery

Vasoplegic syndrome is a relatively common complication that can happen during and after major adult cardiac surgery. It is associated with a higher rate of complications, including postoperative renal failure, longer duration of mechanical ventilation, and intensive care unit stay, as well as increased mortality. The underlying pathophysiology of vasoplegic syndrome is that of profound vascular hyporesponsiveness, and involves a complex interplay among inflammatory cytokines, cellular surface receptors, and nitric oxide (NO) production. The pharmacotherapy approaches for the treatment of vasoplegia include medications that increase vascular smooth muscle contraction via increasing cytosolic calcium in myocytes, reduce the vascular effects of NO and inflammation, and increase the biosynthesis of and vascular response to norepinephrine. Clinical trials have demonstrated the clinical efficacy of non-catecholamine pharmacologic agents in the treatment of vasoplegic syndrome. With an increase in their use today, it is important for clinicians to understand the adverse clinical outcomes and patient risk profiles associated with these agents, which will allow better-tailored medical therapy.

Epidemiology of Glucose-6-Phosphate Dehydrogenase Deficiency in Arab Countries: Insights from a Systematic Review

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common metabolic disorder affecting more than 400 million individuals worldwide. Being an X-linked disorder, the disease is more common among males than females. Various Arab countries estimated the prevalence of G6PD deficiency; however, findings from different countries have not been synthesized collectively. Hence, a systematic review was undertaken to synthesize the findings on the epidemiology of G6PD deficiency in all Arab countries. We performed an electronic systematic literature search based on the eligibility criteria using databases, including MEDLINE, Embase, and CINHAL. The studies included in the review were primary and original research studies assessing the prevalence or incidence, risk factors, or determinants of G6PD deficiency, and published in the English language in a peer-reviewed scientific journal between 2000 and 2022. The systematic review was carried out with the help of an updated PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist. After the screening, 23 full texts were finalized for data extraction. The prevalence of G6PD deficiency ranged from 2 to 31% with a greater burden among high-risk populations like neonates with sickle cell anemia. The determinants included males, family history, consanguineous marriages, and geographic regions, which were all risk factors, except for body weight, which was a protective factor. The prevalence of G6PD deficiency varies across Arab countries, with a higher prevalence in males than females. Different regions of Arab countries need to revisit their screening and diagnostic guidelines to detect G6PD deficiency promptly and prevent unnecessary morbidity and mortality among their communities.

Prevalence of glucose-6-phosphate dehydrogenase deficiency in jaundiced Egyptian neonates

BACKGROUND

The enzyme, Glucose-6-phosphate dehydrogenase (G6PD), deficiency leads to impaired production of reduced glutathione and predisposes the red cells to be damaged by oxidative metabolites, causing hemolysis. Deficient neonates may manifest clinically as hyperbilirubinemia or even kernicterus.

OBJECTIVE

This study was carried out to detect erythrocyte G6PD deficiency in neonatal hyperbilirubinemia.

METHODS AND DESIGN

To determine the frequency and effect of G6PD deficiency, this study was conducted on 202 neonates with indirect hyperbilirubinemia. All term and preterm babies up to 13 day of age admitted with clinically evident jaundice were taken for the study. G6PD activity is measured by the UV-Kinetic Method using cellular enzyme determination reagents by spectrophotometry according to manufacturer's instructions.

RESULTS

A total of 202 babies were enrolled in this study. Male babies outnumbered the female (71.3% versus 28.7%). Mean age of the study newborns was 3.75 ± 2.5 days. Eighteen neonates (8.9%) had G6PD deficiency, all are males. One case had combined G6PD deficiency and RH incompatibility. Mean serum total bilirubin was 17.2 ± 4.4 in G6PD deficient cases. There was significant positive correlation between the time of appearance of jaundice in days and G6PD levels in G6PD deficient cases.

CONCLUSION

Neonatal hyperbilirubinemia is associated with various clinical comorbidities. G6PD deficiency is found to one important cause of neonatal jaundice developing on day 2 onwards.

The human NADPH oxidase: primary and secondary defects impairing the respiratory burst function and the microbicidal ability of phagocytes

Phagocytes, such as granulocytes and monocytes/macrophages, contain a membrane-associated NADPH oxidase that produces superoxide leading to other reactive oxygen species with microbicidal, tumoricidal and inflammatory activities. Primary defects in oxidase activity in chronic granulomatous disease (CGD) lead to severe, life-threatening infections that demonstrate the importance of the oxygen-dependent microbicidal system in host defence. Other immunological disturbances may secondarily affect the NADPH oxidase system, impair the microbicidal activity of phagocytes and predispose the host to recurrent infections. This article reviews the primary defects of the human NADPH oxidase leading to classical CGD, and more recently discovered immunological defects secondarily affecting phagocyte respiratory burst function and resulting in primary immunodeficiencies with varied phenotypes, including susceptibilities to pyogenic or mycobacterial infections.

Investigation of the Mutation Points and Effects of Some Drugs on Glucose-6-phosphate Dehydrogenase-deficient People in the Erzurum Region

We have carried out a systematic study of the molecular basis of glucose-6-phosphate dehydrogenase (G6PD) deficiency on three samples of 1,183 children aged 0.5-6 years from Erzurum, in eastern Anatolia. Total genomic DNAs were isolated from the blood samples of a healthy person and the three persons determined with G6PD deficiency by examining the enzyme activity and hemoglobin ratio. Then PCR amplification of the entire coding region in eight fragments was carried out followed by Agarose gel electrophoresis. The 540-bp PCR fragment containing exons VI-VII and the 550bp PCR fragment containing exons XI-XIII were digested with EcoRI and with NIaIII, respectively. SSCP techniques for eight fragments (exons II, III-IV, V, VI-VII, VIII, IX, X, and XI-XIII) were employed to determine the mutations on the exons of the G6PD gene. A mutation occurred on the region of the exons 6 and 7 of one person (person-1) and exon 5 of two G6PD-deficient persons (person 2 and 3) examined. The sequential approach described is fast and efficient and could be applied to other populations. Effects of analgesic drugs on G6PD were studied on the purified enzyme (ammonium fractionation, dialysis and 2',5' ADP-Sepharose 4B affinity chromatography) for the healthy person and G6PD-deficient persons 1, 2 and 3. The effects of remifentanil hydrochloride, fentanyl citrate, alfentanil hydrochloride and pethidine hydrochloride, as analgesic drugs, on G6PD activity were tested. Although remifentanil hydrochloride, fentanyl citrate (I50 values; 1.45mM and 6.1 mM, respectively) inhibited the activity of the enzyme belonging to the healthy person, they did not alter enzyme activity on two of the three persons with G6PD deficiency. Other drugs (alfentanil hydrochloride and pethidine hydrochloride) did not effect the enzyme activity of the healthy or G6PD-deficient children.

Medications and glucose-6-phosphate dehydrogenase deficiency: an evidence-based review

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect and one of the most common genetic disorders worldwide, with an estimated 400 million people worldwide carrying a mutation in the G6PD gene that causes deficiency of the enzyme. Although drug-induced haemolysis is considered the most common adverse clinical consequence of G6PD deficiency, significant confusion exists regarding which drugs can cause haemolytic anaemia in patients with G6PD deficiency. In the absence of consensus among physicians, patients are subject to conflicting advice, causing uncertainty and distress. In the current review we aimed, by thorough search of the medical literature, to collect evidence on which to base decisions either to prohibit or allow the use of various medications in patients with G6PD deficiency. A literature search was conducted during May 2009 for studies and case reports on medication use and G6PD deficiency using the following sources: MEDLINE (1966-May 2009), PubMed (1950-May 2009), the Cochrane database of systematic reviews (2009), and major pharmacology, internal medicine, haematology and paediatric textbooks. After assessing the literature, we divided medications into one of three groups: medications that should be avoided in individuals with G6PD deficiency, medications that were considered unsafe by at least one source, but according to our review can probably be given safely in normal therapeutic dosages to individuals with G6PD deficiency as evidence does not contravene their use, and medications where no evidence at all was found to contravene their use in G6PD-deficient patients. It is reasonable to conclude that, over time, many compounds have been wrongly cited as causing haemolysis because they were administered to patients experiencing an infection-related haemolytic episode. We found solid evidence to prohibit only seven currently used medications: dapsone, methylthioninium chloride (methylene blue), nitrofurantoin, phenazopyridine, primaquine, rasburicase and tolonium chloride (toluidine blue). Regarding all other medications, our review found no evidence to contravene their use in normal therapeutic doses to G6PD-deficient patients. There is a need for evidence-based global consensus regarding medication use in G6PD-deficient patients.

Multi-mutational analysis of fifteen common mutations of the glucose 6-phosphate dehydrogenase gene in the Mediterrranean population

BACKGROUND

Glucose-6-phosphate dehydrogenase (G6PD) is a cytosolic enzyme encoded by a housekeeping X-linked gene whose main function is to produce NADPH, a key electron donor in the defence against oxidizing agents and in reductive biosynthetic reactions. Many variants of G6PD have been described, mostly produced from missense mutations, with wide ranging levels of enzyme activity and associated clinical symptoms.

METHOD

A single base extension assay is used, yielding a single base difference of the extended products. Primers are designed to amplify products of different sizes with distinct fluorescent dyes in order to accurately distinguish all possible combinations of genotypes (homozygous and heterozygous for each mutation) in a multiplex PCR analysis.

RESULTS

We present the first application of a multiplex multicolour assay to detect 15 of the most frequent G6PD-related mutations in Spain, which are studied in three multiplex reactions. Capillary electrophoresis analysis of the amplified products enables easy, rapid, unambiguous and high-resolution discrimination between wild-type and mutant alleles, even though various mutations may be present in the multiplex analysis.

CONCLUSION

The analytical method described herein offers greater diagnostic power in Spanish and Mediterranean populations and would facilitate automated genotyping in routine molecular diagnostics and large-scale genetic studies (e.g., newborn screening programs).

Glucose-6-phosphate dehydrogenase deficiency

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect, being present in more than 400 million people worldwide. The global distribution of this disorder is remarkably similar to that of malaria, lending support to the so-called malaria protection hypothesis. G6PD deficiency is an X-linked, hereditary genetic defect due to mutations in the G6PD gene, which cause functional variants with many biochemical and clinical phenotypes. About 140 mutations have been described: most are single base changes, leading to aminoacid substitutions. The most frequent clinical manifestations of G6PD deficiency are neonatal jaundice, and acute haemolytic anaemia, which is usually triggered by an exogenous agent. Some G6PD variants cause chronic haemolysis, leading to congenital non-spherocytic haemolytic anaemia. The most effective management of G6PD deficiency is to prevent haemolysis by avoiding oxidative stress. Screening programmes for the disorder are undertaken, depending on the prevalence of G6PD deficiency in a particular community.

Glucose-6-phosphate dehydrogenase deficiency in female octogenarians, nanogenarians, and centenarians

BACKGROUND

Age-related skewing of X-chromosome inactivation leading to glucose-6-phosphate dehydrogenase (G6PD) deficiency in elderly women in a population with prevalent G6PD gene mutations was investigated.

METHODS

G6PD activity was measured biochemically. G6PD mutations were detected by polymerase chain reaction (PCR) and allele-specific extension, and analyzed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and Sequenom MassARRAY. X-chromosome inactivation was quantified by semiquantitative PCR for the HUMARA gene, before and after HpaII digestion.

RESULTS

In 173 women (median age: 90 years; range, 80-107 years), 18 heterozygotes for G6PD mutations were identified. Three heterozygotes were G6PD deficient, owing to skewed X-chromosome inactivation affecting the wild-type allele. Fifteen heterozygotes, with skewing apparently affecting the mutant alleles, had normal but significantly lower G6PD levels. At 1.73%, G6PD deficiency was significantly more frequent than expected from population screening at birth.

CONCLUSION

Due to skewed X-chromosome inactivation, elderly women in populations with prevalent G6PD mutations are at risk of G6PD deficiency.

Oxidant stress and haemolysis of the human erythrocyte

The erythrocyte is a highly specialised cell with a limited metabolic repertoire. As an oxygen shuttle, it must continue to perform this essential task while exposed to a wide range of environments on each vascular circuit, and to a variety of xenobiotics across its lifetime. During this time, it must continuously ward off oxidant stress on the haeme iron, the globin chain and on other essential cellular molecules. Haemolysis, the acceleration of the normal turnover of senescent erythrocytes, follows severe and irreversible oxidant injury. A detailed understanding of the molecular mechanisms underlying oxidant injury and its reversal, and of the clinical and laboratory features of haemolysis is important to the medical toxicologist. This review will also briefly review glucose-6-phosphate deficiency, a common but heterogeneous range of enzyme-deficient states, which impairs the ability of the erythrocyte to respond to oxidant injury.

Oxidative stress, glucose-6-phosphate dehydrogenase and the red cell

As discussed above, the process by which normal senescent red cells are selected for removal from the circulation is the subject of much ongoing research and is not yet well understood. This in turn creates a problem for studies on the enhanced removal that occurs in xenobiotic-induced hemolytic states; specifically, whether the enhanced removal should be considered as an increase in rate of the normal sequestration mechanism or as an unrelated process, in part or in whole. This difficulty bears directly on the interpretation of much of the mechanistic hemolytic literature. Because of its dual in vivo and in vitro hemolytic capability, and because of its capacity to induce frank lysis in the incubation mixture, phenylhydrazine has been used extensively as a model compound for mechanistic studies. These data have contributed heavily to our current concepts of how chemicals induce damage in the red cell. The comparison studies presented above cast doubt on the relevance of many of these phenylhydrazine studies for the in vivo hemolytic response. Phenylhydrazine, like divicine and DDS-NOH, shows an overwhelming predominance of uptake into the spleen, as distinct from removal by the RES system in general, as evidenced by relatively low liver uptake. This suggests strongly that damaged cells are removed intact by the spleen and do not lyse or fragment in the general circulation, at least to any significant extent. The studies with DDS-NOH indicate that neither Heinz body formation nor lipid peroxidation per se are essential steps in the process by which damaged red cells are removed from the circulation in the rat. It is not yet clear whether this lack of obligatory involvement of Heinz bodies and lipid peroxidation is peculiar to the arylhydroxylamine-induced hemolytic state or whether it will prove to be of general applicability. On the other hand, cysteamine failed to reverse the hemolytic damage caused by phenylhydrazine. Since cysteamine "rescued" DDS-NOH treated cells under the same experimental conditions, this observation raises the possibility that protein-thiol oxidation per se is also not an obligatory step in the sequence of events leading to premature sequestration. Clearly, the ratio of lipid to protein oxidation is markedly different in these three examples of hemotoxic compounds. DDS-NOH showed high protein oxidation with no discernible lipid oxidation, divicine showed both high protein and high lipid oxidation, and phenylhydrazine showed high lipid and low protein oxidation. While the significance of these markedly different patterns of injury is far from clear, it seems reasonable to conclude that there is more than one way by which chemicals damage the red cell. It is intriguing that these apparently different chemical insults within the red cell result in a common "message" on the outside of the cell, such that the cell appears as "prematurely" aged. Although the pattern of injury inside the cell may be significantly different, the process by which the three hemotoxic compounds enhance uptake by splenic macrophages may remain the same. That is, there may be a variety of insults sustained within the red cell that lead by different pathways to similar "recognition-specific" changes on the external surface of the red cell. Clearly, comparison of the effects of the three hemotoxic compounds will shed light on both the hemolytic process and on normal red cell sequestration mechanisms.

Protein methylation as a marker of aspartate damage in glucose-6-phosphate dehydrogenase-deficient erythrocytes: role of oxidative stress

The 'Mediterranean' variant of glucose-6-phosphate dehydrogenase (G6PD) deficiency is due to the C563CT point mutation, leading to replacement of Ser with Phe at position 188, resulting in acute haemolysis triggered by oxidants. Previous work has shown increased formation of altered aspartate residues in membrane proteins during cell ageing and in response to oxidative stress in normal erythrocytes. These abnormal residues are specifically recognized by the repair enzyme L-isoaspartate (d-aspartate) protein O-methyltransferase (PCMT; EC 2.1.1.77). The aim of this work was to study the possible involvement of protein aspartate damage in the mechanism linking the G6PD defect and erythrocyte injury, through oxidative stress. Patients affected by G6PD deficiency (Mediterranean variant) were selected. In situ methylation assays were performed by incubating intact erythrocytes in the presence of methyl-labelled methionine. Altered aspartate residues were detected in membrane proteins by methyl ester quantification. We present here evidence that, in G6PD-deficient erythrocytes, damaged residues are significantly increased in membrane proteins, in parallel with the decay of pyruvate kinase activity, used as a cell age marker. Erythrocytes from patients were subjected to oxidative stress in vitro, by treatment with t-butylhydroperoxide, monitored by a rise in concentration of both methaemoglobin and thiobarbituric acid-reactive substances. L-Isoaspartate residues increased dramatically in G6PD-deficient erythrocytes in response to such treatment, compared with baseline conditions. The increased susceptibility of G6PD-deficient erythrocytes to membrane protein aspartate damage in response to oxidative stress suggests the involvement of protein deamidation/isomerization in the mechanisms of cell injury and haemolysis.

Human mutations in glucose 6-phosphate dehydrogenase reflect evolutionary history

Glucose 6-phosphate dehydrogenase (G6PD) is a cytosolic enzyme encoded by a housekeeping X-linked gene whose main function is to produce NADPH, a key electron donor in the defense against oxidizing agents and in reductive biosynthetic reactions. Inherited G6PD deficiency is associated with either episodic hemolytic anemia (triggered by fava beans or other agents) or life-long hemolytic anemia. We show here that an evolutionary analysis is a key to understanding the biology of a housekeeping gene. From the alignment of the amino acid (aa) sequence of 52 glucose 6-phosphate dehydrogenase (G6PD) species from 42 different organisms, we found a striking correlation between the aa replacements that cause G6PD deficiency in humans and the sequence conservation of G6PD: two-thirds of such replacements are in highly and moderately conserved (50-99%) aa; relatively few are in fully conserved aa (where they might be lethal) or in poorly conserved aa, where presumably they simply would not cause G6PD deficiency. This is consistent with the notion that all human mutants have residual enzyme activity and that null mutations are lethal at some stage of development. Comparing the distribution of mutations in a human housekeeping gene with evolutionary conservation is a useful tool for pinpointing amino acid residues important for the stability or the function of the corresponding protein. In view of the current explosive increase in full genome sequencing projects, this tool will become rapidly available for numerous other genes.

Chronic non-spherocytic haemolytic disorders associated with glucose-6-phosphate dehydrogenase variants

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect, being present in over 400 million people world wide. In a small number of cases, G6PD deficiency can lead to mild-to-severe chronic haemolysis, which is further exacerbated by oxidative stress. Such G6PD variants have been described all over the world and are responsible for chronic non-spherocytic haemolytic anaemia (CNSHA). To date 61 G6PD molecular variants associated with CNSHA have been identified, only some of which can cause the severe reduction in stability of the red blood cell enzyme. The distribution of the different mutations shows a predominance of small mutational events, and many have been found repeatedly in different parts of the world. By revisiting the 61 class I variants described so far, we can observe that a low inhibition constant (Ki) for NADPH, a higher Km for substrates and a reduced thermostability are common.

Glucose-6-phosphate dehydrogenase deficiency

Glucose-6-phosphate dehydrogenase (G6PD) is expressed in all tissues, where it catalyses the first step in the pentose phosphate pathway. G6PD deficiency is prevalent throughout tropical and subtropical regions of the world because of the protection it affords during malaria infection. Although most affected individuals are asymptomatic, there is a risk of neonatal jaundice and acute haemolytic anaemia, triggered by infection and the ingestion of certain drugs and broad beans (favism). A rare but more severe form of G6PD deficiency is found throughout the world and is associated with chronic non-spherocytic haemolytic anaemia. Many deficient variants of G6PD have been described. DNA sequence analysis has shown that the vast majority of these are caused by single amino acid substitutions. The three-dimensional structure of G6PD shows a classical dinucleotide binding domain and a novel beta + alpha domain involved in dimerization.

Molecular characterization of a German variant of glucose-6-phosphate dehydrogenase deficiency (G6PD Aachen)

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-chromosome-linked hereditary disorder. Clinically, patients with G6PD deficiency often present with drug- or food-induced hemolytic crises or neonatal jaundice. G6PD is involved in the generation of NADPH and reduced glutathione. In contrast to American, Mediterranean, and African ancestries, only few variants are known from Middle and Northern Europe. We describe the molecular characterization of a distinct variant from the northwestern area of Germany, G6PD Aachen. The sequence of the G6PD gene from three afflicted males was found to be hemizygous at cDNA residue 1089 for a C-->G mutation with a predicted amino acid change of Asn363Lys. The 1089 C-->G point mutation is unique, but produces the identical amino acid change found in a Mexican variant of G6PD deficiency, G6PD Loma Linda. This G6PD-deficient variant is caused by a 1089 C-->A mutation. The 363-amino-acid replacement is located outside a known mutation cluster region between amino acid residues 380 and 450, but may disrupt or weaken dimer interactions of G6PD enzyme subunits.

Three major G6PD-deficient polymorphic variants identified among the Mauritian population

We report the results of the first epidemiological study investigating glucose 6-phosphate dehydrogenase (G6PD) deficiency among the heterogenous Mauritian population. Mauritius has a population of approximately 1 million, and of these 66.8% are Indo-Mauritian (of Indian origin), 27.9% are Creoles (of African ancestry) and 2.1% are Sino-Mauritian, predominantly of Chinese origin. Of the 1435 Mauritian males tested, 73 (5.1%) were G6PD deficient. However, the prevalence varied considerably between the two major ethnic groups: 35/1157 (3.0%) for Indo-Mauritians and 37/267 (13.9%) for Creoles. Molecular analysis revealed three major deficient polymorphic variants; G6PD Orissa, G6PD Mediterranean and G6PD A-. G6PD Orissa (nt 131 G-->C; residue 44 Ala-->Gly) was found to be the most common variant among Indo-Mauritians: this deficient variant was recently identified to be highly characteristic of the tribal groups in central India. In Creoles the most common deficient variant was G6PD A- (27/37). These data are consistent with the different ancestral contributions to the present gene pool of the Mauritian population. This study has provided further information as to the precise nature of G6PD deficiency at the molecular level among Indians, about whom previously there was scant information. The data presented suggest that G6PD Orissa is widespread in central and southern states of India. Additionally, the identification and frequency of G6PD-deficient alleles in Mauritius is of public-health importance.

Amino acid conservation and clinical severity of human glucose-6-phosphate dehydrogenase mutations

More than a hundred naturally occurring mutations of human glucose-6-phosphate dehydrogenase (G6PD) have been identified at the amino acid level. The abundance of distinct mutation sites and their clinical manifestations make this enzyme ideal for structure-function analysis studies. We present here a sequence and structure combined analysis by which the severity of clinical symptoms resulting from point mutations of this enzyme is correlated with quantified degrees of amino acid conservation within 23 G6PD sequences from different organisms. Our analysis verifies, on a quantitative basis, a widely held notion that clinically severer mutations of G6PD usually occur at conserved amino acids. However, marked exceptions to this general trend exist which are most notably revealed by a number of mutations associated with chronic nonspherocytic hemolytic anemia (class I variants). When mapped onto a homology-derived structural model of human G6PD, these class I mutational sites of low amino acid conservation appear to localize in two spatially distinct clusters, both of which are populated with mutations consisting mainly of clinically severer variants (i.e. class I and class II). These results of computer-assisted analyses contribute to a further understanding of the structure-function relationships of human G6PD deficiency.

Impaired production of nitric oxide, superoxide, and hydrogen peroxide in glucose 6-phosphate-dehydrogenase-deficient granulocytes

Since the generation of superoxide and hydrogen peroxide by NADPH oxidase and nitric oxide (NO) by NO synthase (NOS) in granulocytes is NADPH-dependent, we investigated the production of NO, superoxide and H2O2 in glucose 6-phosphate dehydrogenase (G6PD)-deficient human granulocytes. Our results showed that upon stimulation with either 5 microg/ml of lipopolysaccharide (LPS) or 10 microM of phorbol 12-myristate 13-acetate (PMA), the production of nitrite in normal granulocytes was elevated, 252 +/- 135% and 239 +/- 72%, respectively, compared to the resting stage. In contrast, G6PD-deficient granulocytes did not produce more nitrite upon stimulation with either LPS or PMA compared to the resting stage. Western blot analysis indicated a normal expression pattern of inducible NOS in G6PD-deficient granulocytes. In addition, the production of H2O2 and superoxide was also significantly impaired in G6PD-deficient granulocytes compared to control cells. These data demonstrate that G6PD deficiency causes an impairment in the production of NO, superoxide and H2O2.