Impaired inflammasome activation and bacterial clearance in G6PD deficiency due to defective NOX/p38 MAPK/AP-1 redox signaling.

Glucose-6-phosphate dehydrogenase (G6PD) is the rate-limiting enzyme of the pentose phosphate pathway that modulates cellular redox homeostasis via the regeneration of NADPH. G6PD-deficient cells have a reduced ability to induce the innate immune response, thus increasing host susceptibility to pathogen infections. An important part of the immune response is the activation of the inflammasome. G6PD-deficient peripheral blood mononuclear cells (PBMCs) from patients and human monocytic (THP-1) cells were used as models to investigate whether G6PD modulates inflammasome activation. A decreased expression of IL-1ß was observed in both G6PD-deficient PBMCs and PMA-primed G6PD-knockdown (G6PD-kd) THP-1 cells upon lipopolysaccharide (LPS)/adenosine triphosphate (ATP) or LPS/nigericin stimulation. The pro-IL-1ß expression of THP-1 cells was decreased by G6PD knockdown at the transcriptional and translational levels in an investigation of the expression of the inflammasome subunits. The phosphorylation of p38 MAPK and downstream c-Fos expression were decreased upon G6PD knockdown, accompanied by decreased AP-1 translocation into the nucleus. Impaired inflammasome activation in G6PD-kd THP-1 cells was mediated by a decrease in the production of reactive oxygen species (ROS) by NOX signaling, while treatment with hydrogen peroxide (H2O2) enhanced inflammasome activation in G6PD-kd THP-1 cells. G6PD knockdown decreased Staphylococcus aureus and Escherichia coli clearance in G6PD-kd THP-1 cells and G6PD-deficient PBMCs following inflammasome activation. These findings support the notion that enhanced pathogen susceptibility in G6PD deficiency is, in part, due to an altered redox signaling, which adversely affects inflammasome activation and the bactericidal response.

Safe fluoroquinolones prophylaxis in blood cancer patients with chemotherapy-induced neutropenia and Glucose-6-Phosphate-Dehydrogenase deficiency.

WHAT IS KNOWN AND OBJECTIVE: Bacterial infections are the leading causes of morbidity and mortality in haematologic patients with chemotherapy-induced neutropenia. The only strategy shown to be effective in reducing febrile neutropenia incidence is fluoroquinolone prophylaxis, but the safety of this class of drugs in patients with glucose-6-phosphate dehydrogenase deficiency (G6PD-), the most common human enzyme defect, is still controversial because of the claimed association with acute haemolytic anaemia. METHODS: We retrospectively analysed 242 patients treated with 628 intensive chemotherapy courses. Of these, 59 patients were with G6PD-. All patients underwent fluoroquinolone prophylaxis and were transfused according to our single-unit transfusion policy. The principal endpoint was the incidence of acute haemolytic anaemia. Secondary endpoints included the incidence of febrile neutropenia, microbiologically and clinically documented infection (MDI and CDI) and the incidence of Gram-positive or Gram-negative infections. RESULTS AND DISCUSSIONS: No episode of acute haemolytic anaemia was observed in the entire cohort. The incidence of MDI and CDI was similar, but the incidence of invasive fungal disease (IFD; P<.0001, HR 11.4, 95%CI 3.5-37.05) and Candida sepsis (P=.008, HR 37, 95%CI 2.01-680.9) was higher in patients with G6PD-. Interestingly, we observed a reduced incidence of febrile neutropenia in patients with G6PD- (P=.01, HR 0.46, 95%CI 0.25-0.8). WHAT IS NEW AND CONCLUSIONS: Our data suggest that fluoroquinolone prophylaxis in patients with G6PD-, treated with intensive chemotherapy, is feasible and safe. Our findings on the incidence of IFD and febrile neutropenia suggest that G6PD may be important in susceptibility to opportunistic pathogens and host response in neutropenic patients.

Clostridium difficile infection precipitating hemolysis in glucose-6-phosphate dehydrogenase-deficient preterm twins causing severe neonatal jaundice.

The incidence of glucose-6-phosphate dehydrogenase deficiency in neonates of immigrant mothers in Canada is increasing. Newborn screening programs in Canada do not screen for this disorder. Infants with G-6-PD deficiency may develop jaundice resulting in kernicterus with devastating sequelae. In this case report, we speculate that Clostridium difficile infection may have triggered severe jaundice in G-6-PD-deficient neonates.

Glucose-6-phosphate dehydrogenase deficiency inhibits in vitro growth of Plasmodium falciparum.

Glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49)-deficient red blood cells from male hemizygotes and female heterozygotes from the island of Sardinia were studied for their ability to support growth in vitro of the malaria-causing organism Plasmodium falciparum. Parasite growth was approximately one-third of normal in both hemi- and heterozygotes for G6PD deficiency. In Sardinians with the beta 0-thalassemia trait, parasite growth was normal except when G6PD deficiency occurred together with the thalassemia trait. The data support the hypothesis that G6PD deficiency may confer a selective advantage in a malarious area; the female heterozygote may be at a particular advantage because resistance to malaria equals that of male hemizygotes, but the risk of fatal hemolysis may be less. However, more female heterozygotes must be studied to confirm this hypothesis. No protective effect of beta 0-thalassemia trait could be demonstrated in vitro.