Chronic Granulomatous Disease Phenotype Research Articles

First report of Mycobacterium chimaera infection in a patient with chronic granulomatous disease

Chronic granulomatous disease (CGD) is an inborn error of immunity. NADPH oxidase is an enzyme complex that produces various reactive oxygen species, such as superoxide anions and hydrogen peroxide. Mycobacterial infections in CGD are commonly observed in countries with a high prevalence of these microorganisms, such as those receiving the BCG vaccination at birth or having a high prevalence of tuberculosis. Non-tuberculous mycobacteria (NTM) infections are rare in CGD. The patient also presented with hemophagocytic lymphohistiocytosis, which resolved with gammaglobulin and cyclosporine. Herein, we describe the first case of M. chimaera infection in a female patient with autosomal recessive CGD caused by a pathogenic variant in CYBA.

Bi-fluorescent Staphylococcus aureus infection enables single-cell analysis of intracellular killing in vivo.

Techniques for studying the clearance of bacterial infections are critical for advances in understanding disease states, immune cell effector functions, and novel antimicrobial therapeutics. Intracellular killing of Staphylococcus aureus by neutrophils can be monitored using a S. aureus strain stably expressing GFP, a fluorophore that is quenched when exposed to the reactive oxygen species (ROS) present in the phagolysosome. Here, we expand upon this method by developing a bi-fluorescent S. aureus killing assay for use in vivo. Conjugating S. aureus with a stable secondary fluorescent marker enables the separation of infected cell samples into three populations: cells that have not engaged in phagocytosis, cells that have engulfed and killed S. aureus, and cells that have viable internalized S. aureus. We identified ATTO647N-NHS Ester as a favorable dye conjugate for generating bi-fluorescent S. aureus due to its stability over time and invariant signal within the neutrophil phagolysosome. To resolve the in vivo utility of ATTO647N/GFP bi-fluorescent S. aureus, we evaluated neutrophil function in a murine model of chronic granulomatous disease (CGD) known to have impaired clearance of S. aureus infection. Analysis of bronchoalveolar lavage (BAL) from animals subjected to pulmonary infection with bi-fluorescent S. aureus demonstrated differences in neutrophil antimicrobial function consistent with the established phenotype of CGD.

NADPH Oxidase Modulates Ca2+-Dependent Formation of Neutrophil Extracellular Traps

Chronic granulomatous disease (CGD) is a severe hereditary immunodeficiency associated with recurrent bacterial and fungal infections as well as aberrant inflammatory processes. The CGD phenotype depends on the deficiency of phagocytic NADPH oxidase causing the inability of phagocytes to produce reactive oxygen species (ROS). Such phagocytes have a limited ability to execute phagocytosis, degranulation, and the formation of neutrophil extracellular traps (NETs) as a reaction to many receptor and pharmacological stimuli. However, neutrophil trapping in CGD patients in response to calcium ionophores has been previously described in one of the authors' studies. Some researches have shown that NADPH-oxidase-deficient neutrophils are not only incapable of generating ROS but also have major disturbances in the influx of extracellular Ca2+ due to the absence of the electrogenic function of the enzyme and the membrane depolarization during the activation and consequently multiple abnormalities in the synthesis of proinflammatory cytokines. In this study, it has been shown that the formation of NETs by neutrophils deficient in NADPH oxidase in response to calcium ionophore A23187 is accompanied by excessive accumulation of intracellular Ca2+. We propose that this violation is because of the absence of the electrogenic function in mutant NADPH oxidase that normally induces depolarization of the plasma membrane. The results have indicated the important role of phagocytic NADPH oxidase as a modulator of extracellular Ca2+ transport and that it can be used to find the cure for CGD.

Long-term observational studies of chronic granulomatous disease.

Chronic granulomatous disease (CGD) is a primary immunodeficiency, with a defect of phagocytes in killing specific pathogens. CGD is characterized by severe recurrent bacterial and fungal infections and dysregulated inflammatory response. Since its first description as fatal disease about 60 years ago, a significant improvement in outcome has been achieved in the last 20 years. The purpose of this review is to framework recent advances in CGD immunopathogenesis, management of disease manifestation and cure of CGD patients. For years, CGD is a known cause of life-threatening infections and excessive inflammation. The cause and the management of inflammatory reactions, however, have not been clarified, and the range of clinical presentation is growing with corresponding novel therapeutic interventions. Recent work focuses on the best outcome of hematopoietic stem cell transplantation (HSCT) and gene therapy for the cure of CGD patients, more specifically, those with X-linked and p47 mutations. The genetics and phenotype of CGD is well characterized; however, the underlying mechanisms, the treatment of its inflammatory manifestations and the cure of CGD is under further investigation.

Human miR223 Promoter as a Novel Myelo-Specific Promoter for Chronic Granulomatous Disease Gene Therapy

Targeting transgene expression to specific hematopoietic cell lineages could contribute to the safety of retroviral vectors in gene therapeutic applications. Chronic granulomatous disease (CGD), a defect of phagocytic cells, can be managed by gene therapy, using retroviral vectors with targeted expression to myeloid cells. In this context, we analyzed the myelospecificity of the human miR223 promoter, which is known to be strongly upregulated during myeloid differentiation, to drive myeloid-restricted expression of p47(phox) and gp91(phox) in mouse models of CGD and in primary patient-derived cells. The miR223 promoter restricted the expression of p47(phox), gp91(phox), and green fluorescent protein (GFP) within self-inactivating (SIN) gamma- and lentiviral vectors to granulocytes and macrophages, with only marginal expression in lymphocytes or hematopoietic stem and progenitor cells. Furthermore, gene transfer into primary CD34+ cells derived from a p47(phox) patient followed by ex vivo differentiation to neutrophils resulted in restoration of Escherichia coli killing activity by miR223 promoter-mediated p47(phox) expression. These results indicate that the miR223 promoter as an internal promoter within SIN gene therapy vectors is able to efficiently correct the CGD phenotype with negligible activity in hematopoietic progenitors, thereby limiting the risk of insertional oncogenesis and development of clonal dominance.

X-linked chronic granulomatous disease secondary to skewed X chromosome inactivation in a female with a novel CYBB mutation and late presentation

Chronic granulomatous disease (CGD) is characterized by defects in the superoxide producing enzyme NADPH oxidase causing phagocytes to improperly clear invading pathogens. Here we report findings of a late presenting 16-year-old female with X-linked CGD. The patient presented with community-acquired pneumonia, but symptoms persisted for 2 weeks during triple antimicrobial coverage. Cultures revealed Aspergillus fumigatus which was resolved through aggressive voriconazole treatment. Neutrophil studies revealed NADPH oxidase activity and flavocytochrome b 558 levels that were 4–8% of controls and suggested carrier status of the mother. We found a null mutation in the CYBB gene (c.252insAG) predicting an aberrant gp91 phox protein (p.Cys85fsX23) in the heterozygous state. Methylation analysis demonstrated extremely skewed X chromosome inactivation favoring the maternally inherited defective gene. In conclusion, a novel mutation in the CYBB gene and an extremely skewed X-inactivation event resulted in the rare expression of the CGD phenotype in a carrier female.

Mutations of chronic granulomatous disease in Turkish families

Chronic granulomatous disease (CGD) is an inherited disorder of the innate immune system characterized by impairment of intracellular microbicidal activity of phagocytes. Mutations in one of four known NADPH-oxidase components preclude generation of superoxide and related antimicrobial oxidants, leading to the phenotype of CGD. Defects in gp91-phox, encoded by CYBB, lead to X-linked CGD and have been reported to be responsible for approximately 70% of all CGD cases. The aim of this study was to identify the CGD mutations in a group of Turkish CGD patients and to evaluate the predominance of CGD mutations as X-linked or autosomal recessive (AR) within the Turkish CGD families with known mutations. Two Turkish CGD families were included in the study, and mutations were identified by sequence analysis of DNA and RNA from peripheral blood in the patients. Before mutation analysis, subgroup analysis of patients was made by flow cytometry with antibodies against NADPH oxidase components and with DHR-123 oxidase activity assay. For comparison, we included previously reported results from four other Turkish CGD families. Two different mutations were identified, one of them a novel mutation g.700G>T located in exon 7 of CYBB, and the other a hot-spot mutation located in exon 2 of the NCF1 gene. These mutations were detected in three patients from two Turkish families. Until now, we have altogether identified mutations in six Turkish CGD families. In this limited number of families our results show AR-CGD in two-thirds of the Turkish families investigated, in contrast to previous reports in the literature. This is probably due to the high rate of consanguineous marriages in Turkey. Consanguineous parents were found in 75% of the families with AR-CGD patients, which favours homozygous deficiencies.

Novel sources of reactive oxygen species in the human body

There are several sources of reactive oxygen in the human body. Production of superoxide in mitochondria is a by-product of the function of the respiratory chain [1]. The first known example of regulated generation of reactive oxygen species (ROS) in mammalian cells was through the respiratory burst of phagocytic cells by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. This enzyme complex uses electrons derived from intracellular NADPH to generate superoxide anion, which is further processed to form hydrogen peroxide and other ROS-providing host defense against bacterial and fungal pathogens [2]. The essential role of the phagocytic oxidase in host defense is well illustrated by the serious phenotype of chronic granulomatous disease (CGD), in which susceptibility to infections develops in the absence of a functional phagocytic oxidase [3]. Non-mitochondrial production of ROS was detected in various cell types, showing that intentional generation of ROS is a general feature of many tissues, rather than a unique function of phagocytes. Homology searches in human genome databases resulted in the discovery of six novel NADPH oxidase enzymes: Nox1, Nox3, Nox4, Nox5, Duox1 and Duox2 [4–6]. They all have at least partially similar structure and generate ROS in response to various stimuli. The physiological function of these proteins and their potential role in the pathogenesis of human diseases is currently under intensive investigation. Structural aspects

Skewing of X‐chromosome inactivation in three generations of carriers with X‐linked chronic granulomatous disease within one family

Chronic granulomatous disease (CGD) is an inherited disorder of the innate immune system characterized by impairment of intracellular microbicidal activity of phagocytes. Mutations in one of the four known NADPH-oxidase components preclude generation of superoxide and related antimicrobial oxidants, leading to the phenotype of CGD. Defects in gp91-phox, encoded by CYBB, lead to X-linked CGD, responsible for approximately 70% of all CGD cases. The aim of the study was to evaluate the hypothesis that age-related skewing of X-chromosome inactivation, as described in several CGD families, is caused by preferential survival of bone marrow clones with an inactive NADPH oxidase. We studied the neutrophils from three patients and four carriers in three generations of a Turkish family with X-linked CGD. Carrier detection was carried out by the dihydrorhodamine (DHR)-1,2,3 assay, which measures on a per-cell basis the NADPH oxidase-dependent oxidation of DHR by phagocytes. The X-chromosome inactivation pattern was determined with the HUMARA assay in DNA from leucocytes as well as in DNA from a buccal smear of the four carriers. The three patients were identified by a negative DHR test, and the mutation in their CYBB gene was characterized by DNA sequencing. Moreover, we found an age-related degree of skewing of X-chromosome inactivation in the leucocytes of the four X-CGD carriers, both at the protein level (NADPH oxidase activity) and at the DNA level (HUMARA assay). However, similar skewing of X-chromosome inactivation was found in the buccal DNA from these women. These novel findings indicate that the age-related degree of skewing was probably a chance finding, not related to preferential survival of NADPH oxidase-deficient precursor cells, because this enzyme is not expressed in (buccal) epithelial cells.

X-Linked Chronic Granulomatous Disease: First Report of Mutations in Patients of Argentina.

Chronic granulomatous disease (CGD) is a primary immunodeficiency due to absent or decreased NADPH oxidase activity in phagocytic cells. The X-linked form of the disease (X-CGD) arises from mutations in the CYBB gene, which encodes the 91-kD glycoprotein gp91, the largest component of the oxidase. The authors recently started the molecular characterization of X-CGD in 18 patients reported to the Argentinean Registry of Primary Immunodeficiency Diseases. The authors reviewed data from clinical records to examine the relationship of clinical presentation and the type of mutations responsible for the genotype. The frequency and type of infections present in these patients were similar to prior reports. However, pulmonary tuberculosis was observed in the group as well as unusual complications such as eosinophilic cystitis, hepatic abscess with cholangitis, and chronic orchitis. Eleven different mutations in the CYBB gene were identified, and seven of them were novel. The types of mutations were intronic, single-nucleotide substitution resulting in nonsense or missense codons and one or two nucleotide deletions resulting in frameshifts. Molecular studies of 18 mothers revealed X-CGD carrier status in all but 2. No correlation existed between the type of mutation and the clinical phenotype of the disease: the molecular defects identified resulted in no expression of the flavocytochrome b558 in patients' neutrophils, leading to the X91°-CGD phenotype. The lack of gp91 protein could explain the early onset and the severity of the clinical manifestations of CGD in this group of patients from Argentina.

Severe clinical forms of cytochrome b-negative chronic granulomatous disease (X91-) in 3 brothers with a point mutation in the promoter region of CYBB.

Chronic granulomatous disease (CGD) is a rare congenital syndrome that results in severe, recurrent bacterial and fungal infections. The most common form is caused by defects in the CYBB gene, leading to the absence of gp91phox associated with totally abolished NADPH oxidase activity (X91(0) CGD). We report 3 brothers with atypical cases of X-linked CGD, characterized by low levels of expression of gp91phox (X91(-) CGD). A point mutation (T-55C) identified in the CYBB gene's promoter region appears to prevent the full expression of this gene in neutrophils. This results in low levels of expression of gp91phox protein that are correlated with residual oxidase activity in the whole population of neutrophils. The total O(2)(-) production in these cells was approximately 5% of normal. Despite this oxidase activity, the patients experienced severe and life-threatening infections. It was concluded that the O(2)(-) production in the neutrophils of these patients was not sufficient to protect them against infections, and this X91(-) CGD phenotype must be considered to be a severe clinical form of CGD.

Dose-Dependent Enhancements by Interferon-γ on Functional Responses of Neutrophils From Chronic Granulomatous Disease Patients

AbstractInterferon-γ (IFN-γ) is recommended as prophylaxis against infections in patients with chronic granulomatous disease (CGD). However, since the optimal dose, the dosing interval, and the mechanisms of action are not well-defined, we studied the effects on CGD neutrophil (PMN) functions ex vivo of interferon-γ (IFN-γ). Evaluations were made on oxidative capacity, measured by superoxide anion production and chemiluminescence after stimulation with f-met-leu-phe (f-MLP) or phorbol-myristate-acetate, the killing of Aspergillus fumigatus hyphae (assessed as conversion of the tetrazolium salt MTT to formazan), and on the expression of FcγRI receptor (CD64). After randomization, 9 CGD patients (4 with gp91phox, 3 with p47phox, 1 with p67phox deficiency and 1 with unspecified CGD) were given IFN-γ, either 50 or 100 μg/m2 subcutaneously on 2 consecutive days after double blinded randomization. Furthermore, one female hyperlyonized X-linked carrier with a CGD phenotype was also studied separately after IFN-γ treatment. Evaluations were made the day before and on days 1, 3, 8, and 18 after IFN-γ administration. The killing of A fumigatus hyphae, being close to zero before IFN-γ, was enhanced on day 3, being 36% higher than pretreatment values in the high-dose CGD group and 17% in the low-dose group. The expression of FcγRI on PMN increased 3.7-fold in the high-dose and 2.3-fold in the low-dose CGD group, being maximal on day 1. Oxidative functions were raised in only selected patients represented by different subtypes of CGD. The hyperlyonized carrier of X-linked CGD responded to IFN-γ with more enhanced oxidative responses and Aspergillus killing of her PMNs than the other patients. This study suggests that a higher dose of IFN-γ than currently recommended confers transient enhancements of certain PMN functions in CGD patients.

Interferon-γ and chronic granulomatous disease

The molecular and biochemical characterization of many components of the phagocyte oxidase complex that generates superoxide have greatly advanced our understanding of this important pathway. Genetic defects in one or more of the components of this host defense system result in the chronic granulomatous disease phenotype. Biochemical advances and the results of a clinical trial that established the efficacy of recombinant human interferon-γ for prophylaxis of infections in chronic granulomatous disease are the highlights of recent achievements in this area of phagocyte biology.

Recombinant human interferon-gamma reconstitutes defective phagocyte function in patients with chronic granulomatous disease of childhood.

Monocytes from 19 of 30 patients with the classic phenotype of chronic granulomatous disease of childhood (CGD) responded to 3 days of treatment in culture with recombinant human interferon-gamma (rHuIFN-gamma) at 100 units/ml by producing superoxide after stimulation with phorbol 12-myristate 13-acetate. Cells from 15 of 16 patients with cytochrome b-positive CGD (15 with autosomal and 1 with X chromosome-linked inheritance) and cells from 4 of 14 patients with cytochrome b-negative CGD (13 with X chromosome-linked and 1 with autosomal recessive inheritance) responded. Subcutaneous rHuIFN-gamma (0.01-0.05 mg/m2) administered as a single dose, daily or every other day, for five or six doses to 3 patients whose phagocytes responded to rHuIFN-gamma in vitro resulted in significant improvement in phagocyte bactericidal activity against Staphylococcus aureus and increases in superoxide production. Studies on 1 patient's cells indicated the increases in superoxide production correlated with increased membrane cytochrome b. The effects of rHuIFN-gamma persisted for more than a week following cessation of therapy. Thus, we have demonstrated a partial correction in vivo of these CGD patients' phagocyte defect with rHuIFN-gamma. Moreover, the data suggest that a significant proportion of patients with CGD will respond to rHuIFN-gamma with augmentation of phagocyte microbicidal function.

Deficient flavoprotein component of the NADPH-dependent O2-.-generating oxidase in the neutrophils from three male patients with chronic granulomatous disease.

The NADPH-dependent O2-.-generating oxidase in subcellular fractions from the neutrophils of three male patients with chronic granulomatous disease was compared with the corresponding preparations from normal neutrophils. The oxidase from normal neutrophils contained flavin adenine dinucleotide in an approximately 0.9:1 molar ratio with cytochrome b559. Each of the three chronic granulomatous disease patients had decreased amounts of the flavoprotein component of the oxidase fraction. The oxidase from two chronic granulomatous disease patients had undetectable amounts of cytochrome b559 whereas the third patient had a normal content of cytochrome b559, which was spectrally indistinguishable from the normal. The intrinsic cytochrome b559 in the oxidase fraction from stimulated neutrophils of the latter chronic granulomatous disease patient was not reduced by NADPH under anaerobic conditions, in distinction with the previously reported reduction of the normal cytochrome b559 under identical conditions. We conclude that the flavoprotein component of the oxidase may mediate transfer of electrons from NADPH to the cytochrome b559 in normal neutrophils, and that deficiency of this flavoprotein is associated with the chronic granulomatous disease phenotype in the three patients studied.