Chronic granulomatous disease in Israel: Clinical, functional and molecular studies of 38 patients

Genotype-phenotype correlations in chronic granulomatous disease: insights from a large national cohort

ABSTRACT

Neutrophils are the first line of defense against invading pathogens. Neutrophils execute and modulate immune responses by generating reactive oxygen species (ROS). Chronic granulomatous disease (CGD) is a primary immune deficiency disorder of phagocytes, caused by inherited mutations in the genes of the nicotinamide adenine dinucleotide phosphate reduced oxidase enzyme. These mutations lead to failure of ROS generation followed by recurrent bacterial and fungal infections, frequently associated with hyperinflammatory manifestations. We report a multicenter cumulative experience in diagnosing and treating patients with CGD. From 1986 to 2021, 2918 patients experiencing frequent infections were referred for neutrophil evaluation. Among them, 110 patients were diagnosed with CGD: 56 of Jewish ancestry, 48 of Arabic ancestry, and 6 of non-Jewish/non-Arabic ancestry. As opposed to other Western countries, the autosomal recessive (AR) CGD subtypes were predominant in Israel (71/110 patients). Thirty-nine patients had X-linked CGD, in most patients associated with severe infections (clinical severity score ≥3) and poor outcomes, presenting at a significantly earlier age than AR-CGD subtypes. The full spectrum of infections and hyperinflammatory manifestations is described. Six patients had hypomorphic mutations with significantly milder phenotype, clinical severity score ≤2, and better outcomes. Hematopoietic stem cell transplantation was implemented in 39 of 110 patients (35.5%). Successful engraftment was achieved in 92%, with 82% long-term survival and 71% full clinical recovery. CGD is a complex disorder requiring a multiprofessional team. Early identification of the genetic mutation is essential for prompt diagnosis, suitable management, and prevention.

Diagnosis of Chronic Granulomatous Disease: Strengths and Challenges in the Genomic Era

Chronic granulomatous disease (CGD) is a group of rare primary inborn errors of immunity characterised by a defect in the phagocyte respiratory burst, which leads to severe and life-threatening infective and inflammatory complications. Despite recent advances in our understanding of the genetic and molecular pathophysiology of X-linked and autosomal recessive CGD, and growth in the availability of functional and genetic testing, there remain significant barriers to early and accurate diagnosis. In the current review, we provide an up-to-date summary of CGD pathophysiology, underpinning current methods of diagnostic testing for CGD and closely related disorders. We present an overview of the benefits of early diagnosis and when to suspect and test for CGD. We discuss current and historical methods for functional testing of NADPH oxidase activity, as well as assays for measuring protein expression of NADPH oxidase subunits. Lastly, we focus on genetic and genomic methods employed to diagnose CGD, including gene-targeted panels, comprehensive genomic testing and ancillary methods. Throughout, we highlight general limitations of testing, and caveats specific to interpretation of results in the context of CGD and related disorders, and provide an outlook for newborn screening and the future.

Chronic Granulomatous Disease (CGD): Commonly Associated Pathogens, Diagnosis and Treatment

Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by a defect in the phagocytic function of the innate immune system owing to mutations in genes encoding the five subunits of the nicotinamide adenine dinucleotide phosphatase (NADPH) oxidase enzyme complex. This review aimed to provide a comprehensive approach to the pathogens associated with chronic granulomatous disease (CGD) and its management. Patients with CGD, often children, have recurrent life-threatening infections and may develop infectious or inflammatory complications. The most common microorganisms observed in the patients with CGD are Staphylococcus aureus, Aspergillus spp., Candida spp., Nocardia spp., Burkholderia spp., Serratia spp., and Salmonella spp. Antibacterial prophylaxis with trimethoprim-sulfamethoxazole, antifungal prophylaxis usually with itraconazole, and interferon gamma immunotherapy have been successfully used in reducing infection in CGD. Haematopoietic stem cell transplantation (HCT) have been successfully proven to be the treatment of choice in patients with CGD.

Recent topics and advanced therapies in chronic granulomatous disease

Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by the inability of phagocytes to produce reactive oxygen species (ROS) owing to a defect in any of the five components (CYBB/gp91phox, CYBA/p22phox, NCF1/p47phox, NCF2/p67phox, and NCF4/p40phox) and a concomitant regulatory component of Rac1/2 and CYBC1/Eros of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. Patients with CGD are at an increased risk of life-threatening infections caused by catalase-positive bacteria and fungi and of inflammatory complications such as CGD colitis. Antimicrobial and azole antifungal prophylaxes have considerably reduced the incidence and severity of bacterial and improved fungal infections and overall survival. CGD studies have revealed the precise epidemiology and role of NADPH oxidase in innate immunity which has led to a new understanding of the importance of phagocyte oxygen metabolism in various host-defense systems and the fields leading to cell death processes. Moreover, ROS plays central roles in the determination of cell fate as secondary messengers and by modifying of various signaling molecules. According to this increasing knowledge about the effects of ROS on the inflammasomal system, immunomodulatory treatments, such as IFN-γ and anti-IL-1 antibodies, have been established. This review covers the current topics in CGD and the relationship between ROS and ROS-mediated pathophysiological phenomena. In addition to the shirt summary of hematopoietic stem cell transplantation and gene therapy, we introduce a novel ROS-producing enzyme replacement therapy using PEG-fDAO to compensate for NADPH oxidase deficiency.

Long-Term Observational Study of Chronic Granulomatous Disease About 41 Patients From Tunisia and Comparison to Other Long-Term Follow-Up Studies

Chronic granulomatous disease (CGD) is an inherited autosomal recessive or X-Linked primitive immunodeficiency (PID), due to a defective nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex impairing anti-infectious and anti-inflammatory role of peripheral blood mononuclear cells. It is characterized by severe bacterial and fungal infections and by excessive inflammation leading to granulomatous complications. This work was made over a period of 34 years on 41 Tunisian patients suffering from CGD. Cumulative follow-up of patients was 2768.5 months, median 31 months. Survival was studied by survival curves according to Kaplan-Meier method. Lymphatic nodes, pulmonary and cutaneous infections predominate as revealing manifestations and as infectious events during patients' monitoring. At study end 12 patients died mainly of invasive pulmonary aspergillosis and septicemia. Median age of death was 30 months. CGD remains compatible with a decent quality of life. Early diagnosis, anti-infectious prophylaxis, and initiation of adequate management, as soon as complication is perceived, promote pretty good evolution.

Variant Type X91+ Chronic Granulomatous Disease: Clinical and Molecular Characterization in a Chinese Cohort

PURPOSE

We aimed to report the clinical and immunological characteristics of variant type X91⁺ chronic granulomatous disease (CGD) in a Chinese cohort.

METHODS

The clinical manifestations and immunological phenotypes of patients with X91⁺ CGD were collected. A dihydrorhodamine (DHR) analysis was performed to evaluate neutrophil function. Gp91^phox protein expression was determined using extracellular staining with the monoclonal antibody (mAb) 7D5 and flow cytometry.

RESULTS

Patients with X91⁺ CGD accounted for 8% (7/85) of all patients with CGD. The median age of onset in the seven patients with X91⁺ CGD was 4 months. Six patients received the BCG vaccine, and 50% (3/6) had probable BCG infections. Mycobacterium tuberculosis infection was prominent. The most common sites of infection were the lung (6/7), lymph nodes (5/7), and soft tissue (3/7). Two patients experienced recurrent oral ulcers. The stimulation index (SI) of the patients with X91⁺ CGD ranged widely from 1.9 to 67.3. The difference in the SI among the three groups of patients (X91⁺ CGD, X91^- CGD, and X91⁰ CGD) was statistically significant (P = 0.0071). The three groups showed no significant differences in onset age, diagnosis age, or severe infection frequency. CYBB mutations associated with X91⁺ CGD were commonly located in the second transmembrane or intracellular regions. Three novel X91⁺ CGD-related mutations (c.1462-2 A > T, c.1243C > T, and c.925G > A) were identified.

CONCLUSIONS

Variant type X91⁺ CGD may result in varied clinical manifestations. Moreover, the laboratory findings might indicate a moderate neutrophil SI. We should deepen our understanding of variant X91⁺ CGD to prevent missed diagnoses.

Chronic Granulomatous Disease: an Updated Experience, with Emphasis on Newly Recognized Features

Purpose

Chronic granulomatous disease (CGD) is an uncommon, inborn error of immunity. We updated our large, single-center US experience with CGD and describe some newly recognized features.

Methods

We retrospectively reviewed 26 patients seen from November 2013 to December 2019. Serious infections required intravenous antibiotics or hospitalization.

Results

There were 21 males and 5 females. The most frequent infectious agents at presentation were aspergillus (4), serratia (4), burkholderia (2), Staphylococcus aureus (2), and klebsiella (2). The most common serious infections at presentation were pneumonia (6), lymphadenitis (6), and skin abscess (3). Our serious infection rate was 0.2 per patient-year from December 2013 through November 2019, down from 0.62 per patient-year from the previous study period (March 1985–November 2013). In the last 6 years, four patients were evaluated for human stem cell transplantation, two were successfully transplanted, and we had no deaths. Several patients had unusual infections or autoimmune manifestations of disease, such as pneumocystis pneumonia, basidiomycete/phellinus fungal pneumonia, and retinitis pigmentosa. We included one carrier female with unfavorable Lyonization in our cohort.

Conclusion

We update of a large US single-center experience with CGD and describe some recently identified features of the illness.

Phenomic Analysis of Chronic Granulomatous Disease Reveals More Severe Integumentary Infections in X-Linked Compared With Autosomal Recessive Chronic Granulomatous Disease

Background

Chronic granulomatous disease (CGD) is an inborn error of immunity (IEI), characterised by recurrent bacterial and fungal infections. It is inherited either in an X-linked (XL) or autosomal recessive (AR) mode. Phenome refers to the entire set of phenotypes expressed, and its study allows us to generate new knowledge of the disease. The objective of the study is to reveal the phenomic differences between XL and AR-CGD by using Human Phenotype Ontology (HPO) terms.

Methods

We collected data on 117 patients with genetically diagnosed CGD from Asia and Africa referred to the Asian Primary Immunodeficiency Network (APID network). Only 90 patients with sufficient clinical information were included for phenomic analysis. We used HPO terms to describe all phenotypes manifested in the patients.

Results

XL-CGD patients had a lower age of onset, referral, clinical diagnosis, and genetic diagnosis compared with AR-CGD patients. The integument and central nervous system were more frequently affected in XL-CGD patients. Regarding HPO terms, perianal abscess, cutaneous abscess, and elevated hepatic transaminase were correlated with XL-CGD. A higher percentage of XL-CGD patients presented with BCGitis/BCGosis as their first manifestation. Among our CGD patients, lung was the most frequently infected organ, with gastrointestinal system and skin ranking second and third, respectively. Aspergillus species, Mycobacterium bovis, and Mycobacteirum tuberculosis were the most frequent pathogens to be found.

Conclusion

Phenomic analysis confirmed that XL-CGD patients have more recurrent and aggressive infections compared with AR-CGD patients. Various phenotypic differences listed out can be used as clinical handles to distinguish XL or AR-CGD based on clinical features.

"Oral Manifestations of Patients with Inherited Defect in Phagocyte Number or Function" a systematic review

INTRODUCTION

Inherited phagocyte defects are one of the subgroups of primary immunodeficiency diseases (PIDs) with various clinical manifestations. As oral manifestations are common at the early ages, oral practitioners can have a special role in the early diagnosis.

MATERIALS AND METHODS

A comprehensive search was conducted in this systematic review study and data of included studies were categorized into four subgroups of phagocyte defects, including congenital neutropenia, defects of motility, defects of respiratory burst, and other non-lymphoid defects.

RESULTS

Among all phagocyte defects, 12 disorders had reported data for oral manifestations in published articles. A total of 987 cases were included in this study. Periodontitis is one of the most common oral manifestations.

CONCLUSION

There is a need to organize better collaboration between medical doctors and dentists to diagnose and treat patients with phagocyte defects. Regular dental visits and professional oral health care are recommended from the time of the first primary teeth eruption in newborns.

Second Report of Chronic Granulomatous Disease in Jordan: Clinical and Genetic Description of 31 Patients From 21 Different Families, Including Families From Lybia and Iraq

Chronic granulomatous Disease (CGD) is a rare innate immunodeficiency disorder caused by mutations in one of the six genes (CYBA, CYBB, NCF1, NCF2, NCF4, and CYBC1/EROS) encoding the superoxide-producing nicotinamide adenine dinucleotide phosphate (NADPH)—oxidase complex in phagocytes. In the Western population, the most prevalent form of CGD (about two-thirds of all cases) is the X-linked form (X-CGD) caused by mutations in CYBB. The autosomal recessive forms (AR-CGD), due to mutations in the other genes, collectively account for the remaining one-third of CGD cases. We investigated the clinical and molecular features of 22 Jordanian, 7 Libyan, and 2 Iraqi CGD patients from 21 different families. In addition, 11 sibling patients from these families were suspected to have been died from CGD as suggested by their familial and clinical history. All patients except 9 were children of consanguineous parents. Most of the patients suffered from AR-CGD, with mutations in CYBA, NCF1, and NCF2, encoding p22^phox, p47^phox, and p67^phox proteins, respectively. AR-CGD was the most frequent form, in Jordan probably because consanguineous marriages are common in this country. Only one patient from non-consanguineous parents suffered from an X91⁰ CGD subtype (0 indicates no protein expression). AR67⁰ CGD and AR22⁰ CGD appeared to be the most frequently found sub-types but also the most severe clinical forms compared to AR47⁰ CGD. As a geographical clustering of 11 patients from eight Jordanian families exhibited the c.1171_1175delAAGCT mutation in NCF2, segregation analysis with nine polymorphic markers overlapping NCF2 indicates that a common ancestor has arisen ~1,075 years ago.

Mystery of a Family with Recurrent Male Infant Deaths- Solved by Autopsy and Molecular Tests

The authors report a case of a six weeks old boy who presented with acute febrile illness and progressive abdominal distension. There was a significant family history of early male sibling deaths. Autopsy showed multiorgan abscesses. Molecular test revealed final diagnosis of the child.

Clinical and Immunological Characteristics of 63 Patients with Chronic Granulomatous Disease: Hacettepe Experience

BACKGROUND

Chronic granulomatous disease (CGD), one of the phagocytic system defects, is the primary immunodeficiency caused by dysfunction of the NADPH oxidase complex which generates reactive oxygen species (ROS), which are essential for killing pathogenic microorganisms, especially catalase-positive bacteria and fungi.

OBJECTIVE

The objective of our study was to assess the clinical and laboratory characteristics, treatment modalities, and prognosis of patients with CGD.

METHODS

We retrospectively reviewed 63 patients with CGD who have been diagnosed, treated, and/or followed-up between 1984 and 2018 in Hacettepe University, Ankara, in Turkey, as a developing country.

RESULTS

The number of female and male patients was 26/37. The median age at diagnosis was 3.8 (IQR: 1.0-9.6) years. The rate of consanguinity was 63.5%. The most common physical examination finding was lymphadenopathy (44/63), growth retardation (33/63), and hepatomegaly (27/63). One adult patient had squamous cell carcinoma of the lung. The most common infections were lung infection (53/63), skin abscess (43/63), and lymphadenitis (19/63). Of the 63 patients with CGD, 6 patients had inflammatory bowel disease (IBD). Twelve of the 63 patients died during follow-up. CYBA, NCF1, CYBB, and NCF2 mutations were detected in 35%, 27.5%, 25%, and 12.5% of the patients, respectively.

CONCLUSION

We identified 63 patients with CGD from a single center in Turkey. Unlike other cohort studies in Turkey, due to the high consanguineous marriage rate in our study group, AR form of CGD was more frequent, and gastrointestinal involvement were found at relatively lower rates. The rate of patients who treated with HSCT was lower in our research than in the literature. A majority of the patients in this study received conventional prophylactic therapies, which highlight on the outcome of individuals who have not undergone HSCT.

Geographic Variability and Pathogen-Specific Considerations in the Diagnosis and Management of Chronic Granulomatous Disease

Chronic granulomatous disease (CGD) is a rare but serious primary immunodeficiency with varying prevalence and rates of X-linked and autosomal recessive disease worldwide. Functional defects in the phagocyte nicotinamide adenine dinucleotide phosphate oxidase complex predispose patients to a relatively narrow spectrum of bacterial and fungal infections that are sometimes fastidious and often difficult to identify. When evaluating and treating patients with CGD, it is important to consider their native country of birth, climate, and living situation, which may predispose them to types of infections that are atypical to your routine practice. In addition to recurrent and often severe infections, patients with CGD and X-linked female carriers are also susceptible to developing many non-infectious complications including tissue granuloma formation and autoimmunity. The DHR-123 oxidation assay is the gold standard for making the diagnosis and it along with genetic testing can help predict the severity and prognosis in patients with CGD. Disease management focuses on prophylaxis with antibacterial, antifungal, and immunomodulatory medications, prompt identification and treatment of acute infections, and prevention of secondary granulomatous complications. While hematopoietic stem-cell transplantation is the only widely available curative treatment for patients with CGD, recent advances in gene therapy may provide a safer, more direct alternative.

Novel NCF2 Mutation Causing Chronic Granulomatous Disease

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency disorder caused by defects in the NADPH oxidase complex. Mutations in NCF2 encoding the cytosolic factor p67^phox result in autosomal recessive CGD. We describe three patients with a novel c.855G>C NCF2 mutation presenting with diverse clinical phenotype. Two siblings were heterozygous for the novel mutation and for a previously described exon 8-9 duplication, while a third unrelated patient was homozygous for the novel mutation. Mutation pathogenicity was confirmed by abnormal DHR123 assay and absent p67^phox production and by sequencing of cDNA which showed abnormal RNA splicing. Clinically, the homozygous patient presented with suspected early onset interstitial lung disease and NCF2 mutation was found on genetic testing performed in search for surfactant-related defects. The two siblings also had variable presentation with one having history of severe pneumonia, lymphadenitis, and recurrent skin abscesses and the other presenting in his 30s with discoid lupus erythematosus and without significant infectious history. We therefore identified a novel pathogenic NCF2 mutation causing diverse and unusual clinical phenotype.

Inflammatory consequences of inherited disorders affecting neutrophil function

Primary immunodeficiencies affecting the function of neutrophils and other phagocytic leukocytes are notable for an increased susceptibility to bacterial and fungal infections as a result of impaired leukocyte recruitment, ingestion, and/or killing of microbes. The underlying molecular defects can also impact other innate immune responses to infectious and inflammatory stimuli, leading to inflammatory and autoimmune complications that are not always directly related to infection. This review will provide an update on congenital disorders affecting neutrophil function in which a combination of host defense and inflammatory complications are prominent, including nicotinamide dinucleotide phosphate oxidase defects in chronic granulomatous disease and β2 integrin defects in leukocyte adhesion deficiency.

Genetic and molecular findings of 38 Iranian patients with chronic granulomatous disease caused by p47-phox defect

One of the components of NADPH oxidase is p47-phox, encoded by NCF1 gene. This study aims to find new genetic changes and clinical features in 38 Iranian patients with autosomal recessive chronic granulomatous disease (AR-CGD) caused by NCF1 gene defect. Patients who had abnormal NBT and DHR-1,2,3 assay with loss of p47-phox in Western blotting were included in this study. After recording demographic and clinical data, PCR amplification was performed followed by direct sequencing for all exons and exon-intron boundaries. The most common form of CGD in Iran was AR-CGD due to consanguinity marriages. Among patients with AR-CGD, NCF1 deficiency was found to be more common than other forms. Cutaneous involvements (53%), pulmonary infections (50%) and lymphadenopathy (29%) were more prevalent than other clinical manifestations of CGD. Mutation analysis of NCF1 gene identified five different mutations. Homozygous delta GT deletion (c.75_76delGT) was the most frequent mutation and was detected in more than 63% of families. Six families had a nonsense mutation in exon 7 (c.579G > A). Two novel mutations were found in exon 4 in two families, including a missense mutation (c.328C > T) and a nine-nucleotide deletion (c.331_339delTGTCCCCAC). Genetic detection of these mutations may result in early diagnosis and prevention of possible complications of the disease. This could be useful for timely decision-making for haematopoietic stem cell transplantation and for carrier detection as well as prenatal diagnosis of next children in the affected families. Our findings might help to predict outcomes, raise awareness and help effective treatment in these patients.

A Cohort of 169 Chronic Granulomatous Disease Patients Exposed to BCG Vaccination: a Retrospective Study from a Single Center in Shanghai, China (2004-2017)

PURPOSE

Clinical diagnosis and treatment for chronic granulomatous disease (CGD) have advanced greatly in recent years. However, CGD patients in China have unique clinical features and infection spectrums, which are challenging to their caretakers. Here, we summarized the clinical characteristics, genetic features, treatment, and prognosis of CGD in a single center in Shanghai.

METHODS

One hundred sixty-nine CGD patients were recruited between January 2004 and May 2017 based on clinical diagnosis. Electronic medical charts were reviewed to collect clinical data.

RESULTS

Among the 169 patients recruited, CYBB mutations were identified in 150 cases, whereas CYBA mutations were identified in 7 cases, NCF1 in 5, and NCF2 in 7. The medium age at onset was 1 month (interquartile range 1-3). The medium age at diagnosis was 8 months (interquartile range 3-19). The most common infection sites were the lung (95.9%), lymph node (58.5%), skin (45.4%), intestinal (43.1%), and perianal (38.5%). Bacillus Calmette-Guérin (BCG) infections were common (59.2%). In addition, other non-infectious complications were also common, including anemia (55.4%) and impaired liver functions (34.6%). Thirty-one patients received stem cell transplantation. By the end of this study, 83/131 patients survived.

CONCLUSIONS

Similar to other non-consanguineous populations, X-linked CGD accounted for the majority of the cases in China. However, BCG infections were a clinical challenge unique to China. In addition, severe infections were the major cause of death and the overall mortality was still high in China.

Staphylococcus aureus, phagocyte NADPH oxidase and chronic granulomatous disease

Dysfunction of phagocytes is a relevant risk factor for staphylococcal infection. The most common hereditary phagocyte dysfunction is chronic granulomatous disease (CGD), characterized by impaired generation of reactive oxygen species (ROS) due to loss of function mutations within the phagocyte NADPH oxidase NOX2. Phagocytes ROS generation is fundamental to eliminate pathogens and to regulate the inflammatory response to infection. CGD is characterized by recurrent and severe bacterial and fungal infections, with Staphylococcus aureus as the most frequent pathogen, and skin and lung abscesses as the most common clinical entities. Staphylococcus aureus infection may occur in virtually any human host, presumably because of the many virulence factors of the bacterium. However, in the presence of functional NOX2, staphylococcal infections remain rare and are mainly linked to breaches of the skin barrier. In contrast, in patients with CGD, S. aureus readily survives and frequently causes clinically apparent disease. Astonishingly, little is known why S. aureus, which possesses a wide range of antioxidant enzymes (e.g. catalase, SOD), is particularly sensitive to control through NOX2. In this review, we will evaluate the discovery of CGD and our present knowledge of the role of NOX2 in S. aureus infection.

Three novel mutations in CYBA among 22 Iranians with Chronic granulomatous disease

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by defect in one of the components of nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase enzyme. The enzyme is at least composed of membrane-bound subunits gp91-phox and p22-phox (also named cytochrome b₅₅₈ ), and cytosolic ones p40-phox, p47-phox and p67-phox. A defect in the enzyme activity leads to impaired intracellular killing of phagocytic cells. The CYBA gene encoding p22-phox is located on chromosome 16q24. In this study, new genetic changes of CYBA gene in 22 Iranian patients with autosomal recessive-CGD (AR-CGD) were identified. Twenty-two patients with CGD were referred to Immunology, Asthma and Allergy Research Institute (IAARI) and enrolled in this study based on defect in NADPH oxidase activity, demographic data and clinical histories. All patients had p22-phox deficiency based on Western blotting. Genomic DNA was extracted from peripheral blood mononuclear cells (PBMCs), and PCR followed by direct sequencing was performed to find p22-phox mutations. Mutation analysis of CYBA revealed 12 different mutations, including three novel mutations: one was deletion of exon 1, and two were point mutations in exon 3 (c.136G>A (p.Gly46Ser)), and exon 6 (c.388C>T (p.Gln130X)). Three new mutations of CYBA gene in four of 22 Iranian patients with AR-CGD were found. These three novel mutations can partly complete the database of Human Gene Mutation Database (HGMD) and other related ones. It can also be helpful for further prenatal diagnosis in the affected families. Given that currently bone marrow transplantation is considered to be the curative treatment for patients with CGD, finding mutations will also be useful for timely decision-making in bone marrow transplantation.

Infection Profile in Chronic Granulomatous Disease: a 23-Year Experience from a Tertiary Care Center in North India

PURPOSE

Chronic granulomatous disease (CGD) is an inherited phagocytic disorder characterized by recurrent infections with usually catalase-positive organisms. Infections in CGD from developing countries are expected to be different from those in the Western countries. We report the profile of infections in children diagnosed with CGD from a tertiary care center in North India.

METHODOLOGY

Case records of children diagnosed with CGD at Pediatric Immunodeficiency Clinic, Advanced Pediatrics Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India, from August 1993 to April 2016 (23 years) were analyzed.

RESULTS

Thirty-eight children were diagnosed to have CGD. Median follow-up of patients was 2 years (interquartile range 0.75, 6.0). Staphylococcus aureus and Pseudomonas spp. were the two most common causative bacteria isolated. Aspergillus was the most common fungus isolated. The most common organ involved was the lung (94.7%). Liver abscesses were identified in 5 patients (13.2%), and 20 (52.6%) patients had lymphadenitis. Infections with Pseudomonas spp. were high in our cohort (15.7%) compared to the other studies. Infections with some unusual organisms (e.g., Fusarium dimerium and Chryseobacterium gleum) were also seen in our cohort. Children with X-linked CGD presented earlier and also had a greater number of infections as compared to autosomal recessive CGD.

CONCLUSIONS

Various socioeconomic factors coupled with the lack of awareness and paucity of readily available diagnostic facilities for primary immunodeficiencies accounted for a late clinical presentation with severe infections and increased mortality (28.9%) in our cohort. However, mortality was similar in X-linked and autosomal recessive CGD as was the number of fungal infections. The incidence of infections and mortality was significantly lower after initiation of antibacterial and antifungal prophylaxis.

Prostatic abscess in a patient with chronic granulomatous disease: a multi-disciplinary intervention

INTRODUCTION

Chronic granulomatous disease (CGD) is a rare pathology that increases patients' susceptibility to infections, given the inability to generate oxygen radicals to fight microorganisms.In the context of CGD, primary prostatic involvement has been described only once in the past, in a pediatric patient.

CASE REPORT

We report the case of a 35-year old patient with CGD presenting with persistent fever. After hospital admission, blood and urine were sent for culture and antibiotic therapy was initiated. Patient´s conditions continued to deteriorate and an aggressive antibiotic therapy was administered to treat the septic scenario. Urine culture grew a multidrug-resistant Escherichia Coli. After patient's condition improved, a CT scan was performed. The depiction showed multiple abscesses within the prostate. A rectal approach was excluded given patient's underlying disease. A TURP was performed and prostatic pathology resolved. Patient was discharged on postoperative day 14. At 6-month follow-up he hasn't experienced major infections.To the best of our knowledge, this is the first case of septic shock originating from a prostatic abscess in an adult patient with CGD.

CONCLUSIONS

Aggressive medical therapy along with TURP resulted curative in our case. A multi-disciplinary approach was mandatory.

Chronic granulomatous disease: Clinical, functional, molecular, and genetic studies. The Israeli experience with 84 patients

Chronic granulomatous disease (CGD) is an innate immunodeficiency with a genetic defect of the nicotinamide adenosine dinucleotide phosphate, reduced, oxidase components. This leads to decreased reactive oxygen species (ROS) production, which renders patients susceptible to life-threatening infections. Over the course of 30 years, we diagnosed CGD in 84 patients from 61 families using functional, molecular, and genetic studies. The incidence of CGD in Israel is 1.05 per 100,000 live-births in the Jewish population and 1.49 in the Israeli Arab population. We diagnosed 52 patients (62%) with autosomal recessive inheritance (AR-CGD) and 32 (38%) with X-linked recessive inheritance (XLR-CGD). Consanguinity was detected in 64% of AR-CGD families (14% in Jews and 50% in Israeli Arabs). We found 36 different mutations (23 in XLR-CGD and 13 in AR-CGD patients), 15 of which were new. The clinical spectrum of CGD varied from mild to severe disease in both XLR and AR forms, although the AR subtype is generally milder. Further, residual ROS production correlated with milder clinical expression, better prognosis and improved overall survival. Patients with recurrent pyogenic infections developed fibrosis and hyperinflammatory states with granuloma formation. The management of CGD has progressed substantially in recent years, evolving from a fatal disease of early childhood to one of long-term survival. Our present cohort displays an encouraging 81% overall long term survival. Early hematopoietic stem cell transplantation is advisable before tissue damage is irreversible. Successful transplantation was performed in 18/21 patients. Therapeutic gene modification could become an alternative cure for CGD. Am. J. Hematol. 92:28-36, 2017. © 2016 Wiley Periodicals, Inc.

Primary immune deficiencies with defects in neutrophil function

Immune deficiencies resulting from inherited defects in neutrophil function have revealed important features of the innate immune response. Although sharing an increased susceptibility to bacterial and fungal infections, these disorders each have distinctive features in their clinical manifestations and characteristic microbial pathogens. This review provides an update on several genetic disorders with impaired neutrophil function, their pathogenesis, and treatment strategies. These include chronic granulomatous disease, which results from inactivating mutations in the superoxide-generating nicotinamide dinucleotide phosphate oxidase. Superoxide-derived oxidants play an important role in the control of certain bacterial and fungal species, and also contribute to the regulation of inflammation. Also briefly summarized are updates on leukocyte adhesion deficiency, including the severe periodontal disease characteristic of this disorder, and a new immune deficiency associated with defects in caspase recruitment domain-containing protein 9, an adaptor protein that regulates signaling in neutrophils and other myeloid cells, leading to invasive fungal disease.

Patterns of Primary Immunodeficiency Disorders Among a Highly Consanguineous Population: Cairo University Pediatric Hospital's 5-Year Experience

INTRODUCTION

Primary immunodeficiency disorders (PIDs) are heterogeneous disorders that mainly present with severe, persistent, unusual, or recurrent infections in childhood. Reports from different parts of the world indicate a difference between Western and Eastern populations.

AIM

The aim of this study was to report on the different patterns of PIDs and identify subgroup characteristics in a highly consanguineous population in Egypt.

METHODS

We performed a retrospective chart review for children below 18 years diagnosed with PID at Cairo University Pediatric Hospital from 2010 to 2014.

RESULTS

Four hundred seventy-six children were diagnosed with PID disorders. Major categories included combined immunodeficiency disorders, which constituted a large proportion (30 %) of cases, along with predominantly antibody disorders (18 %) followed by syndromic combined disorders (16.8 %), phagocytic disorders (13.2 %), immune dysregulation disorders (10.5 %), and autoinflammatory disorders (9 %).

CONCLUSION

PIDs have different patterns within inbred populations with high consanguinity.

Aspergillosis in Chronic Granulomatous Disease

Patients with chronic granulomatous disease (CGD) have the highest life-time incidence of invasive aspergillosis and despite the availability of antifungal prophylaxis, infections by Aspergillus species remain the single most common infectious cause of death in CGD. Recent developments in curative treatment options, such as haematopoietic stem cell transplantation, will change the prevalence of infectious complications including invasive aspergillosis in CGD patients. However, invasive aspergillosis in a previously healthy host is often the first presenting feature of this primary immunodeficiency. Recognizing the characteristic clinical presentation and understanding how to diagnose and treat invasive aspergillosis in CGD is of utmost relevance to improve clinical outcomes. Significant differences exist in fungal epidemiology, clinical signs and symptoms, and the usefulness of non-culture based diagnostic tools between the CGD host and neutropenic patients, reflecting underlying differences in the pathogenesis of invasive aspergillosis shaped by the nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase deficiency.

Role of Flow Cytometry in the Diagnosis of Chronic Granulomatous Disease: the Egyptian Experience

INTRODUCTION

Chronic granulomatous disease (CGD) is an inherited mutational defect in any of the NADPH oxidase complex, CYBB (gp91-phox), NCF1 (p47-phox), CYBA (p22-phox), NCF2 (p67-phox), or NCF4 (p40-phox) leading to inability of phagocytes to perform effective respiratory burst and thus diminished killing of bacteria and fungi. The identification of defective proteins aids in establishing a diagnosis prior to genetic analysis, which is rather labor-intensive, expensive, and time-consuming.

AIM

The present study aims at assessing the NADPH proteins by performing the intracellular staining with specific monoclonal antibodies and their assessment on flow cytometry. The use of flow cytometry is less laborious and faster to perform than western blot. It also confirms the diagnosis of CGD and detects the affected components allowing proper management of patients.

MATERIALS AND METHODS

Twenty-eight patients from 25 different kindred, clinically suspected as CGD were recruited in Egypt. Dihydrorhodamine test was performed to confirm the diagnosis of the patients. Intracellular staining of NADPH components using specific monoclonal antibodies was performed followed by flow cytometric analysis.

RESULTS

The present study revealed that the most common defective protein in our cohort is p22-phox, found in 13 patients (46.4 % of cases) followed by p47-phox in 8 patients (28.6 %), gp91-phox in 5 patients (17.9 %), and finally p67-phox in 2 patients (7.1 %).

CONCLUSION

In countries with limited resources and yet large number of CGD patients, the analysis of the defective proteins by flow cytometry is an optimum solution for confirming the diagnosis and is a step for targeted sequencing in families seeking prenatal diagnosis.

CYBA encoding p22(phox), the cytochrome b558 alpha polypeptide: gene structure, expression, role and physiopathology

P22(phox) is a ubiquitous protein encoded by the CYBA gene located on the long arm of chromosome 16 at position 24, containing six exons and spanning 8.5 kb. P22(phox) is a critical component of the superoxide-generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs). It is associated with NOX2 to form cytochrome b558 expressed mainly in phagocytes and responsible for the killing of microorganisms when bacterial and fungal infections occur. CYBA mutations lead to one of the autosomal recessive forms of chronic granulomatous disease (AR22(0)CGD) clinically characterized by recurrent and severe infections in early childhood. However, p22(phox) is also the partner of NOX1, NOX3 and NOX4, but not NOX5, which are analogs of NOX2, the first identified member of the NOX family. P22(phox)-NOX complexes have emerged as one of the most relevant sources of reactive oxygen species (ROS) in tissues and cells, and are associated with several diseases such as cardiovascular and cerebrovascular diseases. The p22(phox)-deficient mouse strain nmf333 has made it possible to highlight the role of p22(phox) in the control of inner ear balance in association with NOX3. However, the relevance of p22(phox) for NOX3 function remains uncertain because AR22(0)CGD patients do not suffer from vestibular dysfunction. Finally, a large number of genetic variations of CYBA have been reported, among them the C242T polymorphism, which has been extensively studied in association with coronary artery and heart diseases, but conflicting results continue to be reported.

Chronic Granulomatous Disease: A Large, Single-center US Experience

BACKGROUND

Chronic granulomatous disease (CGD) is an uncommon primary immunodeficiency that can be inherited in an X-linked (XL) or an autosomal recessive (AR) manner. We reviewed our large, single-center US experience with CGD.

METHODS

We reviewed 27 patients at Ann & Robert H. Lurie Children's Hospital of Chicago from March 1985 to November 2013. Fisher exact test was used to compare differences in categorical variables, and Student t test was used to compare means for continuous variables. Serious infections were defined as those requiring intravenous antibiotics or hospitalization.

RESULTS

There were 23 males and 4 females; 19 were XL and 8 were AR. The average age at diagnosis was 3.0 years; 2.1 years for XL and 5.3 years for AR inheritance (P = 0.02). There were 128 serious infections. The most frequent infectious agents were Staphylococcus aureus (n = 13), Serratia (n = 11), Klebsiella (n = 7), Aspergillus (n = 6) and Burkholderia (n = 4). The most common serious infections were pneumonia (n = 38), abscess (n = 32) and lymphadenitis (n = 29). Thirteen patients had granulomatous complications. Five patients were below the 5th percentile for height and 4 were below the 5th percentile for weight. Average length of follow-up after diagnosis was 10.1 years. Twenty-four patients were compliant and maintained on interferon-γ, trimethoprim-sulfamethoxazole and an azole. The serious infection rate was 0.62 per patient-year. Twenty-three patients are alive (1 was lost to follow-up).

CONCLUSIONS

We present a large, single-center US experience with CGD. Twenty-three of 27 patients are alive after 3276 patient-months of follow-up (1 has been lost to follow-up), and our serious infection rate was 0.62 per patient-year.

Long-term outcome of patients with p22 (phox) -deficient chronic granulomatous disease on Jeju Island, Korea

Purpose

This study investigated the long-term clinical outcomes of patients with p22^phox-deficient chronic granulomatous disease (CGD) on Jeju Island and retrospectively evaluated the effects of interferon-gamma (IFN-γ) prophylaxis.

Methods

The medical records of 15 patients with CGD were retrospectively reviewed. The efficacy of IFN-γ prophylaxis was evaluated by comparing the frequency of severe infections before and after starting continuous prophylaxis with IFN-γ.

Results

At the time of the analysis, 14 patients were alive, with a median age of 14.3 years. The diagnosis of CGD was made at a median age of 2.4 years, and the median age at onset of severe infection was 0.3 years. Thirteen of the 15 patients had their first severe infection within the first year of life. The overall incidence of severe infection was 1.36 infections per patient-year; pneumonia, suppurative lymphadenitis, and skin and subcutaneous abscesses were the most common infections. Aspergillus species were the most frequently isolated microorganisms, present in 15.8% of isolates. IFN-γ did not significantly change the rate of severe infection. The survival rate for patients after 2 years of age was 93%; there was a prolonged survival plateau beyond the age of 2.

Conclusion

Compared with cases of X-linked CGD reported in other studies, patients with CGD on Jeju Island did not show obviously different clinical manifestations, but they had a significantly higher survival rate. Further studies with a substantially longer period of observation, and with more patients under intensive surveillance are necessary to elucidate the prophylactic efficiency of IFN-γ.

Chronic granulomatous disease: Review of a cohort of Egyptian patients

BACKGROUND

Chronic granulomatous disease (CGD) is an inherited disease that results from a defect in the phagocytic cells of the immune system. It is caused by defects in one of the major subunits of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. The clinical presentations of CGD patients are heterogeneous.

OBJECTIVES

This is the first report from Egypt discussing clinical and laboratory data of twenty-nine patients (from 26 families) with CGD from a single tertiary referral centre.

RESULTS

There were twenty male and nine female patients. The consanguinity rate was 76% (19/25). Their age of diagnosis ranged from 2 to 168 months with a mean of 52.8 months ± 49.6 SD. The most common manifestations were abscesses in 79.3% (deep organ abscesses in 37.9% of patients), followed by pneumonia in 75.8% and gastrointestinal symptoms in 27.5%. Rare but fatal complications were also reported among patients as one patient developed haemophagocytic lymphohistiocytosis (HLH) syndrome. Although X linked-CGD universally constitutes the most common pattern of inheritance; only 6 of our patients 6/25 (24%) belonged to this group with a Stimulation Index (SI) of 1-5, and confirmed by carrier pattern of their mothers. Mothers were not available for testing in four male children. Nineteen patients (76%) had autosomal recessive patterns; ten males and nine females patients based on having abnormal SI, positive history of consanguinity and their mothers showing normal SI.

CONCLUSION

Increasing the awareness of physicians about symptoms of CGD may lead to earlier diagnosis of the disease, thus enhancing proper management and better quality of life.

Common severe infections in chronic granulomatous disease

BACKGROUND

Chronic granulomatous disease (CGD) is due to defective nicotinamide adenine dinucleotide phosphate oxidase activity and characterized by recurrent infections with a limited spectrum of bacteria and fungi as well as inflammatory complications. To understand the impact of common severe infections in CGD, we examined the records of 268 patients followed at a single center over 4 decades.

METHODS

All patients had confirmed diagnoses of CGD, and genotype was determined where possible. Medical records were excerpted into a standard format. Microbiologic analyses were restricted to Staphylococcus, Burkholderia, Serratia, Nocardia, and Aspergillus.

RESULTS

Aspergillus incidence was estimated at 2.6 cases per 100 patient-years; Burkholderia, 1.06 per 100 patient-years; Nocardia, 0.81 per 100 patient-years; Serratia, 0.98 per 100 patient-years, and severe Staphylococcus infection, 1.44 per 100 patient-years. Lung infection occurred in 87% of patients, whereas liver abscess occurred in 32%. Aspergillus incidence was 55% in the lower superoxide-producing quartiles (quartiles 1 and 2) but only 41% in the higher quartiles (rate ratio, <0.0001). Aspergillus and Serratia were somewhat more common in lower superoxide producing gp91phox deficiency. The median age at death has increased from 15.53 years before 1990 to 28.12 years in the last decade. Fungal infection carried a higher risk of mortality than bacterial infection and was the most common cause of death (55%). Gastrointestinal complications were not associated with either infection or mortality.

CONCLUSIONS

Fungal infections remain a major determinant of survival in CGD. X-linked patients generally had more severe disease, and this was generally in those with lower residual superoxide production. Survival in CGD has increased over the years, but infections are still major causes of morbidity and mortality.

Mendelian susceptibility to mycobacterial disease: genetic, immunological, and clinical features of inborn errors of IFN-γ immunity

Mendelian susceptibility to mycobacterial disease (MSMD) is a rare condition characterized by predisposition to clinical disease caused by weakly virulent mycobacteria, such as BCG vaccines and environmental mycobacteria, in otherwise healthy individuals with no overt abnormalities in routine hematological and immunological tests. MSMD designation does not recapitulate all the clinical features, as patients are also prone to salmonellosis, candidiasis and tuberculosis, and more rarely to infections with other intramacrophagic bacteria, fungi, or parasites, and even, perhaps, a few viruses. Since 1996, nine MSMD-causing genes, including seven autosomal (IFNGR1, IFNGR2, STAT1, IL12B, IL12RB1, ISG15, and IRF8) and two X-linked (NEMO, and CYBB) genes have been discovered. The high level of allelic heterogeneity has already led to the definition of 18 different disorders. The nine gene products are physiologically related, as all are involved in IFN-γ-dependent immunity. These disorders impair the production of (IL12B, IL12RB1, IRF8, ISG15, NEMO) or the response to (IFNGR1, IFNGR2, STAT1, IRF8, CYBB) IFN-γ. These defects account for only about half the known MSMD cases. Patients with MSMD-causing genetic defects may display other infectious diseases, or even remain asymptomatic. Most of these inborn errors do not show complete clinical penetrance for the case-definition phenotype of MSMD. We review here the genetic, immunological, and clinical features of patients with inborn errors of IFN-γ-dependent immunity.

Inflammatory manifestations in a single-center cohort of patients with chronic granulomatous disease

BACKGROUND

Chronic granulomatous disease (CGD) is a rare phagocytic disorder that results in not only infections but also potentially severe inflammatory manifestations that can be difficult to diagnose and treat.

OBJECTIVE

To describe inflammatory manifestations in a single-center cohort of patients with CGD.

METHODS

Medical records of patients treated at Necker-Enfants Malades Hospital (Paris, France) between 1968 and 2009 and registered at the French National Reference Center for Primary Immunodeficiencies (CEREDIH) were retrospectively reviewed.

RESULTS

In a study population of 98 patients, a total of 221 inflammatory episodes were recorded in 68 individuals (69.4%). The incidence rate of inflammatory episodes was 0.15 per person-year (0.18 in patients with X-linked [XL] CGD and 0.08 in patients with autosomal-recessive [AR] CGD). The most commonly affected organs were the gastrointestinal tract (in 88.2% of the patients), lungs (26.4%), the urogenital tract (17.6%), and eyes (8.8%). Inflammation at other sites (the skin, central nervous system, and tympanum) and autoimmune manifestations (lupus, arthritis, etc) were recorded in 19.1% and 10.3% of the patients, respectively. Granuloma was found in 50% of the 44 histological analyses reviewed. The risk of inflammatory episodes was 2-fold higher in patients with XL-CGD than in patients with AR-CGD (relative risk, 2.22; 95% CI, 1.43-3.46).

CONCLUSIONS

Patients with XL-CGD have a higher risk of developing inflammatory episodes than do patients with AR-CGD. Although the most commonly affected organ is the gastrointestinal tract, other sites can be involved, making the management of patients with CGD a complex, multidisciplinary task.

Deficits in bioenergetics and impaired immune response in granulocytes from children with autism

Despite the emerging role of mitochondria in immunity, a link between bioenergetics and the immune response in autism has not been explored. Mitochondrial outcomes and phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst were evaluated in granulocytes from age-, race-, and gender-matched children with autism with severity scores of ≥7 (n = 10) and in typically developing (TD) children (n = 10). The oxidative phosphorylation capacity of granulocytes was 3-fold lower in children with autism than in TD children, with multiple deficits encompassing ≥1 Complexes. Higher oxidative stress in cells of children with autism was evidenced by higher rates of mitochondrial reactive oxygen species production (1.6-fold), higher mitochondrial DNA copy number per cell (1.5-fold), and increased deletions. Mitochondrial dysfunction in children with autism was accompanied by a lower (26% of TD children) oxidative burst by PMA-stimulated reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase and by a lower gene expression (45% of TD children's mean values) of the nuclear factor erythroid 2-related factor 2 transcription factor involved in the antioxidant response. Given that the majority of granulocytes of children with autism exhibited defects in oxidative phosphorylation, immune response, and antioxidant defense, our results support the concept that immunity and response to oxidative stress may be regulated by basic mitochondrial functions as part of an integrated metabolic network.

Clinical, functional, and genetic characterization of chronic granulomatous disease in 89 Turkish patients

BACKGROUND

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency disorder of phagocytes resulting in impaired killing of bacteria and fungi. A mutation in one of the 4 genes encoding the components p22(phox), p47(phox), p67(phox), and p40(phox) of the leukocyte nicotinamide dinucleotide phosphate reduced (NADPH) oxidase leads to autosomal recessive (AR) CGD. A mutation in the CYBB gene encoding gp91(phox) leads to X-linked recessive CGD.

OBJECTIVE

The aim of this study is to show the correlation between clinical, functional, and genetic data of patients with CGD from Turkey.

METHODS

We report here the results of 89 patients with CGD from 73 Turkish families in a multicenter study.

RESULTS

Most of the families (55%) have an AR genotype, and 38% have an X-linked genotype; patients from 5 families with a suspected AR genotype (7%) were not fully characterized. We compared patients with CGD according to the severity of NADPH oxidase deficiency of neutrophils. Patients with A22(0), A67(0) or X91(0) phenotypes with a stimulation index of 1.5 or less have early clinical presentation and younger age at diagnosis (mean, 3.2 years). However, in p47(phox)-deficient cases and in 5 other AR cases with high residual oxidase activity (stimulation index ≥ 3), later and less severe clinical presentation and older age at diagnosis (mean, 7.1 years) were found. Pulmonary involvement was the most common clinical feature, followed by lymphadenitis and abscesses.

CONCLUSION

Later and less severe clinical presentation and older age at diagnosis are related to the residual NADPH oxidase activity of neutrophils and not to the mode of inheritance. CGD caused by A22(0) and A67(0) subtypes manifests as severe as the X91(0) subtype.

Pediatric allergy and immunology in Israel

After the geographic and sociodemographic settings as well as the health care in Israel are briefly described, the scope of pediatric allergy and immunology in Israel is presented. This includes specific disorders commonly encountered, the environment that induces symptoms, the specialists who treat them, and the common challenges of patients, parents, doctors, and allied health personnel who collaborate to manage the maladies and patient care. Allergies usually affect some overall 15-20% of the pediatric population. The main allergens are inhaled, ingested, or injected (insects stings). Generally, the incidence of the various allergens affecting children in Israel, is similar to other parts of the Western world. Owing to the high consanguinity rate in the Israeli population, the prevalence of the various immunodeficiency conditions (in the adaptive as well as the innate system) is higher than that reported worldwide. Pediatric allergists/immunologists also treat autoimmune disorders affecting the pediatric group. Pediatric allergy and clinical immunology are not separate specialties. The 25 specialists who treat children with allergic/immunologic diseases have undergone a basic training in Pediatrics. They also received an additional 2-yr training in allergy and clinical immunology and then have to pass the board examinations. They work mainly in pediatric allergy units, in several hospitals that are affiliated to the five medical schools in the country. Aside from clinical work, most of the centers are also heavily involved in clinical and basic research in allergy and immunology.

Infections associated with chronic granulomatous disease: linking genetics to phenotypic expression

Chronic granulomatous disease (CGD) is an inherited primary immunodeficiency characterized by the absence or malfunction of the NADPH oxidase in phagocytic cells. As a result, there is an impaired ability to generate superoxide anions and the subsequent reactive oxygen intermediates. Consequently, CGD patients suffer from two clinical manifestations: recurrent, life-threatening bacterial and fungal infections and excessive inflammatory reactions leading to granulomatous lesions. Although the genotype of CGD was linked to the phenotypic expression of the disease, this connection is still controversial and poorly understood. Certain correlations were reported, but the clinical expression of the disease is usually unpredictable, regardless of the pattern of inheritance. CGD mainly affects the lungs, lymph nodes, skin, GI tract and liver. Patients are particularly susceptible to catalase-positive microorganisms, including Staphyloccocus aureus, Nocardia spp. and Gram-negative bacteria, such as Serratia marcescens, Burkholderia cepacea and Salmonella spp. Unusually, catalase-negative microorganisms were reported as well. New antibacterial and antimycotic agents considerably improved the prognosis of CGD. Therapy with IFN-γ is still controversial. Bone marrow stem cell transplantation is currently the only curative treatment and gene therapy needs further development. In this article, the authors discuss the genetic, functional and molecular aspects of CGD and their impact on the clinical expression, infectious complications and the hyperinflammatory state.

Chronic granulomatous disease

Chronic granulomatous disease (CGD) is a paradigm for nonlymphoid primary immune defects, and has guided elucidation of oxygen metabolism in the phagocyte, vasculature, and brain. It has been in the forefront of the development of antimicrobial prophylaxis before the advent of advanced HIV and before its routine use in neutropenia. It has been an attractive target for gene therapy and bone marrow transplantation for nonmalignant diseases. Therefore, CGD is worthy of attention for its historical interest and because it is a disease for which expert management is imperative.

Evidence for bistable bacteria-neutrophil interaction and its clinical implications

Neutropenia, which may develop as a consequence of chemotherapy, increases the risk of bacterial infection. Similarly, increased risk of bacterial infection appears in disorders of phagocytic functions, such as the genetic disorder chronic granulomatous disease. To elucidate the organizing principles behind these distinct immunodeficiency conditions, we investigated the interaction between in vitro bacteria and human neutrophils by experiments and mathematical modeling. The model and the experiments showed that the in vitro bacterial dynamics exhibit bistability for a certain range of neutrophil concentration and function. Thus, there is a critical bacterial concentration above which infection develops, and below which neutrophils defeat the bacteria. Whereas with normal neutrophil concentration and function, an infection may develop when the initial bacterial concentration is very high, under neutropenic conditions or when there is neutrophil dysfunction, the critical bacterial concentration can be lower, within the clinically relevant range. We conclude that critical bacterial concentration has clinically relevant implications. The individual maximum bearable bacterial concentration depended on neutrophil concentration, phagocytic activity, and patient barrier integrity; thus, the resulting maximal bearable bacterial concentration may vary by orders of magnitude between patients. Understanding the interplay between neutrophils and bacteria may enhance the development of new therapeutic approaches to bacterial infections.

Invasive mold infections in chronic granulomatous disease: a 25-year retrospective survey

BACKGROUND

Invasive fungal infection (IFI) represents a life-threatening condition for patients with chronic granulomatous disease (CGD) and causes one-third of deaths in this population. This study offers a descriptive review of invasive mold infection (mIFI) in children with CGD over an extended period of time.

METHODS

In a cohort of patients with CGD registered in the French National database for Primary Immunodeficiency, we performed a retrospective review of proven mIFI episodes (European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group 2008 criteria) occurring from 1984 through 2009.

RESULTS

Twenty-nine proven mIFIs were identified in 24 patients. Thirteen (54%) of 24 children were receiving itraconazole prophylaxis. Seven episodes were caused by Aspergillus fumigatus, 10 by Aspergillus nidulans, 2 by Aspergillus species, and 6 by other opportunistic molds (4 patients only had positive pathological examination findings). First proven mIFI occurred later in the group that received itraconazole than in the group without (median time to mIFI, 10 vs 4 years; P < .01), with a higher proportion of infections due to A. nidulans and other opportunistic molds (P < .05). Course of IFI was complex, with the median duration of therapy and hospitalization reaching 446 and 153 days, respectively. Combined antifungal therapy was commonly used. Four patients received geno-identical hematopoietic stem cell transplantation as salvage therapy. Global cure rate among the cohort reached 75%, but sequelae were frequent. Prognosis has improved over time (43% mortality during 1985-1990 vs 6% thereafter; P = .06). Mortality tended to be lower in the group that recieved itraconazole prophylaxis but at the cost of a longer duration of therapy among cured patients.

CONCLUSIONS

Management of mIFI remains challenging in patients with CGD, but significant improvements have been made over the past decade.