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.

Anakinra Activates Superoxide Dismutase 2 to Mitigate Inflammasome Activity

Inflammasomes are powerful cytosolic sensors of environmental stressors and are critical for triggering interleukin-1 (IL-1)-mediated inflammatory responses. However, dysregulation of inflammasome activation may lead to pathological conditions, and the identification of negative regulators for therapeutic purposes is increasingly being recognized. Anakinra, the recombinant form of the IL-1 receptor antagonist, proved effective by preventing the binding of IL-1 to its receptor, IL-1R1, thus restoring autophagy and dampening NLR family pyrin domain containing 3 (NLRP3) activity. As the generation of mitochondrial reactive oxidative species (ROS) is a critical upstream event in the activation of NLRP3, we investigated whether anakinra would regulate mitochondrial ROS production. By profiling the activation of transcription factors induced in murine alveolar macrophages, we found a mitochondrial antioxidative pathway induced by anakinra involving the manganese-dependent superoxide dismutase (MnSOD) or SOD2. Molecularly, anakinra promotes the binding of SOD2 with the deubiquitinase Ubiquitin Specific Peptidase 36 (USP36) and Constitutive photomorphogenesis 9 (COP9) signalosome, thus increasing SOD2 protein longevity. Functionally, anakinra and SOD2 protects mice from pulmonary oxidative inflammation and infection. On a preclinical level, anakinra upregulates SOD2 in murine models of chronic granulomatous disease (CGD) and cystic fibrosis (CF). These data suggest that protection from mitochondrial oxidative stress may represent an additional mechanism underlying the clinical benefit of anakinra and identifies SOD2 as a potential therapeutic target.

The phagocyte NOX2 NADPH oxidase in microbial killing and cell signaling

The phagocyte NADPH oxidase possesses a transmembrane electron transferase comprised of gp91phox (aka NOX2) and p22phox and two multicomponent cytosolic complexes, which in stimulated phagocytes translocate to assemble a functional enzyme complex at plasma or phagosomal membranes. The NOX2-centered NADPH oxidase shuttles electrons from cytoplasmic NADPH to molecular oxygen in phagosomes or the extracellular space to produce oxidants that support optimal antimicrobial activity by phagocytes. Additionally, NOX2-generated oxidants have been implicated in both autocrine and paracrine signaling in a variety of biological contexts. However, when interpreting experimental results, investigators must recognize the complexity inherent in the biochemistry of oxidant-mediated attack of microbial targets and the technical limitations of the probes currently used to detect intracellular oxidants.

Intersecting Stories of the Phagocyte NADPH Oxidase and Chronic Granulomatous Disease

Neutrophils serve as the circulating cells that respond early and figure prominently in human host defense to infection and in inflammation in other settings. Optimal oxidant-dependent antimicrobial activity by neutrophils relies on the ability of stimulated phagocytes to utilize a multicomponent NADPH oxidase to generate oxidants. The frequent, severe, and often fatal infections experienced by individuals with chronic granulomatous disease (CGD), an inherited disorder in which one of the NADPH oxidase components is absent or dysfunctional, underscore the link between a functional phagocyte NADPH oxidase and robust host protection against microbial infection.The history of the discovery and characterization of the normal neutrophil NADPH oxidase and the saga of recognizing CGD and its underlying causes together illustrate how the observations of astute clinicians and imaginative basic scientists synergize to forge new understanding of both basic cell biology and pathogenesis of human disease.In this chapter, we review the events in the stepwise evolution of our understanding of the phagocyte NADPH oxidase, both in the context of normal human neutrophil function and in the setting of CGD. The phagocyte oxidase complex employs a heterodimeric transmembrane protein composed of gp91phox and p22phox to relay electrons from NADPH to molecular oxygen, while other cofactors contribute to localization and regulation of the activity of the assembled oxidase. The b-type cytochrome gp91phox, also known as NOX2, serves as the catalytic component of this multicomponent enzyme complex. Although many of the features of the composition and regulation of the phagocyte oxidase may apply as well to NOX2 expressed in non-phagocytes and to other members of the NOX protein family, exceptions exist and pose special challenges to investigators exploring the biology of NADPH oxidases.

Chronic Granulomatous Disease

Chronic granulomatous disease is a clinical condition that stems from inactivating mutations in NOX2 and its auxiliary proteins. Together, these proteins form the phagocyte NADPH oxidase enzyme that generates superoxide. Superoxide (O₂^ċ-) and its reduced product hydrogen peroxide (H₂O₂) give rise to several additional reactive oxygen species (ROS), which together are necessary for adequate killing of pathogens. Thus, CGD patients, with a phagocyte NADPH oxidase that is not properly functioning, suffer from recurrent, life-threatening infections with certain bacteria, fungi, and yeasts. Here, I give a short survey of the genetic mutations that underlie CGD, the effect of these mutations on the activity of the leukocyte NADPH oxidase, the clinical symptoms of CGD patients, and the treatment options for these patients.

Diagnostic Testing for Chronic Granulomatous Disease

Chronic granulomatous disease (CGD) is a rare genetic immunodeficiency associated with recurrent bacterial infections, granulomas, and increased mortality. It is characterized by the inability of phagocytes (neutrophils, monocytes, etc.) to generate reactive oxygen species (ROS), a major component of the microbicidal repertoire of phagocytes. Diagnosis of patients with CGD is commonly based on the assessment of ROS production by neutrophils. Multiple assays to assess ROS production are described-a flow cytometric dihydrorhodamine assay and a histochemical nitroblue tetrazolium assay, both of which can be used to visualize ROS production in individual cells, and two quantitative assays-O₂^˙- reduction of ferricytochrome c and a ROS-dependent, luminol-enhanced chemiluminescence assay that will quantitate the response of a population of cells. In addition, two approaches to identify the defective phox protein defect are described-standard immunoblotting and flow cytometry of neutrophils stained with phox-specific antibodies. When determining the status of a patient, several assays should be used to assess ROS production and identify the protein defect. The results of these assays should agree and can be used to develop a comprehensive package, which includes confirmation of a diagnosis of CGD, identification of the specific protein target for genetic sequencing, and an indication of the prognosis for the patient.

Granulomatous lymphadenitis mimicking metastatic lymphadenopathy in the neck after lymphatic embolization of chyle leakage: A case report

RATIONALE

Lymphatic embolization is a minimally invasive treatment option for managing chyle leakage after nodal dissection in the neck. After the procedure, the embolic material may cause foreign body granulomatous lymphadenitis and can be a diagnostic challenge for radiologists because of sonographic similarity to metastatic lymph node. Herein, we describe a clinical case of granulomatous lymphadenitis due to embolic material mimicking nodal metastasis detected on ultrasonography (US) with cytologic findings in a patient with thyroid cancer who underwent lymphatic embolization to treat chyle leakage after total thyroidectomy and neck dissection. We also review the relevant literature regarding this disease with technical background of the procedure and suggest the importance of clinical suspicion in diagnosing the granulomatous lymphadenitis in patients with a history of lymphatic embolization.

PATIENT CONCERNS

A 40-year-old man who underwent total thyroidectomy and bilateral modified radical neck dissection due to papillary thyroid carcinoma had suspicious cervical lymph node on US after lymphatic embolization of chyle leakage.

DIAGNOSES

The suspicious cervical lymph node proved to be foreign body granulomatous lymphadenitis due to embolic material by US-guided fine-needle aspiration.

INTERVENTIONS

The patient did not undergone additional surgery because the pathologic cervical lymph node was confirmed to be foreign body granulomatous lymphadenitis.

OUTCOMES

The patient is being followed up regularly at the outpatient department.

LESSONS

Clinical awareness of the technical background of lymphatic embolization and possible sonographic features of granulomatous lymphadenitis is important for an accurate diagnosis and the appropriate management in patients who underwent lymphatic embolization.

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.

Granulomatous dacryoadenitis in regional enteritis (crohn disease)

PURPOSE

To evaluate the clinical and immunopathologic features of 2 patients with bilateral dacryoadenitis associated with regional enteritis.

DESIGN

Retrospective, clinicopathologic study.

METHODS

Clinical records, photographs, and imaging studies were reviewed and microscopic sections of lacrimal gland biopsy samples were critically re-evaluated. The microscopic slides were stained with hematoxylin and eosin, special stains for organisms, and a range of immunohistochemical biomarkers, including CD3, CD4, CD5, CD8, CD20, CD68, CD138, CD1a, and immunoglobulins Ig G, IgG4, and IgA.

RESULTS

Both patients were young women with a well-established diagnosis of regional enteritis. Histopathologic examination of biopsy samples disclosed moderate intraparenchymal fibrosis and lymphoplasmacytic infiltrates without lymphoid follicles. Small to medium intraparenchymal, noncaseating granulomas lacking multinucleated giant cells and, in 1 patient, CD68-positive and CD1a-negative palisading granulomas in widened interlobular fibrous septa were detected. Vasculitis and IgG4 plasma cells were not observed. Additional immunohistochemical studies revealed that CD8 T lymphocytes (suppressor or cytotoxic subset) predominated over CD4-positive T lymphocytes (helper cells) surrounding the necrobiotic foci and were intermixed with the CD68-positive histiocytes in the absence of CD20 B lymphocytes. Special stains for organisms demonstrated negative results.

CONCLUSIONS

Dacryoadenitis is the rarest form of ocular adnexal involvement in regional enteritis, which affects the orbit far more frequently than ulcerative colitis. It is a granulomatous process with the possibility of palisading necrobiotic foci. In contrast, ulcerative colitis causes an interstitial lymphocytic and nongranulomatous myositis. Sarcoidosis, Wegener granulomatosis, and pseudorheumatoid nodules must be ruled out. Treatment options entail a wide variety of agents with selection based on empirical considerations and tailored to the patient's symptoms.

Identification and functional characterization of two novel mutations in the α-helical loop (residues 484-503) of CYBB/gp91(phox) resulting in the rare X91(+) variant of chronic granulomatous disease

Chronic granulomatous disease (CGD) is mainly caused by mutations in X-linked CYBB that encodes gp91. We have identified two novel mutations in CYBB resulting in the rare X91(+)-CGD variant, c.1500T>G (p.Asp500Glu) in two male siblings and c.1463C>A (p.Ala488Asp) in an unrelated male. Zymosan and/or PMA (Phorbol 12-myristate 13-acetate)-induced recruitment of p47(phox) and p67(phox) to the membrane fraction was normal for both mutants. Cell-free assays using recombinant wild-type and the mutant proteins revealed that these mutants were not activated by NADPH (nicotinamide adenine dinucleotide phosphate). Interestingly, the Ala488Asp mutant was activated by NADPH in the presence of glutathione. These data suggest that the mutations prevented NADPH from binding to gp91(phox) and the requirement of a negative charge at residue 500 in gp91(phox) for NADPH oxidase assembly, in contrast to a previously described Asp500Gly change. These mutations and the effect of glutathione provide a unique insight into disease pathogenesis and potential therapy in variant X91(+)-CGD.

Hypomorphic Rag mutations can cause destructive midline granulomatous disease

Destructive midline granulomatous disease characterized by necrotizing granulomas of the head and neck is most commonly caused by Wegener granulomatosis, natural killer/T-cell lymphomas, cocaine abuse, or infections. An adolescent patient with myasthenia gravis treated with thymectomy subsequently developed extensive granulomatous destruction of midface structures, palate, nasal septum, airways, and epiglottis. His lymphocyte numbers, total immunoglobulin G level, and T-cell receptor (TCR) repertoire appeared normal. Sequencing of Recombination activating gene-1 (Rag1) showed compound heterozygous Rag1 mutations; a novel deletion with no recombinase activity and a missense mutation resulting in 50% Rag activity. His thymus was dysplastic and, although not depleted of T cells, showed a notable absence of autoimmune regulator (AIRE) and Foxp3(+) regulatory T cells. This distinct Rag-deficient phenotype characterized by immune dysregulation with granulomatous hyperinflammation and autoimmunity, with relatively normal T and B lymphocyte numbers and a diverse TCR repertoire expands the spectrum of presentation in Rag deficiency. This study was registered at www.clinicaltrials.gov as #NCT00128973.

[Disseminated cutaneous granulomatosis]

The disseminated cutaneous granulomatosis (DCG) are heterogeneous cutaneous diseases histologically characterized by a granulomatous infiltrate. The most frequent cutaneous granulomatosis is sarcoidosis, but many other causes can be found, because DCG are probably a skin granulomatous reaction to different stimuli: infectious, inflammatory, neoplastic, metabolic or chemical. The histopathological examination is useful for the diagnosis of DCG, but gives rarely an etiological diagnosis. In this article, we will propose a strategy for the etiological diagnosis of DCG, and propose therapeutic recommendations based on recent data from the literature.

Fulminant mulch pneumonitis: an emergency presentation of chronic granulomatous disease

BACKGROUND

Chronic granulomatous disease (CGD) is associated with multiple and recurrent infections. In patients with CGD, invasive pulmonary infection with Aspergillus species remains the greatest cause of mortality and is typically insidious in onset. Acute fulminant presentations of fungal pneumonia are catastrophic.

METHODS

Case records, radiograph findings, and microbiologic examination findings of patients with CGD who had acute presentations of dyspnea and diffuse pulmonary infiltrates caused by invasive fungal infection were reviewed and excerpted onto a standard format.

RESULTS

From 1991 through 2004, 9 patients who either were known to have CGD or who received a subsequent diagnosis of CGD presented with fever and new onset dyspnea. Eight patients were hypoxic at presentation; bilateral pulmonary infiltrates were noted at presentation in 6 patients and developed within 2 days after initial symptoms in 2 patients. All patients received diagnoses of invasive filamentous fungi; 4 patients had specimens that also grew Streptomyces species on culture. All patients had been exposed to aerosolized mulch or organic material 1-10 days prior to the onset of symptoms. Cases did not occur in the winter. Five patients died. Two patients, 14 years of age and 23 years of age, who had no antecedent history of recognized immunodeficiency, were found to have p47(phox)-deficient CGD.

CONCLUSIONS

Acute fulminant invasive fungal pneumonia in the absence of exogenous immunosuppression is a medical emergency that is highly associated with CGD. Correct diagnosis has important implications for immediate therapy, genetic counseling, and subsequent prophylaxis.

[Nodular thrombophlebitis and granulomatous systemic disease]

INTRODUCTION

Nodular thrombophlebitis is septal hypodermitis characterised by vasculitis with vein thrombosis. It may indicate serious underlying disorders.

EXEGESIS

We present two cases of nodular superficial phlebitis, which revealed tuberculosis and sarcoidosis.

CONCLUSION

Nodular thrombophlebitis are classic during evolution of Behçet disease or Buerger vasculitis. In sarcoidosis, erythema nodosum and granulomatous involvement are the most common cutaneous manifestation. Nodular thrombophlebitis has never been described. Panniculitis are classical in tuberculosis. But most cases are erythema nodosum and cases of erythema induratum of Bazin. Nodular thrombophlebitis could reveal thrombophilic abnormalities, and even more neoplasms especially when they are recurrent and migratory.

Glycosyl-phosphatidyl-inositol-defective granulocytes from paroxysmal nocturnal haemoglobinuria patients show increased bacterial ingestion but reduced respiratory burst induction

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by the emergence of a GPI-defective clonal hematopoiesis. Its clinical features are hemolytic anemia, cytopenia, and thrombosis. Circulating monocytes and granulocytes are largely GPI-defective in PNH patients. This study aims to investigate the granulocyte functional properties in PNH. We analyzed bacterial-dependent intracellular ingestion and the consequent activation of oxidative burst in GPI-defective granulocytes from four neutropenic PNH patients. Our data show a significant increase in the ability of GPI-defective granulocytes to ingest opsonized bacteria. In addition, an impaired respiratory burst effectiveness in response to two independent bacterial stimuli, the N-formyl-MetLeuPhe (fMLP) synthetic bacterial peptide and E. coli, was revealed. The occurrence of neutropenia and the severe impairment of oxidative burst, occurring in chronic granulomatosis disease, were unable to significantly affect phagocytosis. Thus, additional mechanisms, able to differentially affect ingestion ability and respiratory burst effectiveness, have to be hypothesized. The reduced burst effectiveness of GPI-defective granulocytes was maintained after treatment with phorbol 12-myristate 13-acetate, a pharmacological stimulus able to extensively recruit and to trigger intracellular protein kinase C (PKC). Moreover, blocking of PKC has been observed to severely affect granulocyte respiratory burst with a mild effect on the phagocytosis. These data suggest a role for a modulation of intracellular PKC in the pathogenesis of the impaired granulocyte oxidative burst.

Fever of unknown origin in a patient with common variable immunodeficiency associated with multisystemic granulomatous disease

Non-caseating epithelioid granulomas have been described in a small number of patients with common variable immunodeficiency (CVID). We report a 26-year-old woman diagnosed with CVID nine years earlier, who developed non-caseating granulomas in the liver, bone marrow and skin. She was referred to our department for a fever of more than one year duration without apparent focus. Extensive search for underlying malignancy or occult infection was unremarkable. Empirical treatment with prednisone was begun and the patient showed a marked improvement. The literature on the association between CVID and non-caseating granulomatous disease, and the differential diagnosis of hepatic granulomas as a cause of fever of unknown origin, is also reviewed.

Correction of X-linked chronic granulomatous disease by gene therapy, augmented by insertional activation of MDS1-EVI1, PRDM16 or SETBP1

Gene transfer into hematopoietic stem cells has been used successfully for correcting lymphoid but not myeloid immunodeficiencies. Here we report on two adults who received gene therapy after nonmyeloablative bone marrow conditioning for the treatment of X-linked chronic granulomatous disease (X-CGD), a primary immunodeficiency caused by a defect in the oxidative antimicrobial activity of phagocytes resulting from mutations in gp91(phox). We detected substantial gene transfer in both individuals' neutrophils that lead to a large number of functionally corrected phagocytes and notable clinical improvement. Large-scale retroviral integration site-distribution analysis showed activating insertions in MDS1-EVI1, PRDM16 or SETBP1 that had influenced regulation of long-term hematopoiesis by expanding gene-corrected myelopoiesis three- to four-fold in both individuals. Although insertional influences have probably reinforced the therapeutic efficacy in this trial, our results suggest that gene therapy in combination with bone marrow conditioning can be successfully used to treat inherited diseases affecting the myeloid compartment such as CGD.

Imaging of Chronic Granulomatous Disease in Children

Chronic granulomatous disease (CGD) is a rare immunodeficiency disorder. The inability of phagocytic cells to kill catalase-positive organisms, such as Staphylococcus and Aspergillus species, causes recurrent infections, persistent inflammation, and granuloma formation. The imaging findings in nine cases of CGD were studied. Recurrent pulmonary infection was the most common abnormality (seven cases). Its complications included pulmonary abscesses, bronchiectasis, mediastinal abscesses, osteomyelitis, sepsis, and brain abscesses. Suppurative cervical adenitis was the second most common abnormality (four cases) and was also the presenting abnormality in the youngest patient (aged 31 days). Abdominal manifestations included hepatosplenomegaly, recurrent hepatic and splenic abscesses, necrotic mesenteric adenopathy, and gastric outlet obstruction. Osteomyelitis occurred in two cases secondary to hematogenous spread or spread of contiguous infection from the lung. Persistent infections led to formation of chronic inflammatory masses and granulomas in five cases. With improvements in therapy, the prognosis of CGD patients has improved and the general consensus is that most patients will survive into adulthood. Hence, radiologists are more likely to encounter the complications of CGD and should familiarize themselves with the spectrum of imaging findings.

Identification and first report of Inonotus (Phellinus) tropicalis as an etiologic agent in a patient with chronic granulomatous disease

Although isolates of filamentous basidiomycetes can usually be recognized in a clinical laboratory setting, identification is problematic, as they seldom exhibit diagnostic morphological features formed in nature. This paper is the first report of Inonotus (Phellinus) tropicalis inciting human disease and describes the methods used to support the identification.

Opposing roles for IL-13 and IL-13 receptor alpha 2 in health and disease

Interleukin (IL)-13 is a key inducer of several type-2 cytokine-dependent pathologies. It regulates inflammation, mucus production, tissue remodeling, and fibrosis. Consequently, it has become an important therapeutic target for a number of debilitating illnesses, including asthma, idiopathic pulmonary fibrosis, ulcerative colitis, as well as several other diseases in which IL-13 is believed to be overproduced. In the murine model of schistosomiasis, IL-13 has emerged as a central mediator of chronic infection-induced liver pathology. Although IL-4, IL-5, IL-10, and IL-13 each regulate distinct aspects of the granulomatous inflammatory response, IL-13 was identified as the primary mediator of liver fibrosis. Thus, elucidating the mechanisms that regulate the production and function of IL-13 has become an intensive area of research. IL-13 signaling is mediated by the type-2 IL-4 receptor, which consists of the IL-4R alpha and IL-13R alpha 1 chains. However, another IL-13-binding chain, IL-13R alpha 2, appears to strongly inhibit the activity of IL-13. Animals deficient in IL-13R alpha 2 fail to downmodulate granuloma formation in the chronic phase of infection. They also develop severe IL-13-dependent fibrosis and portal hypertension and quickly succumb to the infection. Here, we summarize findings from the schistosomiasis model, which illustrate opposing activities for IL-13 and IL-13R alpha 2 in health and disease.

Exuberant inflammation in nicotinamide adenine dinucleotide phosphate-oxidase-deficient mice after allogeneic marrow transplantation

We have shown that NO and superoxide (O-*2)contribute to donor T cell-dependent lung dysfunction after bone marrow transplantation (BMT) in mice. We hypothesized that inhibiting superoxide production during inducible NO synthase induction would suppress oxidative/nitrative stress and result in less severe lung injury. Irradiated mice lacking the phagocytic NADPH-oxidase (phox(-/-)), a contributor to superoxide generation, were conditioned with cyclophosphamide and given donor bone marrow in the presence or absence of inflammation-inducing allogeneic spleen T cells. On day 7 after allogeneic BMT, survival, weight loss, and indices of lung injury between phox(-/-) and wild-type mice were not different. However, the majority of macrophages/monocytes from phox(-/-) mice given donor T cells produced fewer oxidants and contained less nitrotyrosine than cells obtained from T cell-recipient wild-type mice. Importantly, suppressed oxidative stress was associated with marked infiltration of the lungs with inflammatory cells and was accompanied by increased bronchoalveolar lavage fluid levels of the chemoattractants monocyte chemoattractant protein-1 and macrophage-inflammatory protein-1alpha and impaired clearance of recombinant mouse macrophage-inflammatory protein-1beta from the circulation. Furthermore, cultured macrophages/monocytes from NADPH-deficient mice produced 3-fold more TNF-alpha compared with equal number of cells from NADPH-sufficient mice. The high NO production was not modified during NADPH-oxidase deficiency. We conclude that phox(-/-) mice exhibit enhanced pulmonary influx of inflammatory cells after BMT. Although NO may contribute to increased production of TNF-alpha in phox(-/-) mice, the data suggest that NADPH-oxidase-derived oxidants have a role in limiting inflammation and preventing lung cellular infiltration after allogeneic transplantation.

Neutrophil disorders and their management

Neutrophil disorders are an uncommon yet important cause of morbidity and mortality in infants and children. This article is an overview of these conditions, with emphasis on clinical recognition, rational investigation, and treatment. A comprehensive list of references is provided for further reading.

Common variable immunodeficiency

Common variable immunodeficiency (CVI) is a heterogeneous immunodeficiency syndrome characterized by hypogammaglobulinemia, recurrent bacterial infections, and a variety of immunological abnormalities. In addition to recurrent infections, patients with this syndrome also suffer from an increased incidence of autoimmune disease and malignancy. Because the spectrum of associated diseases is broad, patients with CVI are seen by a variety of medical specialists. In this review, the pathogenesis, clinical manifestations, diagnosis, and treatment of CVI are discussed.

A new exon created by intronic insertion of a rearranged LINE-1 element as the cause of chronic granulomatous disease

Long interspersed nuclear element-1 (LINE-1) or L1 elements are DNA elements present in the genome in high copy number and capable of active retrotransposition. Here we present a patient with severe chronic granulomatous disease (CGD) caused by insertion of an L1 sequence into intron 5 of the X-lined gene CYBB. Due to internal rearrangements, the insert introduced new splice sites into the intron. This resulted in a highly heterogeneous splicing pattern with introduction of two L1 fragments as new exons into the transcripts and concomitant skipping of exonic coding sequence. Because no wild-type cDNA was found, this mechanism is probably responsible for the patient's phenotype. The L1 fragment, which belongs to the Ta subset of transcriptionally active LINEs, illustrates a new mechanism by which these elements can modify the transcribed coding sequence of genes.

Molecular analysis of 9 new families with chronic granulomatous disease caused by mutations in CYBA, the gene encoding p22(phox)

Chronic granulomatous disease is a rare inherited disorder caused by nonexistent or severely decreased phagocyte superoxide production that results in a severe defect in host defense and consequent predisposition to microbial infection. The enzyme responsible for generating the superoxide, NADPH oxidase, involves at least 5 protein components. The absence of, or a defect in, any 1 of 4 of these proteins (p22(phox), p47(phox), p67(phox), or gp91(phox)) gives rise to the known types of chronic granulomatous disease. One of the rarest forms of the disease is due to defects in the CYBA gene encoding p22(phox), which together with gp91(phox) forms flavocytochrome b(558), the catalytic core of NADPH oxidase. To date, only 9 kindreds with p22(phox) deficiency have been described in the literature comprising 10 mutant alleles. Four polymorphisms in the CYBA gene have also been reported. Here we describe 9 new, unrelated kindreds containing 12 mutations, 9 of which are novel. In addition, we report 3 new polymorphisms. The novel mutations are (a) deletion of exons 2 and 3, (b) a missense mutation in exon 3 (T155-->C), (c) a splice site mutation at the 5' end of intron 3, (d) a missense mutation in exon 2 (G74-->T), (e) a nonsense mutation in exon 1 (G26-->A), (f) a missense mutation in exon 4 (C268-->T), (g) a frameshift in exon 3 due to the insertion of C at C162, (h) a nonsense mutation in exon 2 (G107-->A), and (i) a missense mutation in exon 2 (G70-->A).

[Role of active forms of oxygen generated by phagocytes in the pathogenesis of diseases]

The review deals with the analysis of the properties of active forms of oxygen (AFO), generated by phagocytic cells, and their role in the development of a number of human diseases. Bacterial and viral infections contribute to the activation of the oxidizing metabolism of phagocytes. In the process of this metabolism the formation of toxic oxygen and nitrogen metabolites occurs. The defect of the system of activation calls prolonged microbial persistence whose most severe manifestation is chronic granulomatosis. On the contrary, the uncontrolled production of oxidants cause tissue lesions. The role of AFO in the pathogenesis of cardiovascular diseases, peptic ulcer, the syndrome of respiratory insufficiency and bronchial asthma is discussed.

TNF and lymphotoxin-alpha polymorphisms associated with common variable immunodeficiency: role in the pathogenesis of granulomatous disease

A subgroup of common variable immunodeficiency (CVID) patients have distinct clinical features, particularly granulomata splenomegaly, characteristic blood lymphocyte phenotype, and elevated circulating TNF levels. To investigate the genetic basis for this phenotype, 150 CVID patients and 200 controls were genotyped for six biallelic TNF and lymphotoxin-alpha (LT alpha) polymorphisms and eight class I and II HLA loci using PCR and sequence specific primers (PCR-SSP) sequence-specific primers. Clinical and immunophenotypic data were collected for 90 patients to examine associations with CVID patient subgroups. The presence of granulomata (22% of patients) was strongly associated with splenomegaly, T and B lymphopenia, reduced CD4+ CD45RA+ T cells, and CD8+ CD57+ lymphocytosis, confirming the concept of a subgroup of patients with distinct clinical and laboratory features. The uncommon TNF +488A allele was strongly associated with this subgroup (p = 0.0005). The association between "granulomatous" CVID and TNF +488A was independent of HLA class I and II associations. We postulate that the presence of the TNF +488A allele, or alleles in linkage disequilibrium with it, contributes to the high levels of TNF and granulomatous complications characteristic of this subgroup of patients.

A p47-phox pseudogene carries the most common mutation causing p47-phox- deficient chronic granulomatous disease

The predominant genetic defect causing p47-phox-deficient chronic granulomatous disease (A47 degrees CGD) is a GT deletion (DeltaGT) at the beginning of exon 2. No explanation exists to account for the high incidence of this single mutation causing a rare disease in an unrelated, racially diverse population. In each of 34 consecutive unrelated normal individuals, both the normal and mutant DeltaGT sequences were present in genomic DNA, suggesting that a p47-phox related sequence carrying DeltaGT exists in the normal population. Screening of genomic bacteriophage and YAC libraries identified 13 p47-phox bacteriophage and 19 YAC clones. The GT deletion was found in 11 bacteriophage and 15 YAC clones. Only 5 exonic and 33 intronic differences distinguished all DeltaGT clones from all wild-type clones. The most striking differences were a 30-bp deletion in intron 1 and a 20-bp duplication in intron 2. These results provide good evidence for the existence of at least one highly homologous p47-phox pseudogene containing the DeltaGT mutation. The p47-phox gene and pseudogene(s) colocalize to chromosome 7q11.23. This close linkage, together with the presence within each gene of multiple recombination hot spots, suggests that the predominance of the DeltaGT mutation in A47 degrees CGD is caused by recombination events between the wild-type gene and the pseudogene(s).

Disturbed interaction of p21-rac with mutated p67-phox causes chronic granulomatous disease

Chronic granulomatous disease (CGD) is characterized by the failure of phagocytic leukocytes to generate superoxide, needed for the intracellular killing of microorganisms. This is caused by mutations in any one of the four subunits of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In a rare, autosomal recessive form of CGD, a 67-kD cytosolic component of this enzyme (p67-phox) is missing. We here report on a patient with a mutation in the p67-phox gene that leads to expression of a nonfunctional p67-phox protein. The purified granulocytes of this patient failed to produce superoxide and contained about half of the normal amount of p67-phox. Analysis of the cDNA and genomic DNA of this patient showed that the patient is a compound heterozygote for a triplet nucleotide deletion in the p67-phox gene, predicting an in-frame deletion of lysine 58 in the p67-phox protein and a larger deletion of 11-13 kb in the other allele. Interestingly, the 58Lys deletion in p67-phox disrupts the interaction with p21-rac1, a ras-related protein involved in the activation of the NADPH oxidase. In contrast to normal neutrophils, in which p47-phox and p67-phox translocate to the plasma membrane upon cell activation, the cells of the patient did not show this translocation, indicating that an interaction between p67-phox and p21-rac1 is essential for translocation of these cytosolic proteins and activation of the NADPH oxidase. Moreover, this CGD patient represents the first case of disease caused by a disturbed binding of a ras-related protein to its target protein.

Granulomatous infections: etiology and classification

Granulomatous disorders are frequently due to a wide variety of infections. Over the past decade advances in molecular diagnostic techniques have allowed identification of organisms involved in granulomatous disorders that previously were of unknown etiology. On the basis of currently available information, granulomatous infections can now be classified in three categories. Group 1 infections are due to a well-recognized organism. Group 2 comprises infections due to organisms that have been recently identified in granulomas by molecular methods but are not readily isolated by conventional microbiological techniques. Group 3 consists of disorders for which the causal organisms have not yet been identified but are strongly suspected; further advances in diagnostic techniques will lead to reclassification of some of these disorders as group 2. This review describes the etiology, histopathologic features, and classification of granulomatous disorders, with an emphasis on those of groups 2 and 3.

[A little known cause of persistent fever and granulomatous hepatitis in children: cat scratch disease]

BACKGROUND

Extensive hepatic and splenic involvement in cat-scratch disease has rarely been reported.

CASE REPORT

A 2 1/2 year-old boy suffered for 2 weeks from high-grade fever, abdominal pain and alteration of his general condition. Ultrasonography revealed multiple hypoechogenic nodules in liver and spleen. The CT scan also showed hypodense lesions. An open liver biopsy was performed 5 weeks after the onset of illness. Histopathology of a resected nodule demonstrated neutrophilic granulomatous inflammation with central abscess formation. Recent cat exposure, suppurated epitrochlear lymph node 15 days before admission were also consistent with cat-scratch disease which was confirmed by elevated anti-Rochalimaea antibody titers. Follow-up showed complete resolution of all hepatic and splenic lesions within 6 months and emergence of splenic calcifications.

CONCLUSION

Cat-scratch disease should be considered in the diagnosis of fever of unknown origin and hepatosplenic abscesses in children.