Chronic granulomatous disease. Report on a national registry of 368 patients

Long-term follow-up and prognosis of chronic granulomatous disease in Yugoslavia: is there a role for early bone marrow transplantation?

We report the long-term follow-up of 12 pediatric-aged patients with chronic granulomatous disease (CGD). The mean age at the onset of infections was 5 months with a median delay in diagnosis of 2.5 years. Bacille Calmette-Guérin lymphadenitis was the most common presenting infection (6) followed by suppurative lymphadenitis (4), liver abscess (1), or Salmonella sepsis (1). Prophylaxis with cotrimoxazole was recommended to all patients. During the mean follow-up of 10 years (range, 4-23 years) pneumonitis was the most prevalent infection (91%) followed by lymphadenitis (83%), aphtous stomatitis (58%), and liver abscesses (25%). Seven (58%) patients developed chronic lung disease due to grossly delayed diagnosis (3) or poor compliance with antimicrobial prophylaxis (4). Five (41%) patients died during the second decade of life of aspergillosis (3) or chronic lung disease (2). Probability of survival into the third decade of life was estimated to be only 19%. We argue that HLA-identical bone marrow transplantation (BMT), if possible, should be attempted at early age because of significant morbidity and mortality in adolescence. BMT also should be considered in patients who suffer severe infections despite antimicrobial prophylaxis or patients with evidence of chronic lung disease. Possibility of elective BMT from unrelated donors remains to be carefully evaluated.

Diminished T cell numbers in patients with chronic granulomatous disease

Chronic granulomatous disease is a neutrophil disorder in which phagocytic cells fail to produce a respiratory burst. Five genetic types of chronic granulomatous disease have been described and in each case the clinical manifestations relate to the inability to effectively kill catalase-positive organisms. It is classically described as a pure disorder of intracellular killing, with preservation of other aspects of phagocytic function such as migration and phagocytosis and normal function of nonmyeloid cells. This article describes a heretofore unrecognized feature of chronic granulomatous disease. Fifty-three patients with chronic granulomatous disease and 42 age-matched controls were studied by flow cytometry. Total T cell numbers and CD4 and CD8 T cell numbers were compared between patients and controls. Patients with chronic granulomatous disease had diminished T cell numbers compared to controls after 3 years of age. The difference increased with age. It is not known whether diminished T cell numbers influence the susceptibility to infections in these patients, but T cell effects could represent a significant cofactor for infection.

Immunodeficiency and genetic conditions that cause arthritis in childhood

Many conditions can cause or be associated with arthritis in childhood. The authors of this paper will review the situations in which underlying immunodeficiency or defective regulation of lymphocyte homeostasis must be suspected, and discuss, for some of these diseases, the genetic bases and pathogenesis. In the second part of this article, the authors will focus on other diseases that can cause arthritis in childhood, often with other symptoms, and for which evidence of an association with genetic abnormalities has been recently discovered. Finally, the authors will discuss the implications of recent findings regarding the role of some genes as causing or modulating factors in juvenile idiopathic arthritis and related disorders, as well as observations made in adults and in animal models of inflammation and autoimmunity.

A practical approach to neutrophil disorders

This review discusses disorders of altered neutrophil number and function and provide a basic framework for patient evaluation and management. The sections begin with neutropenia, neutrophilia and neutrophil dysfunction with a general screening approach to differentiate common, more benign syndromes from rare, often more serious disorders. Also included is a detailed discussion of some specific primary neutrophil syndromes at the end of each section. Focus is placed on specific disorders that are clinically common or particularly instructive.

Identification of a novel NCF-1 (p47-phox) pseudogene not containing the signature GT deletion: significance for A47 degrees chronic granulomatous disease carrier detection

The p47-phox gene, NCF-1, has 2 nearly identical pseudogenes (psiNCF-1) in proximity at chromosomal locus 7q11.23. A dinucleotide deletion (DeltaGT) at the beginning of exon 2 that leads to a frameshift and premature stop codon is considered the signature sequence of the pseudogenes. It is also the most prevalent mutation in p47-phox-deficient (A47 degrees ) chronic granulomatous disease (CGD) as a result of the insertion of a DeltaGT-containing fragment of pseudogene into NCF-1. Extending our study of the relationship between NCF-1 and psiNCF-1 to 53 unaffected control individuals, we found that although in most (n = 44), the ratio of pseudogene (DeltaGT) to functional gene (GTGT) sequence in amplicons spanning exon 2 was 2:1, as previously observed, surprisingly, in 7 persons the ratio was 1:1, and in 2 persons the ratio was 1:2. The lowered ratios are explained by the presence, in a heterozygous or homozygous state, respectively, of a pseudogene that contains GTGT rather than DeltaGT. It is possible that this pseudogene has not undergone deletion of GT, but more likely, based on analysis of additional NCF-1/psiNCF-1 markers, it represents the previously unidentified product of the reciprocal crossover of DNA fragments between the functional gene and one of its pseudogenes. The mutated NCF-1 resulting from this event is the predominant A47 degrees CGD allele. The existence of 2 extended haplotypes encompassing NCF-1/psiNCF-1 further complicates the detection of A47 degrees CGD carriers. Although most have a DeltaGT/GTGT ratio of 5:1, some have a ratio of 2:1 and are indistinguishable by this means from unaffected individuals.

Advances in Burkholderia cepacia complex

Burkholderia cepacia is an important opportunistic pathogen in certain compromised hosts, particularly those with either cystic fibrosis (CF) or chronic granulomatous disease. The "family" of bacteria known as B. cepacia is highly heterogeneous and is composed of at least nine discrete species or genomovars, constituting the B. cepacia complex. Bacteria from the B. cepacia complex are particularly virulent in susceptible hosts, often causing necrotising invasive infection and death. Whereas the microbial determinants of virulence in B. cepacia complex are currently not defined, the bacteria appear to have features facilitating survival within host cells. Burkholderia cepacia is highly resistant to antibiotics and to neutrophil-mediated non-oxidative killing; infection should be treated with combination antimicrobial therapy. Burkholderia cepacia can spread from one CF patient to another. Transmission appears to be facilitated by close personal contact and by certain bacterial factors.

Nocardia infection in chronic granulomatous disease

To determine the clinical characteristics and outcome of Nocardia infection in patients with chronic granulomatous disease (CGD), we reviewed data on 28 episodes of Nocardia infection in 23 patients with CGD. All episodes involved pulmonary infection. The frequency of disseminated nocardiosis was 25% for the case series overall, but it was 56% among episodes in patients receiving neither interferon-gamma (IFN-gamma) nor sulfonamide prophylaxis. Patients receiving prophylaxis with IFN-gamma and/or a sulfonamide were significantly less likely to have disseminated nocardiosis than were patients not receiving these medications, and no patient receiving both medications developed disseminated nocardiosis. One-third of the patients had concomitant fungal infections, and 2 patients had concomitant Legionella infections. The majority of patients were successfully treated with a sulfonamide-containing regimen, even though some patients had developed Nocardia infection while receiving sulfonamide prophylaxis. Nocardia infections in patients with CGD are not usually fatal if treated properly, and prophylaxis with IFN-gamma and a sulfonamide may protect against dissemination.

The role of the gut flora in health and disease, and its modification as therapy

The gut flora is a vast interior ecosystem whose nature is only beginning to be unravelled, due to the emergence of sophisticated molecular tools. Techniques such as 16S ribosomal RNA analysis, polymerase chain reaction amplification and the use of DNA microarrays now facilitate rapid identification and characterization of species resistant to conventional culture and possibly unknown species. Life-long cross-talk between the host and the gut flora determines whether health is maintained or disease intervenes. An understanding of these bacteria-bacteria and bacteria-host immune and epithelial cell interactions is likely to lead to a greater insight into disease pathogenesis. Studies of single organism-epithelial interactions have revealed the large range of metabolic processes that gut bacteria may influence. In inflammatory bowel diseases, bacteria drive the inflammatory process, and genetic predisposition to disease identified to date, such as the recently described NOD2/CARD15 gene variants, may relate to altered bacterial recognition. Extra-intestinal disorders, such as atopy and arthritis, may also have an altered gut milieu as their basis. Clinical evidence is emerging that the modification of this internal environment, using either antibiotics or probiotic bacteria, is beneficial in preventing and treating disease. This natural and apparently safe approach holds great appeal.

CYBB mutation analysis in X-linked chronic granulomatous disease

Chronic granulomatous disease (CGD) results from mutations of phagocyte NADPH oxidase. Seventy percent are X-linked (X-)CGD with absent or defective gp91(phox) protein encoded by the CYBB gene. A subset of X-CGD patients demonstrates partial oxidase activity and/or varied levels of the gp91(phox) protein. Definitive genotypic diagnosis in these unusual patients requires mutation analysis. Typically, CYBB mutation analysis has relied on initial screening of cDNA by single-stranded conformation polymorphism analysis, followed by selective sequencing. We report a fluorescent, automated method for CYBB mutation analysis using genomic DNA that provides more rapid and reliable results. Moreover, the use of genomic DNA in this approach allows mutation detection in the mRNA coding region, promoter/enhancer region, and intronic sequences flanking splice junctions and does not require mRNA preparation. The PCR conditions were optimized for each exon, including those with A+T-rich regions. We analyzed DNA from two unusual X-CGD patients and established the genetic basis for their phenotype. We also sequenced 100 normal X chromosomes to establish wild-type consensus sequences and identify polymorphisms.

Genetic dissection of immunity to mycobacteria: the human model

Humans are exposed to a variety of environmental mycobacteria (EM), and most children are inoculated with live Bacille Calmette-Guérin (BCG) vaccine. In addition, most of the world's population is occasionally exposed to human-borne mycobacterial species, which are less abundant but more virulent. Although rarely pathogenic, mildly virulent mycobacteria, including BCG and most EM, may cause a variety of clinical diseases. Mycobacterium tuberculosis, M. leprae, and EM M. ulcerans are more virulent, causing tuberculosis, leprosy, and Buruli ulcer, respectively. Remarkably, only a minority of individuals develop clinical disease, even if infected with virulent mycobacteria. The interindividual variability of clinical outcome is thought to result in part from variability in the human genes that control host defense. In this well-defined microbiological and clinical context, the principles of mouse immunology and the methods of human genetics can be combined to facilitate the genetic dissection of immunity to mycobacteria. The natural infections are unique to the human model, not being found in any of the animal models of experimental infection. We review current genetic knowledge concerning the simple and complex inheritance of predisposition to mycobacterial diseases in humans. Rare patients with Mendelian disorders have been found to be vulnerable to BCG, a few EM, and M. tuberculosis. Most cases of presumed Mendelian susceptibility to these and other mycobacterial species remain unexplained. In the general population leprosy and tuberculosis have been shown to be associated with certain human genetic polymorphisms and linked to certain chromosomal regions. The causal vulnerability genes themselves have yet to be identified and their pathogenic alleles immunologically validated. The studies carried out to date have been fruitful, initiating the genetic dissection of protective immunity against a variety of mycobacterial species in natural conditions of infection. The human model has potential uses beyond the study of mycobacterial infections and may well become a model of choice for the investigation of immunity to infectious agents.

Amphotericin B formulations exert additive antifungal activity in combination with pulmonary alveolar macrophages and polymorphonuclear leukocytes against Aspergillus fumigatus

Deoxycholate amphotericin B (DAMB) and amphotericin B lipid complex (ABLC) additively augmented the fungicidal activity of pulmonary alveolar macrophages against the conidia of Aspergillus fumigatus. DAMB, ABLC, and liposomal amphotericin B similarly displayed additive effects with polymorphonuclear leukocytes in damaging the hyphal elements of A. fumigatus.

Autoimmunity in human primary immunodeficiency diseases

Human primary immunodeficiency diseases are experiments of nature characterized by an increased susceptibility to infection. In many cases, they are also associated with troublesome and sometimes life-threatening autoimmune complications. In the past few years, great strides have been made in understanding the molecular basis of primary immunodeficiencies, and this had led to more focused and successful treatment. This review has 3 aims: (1) to highlight the variety of autoimmune phenomena associated with human primary immunodeficiency diseases; (2) to explore how primary immunodeficiencies predispose patients to autoimmune phenomena triggered by opportunistic infections; and (3) to consider the rationale for the current treatment strategies for autoimmune phenomena, specifically in relation to primary immunodeficiency diseases. Reviewing recent advances in our understanding of the small subgroup of patients with defined causes for their autoimmunity may lead to the development of more effective treatment strategies for idiopathic human autoimmune diseases.

Neutropenia associated with primary immunodeficiency syndromes

The primary immunodeficiency diseases are a heterogeneous group of more than 75 disorders characterized by intrinsic defects in the functions of the immune system. Many are associated with abnormalities of hematopoiesis as well. This article will review those primary immunodeficiency syndromes in which neutropenia is a prominent finding, including X-linked agammaglobulinemia (XLA), hyper IgM syndrome, common variable immunodeficiency (CVID), IgA deficiency, cartilage-hair hypoplasia (CHH), and reticular dysgenesis, with regards to pathophysiologic findings and treatment.

Perianal rhabdomyosarcoma presenting as a perirectal abscess: A report of 11 cases

BACKGROUND PURPOSE

The organs and soft tissues of the pelvis are some of the most common primary sites for rhabdomyosarcoma (RMS) in children and adolescents. In most cases a mass is detectable on clinical examination, and the initial concern is focused on the possibility of a neoplasm. The current report concerns 11 patients, each presented with a painful perineal-perianal mass suggesting an abscess to the extent that each one of these patients was treated initially with antibiotics or incision and drainage for several weeks to months before the pathologic diagnosis of RMS was established.

METHODS

The authors reviewed the clinical histories of all patients with perirectal/perianal RMS from their respective institutions to identify cases in which the initial clinical diagnosis or impression was that of a perirectal abscess. Pathologic material was reviewed in all cases.

RESULTS

Eleven patients, 7 of whom were girls, ranged in age from 1 to 16 years at diagnosis (median age, 14 years). Fever accompanied the clinical presentation in 2 patients. None of the patients had a past medical history of illness that may have predisposed them to a perirectal abscess, although one patient had a family history of inflammatory bowel disease. Duration of symptoms ranged from 1 month to 1 year (mean, 4.6 months). Each patient presented with a tender perianal/perineal nodule or mass. Inguinal adenopathy was present in 6 patients at diagnosis. White blood cell counts ranged from 6,600/mm(3) to 24,500/mm(3). LDH levels ranged from 414 to 3,432 U/L. The average time from presentation to pathologic diagnosis of RMS was 2.1 months. Nine of the 11 cases showed an alveolar pattern. All were high-stage disease. Of 7 patients with follow-up longer than 1 year, 2 (29%) are alive without disease.

CONCLUSION

This report presents the need to consider the possibility of a malignant neoplasm, in this case RMS, in a child or adolescent with a putative perirectal abscess that fails to respond in the expected manner to incision and drainage and antibiotic therapy.

Innate immunity to Mycobacterium tuberculosis

The different manifestations of infection with Mycobacterium tuberculosis reflect the balance between the bacillus and host defense mechanisms. Traditionally, protective immunity to tuberculosis has been ascribed to T-cell-mediated immunity, with CD4(+) T cells playing a crucial role. Recent immunological and genetic studies support the long-standing notion that innate immunity is also relevant in tuberculosis. In this review, emphasis is on these natural, innate host defense mechanisms, referring to experimental data (e.g., studies in gene knockout mice) and epidemiological, immunological, and genetic studies in human tuberculosis. The first step in the innate host defense is cellular uptake of M. tuberculosis, which involves different cellular receptors and humoral factors. Toll-like receptors seem to play a crucial role in immune recognition of M. tuberculosis, which is the next step. The subsequent inflammatory response is regulated by production of pro- and anti-inflammatory cytokines and chemokines. Different natural effector mechanisms for killing of M. tuberculosis have now been identified. Finally, the innate host response is necessary for induction of adaptive immunity to M. tuberculosis. These basic mechanisms augment our understanding of disease pathogenesis and clinical course and will be of help in designing adjunctive treatment strategies.

Propionibacterium acnes chest infections in patients with chronic granulomatous disease: case reports

Antibiotic prophylaxis in patients with chronic granulomatous disease (CGD) has decreased the prevalence of infections, but uncommon microorganisms are being observed more frequently. Propionibacterium acnes, a saprophyte of the skin, is generally not involved in infections other than acne. Two cases of P. acnes extracutaneous infections in teenagers with CGD are reported.

Hepatic abscess in patients with chronic granulomatous disease

OBJECTIVE

To evaluate the clinical presentation, diagnostic procedures, and surgical management of hepatic abscesses in patients with chronic granulomatous disease (CGD).

SUMMARY BACKGROUND DATA

Chronic granulomatous disease is a rare inherited primary immunodeficiency in which phagocytes cannot destroy catalase-positive bacteria and fungi. Defects in the phagocytic cells' respiratory burst lead to life-threatening infections, including hepatic abscess. These abscesses are recurrent and often multiple and are treated differently from bacterial abscesses in patients without CGD.

METHODS

Between 1980 and 2000, 61 cases of hepatic abscess in 22 patients with CGD were treated at the National Institutes of Health. Clinicopathologic features were investigated by retrospective review of the medical records, radiographs, and histopathology.

RESULTS

Twelve of the 61 cases were primary hepatic abscesses. Twenty-nine of the cases were recurrent hepatic abscesses, and 20 cases were persistent hepatic abscesses. The median age at the time of initial hepatic abscess presentation was 14 years. Subjective fever was the most frequent presenting symptom, and the erythrocyte sedimentation rate was elevated in 98% of cases. Fifty-two cases were managed surgically and eight cases were managed with percutaneous drainage. One patient refused surgery. The surgical complication rate was 56%; however, there were no deaths directly related to the hepatic abscesses. Staphylococcus aureus was the most frequent organism identified in culture (88% of positive cultures). Aggressive surgery and antibiotics ultimately resulted in successful treatment of all patients.

CONCLUSIONS

Hepatic abscesses occurring in patients with CGD represent a difficult diagnostic and treatment challenge. Early excision and treatment with antibiotics directed against S. aureus is necessary. General surgeons should be aware of this rare immunodeficiency and should aggressively manage hepatic abscesses in these patients.

Voriconazole in the treatment of aspergillosis, scedosporiosis and other invasive fungal infections in children

OBJECTIVE

To describe the safety and efficacy of voriconazole in children treated within the compassionate release program.

METHODS

Children received voriconazole on a compassionate basis for treatment of an invasive fungal infection if they were refractory to or intolerant of conventional antifungal therapy. Voriconazole was administered as a loading dose of 6 mg/kg every 12 h i.v. on Day 1 followed by 4 mg/kg every 12 h i.v. thereafter. When feasible the route of administration of voriconazole was changed from i.v. to oral (100 or 200 mg twice a day for patients weighing < 40 or > or = 40 kg, respectively). Outcome was assessed by investigators at the end of therapy or at the last visit as success (complete or partial response), stable infection, or failure, based on protocol-defined criteria.

RESULTS

Sixty-nine children (ages 9 months to 15 years; median, 7 years) received voriconazole; 58 had a proven or probable fungal infection. Among these 58 patients 27 had hematologic malignancies and 13 had chronic granulomatous disease as the most frequent underlying conditions. Forty-two patients had aspergillosis, 8 had scedosporiosis, 4 had invasive candidiasis and 4 had other invasive fungal infections. The median duration of voriconazole therapy was 93 days. At the end of therapy 26 patients (45%) had a complete or partial response. Four patients (7%) had a stable response, 25 (43%) failed therapy and 4 (7%) were discontinued from voriconazole because of intolerance. Success rates were highest in patients with chronic granulomatous disease (62%) and lowest in patients with hematologic malignancies (33%). Two patients experienced treatment-related serious adverse events (ulcerated lips with rash, elevated hepatic transaminases or bilirubin). A total of 23 patients had voriconazole-related adverse events, 3 (13%) of which caused discontinuation of voriconazole therapy. The most commonly reported adverse events included elevation in hepatic transaminases or bilirubin (n = 8), skin rash (n = 8), abnormal vision (n = 3) and a photosensitivity reaction (n = 3).

CONCLUSION

These data support the use of voriconazole for treatment of invasive fungal infections in pediatric patients who are intolerant of or refractory to conventional antifungal therapy.

Fatal disseminated Candida lusitaniae infection in an infant with chronic granulomatous disease

A 3-month-old boy born to a mother carrying an X-linked form of chronic granulomatous disease presented with persistent fever and hepatosplenomegaly. The diagnosis was confirmed as a gp91phox defect by genetic analysis, and the patient was managed with broad spectrum antibacterial agents, gamma-interferon and later amphotericin B. A liver biopsy revealed granulomata with budding yeast forms, and cultures of blood and urine grew Candida lusitaniae. The patient died 26 days after admission.

Antioxidant enzyme expression in clinical isolates of Pseudomonas aeruginosa: identification of an atypical form of manganese superoxide dismutase

Expression of superoxide dismutases (FeSOD and MnSOD) and catalases by laboratory strains of Pseudomonas aeruginosa is modulated by exogenous factors. Whether clinical isolates behave similarly and whether antioxidant enzyme expression influences P. aeruginosa virulence remain unclear. Fifty-seven P. aeruginosa blood culture isolates, plus seven pairs of blood and local-site isolates, were examined for FeSOD, MnSOD, and catalase production in vitro. Under iron-replete growth conditions FeSOD and catalase activities were maximized. MnSOD was not detected. FeSOD and catalase activity decreased under iron-limited growth conditions, whereas MnSOD activity appeared. SOD and catalase activity did not change with site of isolation or by patient. MnSOD could not be expressed by one isolate due to a missense mutation in sodA that produced a premature stop codon. Eleven percent of the isolates expressed a novel, rapidly migrating MnSOD that was associated with missense mutations in the normal stop codon of sodA. We conclude that clinical P. aeruginosa isolates vary little in FeSOD and catalase expression. Some strains produce a newly described MnSOD variant, whereas one is deficient in MnSOD production. The absence of MnSOD expression in a P. aeruginosa strain causing invasive human disease indicates that MnSOD is probably not essential for P. aeruginosa virulence.

Mycobacterial diseases in primary immunodeficiencies

Primary immunodeficiency diseases comprise over 100 conditions, each associated with a variety of viral, bacterial, fungal and protozoan infections. M. tuberculosis and less virulent mycobacteria, such as bacille Calmette-Guérin vaccines and environmental non-tuberculous mycobacteria, may cause severe disease in patients with primary immunodeficiency diseases. However, no previous review has dealt with the issue of which primary immunodeficiency diseases predispose affected individuals to mycobacterial disease. This information is very useful, not only increasing our understanding of human immunity to mycobacteria, but also for the diagnostic investigation of patients with mycobacteriosis. We review here the medical literature on cases of mycobacterial disease in patients with primary immunodeficiency diseases.

Novel aspects of phagocytic cell disorders

This review highlights the various numerical and functional defects in the phagocyte system. It mainly focuses on newly discovered genetic defects in the system and the role played by these defects in the clinical symptoms presented by patients. Novel therapeutic modalities to treat phagocyte abnormalities, which are currently under clinical trials, are also discussed.

Keratitis caused by Candida glabrata in a patient with chronic granulomatous disease

PURPOSE

To report an unusual ocular presentation of Candida glabrata in a patient with chronic granulomatous disease.

METHODS

Interventional case report. A 15-year-old boy with chronic granulomatous disease presented with bilateral limbal infiltrates. He had been receiving broad-spectrum systemic antibiotics for recurrent liver abscesses. The keratitis did not respond to antibiotics and did not resolve after a course of topical steroids.

RESULTS

Corneal cultures revealed Candida glabrata. The same species was simultaneously isolated from the surgical drainage of the liver abscesses. The ocular and hepatic findings resolved on intravenous amphotericin B.

CONCLUSION

Candida glabrata has recently emerged as an important nosocomial pathogen. It may present as a limbal keratitis in the setting of systemic infection.

Gastrointestinal manifestations of primary immunodeficiencies

Congenital immunodeficiencies are relatively rare disorders that result in a marked predisposition to infection and to a variety of gastrointestinal problems. Increasingly recognized in both children and adults, accumulating worldwide experience with these disorders reveals that the long-term prognosis is poor in many cases, despite available treatments. This review highlights the past year's advances concerning the molecular basis of several of these disorders, new diagnostic considerations, and novel therapeutic approaches concerning their gastrointestinal complications. The availability of molecular diagnostic tools increases the options for earlier definitive treatments such as bone marrow transplantation and somatic gene therapy.

The immunologic workup of the child suspected of immunodeficiency

OBJECTIVE

This review is intended to provide an outline for the evaluation of patients suspected of having immunodeficiency, a problem that is frequently encountered in clinical practice.

DATA SOURCES

Information was obtained through a MEDLINE literature search as well as from standard textbooks in immunology. Also included is information that reflects the authors' clinical experience in the field.

RESULTS

In general clinical practice, many physicians feel inadequate to evaluate patients with suspected immune deficiencies. They also think that the process of evaluation is time-consuming, which results in misdiagnosis of a substantial percentage of such disorders. Hence, the prevalence of immunodeficiency disorders is much higher than generally thought. At present, there are >80 unique primary immunodeficiency conditions and >50 syndromes that are associated with various immunologic defects. The prevalence of secondary immunodeficiency has also been increasing because of the tragic epidemic of HIV infection, more usage of immunosuppressive medications and bone marrow stem cell transplantation, and the severe degree of malnutrition in underdeveloped countries. It is necessary for clinicians, particularly the specialists in allergy and immunology, to be able to evaluate the status of the immune system.

CONCLUSIONS

Very valuable information can be gathered from the medical history and physical examination that may exclude or increase the suspicion of immunologic defect. Laboratory tests can then be appropriately selected to define the specific defect. Once the diagnosis has been settled, proper medical management can be instituted with subsequent improvement in morbidity and mortality of such disorders.

Correction of genetic blood defects by gene transfer

Recent clinical trials in patients with a severe combined immunodeficiency disease demonstrate that gene therapy is a powerful tool in the treatment of genetic blood defects. Recent identification of the genes involved in the pathogenesis of inherited lymphohemopoietic disorders led to animal models of gene transfer. Extensive preclinical studies have overcome some of the obstacles involved in the transduction of hemopoietic cells. These promising results led to the approval of several clinical trials that are currently underway. This review focuses on the clinical outcome in patients with genetic blood defects treated by gene transfer and examines the progress achieved to date and the problems that have been encountered. Despite the obstacles, improved clinical results for several of these diseases are expected within the next 5 years.

Diagnostic and therapeutic impact of whole body positron emission tomography using fluorine-18-fluoro-2-deoxy-D-glucose in children with chronic granulomatous disease

AIMS

To compare whole body positron emission tomography (PET) using fluorine-18-fluoro-2-deoxy-D-glucose (FDG) with computed tomography (CT) in detecting active infective foci in children with chronic granulomatous disease.

METHODS

We performed 22 whole body FDG PET studies in seven children with X linked (n = 6) or autosomal recessive (n = 1) CGD. All had clinical signs of infection and/or were evaluated prior to bone marrow transplantation (BMT). Nineteen PET studies were also correlated with chest and/or abdominal CT. All PET scans were interpreted blinded to the CT findings. Diagnoses were confirmed histologically and bacteriologically.

RESULTS

We detected 116 lesions in 22 FGD PETs and 126 lesions on 19 CTs. Only two of the latter could be classified reliably as active lesions by virtue of contrast enhancement suggesting abscess formation. PET excluded 59 lesions suspicious for active infection on CT and revealed 49 infective lesions not seen on CT. All seven active infective lesions were identified by PET, allowing targeted biopsy and identification of the infective agent followed by specific antimicrobial treatment, surgery, or subsequent BMT.

CONCLUSIONS

Identification of infective organisms is more precise if active lesions are biopsied. CT does not discriminate between active and inactive lesions. Whole body FDG PET can be used to screen for active infective lesions in CGD patients.

Dysfunctional LAD-1 neutrophils and colitis

Leukocyte adhesion deficiency 1 (LAD-1) is characterized by absent or dysfunctional beta2 integrin (CD18), leading to defective chemotaxis, adherence, phagocytosis, and bacterial killing. Colitis, except for rare intestinal necrotizing events, is not a well-recognized feature of this immunodeficiency. A case of nonspecific colitis clinically resembling Crohn's disease in a patient with the severe form of LAD-1 (0.5% < CD18) has been previously reported. We describe an adult patient with the moderate form of LAD-1 and chronic colitis characterized by extensive inflammation and ulceration of the right colon and terminal ileum, leading to adhesions and strictures. The chronic colitis described in this article associated with the dysfunctional neutrophils of LAD-1 represents a distinct pathology from the commonly encountered forms of inflammatory bowel disease (IBD). The existence of active IBD in the presence of dysfunctional CD18/CD11(a-b) intercellular adhesion molecules (ICAM-1) interaction is relevant to the proposed targeting of ICAM-1 for the treatment of Crohn's disease.

An unusual intronic mutation in the CYBB gene giving rise to chronic granulomatous disease

The most common, X-linked, form of chronic granulomatous disease (CGD) is caused by mutations in the CYBB gene located at Xp21.1. The product of this gene is the large subunit of flavocytochrome b558, gp91phox, which forms the catalytic core of the antimicrobial superoxide-generating enzyme, NADPH oxidase. In the overwhelming majority of cases, mutations are family-specific and occur in the exonic regions of the gene, or more rarely at the intron/exon borders. Alternatively, they are large (often multi-gene) deletions. In addition, four mutations have been found in the promoter region. In contrast, very few intronic mutations have been reported. Here we describe an intronic mutation that causes X-linked CGD. A single nucleotide substitution in the middle of intron V creates a novel 5' splice site and results in multiple abnormal mRNA products.

Disseminated nocardiosis in a patient with X-linked chronic granulomatous disease and human immunodeficiency virus infection

We report the first case of HIV infection in a patient with underlying X-linked chronic granulomatous disease (CGD) who presented with hepatopulmonary nocardiosis. Despite the coexistence of CGD and HIV, the response to therapy was normal, and no unusual sequelae were noted. The patient's high virus burden was successfully repressed with antiretroviral therapy, suggesting that the nicotinamide adenine dinucleotide phosphate oxidase system is not essential for active viral replication or response to antiretroviral agents.

Successful unrelated bone marrow transplantation for a patient with chronic granulomatous disease and associated resistant pneumonitis and Aspergillus osteomyelitis

We describe the successful treatment of a 20-year-old patient with chronic granulomatous disease (CGD), by unrelated bone marrow transplantation (UBMT). The patient is relatively old compared to other CGD patients treated with BMT. He had had repeated serious infections from early childhood and was diagnosed as CGD, gp91-phox deficiency. Prolonged antibiotic-resistant pneumonitis worsened when the patient was 18 years old. In addition, he suffered Aspergillus osteomyelitis and acute renal failure due to amphotericin B. He received 94 granulocyte transfusions from 94 adult donors and the infections gradually improved. In September 1998, at 20 years of age, he underwent UBMT from an HLA 6 antigen-matched male donor, with CY and TBI conditioning. He received MTX and CsA as prophylaxis against GVHD. No serious complications occurred and rapid engraftment was achieved. Acute GVHD (grade 2, at day 19) and chronic GVHD (limited, at day 192) occurred. However, both were easily controlled. The patient is alive and well with no late rejection 26 months after UBMT.

Variable correction of host defense following gene transfer and bone marrow transplantation in murine X-linked chronic granulomatous disease

Chronic granulomatous disease (CGD) is an inherited immunodeficiency in which the absence of the phagocyte superoxide-generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidase results in recurrent bacterial and fungal infections. A murine model of X-linked CGD (X-CGD) was used to explore variables influencing reconstitution of host defense following bone marrow transplantation and retroviral-mediated gene transfer. The outcomes of experimental infection with Aspergillus fumigatus, Staphylococcus aureus, or Burkholderia cepacia were compared in wild-type, X-CGD mice, and transplanted X-CGD mice that were chimeric for either wild-type neutrophils or neutrophils with partial correction of NADPH oxidase activity after retroviral-mediated gene transfer. Host defense to these pathogens was improved in X-CGD mice even with correction of a limited number of neutrophils. However, intact protection against bacterial pathogens required relatively greater numbers of oxidant-generating phagocytes compared to protection against A fumigatus. The host response also appeared to be influenced by the relative level of cellular NADPH oxidase activity, particularly for A fumigatus. These results may have implications for developing effective approaches for gene therapy of CGD. (Blood. 2001;97:3738-3745)

Cellular aspects of Burkholderia cepacia infection

The Gram-negative bacterium Burkholderia cepacia has recently emerged as an important opportunistic pathogen in humans. This review focuses on the cellular aspects of B. cepacia infection and the dynamics of the B. cepacia-host cell interaction, including recent advances in our understanding of the ability of B. cepacia to adhere to, enter, and survive intracellularly within human cells.

The neutrophil: function and regulation in innate and humoral immunity

The neutrophil is a critical effector cell in humoral and innate immunity and plays vital roles in phagocytosis and bacterial killing. Discussed here are the neutrophil components necessary for these processes and the diseases in which these components are either lacking or dysfunctional, illustrating that normal neutrophil function is vital for health.

Treatment of chronic granulomatous disease with nonmyeloablative conditioning and a T-cell-depleted hematopoietic allograft

BACKGROUND

The treatment of chronic granulomatous disease with conventional allogeneic hematopoietic stem-cell transplantation carries a high risk of serious complications and death. We investigated the feasibility of stem-cell transplantation without ablation of the recipient's bone marrow.

METHODS

Ten patients, five children and five adults, with chronic granulomatous disease underwent peripheral-blood stem-cell transplantation from an HLA-identical sibling. We used a nonmyeloablative conditioning regimen consisting of cyclophosphamide, fludarabine, and antithymocyte globulin. The allograft was depleted of T cells to reduce the risk of severe graft-versus-host disease. Donor lymphocytes were administered at intervals of 30 days or more after the transplantation to facilitate engraftment.

RESULTS

After a median follow-up of 17 months (range, 8 to 26), the proportion of donor neutrophils in the circulation in 8 of the 10 patients was 33 to 100 percent, a level that can be expected to provide normal host defense; in 6 the proportion was 100 percent. In two patients, graft rejection occurred. Acute graft-versus-host disease (grade II, III, or IV) developed in three of the four adult patients with engraftment, one of whom subsequently had chronic graft-versus-host disease. None of the five children had grade II, III, or IV acute graft-versus-host disease. During the follow-up period, four serious infections occurred among the patients who had engraftment. Three of the 10 recipients died. Preexisting granulomatous lesions resolved in the patients in whom transplantation was successful.

CONCLUSIONS

Nonmyeloablative conditioning followed by a T-cell-depleted hematopoietic stem-cell allograft is a feasible option for patients with chronic granulomatous disease, recurrent life-threatening infections, and an HLA-identical family donor.

Clinical aspects of chronic granulomatous disease

Data from a registry of 368 patients with chronic granulomatous disease (CGD) documenta shift in the most common infecting organisms away from staphylococci and enteric bacteria to Aspergillus species, although staphylococci remain a threat. A. nidulans appears to have a particular virulence in CGD. Burkholderia cepacia sepsis/pneumonia was the second most lethal infection in patients in the registry. Seventy-six percent of registry patients had the X-linked recessive (XLR) form of CGD. Chorioretinitis may be more common than previously appreciated, and boys with the XLR disease should probably have routine full eye exams. A new variant of CGD has been described that is caused by an inhibitory mutation in Rac2, which regulates activity of the neutrophil respiratory burst and actin assembly. Interferon-gamma, antibacterial prophylaxis, and, probably, antifungal prophylaxis with itraconazole reduce the rate of infection, and bone marrow transplantation can cure the disease if a histocompatible donor is available. Gene therapy can cure CGD in knockout mouse models. Having even a small percentage of phagocytes that are nicotinamide adenine dinucleotide phospate oxidase-positive can reduce the risk of serious infection, and procedures now under study appear close to achieving that goal, if not a cure.

Primary phagocytic disorders of childhood

Primary phagocytic disorders are rare and usually first manifest during childhood. A phagocytic disorder should be considered in patients with unusually severe or recurrent infections by common pathogens or an infection by certain opportunistic pathogens. Common manifestations of primary phagocytic disorders include recurrent soft-tissue infections requiring incision and drainage, severe dental infections leading to premature tooth loss, recurrent pneumonias, and perirectal infections. Primary phagocytic disorders are caused by defects of neutrophil number or function, and the latter, in turn, can be divided into disorders of oxidative and nonoxidative pathways. Certain phagocytic disorders have unique characteristics apart from the immune defect that may facilitate diagnosis. Early diagnosis of phagocytic disorders can be life-saving or lead to a significant reduction in morbidity and relies on a compatible clinical (or family) history and appropriate laboratory diagnostic studies. Key principles of management of such patients involve early recognition and aggressive treatment of infections and appropriate surgical débridement of localized disease. Prophylactic antibiotics, BMT, and the use of exogenous cytokines, such as IFN-gamma and G-CSF, are appropriate for specific phagocytic disorders. Gene therapy is a promising strategy for several of the phagocytic disorders.

Genetic, biochemical, and clinical features of chronic granulomatous disease

The reduced nicotinamide dinucleotide phosphate (NADPH) oxidase complex allows phagocytes to rapidly convert O2 to superoxide anion which then generates other antimicrobial reactive oxygen intermediates, such as H2O2, hydroxyl anion, and peroxynitrite anion. Chronic granulomatous disease (CGD) results from a defect in any of the 4 subunits of the NADPH oxidase and is characterized by recurrent life-threatening bacterial and fungal infections and abnormal tissue granuloma formation. Activation of the NADPH oxidase requires translocation of the cytosolic subunits p47phox (phagocyte oxidase), p67phox, and the low molecular weight GT-Pase Rac, to the membrane-bound flavocytochrome, a heterodimer composed of the heavy chain gp91phox and the light chain p22phox. This complex transfers electrons from NADPH on the cytoplasmic side to O2 on the vacuolar or extracellular side, thereby generating superoxide anion. Activation of the NADPH oxidase requires complex rearrangements between the protein subunits, which are in part mediated by noncovalent binding between src-homology 3 domains (SH3 domains) and proline-rich motifs. Outpatient management of CGD patients relies on the use of prophylactic antibiotics and interferon-gamma. When infection is suspected, aggressive effort to obtain culture material is required. Treatment of infections involves prolonged use of systemic antibiotics, surgical debridement when feasible, and, in severe infections, use of granulocyte transfusions. Mouse knockout models of CGD have been created in which to examine aspects of pathophysiology and therapy. Gene therapy and bone marrow transplantation trials in CGD patients are ongoing and show great promise.

Inherited Neutrophil Disorders

Recent advances in our understanding of the molecular basis of inherited neutrophil disorders and complementary studies in transgenic mouse models have provided new insights into the normal mechanisms regulating myelopoiesis and the functional responses of mature neutrophils. Neutrophil specific granule deficiency is a rare disorder of neutrophil function characterized by a lack of neutrophil secondary granule proteins and associated with recurrent bacterial infections. The CCAAT/enhancer binding protein (C/EBP) ϵ, a leucine zipper transcription factor expressed primarily in myeloid cells, and C/EBPϵ-deficient mice generated by gene targeting lack specific granules and have impaired host defense are discussed by Dr. Lekstrom-Himes in Section I. The similarity between these phenotypes led to the identification of a loss of function mutation in the C/EBPϵ gene in a subset of patients with specific granule deficiency. Dr. Dale reviews the clinical features and management of congenital neutropenia and cyclic hematopoiesis in Section II. Inherited mutations in the neutrophil elastase gene have recently been identified in both disorders. Specific mutations identified in cyclic and congenital neutropenia are described along with possible mechanisms for regulation of hematopoiesis by neutrophil elastase. In Section III, Dr. Dinauer reviews the molecular genetics of chronic granulomatous disease and studies in knockout mouse models. This work has revealed important features of the regulation of the respiratory burst oxidase and its role in host defense and inflammation. Results from preclinical studies and phase 1 clinical trials for gene therapy for CGD are summarized, in addition to alternative approaches using allogeneic bone marrow transplantation with nonmyeloablative conditioning.

Inherited Neutrophil Disorders

Recent advances in our understanding of the molecular basis of inherited neutrophil disorders and complementary studies in transgenic mouse models have provided new insights into the normal mechanisms regulating myelopoiesis and the functional responses of mature neutrophils. Neutrophil specific granule deficiency is a rare disorder of neutrophil function characterized by a lack of neutrophil secondary granule proteins and associated with recurrent bacterial infections. The CCAAT/enhancer binding protein (C/EBP) ϵ, a leucine zipper transcription factor expressed primarily in myeloid cells, and C/EBPϵ-deficient mice generated by gene targeting lack specific granules and have impaired host defense are discussed by Dr. Lekstrom-Himes in Section I. The similarity between these phenotypes led to the identification of a loss of function mutation in the C/EBPϵ gene in a subset of patients with specific granule deficiency. Dr. Dale reviews the clinical features and management of congenital neutropenia and cyclic hematopoiesis in Section II. Inherited mutations in the neutrophil elastase gene have recently been identified in both disorders. Specific mutations identified in cyclic and congenital neutropenia are described along with possible mechanisms for regulation of hematopoiesis by neutrophil elastase. In Section III, Dr. Dinauer reviews the molecular genetics of chronic granulomatous disease and studies in knockout mouse models. This work has revealed important features of the regulation of the respiratory burst oxidase and its role in host defense and inflammation. Results from preclinical studies and phase 1 clinical trials for gene therapy for CGD are summarized, in addition to alternative approaches using allogeneic bone marrow transplantation with nonmyeloablative conditioning.