Coccidioidomycosis is a human fungal disease cause by inhalation of aerosol spores produced by Coccidioides posadasii or Coccidioides immitis. This disease is a common cause of community-acquired pneumonia in the endemic areas of the Southwestern United States. It also can present as a life-threatening disease as the fungal cells disseminate to skin, bone, and central nervous system. The outcome of coccidioidomycosis is largely determined by the nature of host immune response to the infection. Escalation of symptomatic infections and increased cost of long-term antifungal treatment warrant a concerted effort to better understand the innate and adaptive immune responses and the genetics associated with coccidioidomycosis susceptibility. This knowledge can be harnessed for development of a human vaccine against Coccidioides and advance clinic management of this disease. This review discusses recently reported studies on innate and adaptive immunity to Coccidioides infection, Mendelian susceptibility to disseminated disease and progress toward a human vaccine against this formidable disease.

The hyper-IgE syndromes (HIES; originally named Job's syndrome) are a collection of primary immunodeficiency syndromes resulting in elevated serum IgE levels and typified by recurrent staphylococcal skin abscesses, eczema and pulmonary infections. The disorder has autosomal dominant and recessive forms. Autosomal dominant HIES has been shown to be mainly due to STAT3 mutations and additionally results in connective tissue, skeletal, vascular and dental abnormalities. Autosomal recessive HIES has been shown to be mainly due to mutations in DOCK8; these patients are more prone to viral skin infections instead. This review article discusses the common clinical features of the syndrome, the genetic mutations responsible and the pathogenesis of the disease, as well as treatments currently used.

Interferon-gamma receptor deficiency is a recently described immunodeficiency that is associated with onset of severe mycobacterial infections in childhood. We describe the occurrence of symptomatic and often severe viral infections in 4 patients with interferon-gamma receptor deficiency and mycobacterial disease. The viral pathogens included herpes viruses, parainfluenza virus type 3, and respiratory syncytial virus. We conclude that patients with interferon-gamma receptor deficiency and mycobacterial disease have increased susceptibility to some viral pathogens.

Dedicator of cytokinesis 8 (DOCK8) deficiency is an autosomal recessive, combined immunodeficiency within the spectrum of hyper-IgE syndromes. Epstein-Barr virus-positive lymphomatoid granulomatosis (LYG) (EBV + LYG) is a rare diagnosis and a previously unreported presentation of DOCK8 deficiency. A 10-year-old girl was initially evaluated for mild eczema and recurrent sinopulmonary infections. She had normal immunoglobulins with elevated IgE, poor polysaccharide response with low switched memory B cells, low CD4 count, and normal mitogen and antigen responses. Despite clinical improvement following immunoglobulin replacement, a prolonged cough prompted a CT scan, which showed nodules. Biopsy identified a Grade 2 EBV + LYG. Due to an inadequate response with chemotherapy, further workup for primary immunodeficiency was performed. With her symptoms of eczema and IgE elevation, along with her brother's history of recurrent sinopulmonary infections and warts, targeted sequencing of DOCK8 was performed revealing compound heterozygous mutations for the two siblings. Both patients were successfully transplanted with resolution of the LYG and warts, respectively. This is the first reported case of LYG in DOCK8 deficiency. The EBV-driven lymphoproliferative disease along with the infection history in the brother led to the diagnosis of DOCK8 deficiency and curative hematopoietic stem cell transplants.

Severe combined immunodeficiency (SCID) is most frequently caused by mutations in the cytokine receptor common gamma chain, CD132, encoded by the X-linked gene, IL2RG. Most patients present in the first year of life with failure to thrive, severe, opportunistic infections and absence of CD3+ T cells. We present a patient with pediatric illness and a diagnosis of combined variable immune deficiency (CVID) who was diagnosed at age 23 with an inherited IL2RG mutation causing loss of signal transduction through CD132. His peripheral blood included CD3/CD4 and CD3/CD8 positive cells as well as low levels of CD19+ B cells containing a reversion to the wildtype IL2RG allele. The reversion, which was not present at birth, may account for his mild phenotype and late diagnosis.

BACKGROUND: Pediatric endogenous Cushing syndrome (eCs) is mainly caused by pituitary corticotropin-producing adenomas, and most glucocorticoid-dependent effects progressively regress upon tumor removal. eCs reproduces long-term, high-dose glucocorticoid therapy, representing a clean, natural, and unbiased model in which to study glucocorticoid bona fide effects on immunity. OBJECTIVE: We performed extensive immunologic studies in otherwise healthy pediatric patients with eCs before and 6 to 13 months after tumor resection, as well as in in vitro glucocorticoid-treated control cells. METHODS: Flow cytometry, immunoblotting, enzyme-linked immunosorbent assay, real-time quantitative PCR, and RNA-Seq techniques were used to characterize patients and in vitro glucocorticoid treated cells. RESULTS: Reduced thymic output, decreased naive T cells, diminished proliferation, and increased T-cell apoptosis were detected before surgery; all these defects eventually normalized after tumor removal in patients. In vitro studies also showed increased T-cell apoptosis, with correspondingly diminished NF-κB signaling and IL-21 levels. In this setting, IL-21 addition upregulated antiapoptotic BCL2 expression and rescued T-cell apoptosis in a PI3K pathway-dependent manner. Similar and reproducible findings were confirmed in eCs patient cells as well. CONCLUSIONS: We identified decreased thymic output and lymphocyte proliferation, together with increased apoptosis, as the underlying causes to T-cell lymphopenia in eCs patients. IL-21 was decreased in both natural and in vitro long-term, high-dose glucocorticoid environments, and in vitro addition of IL-21 counteracted the proapoptotic effects of glucocorticoid therapy. Thus, our results suggest that administration of IL-21 in patients receiving long-term, high-dose glucocorticoid therapy may contribute to ameliorate lymphopenia and the complications associated to it.

BACKGROUND: GATA2 deficiency is a genetic disorder of hematopoiesis, lymphatics, and immunity caused by autosomal dominant or sporadic mutations in GATA2. The disease has a broad phenotype encompassing immunodeficiency, myelodysplasia, leukemia, and vascular or lymphatic dysfunction as well as prominent pulmonary manifestations. RESEARCH QUESTION: What are the pulmonary manifestations of GATA2 deficiency? STUDY DESIGN AND METHODS: A retrospective review was conducted of clinical medical records, diagnostic imaging, pulmonary pathologic specimens, and tests of pulmonary function. RESULTS: Of 124 patients (95 probands and 29 ascertained), the lung was affected in 56%. In addition to chronic infections, pulmonary alveolar proteinosis (11 probands) and pulmonary arterial hypertension (nine probands) were present. Thoracic CT imaging found small nodules in 54% (54 probands and 12 relatives), reticular infiltrates in 40% (45 probands and four relatives), paraseptal emphysema in 25% (30 probands and one relative), ground-glass opacities in 35% (41 probands and two relatives), consolidation in 21% (23 probands and two relatives), and a typical crazy-paving pattern in 7% (eight probands and no relatives). Nontuberculous mycobacteria were the most frequent organisms associated with chronic infection. Allogeneic hematopoietic stem cell transplantation successfully reversed myelodysplasia and immune deficiency and also improved pulmonary hypertension and pulmonary alveolar proteinosis in most patients. INTERPRETATION: GATA2 deficiency has prominent pulmonary manifestations. These clinical observations confirm the essential role of hematopoietic cells in many aspects of pulmonary function, including infections, alveolar proteinosis, and pulmonary hypertension, many of which precede the formal diagnosis, and many of which respond to stem cell transplantation.

Background

Autosomal dominant hyper-IgE syndrome (AD-HIES) is caused by mutations in signal transducer and activator of transcription 3 (STAT3). We describe 2 subjects in whom somatic mosaicism was associated with intermediate phenotypes.

Objective

Somatic mosaics might shed light on the pathogenesis of dominant STAT3 mutations and the mechanisms behind the immunologic and nonimmunologic features of the disease.

Methods

Clinical evaluations were conducted. Mutant STAT3 was amplified from different tissues and sequenced, and the percentage of mosaicism in various cell types was calculated. Flow cytometry was performed to determine percentages of IL-17(+) cells, IL-22(+) cells, or both. Suction blisters were induced in 1 subject, and exudate fluid was analyzed for whether emigrating neutrophils were STAT3 mutant or wild-type; neutrophils from peripheral blood were simultaneously examined.

Results

The 2 subjects with STAT3 somatic mosaicism had intermediate phenotypes and were found to have preserved TH17 cell compartments and apparently normal CD8 cells. However, they still had infections, including mucocutaneous candidiasis. The percentage of STAT3 mutant neutrophils migrating into blisters at 16 hours was the same as in peripheral blood, suggesting normal chemotaxis.

Conclusion

STAT3 mosaicism accounts for a milder phenotype and allows for further investigation into the pathogenesis of AD-HIES. Despite having a preserved TH17 cell compartment, both subjects with mosaicism had chronic mucocutaneous candidiasis, suggesting that candidiasis in subjects with AD-HIES is not driven solely by low TH17 cell numbers. The percentage of STAT3 mutant neutrophils emigrating into a suction blister at 16 hours was the same as the percentage in peripheral blood, suggesting that early chemotaxis of STAT3 neutrophils is normal in vivo.

Patients with germline mutations in PIK3CD, immunodeficiency, lymphoproliferation, and autoimmunity show a distinct pattern of abnormal B-cell maturation in the bone marrow.

Purpose

Autosomal Dominant Hyper IgE Recurrent Infection Syndrome (AD-HIES) is caused by mutations in STAT3 and characterized by eczema, recurrent bacterial infections, and skeletal and connective tissue abnormalities. To further understand the minimal trauma fractures of AD-HIES, we examined bone mineral density (BMD) and laboratory markers of bone turnover.

Methods

Patients with AD-HIES enrolled in a prospective natural history study were examined with dual x-ray absorptiometry (DEXA) scans and laboratory studies of bone metabolism. The number of fractures was recorded as well as clinical features of AD-HIES including scoliosis and retained primary teeth. Patients on medications with skeletal effects, including bisphosphonates, were examined separately.

Results

Twenty-three AD-HIES children (6-18 years) and 33 AD-HIES adults (21-50 years) not receiving bone-active drugs were studied. Fourteen of the 23 children (61%) had histories of minimal trauma fractures, as did 26 of the 33 adults (79%). Osteopenia or osteoporosis was found in 79% of children and adults. Only radial BMD correlated with the qualitative occurrence of fractures but it did not correlate with the numbers of fractures. Markers of bone metabolism did not correlate with minimal trauma fractures or BMD. Patients on bone-active medications had improved BMD, but still sustained fractures.

Conclusions

Minimal trauma fractures and decreased BMD are common in AD-HIES. Low radial BMD is associated with fractures, but hip and spine BMD are not. Treatment with bisphosphonates increased BMD but its role in fracture prevention remains undefined.