Whole-exome sequencing reveals activating STAT1 mutations in some patients with autosomal dominant chronic mucocutaneous candidiasis disease.

Since their discovery in patients with autosomal dominant (AD) chronic mucocutaneous candidiasis (CMC) in 2011, heterozygous STAT1 gain-of-function (GOF) mutations have increasingly been identified worldwide. The clinical spectrum associated with them needed to be delineated. We enrolled 274 patients from 167 kindreds originating from 40 countries from 5 continents. Demographic data, clinical features, immunological parameters, treatment, and outcome were recorded. The median age of the 274 patients was 22 years (range, 1-71 years); 98% of them had CMC, with a median age at onset of 1 year (range, 0-24 years). Patients often displayed bacterial (74%) infections, mostly because of Staphylococcus aureus (36%), including the respiratory tract and the skin in 47% and 28% of patients, respectively, and viral (38%) infections, mostly because of Herpesviridae (83%) and affecting the skin in 32% of patients. Invasive fungal infections (10%), mostly caused by Candida spp. (29%), and mycobacterial disease (6%) caused by Mycobacterium tuberculosis, environmental mycobacteria, or Bacille Calmette-Guérin vaccines were less common. Many patients had autoimmune manifestations (37%), including hypothyroidism (22%), type 1 diabetes (4%), blood cytopenia (4%), and systemic lupus erythematosus (2%). Invasive infections (25%), cerebral aneurysms (6%), and cancers (6%) were the strongest predictors of poor outcome. CMC persisted in 39% of the 202 patients receiving prolonged antifungal treatment. Circulating interleukin-17A-producing T-cell count was low for most (82%) but not all of the patients tested. STAT1 GOF mutations underlie AD CMC, as well as an unexpectedly wide range of other clinical features, including not only a variety of infectious and autoimmune diseases, but also cerebral aneurysms and carcinomas that confer a poor prognosis

Clinical analysis of our cohort leads us to define NBO as a distinct disease entity with three clinical presentations: acute NBO, chronic recurrent multifocal osteomyelitis or persistent chronic NBO. Diagnostic criteria were proposed to differentiate NBO from diseases with similar clinical presentation.

Commensal bacteria that colonize mammalian barrier surfaces are reported to influence T helper type 2 (TH2) cytokine–dependent inflammation and susceptibility to allergic disease, although the mechanisms that underlie these observations are poorly understood. In this report, we identify that deliberate alteration of commensal bacterial populations via oral antibiotic treatment resulted in elevated serum immunoglobulin E (IgE) levels, increased steady–state circulating basophil populations, and exaggerated basophil–mediated TH2 cell responses and allergic inflammation. Elevated serum IgE levels correlated with increased circulating basophil populations in mice and subjects with hyperimmunoglobulinemia E syndrome. Furthermore, B cell–intrinsic expression of MyD88 was required to limit serum IgE levels and circulating basophil populations in mice. Commensal–derived signals were found to influence basophil development by limiting proliferation of bone marrow–resident precursor populations. Collectively, these results identify a previously unrecognized pathway through which commensal–derived signals influence basophil hematopoiesis and susceptibility to TH2 cytokine–dependent inflammation and allergic disease.

Patient registries are instrumental for clinical research in rare diseases. They help to achieve a sufficient sample size for epidemiological and clinical research and to assess the feasibility of clinical trials. The European Society for Immunodeficiencies (ESID) registry currently comprises information on >25,000 patients with inborn errors of immunity (IEI). The prerequisite of a patient to be included into the ESID registry is an IEI either defined by a defect in a gene included in the disease classification of the international union of immunological societies (IUIS), or verified by applying clinical criteria. Because a relevant number of patients, including those with common variable immunodeficiency (CVID), representing the largest group of patients in the registry, remains without a genetic diagnosis, consensus on classification of these patients is mandatory. Here, we present clinical criteria for a large number of IEI that were designed in expert panels with external review. They were implemented for novel entries and verification of existing datasets from 2014, yielding a substantial refinement. For instance, 8% of adults and 27% of children with CVID (176 out of 1704 patients) were reclassified to 22 different immunodeficiencies, illustrating progress in genetics, but also the previous lack of standardized disease definitions. Importantly, apart from registry purposes, the clinical criteria are also helpful to support treatment decisions in the absence of a genetic diagnosis or in patients with variants of unknown significance.

Mutations in DOCK8 result in autosomal recessive Hyper-IgE syndrome with combined immunodeficiency (CID). However, the natural course of disease, long-term prognosis, and optimal therapeutic management have not yet been clearly defined. In an international retrospective survey of patients with DOCK8 mutations, focused on clinical presentation and therapeutic measures, a total of 136 patients with a median follow-up of 11.3 years (1.3-47.7) spanning 1693 patient years, were enrolled. Eczema, recurrent respiratory tract infections, allergies, abscesses, viral infections and mucocutaneous candidiasis were the most frequent clinical manifestations. Overall survival probability in this cohort [censored for hematopoietic stem cell transplantation (HSCT)] was 87 % at 10, 47 % at 20, and 33 % at 30 years of age, respectively. Event free survival was 44, 18 and 4 % at the same time points if events were defined as death, life-threatening infections, malignancy or cerebral complications such as CNS vasculitis or stroke. Malignancy was diagnosed in 23/136 (17 %) patients (11 hematological and 9 epithelial cancers, 5 other malignancies) at a median age of 12 years. Eight of these patients died from cancer. Severe, life-threatening infections were observed in 79/136 (58 %); severe non-infectious cerebral events occurred in 14/136 (10 %). Therapeutic measures included antiviral and antibacterial prophylaxis, immunoglobulin replacement and HSCT. This study provides a comprehensive evaluation of the clinical phenotype of DOCK8 deficiency in the largest cohort reported so far and demonstrates the severity of the disease with relatively poor prognosis. Early HSCT should be strongly considered as a potential curative measure.

Background Hyper-IgE Syndrome (HIES) is a rare, autosomal dominant (AD) immunodeficiency characterized by eczema, Staphylococcus aureus skin abscesses, pneumonia with pneumatocele formation, Candida infections, and skeletal/connective tissue abnormalities. Recently it was shown that heterozygous STAT3 mutations cause AD-HIES. Objective To determine the spectrum and functional consequences of heterozygous STAT3 mutations in a cohort of HIES patients. Methods We sequenced the STAT3 gene in 38 HIES patients (NIH-score >40 points) from 35 families, quantified TH17 cells in peripheral blood, and evaluated tyrosine phosphorylation of STAT3. Results Most STAT3 mutations in our cohort were in the DNA-binding domain (DBD) (22/35 families) or SH2 domain (10/35), and were missense mutations. We identified two intronic mutations resulting in exon skipping and in-frame deletions within the DBD. In addition, we identified two mutations located in the transactivation domain downstream of the SH2 domain: A ten amino acid deletion and an amino acid substitution. In one patient, we were unable to identify a STAT3 mutation. TH17 cells were absent or low in the peripheral blood of all patients who were evaluated (n=17). IL-6 induced STAT3-phosphorylation was consistently reduced in patients with SH2 domain mutations, but comparable to normal controls in patients with mutations in the DBD. Conclusion Heterozygous STAT3 mutations were identified in 34/35 unrelated HIES families. Patients had impaired TH17 cell development, and those with SH2 domain mutations had reduced STAT3 phosphorylation. Clinical implication Mutations in STAT3 and decreased TH17 cells identify individuals with AD-HIES, thereby allowing timely diagnosis and early treatment of these patients. Capsule summary Results from this patient cohort expand the spectrum of heterozygous STAT3 mutations in AD-HIES, and demonstrate impaired development of TH17 cells in all and reduced STAT3-phosphorylation in patients with SH2-domain mutations.

Background Mutations in SPINK5, encoding the serine protease inhibitor LEKTI, cause Comèl-Netherton syndrome, an autosomal-recessive disease characterized by congenital ichthyosis, bamboo hair, and atopic diathesis. Despite increased frequency of infections, the immunocompetence of Comèl-Netherton syndrome patients has not been extensively investigated. Objective To define Comèl-Netherton syndrome as a primary immunodeficiency and to explore the benefit of IVIG replacement therapy. Methods We enrolled nine patients with Comèl-Netherton syndrome, sequenced SPINK5, and analyzed LEKTI expression by immunohistochemistry. Immune function was assessed by measuring cognate immunity, serum cytokine-levels and natural killer cell cytotoxicity. Results All patients presented with recurrent skin infections caused predominantly by Staphylococcus aureus. All but one reported recurrent respiratory tract infections; 78% had sepsis and/or pneumonia; 67% suffered from recurrent gastroenteritis and failure to thrive. Mutations in SPINK5 – including six novel mutations- were identified in eight patients. LEKTI expression was decreased or absent in all patients. Immunologic evaluation revealed reduced memory B cells and defective responses to vaccination with Pneumovax® and bacteriophage phiX174, characterized by impaired antibody amplification and class-switching. Immune dysregulation was suggested by a skewed TH1-phenotype and elevated proinflammatory cytokine levels, while serum concentrations of the chemokine RANTES and NK cell cytotoxicity were decreased. Treatment with intravenous immunoglobulin substitution resulted in remarkable clinical improvement and temporarily increased NK cell cytotoxicity. Conclusion These data provide new insights into the immunopathology of Comèl-Netherton syndrome and demonstrate that this multisystem disorder, characterized by lack of LEKTI expression in epithelial cells, is complicated by cognate and innate immunodeficiency that responds favorably to IVIG therapy.