Background Mutations in STAT1 cause a broad spectrum of disease, ranging from severe viral and bacterial infections (amorphic alleles), to mild disseminated mycobacterial disease (hypomorphic alleles), to chronic mucocutaneous candidiasis (hypermorphic alleles). The hypermorphic mutations are also associated with arterial aneurysms, autoimmunity and squamous cell cancers. Objective To investigate the role of STAT1 gain of function mutations in phenotypes other than CMC. Methods We initially screened patients with chronic mucocutaneous candidiasis and autoimmunity for STAT1 mutations. We functionally characterized mutations in vitro and studied immune profiles and regulatory T cells. After our initial case identifications we explored two large cohorts of FOXP3WT IPEX-like patients for STAT1 mutations. Results We identified 5 children with polyendocrinopathy, enteropathy, and dermatitis, reminiscent of IPEX syndrome, all but one had a variety of mucosal and disseminated fungal infections. All patients lacked FOXP3 mutations but had uniallelic STAT1 mutations [c.629 G>T, p.R210I; c.1073 T>G, p.L358W, c.796G>A; p.V266I; c.1154C>T, T385M (2 patients)]. STAT1 phosphorylation in response to IFN-γ, IL-6 and IL-21 was increased and prolonged. CD4+ IL-17 producing T cells were diminished. All patients had a normal percentage of regulatory T cells in the CD4+ T cell compartment and their function was intact in the two patients tested. Patients with cells available for study had normal levels of IL-2-induced STAT5 phosphorylation.. Conclusions Gain-of-function mutations in STAT1 can cause an IPEX-like syndrome with normal frequency and function of regulatory T cells.

BACKGROUND Common variable immunodeficiency (CVID) is characterized by late-onset hypogammaglobulinemia in the absence of predisposing factors. The genetic cause is unknown in the majority of cases, and less than 10% of patients have a family history of the disease. Most patients have normal numbers of B cells but lack plasma cells. METHODS We used whole-exome sequencing and array-based comparative genomic hybridization to evaluate a subset of patients with CVID and low B-cell numbers. Mutant proteins were analyzed for DNA binding with the use of an electrophoretic mobility-shift assay (EMSA) and confocal microscopy. Flow cytometry was used to analyze peripheral-blood lymphocytes and bone marrow aspirates. RESULTS Six different heterozygous mutations in IKZF1, the gene encoding the transcription factor IKAROS, were identified in 29 persons from six families. In two families, the mutation was a de novo event in the proband. All the mutations, four amino acid substitutions, an intragenic deletion, and a 4.7-Mb multigene deletion involved the DNA-binding domain of IKAROS. The proteins bearing missense mutations failed to bind target DNA sequences on EMSA and confocal microscopy; however, they did not inhibit the binding of wild-type IKAROS. Studies in family members showed progressive loss of B cells and serum immunoglobulins. Bone marrow aspirates in two patients had markedly decreased early B-cell precursors, but plasma cells were present. Acute lymphoblastic leukemia developed in 2 of the 29 patients. CONCLUSIONS Heterozygous mutations in the transcription factor IKAROS caused an autosomal dominant form of CVID that is associated with a striking decrease in B-cell numbers. (Funded by the National Institutes of Health and others.)

A primary immunodeficiency syndrome caused by loss-of-function mutations in the IL-21 receptor exhibits impaired B, T, and NK cell function.

No abstract

Background Severe atopic conditions associated with elevated serum IgE are heterogeneous with few known causes. Nearly every patient with autosomal-dominant hyper-IgE syndrome (AD-HIES) due to signal transducer and activator of transcription 3 (STAT3) mutations has a history of eczematous dermatitis and elevated IgE; however, clinical atopy has never been systematically studied. Objective Understanding of genetic determinants of allergic disease may lead to novel therapies in controlling allergic disease. Methods We conducted clinical evaluation of the rates of food allergies and anaphylaxis in patients with AD-HIES, a cohort of patients with no STAT3 mutation but with similar histories of elevated IgE and atopic dermatitis, and healthy volunteers with no history of atopy. Morphine skin prick testing, ImmunoCAP assays for allergen-specific IgE, and basophil activation were measured. A model of systemic anaphylaxis was studied in transgenic mice carrying an AD-HIES mutation. STAT3 was silenced in LAD2 and primary human mast cells to study the role of STAT3 in signaling and degranulation after IgE cross-linking. Results Food allergies and anaphylaxis were markedly diminished in patients with AD-HIES compared with a cohort of patients with no STAT3 mutation but with similar histories of elevated IgE and atopic dermatitis. Morphine skin prick testing and basophil activation were diminished in patients with AD-HIES, whereas mice carrying an AD-HIES mutation were hyporesponsive to systemic anaphylaxis models. Rapid mast cell STAT3 serine727 phosphorylation was noted after IgE cross-linking, and inhibition of STAT3 signaling in mast cells lead to impaired FcεRI-mediated proximal and distal signaling, as well as reduced degranulation. Conclusion This study serves as an example for how mutations in specific atopic pathways can lead to discrete allergic phenotypes, encompassing increased risk of some phenotypes but a relative protection from others.

The lower airways of children with severe asthma display a dominant T1 signature and atypical cytokine profiles that link to allergic status. Our findings deviate from established paradigms and warrant further assessment of the pathogenicity of T1 cells in patients with severe asthma.

BackgroundAboriginal people with cancer experience worse outcomes than other Australians for a range of complex and interrelated reasons. A younger age at diagnosis, higher likelihood of more advanced cancer or cancer type with poorer prognosis, geographic isolation and cultural and language diversity mean that patient pathways are potentially more complex for Aboriginal people with cancer. In addition, variation in the quality and acceptability of care may influence cancer outcomes.ObjectiveThis study sought to understand how care coordination influences Aboriginal people's experiences of cancer treatment.MethodsInterviews with 29 Aboriginal patients or cancer survivors, 11 carers and 22 service providers were carried out. Interviews were semi‐structured and sought to elicit experiences of cancer and the health‐care system. The manifest content of the cancer narratives was entered onto a cancer pathway mapping tool and underlying themes were identified inductively.ResultsThe practice of cancer care coordination was found to address the needs of Aboriginal patients and their families/carers in 4 main areas: “navigating the health system”; “information and communication”; “things to manage at home”; and “cultural safety”.ConclusionsThe CanDAD findings indicate that, when the need for cancer care coordination is met, it facilitated continuity of care in a range of ways that may potentially improve cancer outcomes. However, the need remains unmet for many. Findings support the importance of dedicated care coordination to enable Aboriginal people to receive adequate and appropriate patient‐centred care, so that the unacceptable disparity in cancer outcomes between Aboriginal and non‐Aboriginal people can be addressed.

Asthma encompasses a variety of clinical phenotypes that involve distinct T cell–driven inflammatory processes. Improved understanding of human T-cell biology and the influence of innate cytokines on T-cell responses at the epithelial barrier has led to new asthma paradigms. This review captures recent knowledge on pathogenic CD4+ T cells in asthmatic patients by drawing on observations in mouse models and human disease. In patients with allergic asthma, TH2 cells promote IgE-mediated sensitization, airway hyperreactivity, and eosinophilia. Here we discuss recent discoveries in the myriad molecular pathways that govern the induction of TH2 differentiation and the critical role of GATA-3 in this process. We elaborate on how cross-talk between epithelial cells, dendritic cells, and innate lymphoid cells translates to T-cell outcomes, with an emphasis on the actions of thymic stromal lymphopoietin, IL-25, and IL-33 at the epithelial barrier. New concepts on how T-cell skewing and epitope specificity are shaped by multiple environmental cues integrated by dendritic cell “hubs” are discussed. We also describe advances in understanding the origins of atypical TH2 cells in asthmatic patients, the role of TH1 cells and other non-TH2 types in asthmatic patients, and the features of T-cell pathogenicity at the single-cell level. Progress in technologies that enable highly multiplexed profiling of markers within a single cell promise to overcome barriers to T-cell discovery in human asthmatic patients that could transform our understanding of disease. These developments, along with novel T cell–based therapies, position us to expand the assortment of molecular targets that could facilitate personalized treatments.