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Background No approved treatment for peanut allergy exists for children younger than 4 years of age, and the efficacy and safety of epicutaneous immunotherapy with a peanut patch in toddlers with peanut allergy are unknown. Methods We conducted this phase 3, multicenter, double-blind, randomized, placebo-controlled trial involving children 1 to 3 years of age with peanut allergy confirmed by a double-blind, placebo-controlled food challenge. Patients who had an eliciting dose (the dose necessary to elicit an allergic reaction) of 300 mg or less of peanut protein were assigned in a 2:1 ratio to receive epicutaneous immunotherapy delivered by means of a peanut patch (intervention group) or to receive placebo administered daily for 12 months. The primary end point was a treatment response as measured by the eliciting dose of peanut protein at 12 months. Safety was assessed according to the occurrence of adverse events during the use of the peanut patch or placebo. Results Of the 362 patients who underwent randomization, 84.8% completed the trial. The primary efficacy end point result was observed in 67.0% of children in the intervention group as compared with 33.5% of those in the placebo group (risk difference, 33.4 percentage points; 95% confidence interval, 22.4 to 44.5; P

Molecular diagnosis of paediatric inborn errors of immunity (IEI) influences management decisions and alters clinical outcomes, through early use of targeted and curative therapies. The increasing demand for genetic services has resulted in growing waitlists and delayed access to vital genomic testing. To address this issue, the Queensland Paediatric Immunology and Allergy Service, Australia, developed and evaluated a mainstreaming model of care to support point-of-care genomic testing for paediatric IEI. Key features of the model of care included a genetic counsellor embedded in the department, state-wide multidisciplinary team meetings, and variant prioritisation meetings to review whole exome sequencing (WES) data. Of the 62 children presented at the MDT, 43 proceeded to WES, of which nine (21%) received a confirmed molecular diagnosis. Changes to treatment and management were reported for all children with a positive result, including curative hematopoietic stem cell transplantation (n = 4). Four children were also referred for further investigations of variants of uncertain significance or additional testing due to ongoing suspicion of genetic cause after negative result. Demonstrating engagement with the model of care, 45% of the patients were from regional areas and on average, 14 healthcare providers attended the state-wide multidisciplinary team meetings. Parents demonstrated understanding of the implications of testing, reported minimal decisional regret post-test, and identified benefits to genomic testing. Overall, our program demonstrated the feasibility of a mainstreaming model of care for paediatric IEI, improved access to genomic testing, facilitated treatment decision-making, and was acceptable to parents and clinicians alike.

Inborn and acquired deficits of type I interferon (IFN) immunity predispose to life-threatening COVID-19 pneumonia. We longitudinally profiled the B cell response to mRNA vaccination in SARS-CoV-2 naive patients with inherited TLR7, IRF7, or IFNAR1 deficiency, as well as young patients with autoantibodies neutralizing type I IFNs due to autoimmune polyendocrine syndrome type-1 (APS-1) and older individuals with age-associated autoantibodies to type I IFNs. The receptor-binding domain spike protein (RBD)-specific memory B cell response in all patients was quantitatively and qualitatively similar to healthy donors. Sustained germinal center responses led to accumulation of somatic hypermutations in immunoglobulin heavy chain genes. The amplitude and duration of, and viral neutralization by, RBD-specific IgG serological response were also largely unaffected by TLR7, IRF7, or IFNAR1 deficiencies up to 7 mo after vaccination in all patients. These results suggest that induction of type I IFN is not required for efficient generation of a humoral response against SARS-CoV-2 by mRNA vaccines. ispartof: JOURNAL OF EXPERIMENTAL MEDICINE vol:220 issue:1 ispartof: location:United States status: published

Rare, biallelic loss-of-function mutations in DOCK8 result in a combined immune deficiency characterized by severe and recurrent cutaneous infections, eczema, allergies, and susceptibility to malignancy, as well as impaired humoral and cellular immunity and hyper-IgE. The advent of next-generation sequencing technologies has enabled the rapid molecular diagnosis of rare monogenic diseases, including inborn errors of immunity. These advances have resulted in the implementation of gene-guided treatments, such as hematopoietic stem cell transplant for DOCK8 deficiency. However, putative disease-causing variants revealed by next-generation sequencing need rigorous validation to demonstrate pathogenicity. Here, we report the eventual diagnosis of DOCK8 deficiency in a consanguineous family due to a novel homozygous intronic deletion variant that caused aberrant exon splicing and subsequent loss of expression of DOCK8 protein. Remarkably, the causative variant was not initially detected by clinical whole-genome sequencing but was subsequently identified and validated by combining advanced genomic analysis, RNA-seq, and flow cytometry. This case highlights the need to adopt multipronged confirmatory approaches to definitively solve complex genetic cases that result from variants outside protein-coding exons and conventional splice sites.

Aim: This study aims to evaluate the utility of genetic testing of patients diagnosed with periodic fever syndromes and to assess the validity of existing scoring criteria. Methods: This study retrospectively reviewed the clinical history of patients diagnosed with periodic fever syndromes at Queensland Children's Hospital between November 2014 and June 2018. Results: Forty-three patients were diagnosed with periodic fever syndromes. Diagnoses in the cohort included periodic fever, adenitis, pharyngitis and aphthous stomatitis (10), tumour necrosis factor receptor-associated periodic syndrome (9), cryopyrin-associated periodic syndrome (6), mevalonate kinase deficiency (4) while 14 remained unspecified. No presenting symptoms were uniquely associated with any particular diagnosis. Genetic testing of between 1 and 26 genes was performed in 26 (60%) patients. Two (7.7%) patients had pathogenic variants identified. Variants of uncertain significance which were insufficient to confirm a monogenic disorder were identified in a further 7 (27%) patients. The Eurofever classification criteria correlated with clinical diagnosis for patients diagnosed with cryopyrin-associated periodic syndrome (P = 0.046) and tumour necrosis factor receptor-associated periodic syndrome (P = 0.025) but not for patients diagnosed with mevalonate kinase deficiency (P = 0.47); however, the Eurofever classification criteria were often positive for more than one diagnosis in these patients. Conclusion: The European classification criteria can form a potentially useful tool to guide diagnosis; however, clinical judgement remains essential, because the score is often positive for multiple diagnoses. The diagnostic yield of genetic testing in this cohort was low and genetic testing may be more useful to confirm a strong clinical suspicion than to clarify a diagnosis for patients with less clear symptoms.

International audience; Globally, autosomal recessive IFNAR1 deficiency is a rare inborn error of immunity underlying susceptibility to live attenuated vaccine and wild-type viruses. We report seven children from five unrelated kindreds of western Polynesian ancestry who suffered from severe viral diseases. All the patients are homozygous for the same nonsense IFNAR1 variant (p.Glu386*). This allele encodes a truncated protein that is absent from the cell surface and is loss-of-function. The fibroblasts of the patients do not respond to type I IFNs (IFN-α2, IFN-ω, or IFN-β). Remarkably, this IFNAR1 variant has a minor allele frequency >1% in Samoa and is also observed in the Cook, Society, Marquesas, and Austral islands, as well as Fiji, whereas it is extremely rare or absent in the other populations tested, including those of the Pacific region. Inherited IFNAR1 deficiency should be considered in individuals of Polynesian ancestry with severe viral illnesses.

Rare, biallelic loss-of-function mutations in DOCK8 result in a combined immune deficiency characterized by severe and recurrent cutaneous infections, eczema, allergies, and susceptibility to malignancy, as well as impaired humoral and cellular immunity and hyper-IgE. The advent of next-generation sequencing technologies has enabled the rapid molecular diagnosis of rare monogenic diseases, including inborn errors of immunity. These advances have resulted in the implementation of gene-guided treatments, such as hematopoietic stem cell transplant for DOCK8 deficiency. However, putative disease-causing variants revealed by next-generation sequencing need rigorous validation to demonstrate pathogenicity. Here, we report the eventual diagnosis of DOCK8 deficiency in a consanguineous family due to a novel homozygous intronic deletion variant that caused aberrant exon splicing and subsequent loss of expression of DOCK8 protein. Remarkably, the causative variant was not initially detected by clinical whole-genome sequencing but was subsequently identified and validated by combining advanced genomic analysis, RNA-seq, and flow cytometry. This case highlights the need to adopt multipronged confirmatory approaches to definitively solve complex genetic cases that result from variants outside protein-coding exons and conventional splice sites.

Most patients with autosomal dominant hyper-IgE syndrome (AD-HIES) are heterozygous for rare STAT3 variants. The mechanism of dominance was recently questioned. The authors show that both in-frame and out-of-frame STAT3 variants underlie AD-HIES by negative dominance and not haploinsufficiency., Most patients with autosomal dominant hyper-IgE syndrome (AD-HIES) carry rare heterozygous STAT3 variants. Only six of the 135 in-frame variants reported have been experimentally shown to be dominant negative (DN), and it has been recently suggested that eight out-of-frame variants operate by haploinsufficiency. We experimentally tested these 143 variants, 7 novel out-of-frame variants found in HIES patients, and other STAT3 variants from the general population. Strikingly, all 15 out-of-frame variants were DN via their encoded (1) truncated proteins, (2) neoproteins generated from a translation reinitiation codon, and (3) isoforms from alternative transcripts or a combination thereof. Moreover, 128 of the 135 in-frame variants (95%) were also DN. The patients carrying the seven non-DN STAT3 in-frame variants have not been studied for other genetic etiologies. Finally, none of the variants from the general population tested, including an out-of-frame variant, were DN. Overall, our findings show that heterozygous STAT3 variants, whether in or out of frame, underlie AD-HIES through negative dominance rather than haploinsufficiency., Graphical Abstract

An amendment to this paper has been published and can be accessed via the original article.

This consensus document outlines the recommendations from the Australasian Society of Clinical Immunology and Allergy Transplantation and Primary Immunodeficiency group for the diagnosis and management of patients with severe combined immunodeficiency. It also provides a proposed framework for the early investigation, management and supportive care prior to haematopoietic stem cell transplantation.

Background: WHIM (Warts, Hypogammaglobulinemia, Infections, and Myelokathexis) syndrome is a rare primary immunodeficiency associated with broad cytopenia, including neutropenia. It is caused by gain-of-function mutations in C XCR4, leading to dysregulated immune cell trafficking with retention of neutrophils, lymphocytes, and monocytes in the bone marrow and in some cases, hypogammaglobulinemia. As a result, patients with WHIM syndrome have recurrent bacterial and viral infections, and unusual susceptibility to human papillomavirus infection predisposing individuals to recalcitrant warts and malignancy (McDermott D, et al. Immunol Rev. 2019;91-102). Therapeutic options are limited and do not address the underlying pathogenic mechanism of WHIM syndrome. The investigational oral CXCR4 antagonist mavorixafor directly targets the underlying cause of disease and has been shown to increase absolute neutrophil, lymphocyte, and monocyte counts, and to decrease annualized infection rate, and reduce cutaneous wart burden in a phase 2 trial of adults with WHIM syndrome (NCT03005327; Dale D, et al. Blood. 2020;136: 2994-3003). Findings from an ongoing long-term extension of this study support a sustained clinical benefit of long-term mavorixafor treatment in patients with WHIM syndrome. Here, we describe the design of a global phase 3 registrational trial evaluating the safety and efficacy of mavorixafor in WHIM syndrome in participants aged ≥12 years while reporting on preliminary baseline characteristics of the enrolled population. Methods: This phase 3 trial (4WHIM; NCT03995108) is a randomized, double-blind, placebo-controlled study with open-label extension (OLE) and planned enrollment of 18 to 28 patients from sites in Asia, Australia, Europe, Israel, and the United States. Patients aged ≥12 years with a confirmed CXCR4 mutation consistent with WHIM syndrome phenotype and a screening absolute neutrophil count (ANC) ≤400 cells/µL without clinical evidence of active systemic infection are eligible for enrollment. Patients are randomized 1:1 to receive mavorixafor (400 mg in adults, and adolescents weighing >50 kg; 200 mg in adolescents weighing ≤50 kg) or matching placebo once daily for a total of 52 weeks (≥9 patients per group). Patients who complete the randomized period or are granted early release due to recurrent infections requiring treatment (≤2 requiring hospitalization or 4 requiring intravenous antibiotic or granulocyte colony-stimulating factor) are eligible to enroll in the OLE and receive mavorixafor until commercial availability or study termination. The primary end point is the number of hours above ANC threshold of 500 cells/µL over a 24-hour period, assessed prior to treatment, and 4 times (every 3 months) over the 52-week randomized period. Secondary end points include infection rates adjudicated by a blinded, independent committee, change from baseline in cutaneous warts also with blinded assessment, number of hours above absolute lymphocyte count (ALC) of 1000 cells/µL over a 24-hour period, and patient-reported outcomes such as work/school absence and quality of life assessment using age-appropriate questionnaires. Patient Demographics and Characteristics: As of July 15 2021, the first 18 patients have enrolled from 10 countries and 15 sites. Of these, 56% are pediatric patients, 56% are males, 56% of the patients have warts, 94% have nonsense and 6% have frameshift CXCR4 mutations. All patients had severe neutropenia (ANC ≤400 cells/μL) and majority had significant lymphopenia (ALC ≤1000 cells/μL). Conclusions: Evidence supporting efficacy of current therapies in WHIM syndrome is lacking, and approved therapies targeting the underlying molecular mechanisms and hence, able to address the full clinical spectrum of this condition, are needed. The 4WHIM study is the first double-blind, placebo-controlled, randomized trial in patients with this syndrome and is an important next step in the clinical development of a novel, orally bioavailable targeted therapy for WHIM syndrome and potentially for other individuals with related cellular immunodeficiencies. This robust study will build on the findings of the phase 2 trial that suggested a clinical benefit of mavorixafor for WHIM syndrome by incorporating a broader, global population of patients observed for a longer period of time. Full phase 3 trial results are anticipated in late 2022. Disclosures Dale: X4 Pharmaceuticals: Consultancy, Honoraria, Research Funding. Azar: X4 Pharmaceuticals: Research Funding. Badolato: Angelini: Consultancy; X4 Pharmaceuticals: Consultancy; Janssen: Consultancy; SOBI (IDMC): Other. Bhandari: X4 Pharmaceuticals: Current Employment. Belschner: X4 Pharmaceuticals: Current Employment. Cadavid: X4 Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Dickerson: Bluebird Bio: Membership on an entity's Board of Directors or advisory committees. Hoffman: Zomagen: Research Funding; Novartis: Consultancy, Speakers Bureau; Takeda: Research Funding; Jecure: Research Funding. Jiang: X4 Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Kang: Cartexell: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis Korea: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen Korea: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kulagin: Roche: Speakers Bureau; Sanofi: Speakers Bureau; Generium: Speakers Bureau; Biocad: Research Funding; Apellis: Research Funding; Alexion: Research Funding; X4 Pharmaceuticals: Research Funding; Novartis: Speakers Bureau; Johnson & Johnson: Speakers Bureau; Pfizer: Speakers Bureau. Langguth: RCPA: Membership on an entity's Board of Directors or advisory committees. MacLeod: X4 Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Sharathkumar: Amgen: Research Funding; BMS: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Shire: Membership on an entity's Board of Directors or advisory committees, Research Funding; X4 Pharmaceuticals: Research Funding; NIH Trials of Pediatric VTE: Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees. Shcherbina: X4 Pharmaceuticals: Speakers Bureau. Tang: X4 Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Vossen: X4 Pharmaceuticals: Other: PI in WHIM Trial; Brothers of St. John: Consultancy; Austrian National Bank: Research Funding; Menarini: Honoraria; Gilead: Honoraria; Astro Pharma: Honoraria.

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal allergic disorder. Large population-based FPIES studies are lacking.We sought to determine the incidence and clinical characteristics of FPIES in Australian infants.An Australia-wide survey (2012-2014) was undertaken through the Australian Paediatric Surveillance Unit, with monthly notification of new cases of acute FPIES in infants aged less than 24 months by 1400 participating pediatricians.Two hundred thirty infants with FPIES were identified. The incidence of FPIES in Australian infants (24 months) was 15.4/100,000/y. Median age of first episode, diagnosis, and notification were 5, 7, and 10 months, respectively. There was no sex predilection. Seven percent of infants had siblings with a history of FPIES, and 5% reacted during exclusive breast-feeding. Sixty-eight had a single food trigger (20% had 2 and 12% had ≥3 food triggers). The most common FPIES triggers were rice (45%), cow's milk (33%), and egg (12%). Fifty-one percent of infants reacted on their first known exposure. Infants with FPIES to multiple versus single food groups were younger at the initial episode (4.6 vs 5.8 months [mean], P = .001) and more frequently had FPIES to fruits, vegetables, or both (66% vs 21%, P .0001). Infants exclusively breast-fed for more than 4 months had a trend toward lower rates of FPIES to multiple food groups (23% vs 36%, P = .06). Sixty-four percent of infants with FPIES to multiple foods, which included cow's milk, had coassociated FPIES to solid foods. Forty-two percent of infants with FPIES to fish reacted to other food groups.FPIES is not rare, with an estimated incidence of 15.4/100,000/y. Rice is the most common food trigger in Australia. Factors associated with FPIES to multiple foods included early-onset disease and FPIES to fruits, vegetables, or both.

Mutations in the dedicator of cytokinesis 8 (DOCK8) gene cause an autosomal recessive form of hyper-IgE syndrome, characterized by chronic immunodeficiency with persistent microbial infection and increased incidence of malignancy. These manifestations suggest a defect in cytotoxic lymphocyte function and immune surveillance. However, how DOCK8 regulates NK cell–driven immune responses remains unclear. In this article, we demonstrate that DOCK8 regulates NK cell cytotoxicity and cytokine production in response to target cell engagement or receptor ligation. Genetic ablation of DOCK8 in human NK cells attenuated cytokine transcription and secretion through inhibition of Src family kinase activation, particularly Lck, downstream of target cell engagement or NKp30 ligation. PMA/Ionomycin treatment of DOCK8-deficient NK cells rescued cytokine production, indicating a defect proximal to receptor ligation. Importantly, NK cells from DOCK8-deficient patients had attenuated production of IFN-γ and TNF-α upon NKp30 stimulation. Taken together, we reveal a novel molecular mechanism by which DOCK8 regulates NK cell–driven immunity.

Background Insulin autoimmune syndrome (IAS), characterized by glycemic dysregulation and life-threatening hypoglycemia, can occur in patients with type 1 diabetes (T1D). Diagnostic confirmation is complex but important in order to ensure timely initiation of definitive therapy. Aims We aimed to quantitate the degree of immunoglobulin-insulin complex (IIC) formation and its effects on glycemic control in a patient with T1D and IAS compared with T1D and non-T1D controls and before and after therapeutic plasma exchange (TPE). Materials & Methods The prospective descriptive study was conducted between June 2015 and December 2015 in a quaternary children's hospital in Brisbane, Australia. Percent Free “Immunoreactive” Insulin (%FII) as assessed by polyethylene glycol precipitation studies and its relationship to plasma glucose and serum insulin concentration. Results Samples from the patient with T1D and IAS demonstrated lower mean %FII compared to T1D (23.8 ± 2.0 vs 52.0 ± 6.7; P

Background Dedicator of cytokinesis 8 (DOCK8) deficiency is a combined immunodeficiency caused by autosomal recessive loss-of-function mutations in DOCK8 . This disorder is characterized by recurrent cutaneous infections, increased serum IgE levels, and severe atopic disease, including food-induced anaphylaxis. However, the contribution of defects in CD4 + T cells to disease pathogenesis in these patients has not been thoroughly investigated. Objective We sought to investigate the phenotype and function of DOCK8-deficient CD4 + T cells to determine (1) intrinsic and extrinsic CD4 + T-cell defects and (2) how defects account for the clinical features of DOCK8 deficiency. Methods We performed in-depth analysis of the CD4 + T-cell compartment of DOCK8-deficient patients. We enumerated subsets of CD4 + T helper cells and assessed cytokine production and transcription factor expression. Finally, we determined the levels of IgE specific for staple foods and house dust mite allergens in DOCK8-deficient patients and healthy control subjects. Results DOCK8-deficient memory CD4 + T cells were biased toward a T H 2 type, and this was at the expense of T H 1 and T H 17 cells. In vitro polarization of DOCK8-deficient naive CD4 + T cells revealed the T H 2 bias and T H 17 defect to be T-cell intrinsic. Examination of allergen-specific IgE revealed plasma IgE from DOCK8-deficient patients is directed against staple food antigens but not house dust mites. Conclusion Investigations into the DOCK8-deficient CD4 + T cells provided an explanation for some of the clinical features of this disorder: the T H 2 bias is likely to contribute to atopic disease, whereas defects in T H 1 and T H 17 cells compromise antiviral and antifungal immunity, respectively, explaining the infectious susceptibility of DOCK8-deficient patients.

Bi-allelic inactivating mutations in DOCK8 cause a combined immunodeficiency characterised by severe pathogen infections, eczema, allergies, malignancy and impaired humoral responses. These clinical features result from functional defects in most lymphocyte lineages. Thus, DOCK8 plays a key role in immune cell function. Hematopoietic stem cell transplantation (HSCT) is curative for DOCK8 deficiency. While previous reports have described clinical outcomes for DOCK8 deficiency following HSCT, the effect on lymphocyte reconstitution and function has not been investigated. Our study determined whether defects in lymphocyte differentiation and function in DOCK8-deficient patients were restored following HSCT. DOCK8-deficient T and B lymphocytes exhibited aberrant activation and effector function in vivo and in vitro. Frequencies of αβ T and MAIT cells were reduced while γδT cells were increased in DOCK8-deficient patients. HSCT improved, abnormal lymphocyte function in DOCK8-deficient patients. Elevated total and allergen-specific IgE in DOCK8-deficient patients decreased over time following HSCT. Our results document the extensive catalogue of cellular defects in DOCK8-deficient patients, and the efficacy of HSCT to correct these defects, concurrent with improvements in clinical phenotypes. Overall, our findings provide mechanisms at a functional cellular level for improvements in clinical features of DOCK8 deficiency post-HSCT, identify biomarkers that correlate with improved clinical outcomes, and inform the general dynamics of immune reconstitution in patients with monogenic immune disorders following HSCT.

FOXN1 is the master regulatory gene of thymic epithelium development. FOXN1 deficiency leads to thymic aplasia, alopecia, and nail dystrophy, accounting for the nude/severe combined immunodeficiency (nu/SCID) phenotype in humans and mice. We identified several newborns with low levels of Tcell receptor excision circles (TRECs) and Tcell lymphopenia at birth, who carried heterozygous loss-of-function FOXN1 variants. Longitudinal analysis showed persistent Tcell lymphopenia during infancy, often associated with nail dystrophy. Adult individuals with heterozygous FOXN1 variants had in most cases normal CD4+ but lower than normal CD8+ cellcounts. We hypothesized a FOXN1 gene dosage effect on the function of thymic epithelial cells (TECs) and thymopoiesis and postulated that these effects would be more prominent early in life. To test this hypothesis, we analyzed TEC subset frequency and phenotype, early thymic progenitor (ETP) cell count, and expression of FOXN1 target genes (Ccl25, Cxcl12, Dll4, Scf, Psmb11, Prss16, and Cd83) in Foxn1nu/+ (nu/+) mice and age-matched wild-type (+/+) littermate controls. Both the frequency and the absolute count of ETP were significantly reduced in nu/+ mice up to 3weeks of age. Analysis of the TEC compartment showed reduced expression of FOXN1 target genes and delayed maturation of the medullary TEC compartment in nu/+ mice. These observations establish a FOXN1 gene dosage effect on thymic function and identify FOXN1 haploinsufficiency as an important genetic determinant of Tcell lymphopenia at birth.

Insulin autoimmune syndrome (IAS), characterized by glycemic dysregulation and life-threatening hypoglycemia, can occur in patients with type 1 diabetes (T1D). Diagnostic confirmation is complex but important in order to ensure timely initiation of definitive therapy.We aimed to quantitate the degree of immunoglobulin-insulin complex (IIC) formation and its effects on glycemic control in a patient with T1D and IAS compared with T1D and non-T1D controls and before and after therapeutic plasma exchange (TPE).The prospective descriptive study was conducted between June 2015 and December 2015 in a quaternary children's hospital in Brisbane, Australia. Percent Free "Immunoreactive" Insulin (%FII) as assessed by polyethylene glycol precipitation studies and its relationship to plasma glucose and serum insulin concentration.Samples from the patient with T1D and IAS demonstrated lower mean %FII compared to T1D (23.8 ± 2.0 vs 52.0 ± 6.7; P .0001) and non-T1D (23.8 ± 2.0 vs 102.9 ± 2.7; P .0001) controls. This was associated with loss of glycemic predictability and frequent severe hypoglycemia. TPE increased %FII (23.8 ± 2.0 before TPE vs 83.6 ± 2.5 after TPE, P .0001) and reestablished plasma glucose responsiveness to exogenous insulin.IAS should be considered in T1D patients with unexplained glycemic instability and hypoglycemia. The laboratory plays an integral diagnostic role.TPE is an effective method for removing IICs and normalizing insulin-mediated glucose responses.

Memory B cells, unlike naive B cells, require a reduced level of STAT3 activation to differentiate into antibody-secreting plasmablasts in response to IL-10 and IL-21; however, this process requires IL-21R expression in both naive and memory cells., Long-lived antibody memory is mediated by the combined effects of long-lived plasma cells (PCs) and memory B cells generated in response to T cell–dependent antigens (Ags). IL-10 and IL-21 can activate multiple signaling pathways, including STAT1, STAT3, and STAT5; ERK; PI3K/Akt, and potently promote human B cell differentiation. We previously showed that loss-of-function mutations in STAT3, but not STAT1, abrogate IL-10– and IL-21–mediated differentiation of human naive B cells into plasmablasts. We report here that, in contrast to naive B cells, STAT3-deficient memory B cells responded to these STAT3-activating cytokines, differentiating into plasmablasts and secreting high levels of IgM, IgG, and IgA, as well as Ag-specific IgG. This was associated with the induction of the molecular machinery necessary for PC formation. Mutations in IL21R, however, abolished IL-21–induced responses of both naive and memory human B cells and compromised memory B cell formation in vivo. These findings reveal a key role for IL-21R/STAT3 signaling in regulating human B cell function. Furthermore, our results indicate that the threshold of STAT3 activation required for differentiation is lower in memory compared with naive B cells, thereby identifying an intrinsic difference in the mechanism underlying differentiation of naive versus memory B cells.

One out of three pediatric sepsis deaths in high income countries occur in previously healthy children. Primary immunodeficiencies have been postulated to underlie fulminant sepsis, but this concept remains to be confirmed in clinical practice. Pseudomonas aeruginosa (P. aeruginosa) is a common bacterium mostly associated with healthcare-related infections in immunocompromised individuals. However, in rare cases, it can cause sepsis in previously healthy children. We used exome sequencing and bioinformatic analysis to systematically search for genetic factors underpinning severe P. aeruginosa infection in the pediatric population. We collected blood samples from 11 previously healthy children, with no family history of immunodeficiency, who presented with severe sepsis due to community-acquired P. aeruginosa bacteremia. Genomic DNA was extracted from blood or tissue samples obtained intravitam or postmortem. We obtained high-coverage exome sequencing data and searched for rare loss-of-function variants. After rigorous filtrations, 12 potentially causal variants were identified. 2 out of 8 (25%) fatal cases were found to carry novel pathogenic variants in primary immunodeficiency genes, including BTK and DNMT3B. This study demonstrates that exome sequencing allows to identify rare, deleterious human genetic variants responsible for fulminant sepsis in apparently healthy children. Diagnosing primary immunodeficiencies in such patients is of high relevance to survivors and affected families. We propose that unusually severe and fatal sepsis cases in previously healthy children should be considered for exome/genome sequencing to search for underlying primary immunodeficiencies.

Dedicator of cytokinesis 8 (DOCK8) deficiency is a combined immunodeficiency caused by autosomal recessive loss-of-function mutations in DOCK8. This disorder is characterized by recurrent cutaneous infections, increased serum IgE levels, and severe atopic disease, including food-induced anaphylaxis. However, the contribution of defects in CD4We sought to investigate the phenotype and function of DOCK8-deficient CD4We performed in-depth analysis of the CD4DOCK8-deficient memory CD4Investigations into the DOCK8-deficient CD4

T follicular helper (Tfh) cells are critical for providing the necessary signals to induce differentiation of B cells into memory and Ab-secreting cells. Accordingly, it is important to identify the molecular requirements for Tfh cell development and function. We previously found that IL-12 mediates the differentiation of human CD4(+) T cells to the Tfh lineage, because IL-12 induces naive human CD4(+) T cells to acquire expression of IL-21, BCL6, ICOS, and CXCR5, which typify Tfh cells. We have now examined CD4(+) T cells from patients deficient in IL-12R beta 1, TYK2, STAT1, and STAT3 to further explore the pathways involved in human Tfh cell differentiation. Although STAT1 was dispensable, mutations in IL12RB1, TYK2, or STAT3 compromised IL-12-induced expression of IL-21 by human CD4(+) T cells. Defective expression of IL-21 by STAT3-deficient CD4(+) T cells resulted in diminished B-cell helper activity in vitro. Importantly, mutations in STAT3, but not IL12RB1 or TYK2, also reduced Tfh cell generation in vivo, evidenced by decreased circulating CD4(+)CXCR5(+) T cells. These results highlight the nonredundant role of STAT3 in human Tfh cell differentiation and suggest that defective Tfh cell development and/or function contributes to the humoral defects observed in STAT3-deficient patients. National Health and Medical Research Council of Australia Rockefeller University Center - 5UL1RR024143 United States Department of Health & Human Services National Institutes of Health (NIH) - USA NIH National Center for Research Resources (NCRR) UL1RR024143

SCID resulting from mutations in IL2RG or JAK3 is characterized by lack of T and natural killer cells; B cells are present in normal number, but antibody responses are defective. Hematopoietic cell transplantation (HCT) is curative for SCID. However, B-cell dysfunction persists in a substantial proportion of patients. We hypothesized that impaired B-cell responses after HCT in IL2RG/JAK3 deficiency results from poor donor B-cell engraftment and defective γc-dependent cytokine signaling in host B cells. To test this, and to identify which γc cytokine(s) is critical for humoral immunity, we studied 28 transplanted patients with IL2RG/JAK3 deficiency. Lack of donor B-cell engraftment associated with persistent humoral dysfunction and significantly reduced memory B cells. B-cell proliferation induced by CD40L alone or together with CpG, anti-Ig, IL-4, IL-10, or IL-13 was comparable in healthy controls and in post-HCT SCID patients, irrespective of their chimerism status. However, in vitro stimulation with CD40L/IL-21 induced B-cell proliferation, plasmablast differentiation, and antibody secretion in patients with donor B cells, but not in patients with autologous B cells. These data imply that IL-21–mediated signaling is critical for long-lived humoral immunity and to restore antibody responses in IL2RG/JAK3-deficient patients after HCT. Furthermore, in vitro stimulation with CD40L/IL-21 can predict in vivo B-cell immunity in IL2RG/JAK3 SCID after transplantation.

Many primary immunodeficiency disorders of differing etiologies have been well characterized, and much understanding of immunological processes has been gained by investigating the mechanisms of disease. Here, we have used a whole-genome approach, employing single-nucleotide polymorphism and gene expression microarrays, to provide insight into the molecular etiology of a novel immunodeficiency disorder. Using DNA copy number profiling, we define a hyperploid region on 14q11.2 in the immunodeficiency case associated with the interleukin (IL)-25 locus. This alteration was associated with significantly heightened expression of IL25 following T-cell activation. An associated dominant type 2 helper T cell bias in the immunodeficiency case provides a mechanistic explanation for recurrence of infections by pathogens met by Th1-driven responses. Furthermore, this highlights the capacity of IL25 to alter normal human immune responses.

Noble C, Peake J, Lewindon PJ. Increase in de novo allergies after paediatric liver transplantation: The Brisbane experience. Pediatr Transplantation 2011: 15: 451–454. © 2011 John Wiley & Sons A/S. Abstract: Pediatric liver transplantation is a successful procedure with 10-yr survival rate of 70%; following transplantation, the emphasis on promoting good quality of life is important. The increasing prevalence of allergic disorders in the general population and an increase in food allergy following solid organ transplantation are described in patients, especially in children, but the contribution to morbidity post-OLT has not been addressed. Objectives: Identifying the incidence de novo allergies post-OLT performed by QLTS over 11 yr. Methods: Comprehensive medical record review of OLT recipients during study period. Results: From 1st July 1998 to 1st August 2009, 78 children received 85 cadaveric OLT; 60 children survived. Allergic disease was documented in 24/60 (40%) survivors. De novo food allergies were diagnosed in 12/60 (20%) (Table 2), 9/12 occurred in children who were infants at time of transplant. Ten of 12 had severe allergies, six anaphylactic; 6/60 (10%) carry an EpiPen. Only 31/60 (51%) diagnosed are followed in Queensland, suggesting severe allergic disease in our cohort is an underestimate. Conclusion: Serious allergic disease post-OLT is clinically important, especially in infants at time of transplant, and should be targeted for specialist allergist referral and risk management. Table 2. Allergic diseases reported in pre- and post-OLT Atopy Pre-transplant number N = 78 Post-transplant number N = 78 Asthma 4 5 Eczema 3 6 Allergic rhinitis 1 1 Food allergy 2 14 Eosinophilic oesophagitis 1 4 Other (drug) 6 19 Total 17 reactions 10 patients 49 reactions 24 patients

Engagement of cytokine receptors by specific ligands activate Janus kinase–signal transducer and activator of transcription (STAT) signaling pathways. The exact roles of STATs in human lymphocyte behavior remain incompletely defined. Interleukin (IL)-21 activates STAT1 and STAT3 and has emerged as a potent regulator of B cell differentiation. We have studied patients with inactivating mutations in STAT1 or STAT3 to dissect their contribution to B cell function in vivo and in response to IL-21 in vitro. STAT3 mutations dramatically reduced the number of functional, antigen (Ag)-specific memory B cells and abolished the ability of IL-21 to induce naive B cells to differentiate into plasma cells (PCs). This resulted from impaired activation of the molecular machinery required for PC generation. In contrast, STAT1 deficiency had no effect on memory B cell formation in vivo or IL-21–induced immunoglobulin secretion in vitro. Thus, STAT3 plays a critical role in generating effector B cells from naive precursors in humans. STAT3-activating cytokines such as IL-21 thus underpin Ag-specific humoral immune responses and provide a mechanism for the functional antibody deficit in STAT3-deficient patients.

Roifman Syndrome is a rare congenital disorder characterized by growth retardation, cognitive delay, spondyloepiphyseal dysplasia and antibody deficiency. Here we utilize whole-genome sequencing of Roifman Syndrome patients to reveal compound heterozygous rare variants that disrupt highly conserved positions of the RNU4ATAC small nuclear RNA gene, a minor spliceosome component that is essential for minor intron splicing. Targeted sequencing confirms allele segregation in six cases from four unrelated families. RNU4ATAC rare variants have been recently reported to cause microcephalic osteodysplastic primordial dwarfism, type I (MOPD1), whose phenotype is distinct from Roifman Syndrome. Strikingly, all six of the Roifman Syndrome cases have one variant that overlaps MOPD1-implicated structural elements, while the other variant overlaps a highly conserved structural element not previously implicated in disease. RNA-seq analysis confirms extensive and specific defects of minor intron splicing. Available allele frequency data suggest that recessive genetic disorders caused by RNU4ATAC rare variants may be more prevalent than previously reported., Roifman Syndrome is a rare disorder whose disease manifestations include growth retardation, spondyloepiphyseal dysplasia and immunodeficiency. Here, the authors use whole-genome sequencing to discover that rare compound heterozygous variants disrupting the small nuclear RNA gene RNU4ATAC cause Roifman Syndrome.

SUMMARY A 9-year-old girl presented with a 6-month history of inflamed tender nodules in the pretibial area. These eventually healed leaving depressed areas of atrophy and loss of subcutaneous tissue. Histology showed a predominantly lymphocytic lobular panniculitis, consistent with connective tissue panniculitis. Investigations revealed an elevated thyroid stimulating hormone, elevated thyroid antiperoxidase antibody and a weakly positive antinuclear antibody (titre 1 in 40). She was commenced on hydroxychloroquine 300 mg daily, which resulted in resolution of the panniculitis. She developed focal vitiligo on the thighs. This gradually improved with 0.1% mometasone furoate ointment. The hydroxychloroquine dose was tapered to 200 mg daily after 12 months, then to 100 mg daily after 18 months therapy. Her thyroid autoantibody levels continued to rise and the hydroxychloroquine was increased again to 300 mg daily. She became borderline hypothyroid. Hashimoto's thyroiditis was diagnosed. Thyroxine was instituted with a resultant improvement in her thyroid blood tests. The lipoatrophy has not developed further during 2-year follow up.

Wilson et al. show that individuals with loss-of-function mutations in STAT3 have reduced numbers of peripheral blood MAIT and NKT cells, but not γδ T cells. Residual MAIT cells had normal expression of RORγt, but displayed impaired secretion of IL-17A and IL-17F., Unconventional T cells such as γδ T cells, natural killer T cells (NKT cells) and mucosal-associated invariant T cells (MAIT cells) are a major component of the immune system; however, the cytokine signaling pathways that control their development and function in humans are unknown. Primary immunodeficiencies caused by single gene mutations provide a unique opportunity to investigate the role of specific molecules in regulating human lymphocyte development and function. We found that individuals with loss-of-function mutations in STAT3 had reduced numbers of peripheral blood MAIT and NKT but not γδ T cells. Analysis of STAT3 mosaic individuals revealed that this effect was cell intrinsic. Surprisingly, the residual STAT3-deficient MAIT cells expressed normal levels of the transcription factor RORγt. Despite this, they displayed a deficiency in secretion of IL-17A and IL-17F, but were able to secrete normal levels of cytokines such as IFNγ and TNF. The deficiency in MAIT and NKT cells in STAT3-deficient patients was mirrored by loss-of-function mutations in IL12RB1 and IL21R, respectively. Thus, these results reveal for the first time the essential role of STAT3 signaling downstream of IL-23R and IL-21R in controlling human MAIT and NKT cell numbers.

Primary immunodeficiency disorders in childhood usually present as unusual, recurrent or severe infections, symptomatic infections with organisms of low pathogenicity, or as recognizable syndromes which are known to have associated immunological abnormalities. In many of the primary immunodeficiency disorders, there are known patterns of inheritance, and other family members may be affected. Some primary immunodeficiency disorders are relatively common, such as selective IgA deficiency, and often do not lead to major morbidity. Others, such as the severe combined immune deficiency syndromes, are relatively rare, and are fatal in early life if not recognized and treated early. Diagnosis of a primary immunodeficiency disorder depends on appropriate use of laboratory investigations. Often there will be abnormalities detected on a complete blood film and measurement of immunoglobulin isotypes. More complex investigations should be undertaken in conjunction with a paediatric immunology service. In recent years, many of the clinically defined primary immunodeficiency disorders have been shown to have associated specific gene defects. For some, this has led to the identification and characterization of defective or absent gene products. The consequences of this new knowledge are more accurate diagnosis, early diagnosis including antenatal diagnosis, detection of undiagnosed disease in other family members, and the potential for new therapies including gene or gene product therapy.

To determine whether human X-linked neonatal diabetes mellitus, enteropathy and endocrinopathy syndrome (IPEX; MIM 304930) is the genetic equivalent of the scurfy (sf) mouse, we sequenced the human ortholog (FOXP3) of the gene mutated in scurfy mice (Foxp3), in IPEX patients. We found four non-polymorphic mutations. Each mutation affects the forkhead/winged-helix domain of the scurfin protein, indicating that the mutations may disrupt critical DNA interactions.

Cow's milk protein allergy is a condition commonly managed by general practitioners and paediatricians. The diagnosis is usually made in the first 12 months of life. Management of immediate allergic reactions and anaphylaxis includes the prevention of accidental food ingestion and provision of an adrenaline autoinjector, if appropriate. By contrast, the clinical course of delayed food-allergic manifestations is characterised by chronicity, and is often associated with nutritional or behavioural sequelae. Correct diagnosis of these non-IgE-mediated conditions may be delayed due to a lack of reliable diagnostic markers. This review aims to guide clinicians in the: (i) diagnostic evaluation (skin prick testing or measurement of food-specific serum IgE levels; indications for diagnostic challenges for suspected IgE- and non-IgE-mediated food allergy), (ii) dietary treatment, (iii) assessment of response to treatment, (iv) differential diagnosis and further diagnostic work-up in non-responders, (v) follow-up assessment of tolerance development and (vi) recommendations for further referral.

BACKGROUND: Non‐specific cough is defined as non‐productive cough in the absence of identifiable respiratory disease or known aetiology. It is commonly seen in paediatric practice. These children are treated with a variety of therapies including anti‐histamines. Also, anti‐histamines are advocated as an empirical treatment in adults with chronic cough. OBJECTIVES: To evaluate the effectiveness of anti‐histamines in treating children with prolonged non‐specific cough. SEARCH METHODS: We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE, OLDMEDLINE and EMBASE databases. The latest searches were performed in November 2009. SELECTION CRITERIA: All randomised controlled trials comparing anti‐histamines with a placebo or placebo‐like medication with cough as an outcome, where cough is not primarily related to an underlying respiratory disorder such as cystic fibrosis, asthma, or suppurative lung disease. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study quality and extracted data. MAIN RESULTS: Three included therapeutic studies had 182 randomised participants with 162 completing the trials although in one study, children with recurrent wheeze were also included. The four included safety evaluation studies randomised 3166 participants with 2862 completing the trials. Clinical heterogeneity was evident and limited data prevented combining data for meta‐analysis. The two larger therapeutic studies described significant improvement in both the intervention and the placebo/placebo‐like arms with no significant difference between the two groups. In the study with the smallest sample size, cetirizine (a second generation anti‐histamine) was significantly more efficacious than placebo in reducing chronic cough in children associated with seasonal allergic rhinitis, and the effect was seen within two weeks of therapy. In contrast three of the larger evaluation studies that enrolled children with allergic rhinitis described a non‐significant increase in cough as an adverse event. Combined data from the four safety evaluation studies revealed a non‐significant difference between groups (OR 1.47 , 95% CI 0.86, 2.49) for cough as an adverse event but the trend favoured the placebo arm. AUTHORS' CONCLUSIONS: This review has significant limitations. However, our finding of uncertain efficacy of anti‐histamines for chronic cough are similar to that for acute cough in children. In contrast to recommendations in adults with chronic cough, anti‐histamines cannot be recommended as empirical therapy for children with chronic cough. If anti‐histamines were to be trialled in these children, current data suggest a clinical response (time to response) occurs within two weeks of therapy. However the use of anti‐histamines in children with non‐specific cough has to be balanced against the well known risk of adverse events especially in very young children.

Eczema is common, occurring in 15%-20% of infants and young children. For some infants it can be a severe chronic illness with a major impact on the child's general health and on the family. A minority of children will continue to have eczema as adults. The exact cause of eczema is not clear, but precipitating or aggravating factors may include food allergens (most commonly, egg) or environmental allergens/irritants, climatic conditions, stress and genetic predisposition. Management of eczema consists of education; avoidance of triggers and allergens; liberal use of emollients or topical steroids to control inflammation; use of antihistamines to reduce itch; and treatment of infection if present. Treatment with systemic agents may be required in severe cases, but must be supervised by an immunologist. Urticaria ("hives") may affect up to a quarter of people at some time in their lives. Acute urticaria is more common in children, while chronic urticaria is more common in adults. Chronic urticaria is not life-threatening, but the associated pruritus and unsightly weals can cause patients much distress and significantly affect their daily lives. Angioedema coexists with urticaria in about 50% of patients. It typically affects the lips, eyelids, palms, soles and genitalia. Management of urticaria is through education; avoidance of triggers and allergens (where relevant); use of antihistamines to reduce itch; and short-term use of corticosteroids when antihistamine therapy is ineffective. Referral is indicated for patients with resistant disease.

Background and Aims: Data on acute paediatric anaphylaxis presentations to the emergency department (ED) are limited. All allergic presentations to one Australian paediatric ED were studied to determine epidemiological, clinical, and outcome data. Methods: Retrospective, case based study of patients under 16 years attending one metropolitan, paediatric teaching hospital ED in Australia over three years. The medical records of patients presenting with generalised allergic reactions and anaphylaxis satisfying relevant ICD-9-CM diagnostic codes were studied. The incidence, age, sex ratio, co-morbidities, likely aetiology, clinical features, management, and disposal were determined. Results: A total of 526 children with generalised allergic reactions, and 57 with anaphylaxis were included in the study. This represented incidences of 9.3:1000 ED presentations for generalised allergic reactions and 1:1000 for anaphylaxis. There were no fatalities. In anaphylaxis cases, a cause was recognised in 68.4%. Cutaneous features were present in 82.5%. A past history of asthma was reported in 36.8%. Adrenaline was used in 39.3% of severe anaphylaxis cases. The ED alone definitively cared for 97.8% of all patients. Follow up was inadequate in cases of anaphylaxis. Conclusions: This is the first reported incidence figure for paediatric anaphylaxis ED presentations in Australia, and is less than that reported in adults in the same local population. However, the incidence of generalised allergic reactions of 9.3:1000 was greater than in the adults. Virtually all paediatric allergic cases may be managed in the ED alone, provided that the importance of specialist follow up, particularly for severe anaphylaxis, is recognised.

These guidelines have been developed by the anaphylaxis working party of the Australasian Society of Clinical Immunology and Allergy to provide advice for minimizing the risk of food-induced anaphylaxis in schools, preschools and child-care centres. The guidelines outline four steps for the prevention of food anaphylactic reactions in children at risk and food policy measures specific to school age and preschool age children.

Background Neutrophil oxidative burst (NOB) activity as assessed by dihydrorhodamine-123 flow cytometric assay, is used in the diagnosis of chronic granulomatous disease (CGD) and may provide insight into its inheritance pattern. Case report We present a consanguineous family with complete absence of NOB activity in three male siblings. Each affected sibling suffered a severe form of CGD characterised by clinical manifestations within the first year of life, recurrent bacterial and fungal pneumonia, and death in two siblings by the ages of 3 and 4. This complete absence of NOB activity and severe phenotype is atypical for classic autosomal recessive CGD. The unaffected parents and siblings displayed normal NOB activity. In addition, no bimodal peak was detected in the mother, which is atypical for X-linked CGD. Extreme skewing of lyonisation in the maternal X-chromosome was excluded. CGD mutation analysis was performed by GeneDx (Gaithersburg, USA, 2008) on the proband. A novel autosomal recessive p67-phox (NCF2) homozygous deletion mutation [NM_000433.3(NCF2): c.482delA] was identified. Objective and results A targeted bi-directional PCR sequencing analysis was developed in a local molecular laboratory (Pathology Queensland) to help identify this novel mutation in other members of this family. The heterozygous carrier status in both parents and the homozygous mutation in a newborn male sibling were demonstrated by this analysis. Discussion This case report confirms the autosomal recessive mode of inheritance of this novel c.482delA mutation in the p67-phox (NCF2) gene. The mutation is predicted to result in a frame shift and premature stop codon [NP_000424.2(NCF2): p.Lysl61 Argfs*16], potentially explaining the complete absence of NOB activity and severe clinical phenotype in the affected male siblings.

Osteopetrosis has been described in mice generated by homozygous gene disruption of c-src gene encoding for the p60c-Src protein tyrosine kinase (Src-/- mice). The similarities of bone histologic findings in this murine model to those observed in some patients first seen with autosomal recessive osteopetrosis, "malignant" osteopetrosis, led us to investigate the potential role of p60c-Src in the pathogenesis of malignant osteopetrosis in 13 children. In 4 patients a c-src mutation was ruled out by an intragenic microsatellite segregation study. In the other 9 we analyzed p60c-Src expression and function, as well as c-src sequence. The expression was normal in all of the patients tested. In addition, the tyrosine phosphorylation and kinase activity of p60c-Src were also normal in all of the patients. Moreover, in these patients, sequences of the coding region of c-src were identical to the published sequence of the human c-src complementary DNA. These results exclude a role for c-src in the pathogenesis of human malignant osteopetrosis in the 13 patients analyzed.

Cashew allergy is an evolving clinical problem. A retrospective chart review of 213 children with peanut or tree nut allergy was undertaken over a 42 month period. Anaphylaxis to cashew nut was more common than to peanut (74.1% v 30.5%). Children with cashew allergy are at risk of anaphylaxis.

Supported by project and program grants from the National Health and Medical Research Council (NHMRC) of Australia (to E.K.D., S.G.T., C.S.M., D.A.F., and M.C.C.), Cancer Council NSW (to S.G.T. and U.P.), and Rockefeller University Center for 541 Clinical and Translational science (5UL1RR024143, to J.-L.C.). C.S.M. is a recipient of a Career Development Fellowship and S.G.T. is a recipient of a Principal Research Fellowship from the NHMRC of Australia. Disclosure of potential conflict of interest: C. S. Ma has been supported by one or more grants from the National Health and Medical Research Council of Australia (NHMRC). J. Peake has received one or more payments for lecturing on allergy topics and has been reimbursed for travel/accommodations/meeting expenses. M. A. French has received one or more payments for lecturing from or is on the speakers’ bureau for ViiV Australia, MSD Australia, and Janssen Australia and has received one or more payments for travel/accommodations/meeting expenses from MSD Australia and ViiVAustralia. J.-L. Casanova has been supported by one or more grants from the National Institutes of Health (grant no. 8UL1TR000043); has consultancy arrangements with Regeneron, GlaxoSmithKline, NovImmune, BiogenIdec, Merck, and Sanofi- Aventis; and has received one or more grants from or has one or more grants pending with Merck. S. G. Tangye has been supported by one or more grants from the NHMRC of Australia; has received support for travel from ESID, Keystone Symposia, and the Jeffrey Modell Foundation; and has received one or more fees for serving as an expert witness in a patent dispute. E. K. Deenick has been supported by one or more grants from NHMRC, has received one or more payments for travel/accommodations/meeting expenses from the Japanese Society for Immunology, and has received one or more paid honoraria as an Editor for Immunology and Cell Biology. The rest of the authors declare that they have no relevant conflicts of interest.

Four related male infants presented with neonatal diabetes mellitus, immune dysregulation with extremely high concentrations of immunoglobulin E, and intractable diarrhoea. They were all from one family, and all of them died. As far as is known this X-linked recessive disorder has not been described before. It is suggested that this is a new immunodeficiency in which type 2 T helper responses predominate.