A randomized trial of egg introduction from 4 months of age in infants at risk for egg allergy.

BACKGROUND: Epidemiologic evidence suggests delayed introduction of egg might not protect against egg allergy in infants at risk of allergic disease. OBJECTIVE: We sought to assess whether dietary introduction of egg between 4 and 6 months in infants at risk of allergy would reduce sensitization to egg. METHODS: We conducted a randomized controlled trial in infants with at least 1 first-degree relative with allergic disease. Infants with a skin prick test (SPT) response to egg white (EW) of less than 2 mm were randomized at age 4 months to receive whole-egg powder or placebo (rice powder) until 8 months of age, with all other dietary egg excluded. Diets were liberalized at 8 months in both groups. The primary outcome was an EW SPT response of 3 mm or greater at age 12 months. RESULTS: Three hundred nineteen infants were randomized: 165 to egg and 154 to placebo. Fourteen infants reacted to egg within 1 week of introduction (despite an EW SPT response <2 mm at entry) and were unsuitable for intervention. Two hundred fifty-four (83%) infants were assessed at 12 months of age. Loss to follow-up was similar between groups. Sensitization to EW at 12 months was 20% and 11% in infants randomized to placebo and egg, respectively (odds ratio, 0.46; 95% CI, 0.22-0.95; P = .03, χ2 test). The absolute risk reduction was 9.8% (95% CI, 8.2% to 18.9%), with a number needed to treat of 11 (95% CI, 6-122). Levels of IgG4 to egg proteins and IgG4/IgE ratios were higher in those randomized to egg (P < .0001 for each) at 12 months. There was no effect on the proportion of children with probable egg allergy (placebo, 13; egg, 8). CONCLUSIONS: Introduction of whole-egg powder into the diets of high-risk infants reduced sensitization to EW and induced egg-specific IgG4 levels. However, 8.5% of infants randomized to egg were not amenable to this primary prevention.

Cryopyrin-associated periodic syndrome in Australian children and adults: Epidemiological, clinical and treatment characteristics.

AIM: Cryopyrin-associated periodic syndromes (CAPS) encapsulate three auto-inflammatory conditions, ranging in severity from mild (familial cold auto-inflammatory syndrome: FCAS), moderate (Muckle-Wells syndrome: MWS) and severe (neonatal onset multi-inflammatory disorder: NOMID). We aimed to describe the epidemiology, clinical features and outcomes of Australian children and adults with CAPS. METHODS: Patients were identified and clinical data collected through a questionnaire sent during 2012-2013 to clinicians reporting to the Australian Paediatric Surveillance Unit and subscribing to the Australasian Societies for Allergy/Immunology, Rheumatology and Dermatology. RESULTS: Eighteen cases of CAPS were identified (8 NOMID; 8 MWS, 2 FCAS); 12 in children <18 years of age. The estimated population prevalence of CAPS was 1 per million persons. Diagnostic delay was frequent, particularly in those with milder phenotypes (median diagnostic delay in MWS/FCAS 20.6 years compared with NOMID 2.1 years; P = 0.04). Common presenting features included urticaria (100%), periodic fever (78%), arthralgia (72%) and sensorineural hearing loss (61%). Almost all (90%) MWS patients had a family member similarly affected compared with none in the NOMID group (P = 0.004). A significant proportion of patients on anti-interleukin (IL)-1 therapy (n = 13) no longer had systemic inflammation. Only 50% with sensorineural hearing loss had hearing restored on anti-IL-1 therapy. CONCLUSIONS: Although CAPS are rare, patients often endured prolonged periods of systemic inflammation. This is despite almost all MWS patients having family members with similar symptoms and children with NOMID presenting with chronic infantile urticaria associated with multi-system inflammation. Hearing loss in NOMID/MWS was frequent, and reversible in only 50% of cases.

Compound heterozygous mutations in the noncoding RNU4ATAC cause Roifman Syndrome by disrupting minor intron splicing.

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.

Idiopathic systemic capillary leak syndrome in children.

Adult subjects with systemic capillary leak syndrome (SCLS) present with acute and recurrent episodes of vascular leak manifesting as severe hypotension, hypoalbuminemia, hemoconcentration, and generalized edema. We studied clinical disease characteristics, serum cytokine profiles, and treatment modalities in a cohort of children with documented SCLS. Six children with SCLS were recruited from the United States, Australia, Canada, and Italy. Serum cytokines from SCLS subjects and a group of 10 healthy children were analyzed. Children with SCLS (aged 5-11 years old) presented with at least 1 acute, severe episode of hypotension, hypoalbuminemia, and hemoconcentration in the absence of underlying causes for these abnormalities. In contrast to what is observed in adult SCLS, identifiable infectious triggers precipitated most episodes in these children, and none of them had a monoclonal gammopathy. We found elevated levels of chemokine (C-C motif) ligand 2 (CCL2), interleukin-8, and tumor necrosis factor α in baseline SCLS sera compared with the control group. All patients are alive and well on prophylactic therapy, with 4 patients receiving intravenous or subcutaneous immunoglobulins at regular intervals. The clinical manifestations of pediatric and adult SCLS are similar, with the notable exceptions of frequent association with infections and the lack of monoclonal gammopathy. Prophylactic medication, including high dose immunoglobulins or theophylline plus verapamil, appears to be safe and efficacious therapy for SCLS in children.

Detection of chromosomal breakpoints in patients with developmental delay and speech disorders.

Delineating candidate genes at the chromosomal breakpoint regions in the apparently balanced chromosome rearrangements (ABCR) has been shown to be more effective with the emergence of next-generation sequencing (NGS) technologies. We employed a large-insert (7-11 kb) paired-end tag sequencing technology (DNA-PET) to systematically analyze genome of four patients harbouring cytogenetically defined ABCR with neurodevelopmental symptoms, including developmental delay (DD) and speech disorders. We characterized structural variants (SVs) specific to each individual, including those matching the chromosomal breakpoints. Refinement of these regions by Sanger sequencing resulted in the identification of five disrupted genes in three individuals: guanine nucleotide binding protein, q polypeptide (GNAQ), RNA-binding protein, fox-1 homolog (RBFOX3), unc-5 homolog D (C.elegans) (UNC5D), transmembrane protein 47 (TMEM47), and X-linked inhibitor of apoptosis (XIAP). Among them, XIAP is the causative gene for the immunodeficiency phenotype seen in the patient. The remaining genes displayed specific expression in the fetal brain and have known biologically relevant functions in brain development, suggesting putative candidate genes for neurodevelopmental phenotypes. This study demonstrates the application of NGS technologies in mapping individual gene disruptions in ABCR as a resource for deciphering candidate genes in human neurodevelopmental disorders (NDDs).

Salicylate elimination diets in children: is food restriction supported by the evidence?

A review of case notes from our Sydney-based paediatric allergy services, between 1 January 2003 and 31 December 2011, identified 74 children who had been prescribed diets that eliminated foods containing natural salicylates before attending our clinics. The most common indications for starting the diets were eczema (34/74) and behavioural disturbances (17/74) including attention deficit hyperactivity disorder (ADHD). We could find no peer-reviewed evidence to support the efficacy of salicylate elimination diets in managing these diseases. We do not prescribe these diets, and in a survey of European and North American food allergy experts, only 1/23 respondents used a similar diet for eczema, with none of the respondents using salicylate elimination to treat ADHD. A high proportion (31/66) of children suffered adverse outcomes, including nutritional deficiencies and food aversion, with four children developing eating disorders. We could find no published evidence to support the safety of these diets in children. While this uncontrolled study does not prove a causal relationship between salicylate elimination diets and harm, the frequency of adverse events appears high, and in the absence of evidence of safety or efficacy, we cannot recommend the use of these diets in children.

Safety of food challenges to extensively heated egg in egg-allergic children: a prospective cohort study.

BACKGROUND: Many children with IgE-mediated allergy to egg can tolerate egg in baked foods. However, the clinical characteristics and severity of reactions of egg-allergic children who react to baked egg at open food challenge (OFC) are not well defined. METHODS: Children presenting to our tertiary referral clinic with a diagnosis of egg allergy and following complete egg avoidance in their diet were offered OFC to baked egg. Challenges were performed with incremental dosages to a total of one baked muffin containing 1/6 egg (equivalent to 1 g egg protein) following a standardized protocol. Data were collected prospectively from 2009-2012. RESULTS: Open food challenge to baked egg were carried out on 236 egg-allergic children who had been strictly avoiding egg in their diet. A total of 150 children (64%) passed and successfully incorporated baked egg into their diet. Eighty-six children (36%) reacted to their challenge. Of these, 12 (14%) experienced anaphylaxis (according to WAO criteria), including four to <100 mg extensively heated egg protein. Intramuscular adrenaline was administered to 5 of the 12 children, one of whom required a second dose due to persistent hypotension. Skin prick testing, asthma, or prior egg anaphylaxis were not predictive of challenge outcome. CONCLUSION: The majority of children with IgE-mediated allergy to egg were able to tolerate 1 g of baked egg protein, but the outcome of OFC remained unpredictable, and 14% of children who failed OFC reacted with anaphylaxis. We recommend that OFC to baked egg should take place under medical supervision.

Intravenous immunoglobulin to treat severe atopic dermatitis in children: a case series.

Severe cases of atopic dermatitis (AD) may require systemic immunosuppression to achieve disease control. Unfortunately, some cases continue to be refractory to management or develop unacceptable adverse effects. There are limited reports of the use of intravenous immunoglobulin (IVIg) in the treatment of severe AD, but results are inconsistent. In a retrospective study, we report 10 children with severe AD refractory to systemic immunosuppression and maximal topical therapy who were treated using IVIg. The children received monthly IVIg for an average of 24 months. This resulted in a significant improvement in symptoms, with fewer infection-related exacerbations and hospitalizations, allowing systemic immunosuppression to be tapered. The effect was associated with a significant decrease in serum immunoglobulin E and was sustained after cessation of IVIg in 50% of cases. No significant side effects attributable to the IVIg infusions were noted. In this cohort of children with severe AD and recurrent cutaneous infections, IVIg provided an effective treatment with minimal side effects and significant benefits in school attendance and quality of life.

Beware the lymphopenia: a case of severe combined immunodeficiency.

We present a case of a 2-month-old boy with partially treated meningitis and suspected Pneumocystis carinii pneumonia. A full blood count revealed profound lymphopenia. The child was diagnosed with adenosine deaminase deficiency, a rare cause of severe combined immunodeficiency (SCID). SCID is an immunological emergency and must be considered in any lymphopaenic infant with opportunistic infection. We discuss adenosine deaminase-deficient SCID, which can involve multiple systems and in which other treatment options apart from bone marrow transplant are available.

Chronic urticaria of neonatal onset: a potential sign of autoinflammation.

We present a 6 year old boy with chronic urticaria of neonatal onset associated in childhood with features of neurological and joint inflammation. Genetic analysis confirmed the diagnosis of neonatal onset multi-inflammatory disorder (NOMID). Daily subcutaneous anti-IL-1 receptor antagonist therapy resulted in a dramatic and sustained amelioration of systemic inflammation. NOMID must be considered in any child with chronic urticaria of neonatal/infantile onset, particularly if associated with joint and/or neurological inflammation.

Treatment of a case of pediatric hypereosinophilic syndrome with anti-interleukin-5.

We report the use of anti-interleukin-5 (mepolizumab) during an 18-month period in a pediatric hypereosinophilic syndrome. Infusions every 3 months allowed better control of hypereosinophilic syndrome flares and maintained blood eosinopenia with significantly less steroid use compared with all other therapies (prednisolone alone, interferon alpha, or imatinib mesylate).

Food protein-induced enterocolitis syndrome: 16-year experience.

OBJECTIVE: The goal was to examine the demographic characteristics, causative foods, clinical features, treatments, and outcomes for children presenting with acute food protein-induced enterocolitis syndrome. METHODS: This was a retrospective study of children with food protein-induced enterocolitis syndrome who presented to the Children's Hospital at Westmead (Sydney, Australia) over 16 years. RESULTS: Thirty-five children experienced 66 episodes of food protein-induced enterocolitis syndrome. The mean age at initial presentation was 5.5 months. Children frequently experienced multiple episodes before a correct diagnosis was made. Twenty-nine children reacted to 1 food, and 6 reacted to 2 foods. Causative foods for the 35 children were rice (n = 14), soy (n = 12), cow's milk (n = 7), vegetables and fruits (n = 3), meats (n = 2), oats (n = 2), and fish (n = 1). In the 66 episodes, vomiting was the most common clinical feature (100%), followed by lethargy (85%), pallor (67%), and diarrhea (24%). A temperature of <36 degrees C at presentation was recorded for 24% of episodes. A platelet count of >500 x 10(9) cells per L was recorded for 63% of episodes with blood count results. Only 2 of the 19 children who presented to an emergency department with their initial reactions were discharged with correct diagnoses. Additional investigations of food protein-induced enterocolitis syndrome episodes presenting to the hospital were common, with 34% of patients undergoing abdominal imaging, 28% undergoing a septic evaluation, and 22% having a surgical consultation. Prognosis was good, with high rates of resolution for the 2 most common food triggers (ie, rice and soy) by 3 years of age. CONCLUSIONS: Misdiagnosis and delays in diagnosis for children with food protein-induced enterocolitis syndrome were common, leading many children to undergo unnecessary, often painful investigations. Decreased body temperature and thrombocytosis emerge as additional features of the syndrome.

Wheezy swallow: poorly responsive 'asthma'.

We report two children who presented with cough and wheeze, were initially misdiagnosed with asthma and were subsequently demonstrated to have achalasia as the underlying cause of their symptoms. These cases highlight the importance of considering diagnoses other than asthma when there is a suboptimal response to asthma medications, as well as the value of investigations including chest X-ray and pulmonary function tests in establishing the underlying cause.

Immunocompromised children: conditions and infectious agents.

Individuals with immunodeficiency, either primary or acquired, are increasingly common. These individuals have increased susceptibility to a range of infections which are uncommon in the normal host. An understanding of the individual's immune defect provides important information about the range of organisms that this individual may be susceptible to. As a corollary, identification of an 'opportunistic pathogen' may indicate the patient's type of underlying immune defect.

Allogeneic bone marrow transplantation with reduced intensity conditioning for chronic granulomatous disease complicated by invasive Aspergillus infection.

Chronic granulomatous disease (CGD) is a rare disorder characterized by recurrent infections, often resulting in impaired quality of life and death. Allogeneic BMT provides a definitive cure for CGD, but carries a significant risk of mortality and morbidity. The risk is higher for those who have invasive fungal infection prior to transplant. Reduced intensity conditioning (RIC) is associated with less toxicity from the conditioning agents and may provide an alternative option for all non-malignant diseases. We report a case of successful allogeneic BMT after RIC for a case of X-linked CGD complicated by severe invasive aspergillosis (IA).

Treatment of an infant with X-linked severe combined immunodeficiency (SCID-X1) by gene therapy in Australia.

OBJECTIVE: To report the outcome of gene therapy in an infant with X-linked severe combined immunodeficiency (SCID-X1), which typically causes a lack of T and natural killer (NK) cells. DESIGN AND SETTING: Ex-vivo culture and gene transfer procedures were performed at The Children's Hospital at Westmead, Sydney, NSW, in March 2002. Follow-up to March 2005 (36 months) is available. PATIENT: A 9-month-old male infant with confirmed SCID-X1 (including complete absence of T cells) with an NK+ phenotype (a less common variant of SCID-X1), and no HLA-identical sibling donor available for conventional bone marrow transplantation. PROCEDURE: CD34+ haemopoietic progenitor cells were isolated from harvested bone marrow and cultured with cytokines to stimulate cellular replication. Cells were then genetically modified by exposure to a retrovirus vector encoding human gamma c (the common gamma chain of several interleukin receptors; mutations affecting the gamma c gene cause SCID-X1). Gene-modified cells (equivalent to 1.3 x 10(6) CD34+/gamma c+ cells/kg) were returned to the infant via a central line. RESULTS: T cells were observed in peripheral blood 75 days after treatment, and levels increased rapidly to 0.46 x 10(9) CD3+ cells/L at 5 months. Within 2 weeks of the appearance of T cells, there was a distinct clinical improvement, with early weight gain and clearance of rotavirus from the gut. However, T-cell levels did not reach the reference range, and immune reconstitution remained incomplete. The infant failed to thrive and developed weakness, hypertonia and hyperreflexia in the legs, possibly the result of immune dysregulation. He went on to receive a bone marrow transplant from a matched unrelated donor 26 months after gene therapy. CONCLUSIONS: This is the first occasion that gene therapy has been used to treat a genetic disease in Australia. Only partial immunological reconstitution was achieved, most likely because of the relatively low dose of gene-corrected CD34+ cells re-infused, although viral infection during the early phase of T-cell reconstitution and the infant's NK+ phenotype may also have exerted an effect.