Common Causes of Anaphylaxis in Children

Background Anaphylaxis is an acute, systemic, and potentially fatal allergic reaction. Many things can cause anaphylaxis potentially but some agents are more common like some foods (milk, egg, soy, wheat, peanut, tree nut, shellfish, and fish), insect stings, medications, latex, and food-dependent exercise-induced anaphylaxis. The goal of this study is to show the common causes of anaphylaxis among the children with anaphylaxis history who were referred to the Immunology, Asthma and Allergy Research Institute (IAARI) during a 4-year period (2005-2009).Methods and Materials During those 4 years, we registered all children (<14 years old) with a history of anaphylactic reaction. To prove the cause of anaphylaxis, we performed skin prick tests with suspected agents according to their history and measured specific IgE against them by the ImmunoCAP test. Recognition of common allergens was based on having a positive history for 1 allergen and positive skin prick test or specific IgE for that at the same time, or having positive results from both tests when the allergen was unclear. Idiopathic anaphylaxis was a reaction when any known allergen and positive tests were not obtained.Results One hundred ninety-three nonfatal anaphylactic attacks among 63 children were recognized. In total, the most current cause of anaphylaxis in children was food (89.7%). Milk (49.3%) and wheat (26.1%) were the most common. Other foods were egg (8.7%), nuts (2.8%), and spices (2.8%). Six children (8.7%) were sensitive to multiple food allergens like milk, egg, and wheat. Five (7.1%) of 63 patients had anaphylactic attack because of stinging. Wasp was the trigger in 3 (4.3%) of them and honeybee was the cause in 1 (1.4%). The last one was because of unknown hymenoptera. There were 2 idiopathic cases of all 63 patients.Conclusions Food allergens, especially milk and wheat, are the most common cause of anaphylaxis in children. Because anaphylaxis can be fatal, it is advisable to recognize its causes in different communities to prevent recurrent attacks. Keywords: anaphylaxis, common causes, childre

Cohort of Iranian Patients with Congenital Agammaglobulinemia: Mutation Analysis and Novel Gene Defects

<p><b>Objectives:</b> Impairment in early B-cell development can cause a predominantly antibody deficiency with severe depletion of peripheral B-cells. Mutations in the gene encoding for Bruton’s-tyrosine-kinase (BTK) and the components of the pre-B-cell receptor complex or downstream signaling molecules have been related to this defect in patients with agammaglobulinemia.</p> <p><b>Methods:</b> Iranian patients with congenital agammaglobulinemia were included and the correlation between disease-causing mutations and parameters such as clinical and immunologic phenotypes were evaluated in available patients.</p> <p><b>Results:</b> Out of 87 patients, a molecular investigation was performed on 51 patients leading to identification of 39 cases with BTK (1 novel mutation), 5 cases of µ-heavy chain (3 novel mutations) and 1 case of Igα-deficiencies.</p> <p><b>Conclusion:</b> Although there is no comprehensive correlation between type of responsible <i>BTK</i> mutation and severity of clinical phenotype, our data suggest that BTK-deficient and autosomal recessive agammaglobulinemia patients differ significantly regarding clinical/immunologic characteristics.</p

Comparison of Common Monogenic Defects in a Large Predominantly Antibody Deficiency Cohort

Background: Predominantly antibody deficiencies (PADs) are the most common primary immunodeficiencies, characterized by hypogammaglobulinemia and inability to generate effective antibody responses. Objective: We intended to report most common monogenic PADs and to investigate how patients with PAD who were primarily diagnosed as suffering from agammaglobulinemia, hyper-IgM (HIgM) syndrome, and common variable immunodeficiency (CVID) have different clinical and immunological findings. Methods: Stepwise next-generation sequencing and Sanger sequencing were performed for confirmation of the mutations in the patients clinically diagnosed as suffering from agammaglobulinemia, HIgM syndrome, and CVID. Results: Among 550 registered patients, the predominant genetic defects associated with agammaglobulinemia (48 Bruton's tyrosine kinase [BTK] and 6 μ heavy chain deficiencies), HIgM syndrome (21 CD40 ligand and 7 activation-induced cytidine deaminase deficiencies), and CVID (17 lipopolysaccharides-responsive beige-like anchor deficiency and 12 atypical Immunodeficiency, Centromeric instability, and Facial dysmorphism syndromes) were identified. Clinical disease severity was significantly higher in patients with μ heavy chain and CD40 ligand mutations compared with patients with BTK (P = .003) and activation-induced cytidine deaminase (P = .009) mutations. Paralysis following live polio vaccination was considerably higher in patients with μ heavy chain deficiency compared with BTK deficiency (P < .001). We found a genotype-phenotype correlation among patients with BTK mutations regarding clinical manifestation of meningitis and chronic diarrhea. Surprisingly, we noticed that first presentations in most patients with Immunodeficiency, Centromeric instability, and Facial dysmorphism were respiratory complications (P = .008), whereas first presentations in patients with lipopolysaccharides-responsive beige-like anchor deficiency were nonrespiratory complications (P = .008). Conclusions: This study highlights similarities and differences in the clinical and genetic spectrum of the most common PAD-associated gene defects. This comprehensive comparison will facilitate clinical decision making, and improve prognosis and targeted treatment