RESUMO
PURPOSE: X-linked hyper IgM syndrome (XHIGM) is a combined immunodeficiency caused by mutations in the CD40 ligand (CD40L) gene that typically results in decreased or absent CD40L expression on activated T cells, leading to defective class switching and somatic hypermutation. We describe an infant who presented with respiratory failure due to pulmonary alveolar proteinosis (PAP) with a novel damaging missense mutation in the CD40L gene. METHODS: Whole exome sequencing (WES) was used to identify a mutation in the CD40L gene. CD40L expression and function were determined by flow cytometry. RESULTS: A 5-month-old previously-healthy male presented with respiratory failure and diffuse pulmonary ground glass opacities on CT scan of the chest. Laboratory evaluation revealed an undetectable IgG, normal IgA, and elevated IgM. A bronchoalveolar lavage demonstrated pulmonary alveolar proteinosis. WES demonstrated a c.608G > C mutation in the CD40L gene resulting in p.R203T. Flow cytometry demonstrated normal CD40L expression on activated T cells but absent binding of CD40-Ig to CD40L on activated patient T cells. CONCLUSIONS: The clinical manifestations of XHIGM in our patient had several unique features, including the presentation with PAP, normal serum IgA, and expression of non-functional CD40L on activated T cells. To our knowledge, this is the first published case of PAP in a patient with XHIGM.
Assuntos
Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/diagnóstico , Fenótipo , Proteinose Alveolar Pulmonar/diagnóstico , Biomarcadores , Ligante de CD40/genética , Diagnóstico Diferencial , Humanos , Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/genética , Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/imunologia , Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/terapia , Lactente , Ativação Linfocitária/imunologia , Contagem de Linfócitos , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Masculino , Mutação , Radiografia Torácica , Tomografia Computadorizada por Raios X , Sequenciamento do ExomaRESUMO
BACKGROUND: Penicillin allergy is commonly reported in the pediatric emergency department (ED). True penicillin allergy is rare, yet the diagnosis results from the denial of first-line antibiotics. We hypothesize that all children presenting to the pediatric ED with symptoms deemed to be low-risk for immunoglobulin E-mediated hypersensitivity will return negative results for true penicillin allergy. METHODS: Parents of children aged 4 to 18 years old presenting to the pediatric ED with a history of parent-reported penicillin allergy completed an allergy questionnaire. A prespecified 100 children categorized as low-risk on the basis of reported symptoms completed penicillin allergy testing by using a standard 3-tier testing process. The percent of children with negative allergy testing results was calculated with a 95% confidence interval. RESULTS: Five hundred ninety-seven parents completed the questionnaire describing their child's reported allergy symptoms. Three hundred two (51%) children had low-risk symptoms and were eligible for testing. Of those, 100 children were tested for penicillin allergy. The median (interquartile range) age at testing was 9 years (5-12). The median (interquartile range) age at allergy diagnosis was 1 year (9 months-3 years). Rash (97 [97%]) and itching (63 [63%]) were the most commonly reported allergy symptoms. Overall, 100 children (100%; 95% confidence interval 96.4%-100%) were found to have negative results for penicillin allergy and had their labeled penicillin allergy removed from their medical record. CONCLUSIONS: All children categorized as low-risk by our penicillin allergy questionnaire were found to have negative results for true penicillin allergy. The utilization of this questionnaire in the pediatric ED may facilitate increased use of first-line penicillin antibiotics.
Assuntos
Toxidermias/diagnóstico , Hipersensibilidade a Drogas/diagnóstico , Serviço Hospitalar de Emergência , Testes Imunológicos/métodos , Testes Intradérmicos , Penicilinas/efeitos adversos , Adolescente , Criança , Pré-Escolar , Toxidermias/imunologia , Hipersensibilidade a Drogas/imunologia , Reações Falso-Positivas , Feminino , Humanos , Imunoglobulina E/sangue , Masculino , Penicilinas/administração & dosagem , Penicilinas/imunologia , Inquéritos e Questionários , Adulto JovemRESUMO
OBJECTIVE: Children often present to the pediatric emergency department (ED) with a reported penicillin allergy. The true incidence of pediatric penicillin allergy is low, and patients may be inappropriately denied first-line antibiotics. We hypothesized that more than 70% of reported penicillin allergies in the pediatric ED are low risk for true allergy. METHODS: Parents of children presenting to the pediatric ED with parent-reported penicillin allergy completed an allergy questionnaire. The questionnaire included age at allergy diagnosis, symptoms of allergy, and time to allergic reaction from first dose. The allergy symptoms were dichotomized into high and low risk in consultation with a pediatric allergist before questionnaire implementation. RESULTS: A total of 605 parents were approached; 500 (82.6%) completed the survey. The median (interquartile range) age of the children at diagnosis was 1 year (7 months, 2 years); 75% were diagnosed before their third birthday. Overall, 380 (76%) (95% confidence interval 72.3, 79.7) children had exclusively low-risk symptoms. The most commonly reported symptoms were rash (466, 92.8%) and itching (203, 40.6%). Of the 120 children with one or more high-risk symptom, facial swelling (50, 10%) was the most common. Overall, 354 children (71%) were diagnosed after their first exposure to penicillin. Symptom onset within 24 hours of medication administration occurred in 274 children (54.8%). CONCLUSIONS: Seventy-six percent of patients with parent-reported penicillin allergy have symptoms unlikely to be consistent with true allergy. Determination of true penicillin allergy in patients with low-risk symptoms may permit the increased use of first-line penicillin antibiotics.