Chediak-Higashi syndrome: Lessons from a single-centre case series

Background: Chediak-Higashi syndrome (CHS) is a rare and potentially fatal autosomal recessive disease characterized by frequent bacterial infections, bleeding tendency, oculocutaneous albinism, photosensitivity and progressive neurologic dysfunction. Owing to the rarity of this condition, the objective of this study was to describe patients with CHS. Methods: Retrospective evaluation of patients followed in a paediatric tertiary centre of Allergy and Immunology of São Paulo, Brazil, between 1986 and 2018 with a confirmed diagnosis of CHS. Data were obtained from medical records. Demographic aspects, family history, clinical findings, laboratory data, diagnosis, treatment and outcome were described. Results: A total of 14 patients (five male) were included. Clinical manifestations were first recognized at a median age of two months (at birth-20 months). Median age at diagnosis was 1.7 years (0-5 years). All patients had recurrent infections. Albinism was present in 13 patients and silvery or light hair was present in 14. Seven patients developed hemophagocytic lymphohistiocytosis (HLH); the median age at the diagnosis of HLH was 5.7 years (2.6-6.7 years) and the median interval between the diagnosis of CHS and HLH was 3.3 years (0-5 years). Four of the most recently diagnosed patients underwent bone marrow transplantation (BMT). Nine patients are deceased, and one was lost to follow-up. The median age of death was 6.7 years (3.8-22 years). Five patients died of HLH, one of lymphoma, and three of infection. All the patients who had HLH before the year of 2000 died of HLH. The two most recently diagnosed patients with HLH were able to cure the HLH, although they died of other causes. Four patients are alive, three of them after successful BMT. Conclusion: Thirty years of follow up showed an improvement in the prognosis in patients with CHS. The better understanding of the underlying biological mechanisms of HLH allowed the standardization of management protocols, resulting in survival improvement. BMT is the only treatment that can change CHS prognosis, which emphasizes the need for early identification of the disease

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Baked milk tolerant patient: is there any special feature?

BACKGROUND: Determining whether patients with cow's milk allergy (CMA) can tolerate foods produced with baked milk could provide a better quality of life, a better prognosis, and an option for desensitization. OBJECTIVES: The aim of this study was to identify which patients over four years of age with persistent CMA could tolerate baked milk, to compare the clinical and laboratory characteristics of reactive and non-reactive groups and to describe their clinical evolution. MATERIALS AND METHODS: A cross-sectional study was conducted (January/13 to November/14) that included all the patients followed at a food allergy center who met the inclusion criteria. The patients underwent an oral food challenge (OFC) with a muffin (2.8g of cow's milk protein). To exclude cow's milk (CM) tolerance, the patients were subsequently challenged with unheated CM. RESULTS: Thirty patients met all the inclusion criteria. Fourteen patients (46.7%) were considered non-reactive to baked milk and reactive to unheated CM. When the groups that were reactive and non-reactive to baked milk were compared, no statistically significant differences in clinical features were found. The prick test for α-lactalbumin (p = 0.01) and casein (p = 0.004) and the serum specific IgE for casein (p = 0.05) presented statistical differences. After one year, none of the patients who were reactive to baked milk were ingesting CM, while 28% of the tolerant patients were consuming fresh CM (p = 0.037). CONCLUSIONS: Baked milk can be tolerated by patients with CMA, especially those with lower levels of casein and α-lactalbumin. This option can improve quality of life and accelerate tolerance

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Establishing a cut-off for the serum levels of specific IgE to milk and its components for cow's milk allergy: results from a specific population

BACKGROUND: Cow's milk allergy diagnosis many times requires double-blind placebo-controlled food challenge (DBPCFC), which presents high accuracy but involves risks, specifically in infants and anaphylactic patients. The identification of the cut-off values for specific IgE to milk or its components would contribute to cow's milk allergy (CMA) diagnosis. The aim of this study was to compare discriminating concentration of a cow's milk specific IgE and its fractions (- lactoalbumin, -lactoglobulin, casein) in children for the CMA diagnosis. METHODS: this study included 123 patients (M:F = 1.3:1) median age at diagnosis = 1.91 years, (3.5 m to 13.21 y) with CMA diagnosis via DBPCFC (n = 26), proven anaphylaxis due to cow's milk (n = 46) or a suggestive clinical history associated with a positive skin prick test (n = 51) and open oral food challenge. The control group included 61 patients (1 male:1.1 female) ages ranging from 0.66 to 16.7 years (median = 6.83 years). Receiver operator characteristics (ROC) curves were constructed to determine the best cut-offs that guarantees high specificity (>95%) for cow's milk and its components. RESULTS: considering 98% specificity, cut-off points were: 3.06 kU/L for cow's milk, 2.06 kU/L for -lactalbumin, 1.85 kU/L for -lactoglobulin and 1.47 kU/L for casein. The best ROC curve (area under the curve = 0.929) was obtained evaluating cow's milk. CONCLUSION: this study showed that the cut-off point detected for whole cow's milk revealed a better discriminatory capacity for CMA diagnosis without the necessity of the milk components testing

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Double-blind, placebo-controlled food challenges in Brazilian children: Adaptation to clinical practice

Background: A double-blind, placebo-controlled food challenge (DBPCFC) is considered the gold standard for diagnosing food allergy, but because of methodological difficulties it is rarely conducted in clinical practice, especially in paediatric patients. The purpose of the study was to propose a DBPCFC protocol that is adapted to our conditions for the diagnosis of an IgE-mediated cow's milk allergy (CMA) in a Brazilian reference centre for paediatric allergies. Methods: This study includes the experimental phase (choice of materials, adjustments made to protocols described in the literature) and the test execution phase. DBPCFCs were performed in 58 patients aged 1–15years who were separated into two groups: Group 1 (n=39), sex 1.6 M:F, 5.3years median age, suggestive history of IgE-mediated CMA; and Group 2 (n=19), sex 1.4 M:F, 8.3years median age with symptoms not associated with milk ingestion and laboratory data not compatible with IgE-mediated CMA. Results: The materials were standardised for testing: containers and disposable products, low-lactose cow's milk (CM) and vehicles, such as natural fruit juice, vegetable soup and soybean-based beverages. Each DBPCFC was performed in a single day with two blind, randomised phases with a 2-h interval between them. The milk doses were gradually increased and offered in regular intervals of 15–30min. Following negative or inconclusive results, patients underwent an open oral challenge test with 200mL of low-lactose CM. Conclusions: The proposed adaptation for the DBPCFC allowed to implement this important test for the diagnosis of IgE-mediated CMA in a reference centre for paediatric allergies. It was considered feasible and safe if performed in an appropriate setting with physician supervision(AU)

Sensitisation to aeroallergens in Brazilian adolescents living at the periphery of large subtropical urban centres

Objectives: To evaluate the sensitization to aeroallergens determined by skin prick test (SPT) in Brazilian adolescents, and to correlate its positivity with the diagnosis of asthma and/or rhinitis based on the written questionnaire (WQ) of ISAAC phase III study. Patients and Methods: A total of 996 adolescents (387 boys) were selected by systematic samples. A standard allergen extracts panel (positive/negative control, D pteronyssinus [Dpt], P americana [Pa], B germanica [Bg], dog, cat, fungal and grass mix) was used and its positivity compared with positive responses to asthma, rhinitis or both. Results: Positive SPT to at least one allergen was observed in 466 adolescents (46.8 %), with sensitisation to Dpt in 79.1 %. Positivity to more than one allergen occurred in 232 students (49.8 %). The frequency of positive SPTs was significantly higher among adolescents with asthma (OR = 2.16), rhinitis (OR = 1.69), and asthma and rhinitis (OR = 2.03). Positive SPT to four or more allergens were higher among asthmatics (OR = 2.6) and among adolescents with asthma and rhinitis (OR = 3). Conclusions: A high sensitisation rate to aeroallergens was observed, significantly higher among those with asthma, rhinitis or a combination of both, especially in multiple sensitisations

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