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Recent studies have provided compelling evidence to suggest that various environmental factors play a significant role in the development of food allergies. As our society experiences rapid economic growth, increased urbanization, and a shift towards a more Westernized diet, the incidence of food allergies is also on the rise and the pattern is gradually evolving. This review will delve into the changes in the epidemiology of food allergies within the Asia-Pacific region and the various dietary practices and factors that are postulated to play a role in the rise in food allergies over the years. Although there have been important advancements in the field of food allergies, there are still numerous uncertainties regarding the intricate relationship between diet and food allergies. Specifically, the role of epigenetic factors in influencing the susceptibility to food allergies, as evidenced by studies that assessed the impact of migration and rural-urban dynamics, is not fully understood. Addressing this knowledge gap presents an opportunity to develop more effective prevention and treatment strategies that could greatly benefit individuals living with food allergies.
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Hipersensibilidad a los Alimentos , Humanos , Hipersensibilidad a los Alimentos/epidemiología , Asia/epidemiología , Dieta , Incidencia , Epigénesis GenéticaRESUMEN
BACKGROUND: During the COVID-19 pandemic, national lockdowns were implemented worldwide. Asthma control was reported to have improved. However, some patients lost follow-up from the clinic because they intended to avoid crowds at the hospital. OBJECTIVE: To evaluate the level of asthma control during the COVID-19 pandemic and explore factors influencing asthma outcomes. METHODS: Subjects 8-18 years old from our previous study in 2019 were recruited. The data during the pandemic period were collected between June 2021 - May 2023. The level of asthma control was compared before and during the pandemic. We also evaluated inhaled corticosteroid (ICS) adherence and factors related to poor asthma control during the COVID-19 pandemic. RESULTS: One hundred and three subjects were enrolled. Asthma control levels remained relatively stable during the pandemic. However, an asthma exacerbation was significantly decreased from 36 (36.3%) in 2019 to 19 (19.2%)and 15 (15.1%) in 2021 and 2022 (p = 0.012, p < 0.001), respectively. Spirometry results demonstrated improved pre-bronchodilator FEV1 (89.91 ± 11.02 vs. 101.91 ± 14.11, p < 0.001). The factors related to the poor asthma outcome were not wearing a face mask (aOR = 8.52, 95%CI 1.26-57.79) and previously poor-controlled by the ACT score (aOR = 2.55, 95%CI 1.41-4.63). The median adherence rate during the pandemic was 85%. The main reasons for poor adherence were hectic lifestyle and misunderstandings of disease. CONCLUSION: Asthma exacerbation was significantly decreased during the lockdown. Not wearing a face mask and previously poorly controlled by the ACT score are related to poor asthma outcomes.
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BACKGROUND: The epidemiology and management of anaphylaxis are not well-reported in Asia. METHODS: A regional pediatric anaphylaxis registry was established by the Asia-Pacific Research Network for Anaphylaxis (APRA), using standardized protocols for prospective data collection, to evaluate the triggers and management of anaphylaxis in the Asia-Pacific region. Pediatric patients below 18 years presenting with anaphylaxis across four Asian countries/cities (Thailand, Singapore, Hong Kong (HK), and Qingdao) were included. Allergen triggers, symptoms, anaphylaxis severity, and management were compared. RESULTS: Between 2019 and 2022, 721 anaphylaxis episodes in 689 patients from 16 centers were identified. The mean age at anaphylaxis presentation was 7.0 years (SD = 5.2) and 60% were male. Food was the most common trigger (62%), particularly eggs and cow's milk in children aged 3 years and below. In school-age children, nut anaphylaxis was most common in HK and Singapore, but was rare in the other countries, and wheat was the top allergen in Bangkok. Shellfish anaphylaxis was most common in children aged 7-17. Adrenaline was administered in 60% of cases, with 9% given adrenaline before hospital arrival. Adrenaline devices were prescribed in up to 82% of cases in Thailand but none in Qingdao. CONCLUSIONS: The APRA identified food as the main trigger of anaphylaxis in children, but causative allergens differed even across Asian countries. Fewer than two-thirds of cases received adrenaline treatment, pre-hospital adrenaline usage was low, and adrenaline device prescription remained suboptimal. The registry recognizes an unmet need to strengthen anaphylaxis care and research in Asia-Pacific.
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Anafilaxia , Humanos , Anafilaxia/epidemiología , Anafilaxia/etiología , Anafilaxia/terapia , Niño , Masculino , Femenino , Preescolar , Asia/epidemiología , Adolescente , Hipersensibilidad a los Alimentos/epidemiología , Hipersensibilidad a los Alimentos/terapia , Lactante , Alérgenos/inmunología , Manejo de la Enfermedad , Epinefrina/uso terapéutico , Epinefrina/administración & dosificación , Sistema de RegistrosRESUMEN
BACKGROUND: Factors associated with wheat oral immunotherapy (OIT) difficulties in patients with IgE-mediated wheat allergy have not been well studied. OBJECTIVE: We aimed to assess factors associated with difficulties in wheat OIT. METHODS: We retrospectively collected data from children under 18 years of age with history of IgE-mediated wheat allergy who underwent wheat OIT. The initial specific IgE (sIgE) of wheat and omega-5-gliadin, wheat skin prick test (SPT) sizes, eliciting doses, and adverse reactions during the OIT were evaluated. RESULTS: A total of 81 children were enrolled, with a mean age of 7.0 ± 2.7 years at the initiation of wheat OIT. The median follow-up duration was 2 years (IQR 1.2 -3.0 years). Difficulties in wheat OIT included patients who experienced frequent reactions (at least grade 2 or exercise-induced reactions) or deviated from the up-dosing protocol, which we defined as 'Complicated cases.' Twenty-six patients (32.1%) were complicated cases. Initial wheat-sIgEs were significantly higher in complicated cases than in noncomplicated cases (median of 192.3 kUA/L (IQR 30.4-590.0) vs 6.9 kUA/L (IQR 1.9-100.0) (p = 0.001)). Initial omega-5-gliadin-sIgEs in the complicated group were also significantly higher, with a median of 15.0 kUA/L (IQR 6.3-69.8) vs 1.6 kUA/L (IQR 0.2-11.4) (p < 0.001). The risk factors for complicated cases include higher omega-5-gliadin-sIgEs and anaphylaxis during the oral food challenge test (aOR 1.035 and 5.684, respectively). CONCLUSION: The initial wheat and omega-5-gliadin-sIgEs were significant risk factors for complicated OIT patients and could be used to monitor these patients carefully during the OIT period.
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BACKGROUND: Food allergy (FA) has been reported in one-third of children with moderate-to-severe atopic dermatitis (AD). OBJECTIVE: To identify factor associated with food allergy among preschool children with AD, and to compare AD resolution between preschool children with and without FA. METHODS: A cross-sectional study using database registry and questionnaire interview was conducted at Siriraj Hospital(Bangkok, Thailand) during 2022, and physician-diagnosed AD children aged ≤ 6 years were enrolled. RESULTS: A total of 110 children (60.9% male, median age: 2.3 years) were included. Of those, 53 and 57 children had AD with and without FA, respectively. Very early-onset AD (≤ 3 months) and moderate-to-severe AD at onset were reported in 43.9% and 26.3% of AD without FA, and in 35.8% and 45.3% of AD with FA, respectively. The most commonly reported FAs were hen's egg, cow's milk, and wheat. Moderate-to-severe AD at onset was found significant associated with FA (aOR: 2.50; p = 0.037). Thirty-one (28.2%) patients experienced completed resolution of AD by 5 years of age. Of those, 19 had AD without FA, and 12 had AD with FA (p = 0.213). The median age at AD resolution was 18 months and 22.5 months in the without and with FA groups, respectively. AD with FA showed a strong trend toward a significantly longer duration to achieving AD resolution after adjusting for onset and severity of AD (aHR: 0.46, p = 0.050). CONCLUSION: Preschool AD children with FA were found to have significantly greater AD severity at AD onset and a longer duration to AD resolution compared to AD children without FA.
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Background: Food allergy (FA), which is a condition that has no effective cure and can result in severe life-threatening allergic reactions, remains a global public health concern; however, little is known about how FAs are currently managed in the Asia-Pacific region. Objective: The main objective of this survey was to evaluate the epidemiology of FA, as well as the availability of resources and practices for management of FA and anaphylaxis by health care providers across Asia. Methods: From June 2022 to September 2022, a questionnaire-based survey comprising 66 questions was electronically sent to member societies of the Asia Pacific Association of Allergy Asthma and Clinical Immunology by using Survey Monkey. Results: A total of 20 responses were received from 15 member countries and territories. Compared with the pediatric data, there was a lack of prevalence data for FA in adults. Except for Australia and Japan, most regions had between 0.1 and 0.5 allergists per 100,000 population and some had fewer than 0.1 allergists per 100,000 population. The perceived rate of FA in regions with a short supply of allergists was high. Although specific IgE tests and oral food challenges were available in all regions, the median wait time for oral food challenges at government facilities was 37 days (interquartile range = 10.5-60 days). Seven regions still relied on prescriptions of ampules and syringes of injectable adrenaline, and adrenaline autoinjectors were not accessible in 4 regions. Oral immunotherapy as FA treatment was available in half of the surveyed countries and territories. Conclusions: Our study offers a cross-sectional evaluation of the management practices for FA in each Asia Pacific Association of Allergy Asthma and Clinical Immunology member country or territory. Urgent actions are required to enhance allergy services, improve the accessibility and affordability of adrenaline autoinjectors, and conduct robust epidemiologic studies.
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BACKGROUND: The commercial wheat extract for skin prick test (SPT) provides less sensitivity to predict wheat allergy, compared to in-house gliadin extracts. SPT is a preferred method to study extract stability as it is the aim of developing extract. The role of cell degranulation assay, a functional assay with the same mechanism as SPT, is not widely used to determine extract stability. OBJECTIVE: To study the stability of in-house gliadin extracts stored at different periods, by using protein analysis, SPT and degranulation assay of humanized rat basophilic-leukemia (RBL-SX38) cells. METHODS: Patients with a history of wheat allergy and positive SPT to wheat, were recruited. The gliadin extracts stored for 1, 6, 9, and 12 months at 2-8°C were used in SDS-PAGE, SPT and cell degranulation assay. The cell degranulation was determined by ß-hexosaminidase release. AR patients. RESULTS: Forty children were recruited. The gliadin extract stored for 9 and 12 months provided lighter protein bands than 1 and 6 months. However, the wheal diameters from SPT using extracts stored at different periods, were not significantly different (p = 0.09). There were also no significant differences of the ß-hexosaminidase released using 0.1 and 1 µg/mL of gliadin extracts stored at different periods (p > 0.05). The 10 µg/mL of gliadin extracts stored at longer periods, significantly stimulated higher ß-hexosaminidase release (p = 0.01). The extracts were sterile at all storage times. CONCLUSIONS: To determine the stability of in-house gliadin extracts, SPT or cell degranulation assay provided additional information to SDS-PAGE. The extracts were stable for up to 12 months.
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Objective: To examine causal relationships among asthma self-management behaviors, asthma symptom control, health-related quality of life and the influencing factors among Thai adolescents. Methods: A cross-sectional study was conducted using convenience sampling. A total of 240 adolescent-caregiver dyads from three tertiary hospitals in Bangkok, Thailand was ultimately included. Interviews and self-administered questionnaires assessing health-related quality of life, asthma symptom control, asthma self-management behaviors, health literacy, depression, comorbidities, family support, peer support, home environmental management, and relationships with health care providers were administered between November 2020 and July 2021. A hypothesized model based on the revised self- and family-management framework was proposed. Data were analyzed using descriptive statistics and path analysis. Results: It was shown that the proposed model was a good fit for the empirical data and accounted for 67.2% of the variance in health-related quality of life. Depression and asthma symptom control directly affected quality of life (ß = -0.132, P < 0.05; and ß = 0.740, P < 0.05, respectively), while asthma self-management behaviors did not. Both depression and asthma self-management behaviors had indirect effects on the quality of life through asthma symptom control (ß = -0.382, P < 0.05; and ß = 0.225, P < 0.05, respectively). Health literacy (ß = 0.343, P < 0.05), family support (ß = 0.167, P < 0.05), peer support (ß = 0.163, P < 0.05), and relationships with health care providers (ß = 0.181, P < 0.05) also showed direct effects on asthma self-management behaviors. Conclusion: The findings confirmed the causal relationships among asthma symptom control, self-management behaviors, depression and health-related quality of life. Health literacy, support from family and peers, and relationships with health care providers were also found to influence asthma self-management behaviors. To achieve effective asthma control and good quality of life, a nursing intervention promoting asthma self-management for Thai adolescents should be developed. Early detection and intervention of depressive symptoms are also suggested.
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BACKGROUND: Infants with cow's milk protein allergy (CMPA) are at risk for nutrient inadequacy and impaired growth. OBJECTIVE: To evaluate the effect of a new amino acid-based formula (nAAF) compared with commercial amino acid-based formula (cAAF) on growth and protein status of cow's milk protein (CMP)-allergic infants and to compare their growth with those of healthy infants. METHODS: Infants less than 6 months of age with CMPA were enrolled in the nAAF or cAAF groups. Healthy infants fed breast milk (BM) or infant formula (IF) were controls. They remained on their formula/milk until day 28 of the study. Anthropometric evaluation was performed at birth, day 0 and day 28 of the study and calculated to z-scores of weight-for-age (WAZ), length-for-age (LAZ) and head circumference-for-age (HAZ). Plasma amino acids, albumin, urea nitrogen, and creatinine were assessed for infants with CMPA on day 0 and day 28. RESULTS: The nAAF and cAAF groups did not differ in increases in WAZ [regression coefficient (95%CI): 0.088 (-0.619, 0.796), p = 0.791], LAZ [0.045 (-0.789, 0.880, p = 0.909], and HAZ [-0.645 (-2.082, 0.793), p = 0.337] between day 0 and day 28. The increases in WAZ and LAZ during 28 days in the nAAF group did not differ from the controls. The changes in the blood chemistry values, except albumin, were not different between CMPA groups. CONCLUSIONS: The nAAF, similar to the cAAF, supports growth and protein status for infants with CMPA, and it might be used as a substitute for the cAAF.
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BACKGROUND: Non-allergic rhinitis (NAR) is characterized by symptoms of nasal inflammation without allergic sensitization. The long-term outcome of NAR in children is poorly defined. OBJECTIVE: To determine the natural history of childhood-onset NAR and the development of allergic rhinitis (AR) in these children. METHODS: NAR patients who were followed for more than 10 years were evaluated at 3-5 years (E2) and 9-12 years (E3) after the first evaluation (E1). Nasal symptoms, disease severity, comorbidities, medication used, and aeroallergen sensitization were assessed. RESULTS: Eighty-two NAR patients (58.5% male) completed all 3 evaluations. The age at onset was 2.0 (range 2.0-4.0) years. The follow-up period was 13.6 (range 12.3-14.3) years. At E2, 37.8% of patients developed AR. At E3, the patients were classified into four groups based on results of skin prick tests in E2 and E3 (group I: NARâNARâNAR, 39.0%, group II: NARâNARâAR, 23.2%, group III: NARâARâNAR, 12.2% and group IV: NARâARâAR, 25.6%). The most common aeroallergen sensitization was house dust mite. The family history of atopy, asthma and allergic rhinitis were higher in group III and IV than other groups (p < 0.05). The atopic dermatitis, obstructive sleep apnea and adenotonsillar hypertrophy at E1 and E2 were predominantly found in group IV (p < 0.05). At E2, group III and IV patients had higher proportion of exposure to house dust, animal dander and smoking compared to other groups (p < 0.05). The overall remission rate was 14.6%. CONCLUSIONS: Children with NAR should be reevaluated periodically to determine aeroallergen sensitization for the appropriate diagnosis and management.
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BACKGROUND: Children with wheat anaphylaxis can present with a wide range of wheat-specific IgE (sIgE). OBJECTIVE: To identify differences in clinical features and predominant wheat allergens sensitized by these patients. METHODS: Children with history of wheat anaphylaxis were recruited. Skin prick test (SPT) to wheat, sIgE to wheat, omega-5 gliadin (ω5G), lipid transfer protein (LTP) were investigated. Profiles of IgE-bound wheat allergens were studied to identify predominant wheat allergens. RESULTS: Twenty-nine children (17 males) aged 1-18 years were enrolled. Sixteen patients (55.2%) had wheat-sIgE > 100 kUA/L (WAhi) and 13 patients (44.8%) had wheat-sIgE < 34 kUA/L (WAlo). The median of peak wheat-sIgE in WAhi and WAlo were 340.5 kUA/L (IQR 184.3, 564.5) and 12.2 kUA/L (IQR 1.4, 41.3), respectively. Oral food challenge test (OFC) was carried out in 12 of 13 patients in the WAlo group, all of which had positive results. Eight of these 12 patients developed anaphylaxis during OFC despite having wheat-sIgE less than 10 kUA/L. There were no differences in clinical characteristics and atopic history between WAhi vs. WAlo. Medium to low molecular weight gliadin (< 40 kDa) and glutenin (< 60 kDa) were commonly recognized by patients with WAhi. IgE immunoblot pattern among the WAlo group was more widely dispersed than those with WAhi. CONCLUSIONS: Wheat anaphylaxis can occur in patients with low wheat-sIgE. Predominant wheat allergens recognized by patients with WAlo were different than those with WAhi. Such difference could be responsible for anaphylaxis at even low levels of wheat-sIgE.
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BACKGROUND: Wheat extracts containing both water/salt and alcohol soluble proteins may increase extract's accuracy for diagnosing IgE-mediated wheat allergy. OBJECTIVE: This study aimed to determine the performance of new invented in-house prepared wheat extracts for skin prick test (SPT). METHODS: Children aged 1-18 years with history of immediate wheat allergy were recruited. Four in-house prepared wheat extracts (wheat-Coca-10%EtOH, and 3 new invented extracts, wheat-salt, gliadin, and glutenin) and a commercial wheat extract were used for SPT. Serum specific IgE (sIgE) to wheat and omega-5 (ω-5) gliadin were also determined. Oral food challenge (OFC) with wheat flours was performed in all patients except those with history of wheat-induced anaphylaxis or with recent symptoms within the past 6 months. RESULTS: Thirty-one children were recruited. Of those, 14 were excluded from OFC (12 with history of anaphylaxis and 2 with recent symptom). OFC was positive in 8 of 17 children. Of the 5 extracts and sIgE to wheat and ω-5 gliadin, gliadin extract provided the best SPT performance with 84.2% sensitivity, 88.9% specificity, 94.1% positive predictive value (PPV), 72.7% negative predictive value (NPV), 7.59 positive likelihood ratio (LR), 0.18 negative LR, and 85.7% accuracy. CONCLUSIONS: Compared to other in-house and commercial wheat extracts and sIgE to wheat and ω-5 gliadin, SPT with an in-house gliadin extract yielded the highest performance for the diagnosis IgE-mediated wheat allergy.
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Anafilaxia , Hipersensibilidad Inmediata , Hipersensibilidad al Trigo , Niño , Humanos , Hipersensibilidad al Trigo/diagnóstico , Gliadina , Anafilaxia/diagnóstico , Inmunoglobulina E , Pruebas Cutáneas , Alérgenos , EtanolRESUMEN
BACKGROUND: Food allergy has an impact on the quality of life of both patients and caregivers. It is, therefore, important to have a native language survey to evaluate health-related quality of life (HRQL) among food allergic children. OBJECTIVE: To translate the Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF) to Thai language, and to validate this tool in Thai parents with food allergic children. METHODS: The FAQLQ-PF was translated into Thai language according to WHO guideline. The FAQLQ-PF Thai version was then administered to the parents of food allergic Thai children aged 0-12 years. The FAQLQ-PF Thai version was then readministered to those same parents 10-14 days after they first completed this assessment tool. Internal consistency by Cronbach's α and test-retest reliability by intraclass correlation coefficient (ICC) were assessed. The discriminant validity of the questionnaire was also evaluated. RESULTS: Ninety parents of participants answered the FAQLQ-PF Thai version. Of those, 9 parents (10%) incompletely answered the first questionnaire. The FAQLQ-PF Thai version showed good internal consistency (Cronbach's α ≥ 0.799), but the test-retest reliability was only fair (ICC > 0.6). Factors that adversely affected the quality of life of Thai children with food allergy included age, presence of anaphylaxis, frequency of reactions, and the number of implicated foods. Patients with wheat allergy were negatively impacted in all domains of quality of life, whereas those with shellfish allergy had only emotional impact. CONCLUSIONS: The FAQLQ-PF Thai version is a reliable and valid tool for assessing HRQL in Thai children with food allergy.
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Hipersensibilidad a los Alimentos , Lenguaje , Responsabilidad Parental , Calidad de Vida , Traducciones , Niño , Humanos , Hipersensibilidad a los Alimentos/diagnóstico , Hipersensibilidad a los Alimentos/psicología , Padres/psicología , Calidad de Vida/psicología , Reproducibilidad de los Resultados , Pueblos del Sudeste Asiático , Encuestas y Cuestionarios , TailandiaRESUMEN
BACKGROUND: Mold sensitization has been reported as a factor associated with severe asthma exacerbation (SAE). OBJECTIVE: To identify the factors associated with SAE in asthmatic children, particularly mold sensitization. METHODS: The asthmatic children recruited into this case-control study were classified into an SAE and an outpatient (OPD) group, based on their histories of asthma exacerbation with hospitalization in the preceding year. A skin prick test to common aeroallergens was performed. Possible SAE risk factors were analyzed. RESULTS: A total of 102 patients were enrolled. The 51 patients in the SAE group were significantly younger than the 51 in the OPD group (mean ages of 6.8 ± 3.3 vs 8.7 ±3.2 years, p = 0.005). Higher proportions of patients with partly controlled or uncontrolled asthma were found in the SAE group (41.2% vs 17.6%, p = 0.009). The incidences of a paternal history of atopy, an emergency department visit, and a history of systemic corticosteroid administration in the preceding year were significantly higher for the SAE group (35.3% vs 15.7%, p = 0.023; 100% vs 43.5%, p < 0.001; and 100% vs 31.4%, p < 0.001; respectively). The multivariate logistic regression analysis showed that risk factors for SAE were Alternaria sensitization (adjusted odds ratio [AOR] 3.00; 95% CI 1.09-8.3; p = 0.033), patients who were younger than 6 years (AOR 3.28; 95% CI 1.17-9.18; p = 0.024), and a paternal history of atopy (AOR 2.94; 95% CI 1.05-8.25; p = 0.040). CONCLUSIONS: Alternaria sensitization, an age younger than 6 years, and a paternal history of atopy were associated with SAE in asthmatic children.
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Asma , Hipersensibilidad Inmediata , Humanos , Niño , Preescolar , Estudios de Casos y Controles , Asma/diagnóstico , Asma/epidemiología , Asma/etiología , Alérgenos , Hipersensibilidad Inmediata/complicaciones , HongosRESUMEN
BACKGROUND: A leukocyte adhesion defect (LAD) is a rare primary immunodeficiency disorder. LAD type 1 (LAD-1) is the most common, which is caused by ITGB2 mutation resulting in dysfunction of ß2 integrin, which impairs leukocyte adherence to the endothelium. CASE SUMMARY: The first two cases of LAD-1 in Thailand presented with recurrent omphalitis, soft tissue infection, marked leukocytosis, and neutrophilia. One patient experienced delayed umbilical cord separation. Mutation analysis was performed by direct DNA sequencing of the ITGB2 gene. The results revealed two novel homozygous missense mutations, c.920C>T (p.Leu307Pro) in exon 8 and c.758G>A (p.Arg253His) in exon 7, and one novel homozygous nonsense mutation, c.262C>T (p.Gln88Ter) in exon 4, in the genomic DNA of the first and second patients, respectively. Heterozygous mutations were identified in the parents of both patients, suggesting a carrier status. The patients were administered intravenous antibiotics for infections with good clinical responses. Hematopoietic stem cell transplantation could not be performed due to the unavailability of matched donors. However, a significant decline in infections was observed after antibiotic prophylaxis. Several follow-up visits were conducted for both patients. They are currently 6 years old. CONCLUSION: Molecular analysis is essential for definitive diagnosis, early treatment implementation, and prevention of LAD-1 in future pregnancy.
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BACKGROUND: Clinical management of shrimp allergy is hampered by the lack of accurate tests. Molecular diagnosis has been shown to more accurately reflect the clinical reactivity but the full spectrum of shrimp allergens and their clinical relevance are yet to be established. We therefore sought to comprehend the allergen repertoire of shrimp, investigate and compare the sensitization pattern and diagnostic value of the allergens in allergic subjects of two distinct populations. METHODS: Sera were collected from 85 subjects with challenge-proven or doctor-diagnosed shrimp allergy in Hong Kong and Thailand. The IgE-binding proteins of Penaeus monodon were probed by Western blotting and identified by mass spectrometry. Recombinant shrimp allergens were synthesized and analyzed for IgE sensitization by ELISA. RESULTS: Ten IgE-binding proteins were identified, and a comprehensive panel of 11 recombinant shrimp allergens was generated. The major shrimp allergens among Hong Kong subjects were troponin C (Pen m 6) and glycogen phosphorylase (Pen m 14, 47.1%), tropomyosin (Pen m 1, 41.2%) and sarcoplasmic-calcium binding protein (Pen m 4, 35.3%), while those among Thai subjects were Pen m 1 (68.8%), Pen m 6 (50.0%) and fatty acid-binding protein (Pen m 13, 37.5%). Component-based tests yielded significantly higher area under curve values (0.77-0.96) than shrimp extract-IgE test (0.70-0.75). Yet the best component test differed between populations; Pen m 1-IgE test added diagnostic value only in the Thai cohort, whereas sensitizations to other components were better predictors of shrimp allergy in Hong Kong patients. CONCLUSION: Pen m 14 was identified as a novel shrimp allergen predictive of challenge outcome. Molecular diagnosis better predicts shrimp allergy than conventional tests, but the relevant component is population dependent.
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Hipersensibilidad a los Alimentos , Hipersensibilidad , Alérgenos , Proteínas de Unión a Ácidos Grasos , Hipersensibilidad a los Alimentos/diagnóstico , Humanos , Inmunoglobulina E , Tropomiosina , Troponina CRESUMEN
PURPOSE: Tolerance to shrimp has been reported in some patients with a history of shrimp allergy. The predictors of the natural resolution of shrimp allergy have not been widely explored. This study aimed to investigate the role of specific IgE (sIgE) and specific IgG4 (sIgG4) to shrimp extracts and the cross-reactive shrimp allergens tropomyosin (TM), arginine kinase (AK) and myosin light-chain (MLC), as markers of persistent or resolved shrimp allergy (PSA or RSA). METHODS: Seventeen patients with a 10-year history of allergy to Penaeus monodon (Pm) and/or Macrobachium rosenbergii (Mr) were recruited. Oral shrimp challenges identified 10 patients with PSA and 7 patients with RSA. Sera from these patients were evaluated for sIgE and sIgG4 to Mr and Pm extracts as well as to TM, AK and MLC. RESULTS: The levels of sIgE to Mr and Pm extracts were lower in the RSA than in the PSA groups (P = 0.05 and P = 0.008, respectively), but sIgG4 or sIgG4:sIgE ratio did not show statistical significance. The sIgE to AK and MLC, but not TM, were lower in the RSA group than in the PSA group (P = 0.009 and P = 0.0008, respectively). There was no difference in sIgG4 to TM, AK and MLC between both groups. The ratio of sIgG4:sIgE to MLC, but not TM or AK, was higher in the RSA than in the PSA group (P = 0.02). A higher diversity of sIgE to shrimp components was found in the PSA group than in the RSA group (P = 0.006). CONCLUSIONS: Specific bioassays can be used to identify patients with RSA. Oral shrimp challenges in these patients may provide a higher rate of passing the challenges and finally reintroducing shrimp in their diet.
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BACKGROUND: Skin prick test (SPT) is useful in identifying rat and mouse sensitization. OBJECTIVE: To determine the prevalence of rat and mouse sensitization by using local and commercial allergen extracts. METHODS: Patients with allergic rhinitis or asthma were recruited. SPT of local and commercial rat and mouse allergen extracts were performed. The level of rat and mouse specific IgE (sIgE) was quantified in all patients with positive SPT and randomized patients with negative SPT. RESULTS: Two hundred and thirty patients, 108 male (47%) and median age 14 years (3.2-63.5 years), were enrolled. Rat sensitization by SPT was 11.7% and mouse sensitization was 17.8%. SPT result to local rat and commercial rat allergen extracts were moderately correlated (rs = 0.51, p < 0.001), while SPT result to local mouse and commercial mouse allergen extracts showed low correlation (rs = 0.38, p < 0.001). The concordance of SPT results between local rat and commercial rat allergen extracts was 90.4%. Concordance between the local mouse and commercial mouse allergen extracts was 85.2%. When compared with rat and mouse sIgE, the concordance of local rat, commercial rat and commercial mouse allergen extract were > 80% while that of local mouse was 54.4%. No adverse effect was observed in SPT with any allergen or extract. CONCLUSIONS: The prevalence of rat and mouse sensitization was low compared to the study in USA. SPT with local rat and mouse allergen extract was safe and showed good concordance with the SPT result of commercial allergen extracts and rat and mouse sIgE levels.
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Inmunoglobulina E , Rinitis Alérgica , Masculino , Ratas , Ratones , Animales , Prevalencia , Alérgenos , Rinitis Alérgica/diagnóstico , Rinitis Alérgica/epidemiología , Pruebas Cutáneas/métodos , Extractos VegetalesRESUMEN
BACKGROUND: Allergic conjunctivitis (AC) is the most common ocular condition in allergic children. In tropical countries, the study about the clinical features and outcome of treatment is very limited. OBJECTIVE: To review clinical characteristics and outcomes of treatment in children with ocular allergy. METHODS: Children with history of AC were classified to seasonal allergic conjunctivitis (SAC), perennial allergic conjunctivitis (PAC), vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC). The clinical history and outcome of treatment were recorded. RESULTS: One hundred and sixty-four children were recruited. PAC was the most common type (61.6%), followed by SAC (21.3%), VKC (12.2%), and AKC (4.9%). Male preponderance was found in all groups. Mean age of onset was 6.8 ± 2.8 years. Allergic rhinitis was the most common co-morbidity (97.6%). The common sensitized allergen is house-dust mites (86.1%). Standard treatments in all groups were natural tear and topical olopatadine. Add-on medications were usually needed in severe types of AC (VKC, AKC). History of topical corticosteroid use was 68.8% and 12.5% in VKC and AKC, respectively. All of them can discontinue topical corticosteroid when topical tacrolimus was applied. The overall remission was found 35% in VKC group and 63% in AKC group. The median duration of treatment was 20.5 months in VKC group and 11 months in AKC group. CONCLUSIONS: most Thai children with AC sensitized to house-dust mites. In severe forms of AC, most patients needed addon medication. The use of topical calcineurin inhibitor as an add-on therapy can decrease the use of topical corticosteroid.