Estudio de validez diagnóstica de la prueba de hemorragia oculta fecal en lactantes con proctocolitis alérgica inducida por proteína alimentaria / Diagnostic validity of fecal occult blood test in infants with food protein-induced allergic proctocolitis

Resumen: Introducción: La proctocolitis alérgica inducida por proteína alimentaria (PCA) es la forma más fre cuente de alergia alimentaria no mediada por IgE. El diagnóstico se realiza por prueba de provocación oral, sin embargo, no existe una prueba diagnóstica no invasiva para su diagnóstico. Frecuentemente en Chile se utiliza la prueba de hemorragia oculta fecal (PHOF) para confirmar PCA, pero no hay estudios que respalden su indicación. Objetivo: Determinar la validez diagnóstica de la PHOF en la evaluación de lactantes con PCA. Pacientes y Método: Estudio de casos y controles con recluta miento prospectivo de lactantes con rectorragia y sospecha de PCA y lactantes sanos, en quienes se realizó una PHOF. Se indicó dieta de exclusión a los casos y luego se confirmó diagnóstico de PCA mediante contraprueba. Resultados: Se incluyó a 25 casos y 29 controles sin diferencias signi ficativas en edad, sexo, tipo de parto, alimentación o edad materna. Los casos presentaron con mayor frecuencia comorbilidades alérgicas, uso de medicamentos y antecedentes familiares de alergia. La PHOF fue positiva en 84% de casos y en 34% de controles (p<0,001). La sensibilidad de la PHOF para diagnosticar PCA fue 84%, especificidad 66%, valor predictivo positivo 68% y valor predictivo nega tivo 83%. El área bajo la curva ROC fue de 0,75 (IC 95% 0,61-0,88). Conclusiones: Si bien la PHOF tiene sensibilidad adecuada para detectar PCA en lactantes con rectorragia, resulta alterada en más de un tercio de lactantes sanos por lo que no se recomienda su uso habitual para el diagnóstico de PCA.

Abstract: Introduction: Food protein-induced allergic proctocolitis (FPIAP) is the most frequent presenta tion of non-IgE mediated food allergy (FA). The diagnosis is made by oral food challenge, however, non-invasive diagnostic tests are not available. In Chile, the fecal occult blood test (FOBT) is fre quently used to confirm FPIAP, however, there are no studies that support this practice. Objective: To establish the diagnostic validity of FOBT in the evaluation of infants with FPIAP. Patients and Method: Case-control study with prospective recruitment of infants with rectal bleeding and suspicion of FPIAP, and controls were healthy infants, in whom the FOBT was conducted. All cases underwent an elimination diet, after which the diagnosis of FPIAP was confirmed by oral food cha llenge. Results: 25 cases and 29 controls were included without significant differences in age, gen der, type of delivery, feeding, and maternal age. The cases had higher rates of allergic comorbidities, medication use, and family history of allergy. The FOBT was positive in 84% of cases and in 34% of controls (p < 0.001). The sensitivity of the FOBT for the diagnosis of FPIAP was 84%, specificity was 66%, positive predictive value 68%, and the negative predictive value 83%. The area under the ROC curve was 0.75 (CI 95% 0.61-0.88). Conclusions: Although the FOBT has an adequate sensitivity to diagnose FPIAP in infants with rectal bleeding, this test had abnormal results in more than a third of healthy infants. Therefore, the routine use of FOBT is not recommended for the diagnosis of FPIAP.

Marcadores de inflamación y desarrollo de tolerancia en la proctocolitis alérgica / Markers of inflammation and tolerance development in allergic proctocolitis

Antecedentes: Con el incremento de la proctocolitis alérgica inducida por proteínas de la dieta (PAIPD), son necesarios estudios que aclaren su fisiopatología y determinar marcadores no invasivos y sencillos para el diagnóstico y la evaluación del desarrollo de tolerancia. No hallamos estudios publicados sobre la función del índice de neutrófilos/linfocitos (INL) y el volumen plaquetario medio (VPM), que son marcadores no invasivos fácilmente medibles, en pacientes con PAIPD. Objetivos: Determinar la relación entre el INL y el VPM con el diagnóstico y desarrollo de tolerancia en niños con PAIPD. Métodos: Estudio transversal retrospectivo, los datos se obtuvieron del sistema de registros médicos, los síntomas y los resultados de laboratorio de los pacientes con diagnóstico de PAIPD fueron controlados en los consultorios de alergia y gastroenterología. Se compararon valores del hemograma al momento del diagnóstico con el grupo de niños sanos de edad y sexo similares. Resultados: Entre los 59 pacientes con diagnóstico de PAIPD, los varones representaron el 47,4% y las niñas, el 52,6%. El VPM y el volumen plaquetario relativo (VPR) eran significativamente más altos entre los pacientes con PAIPD en comparación con el grupo de referencia (n: 67) (p < 0,001). Asimismo, VPM y el VPR fueron significativamente elevados en pacientes que no desarrollaron tolerancia comparados con los que la desarrollaron (p= 0,01). Con el INL no hubo diferencias entre los grupos. Conclusiones: El VPM y el VPR se consideraron marcadores adecuados para predecir el pronóstico de los pacientes con PAIPD dado que son rápidos, costo-efectivos y fáciles de medir.

Background. Today, as a result of an increase in the frequency of food protein-induced allergic proctocolitis (FPIAP), there is a need for studies not only to enlighten the pathophysiology of the disease but also to determine simple, non-invasive markers in both diagnosis, and evaluation of the development of tolerance. No study has been found in the literature about the place of neutrophil/lymphocyte ratio (NLR) and mean platelet volume (MPV), which are easy to calculate and non-invasive markers. Objectives. The purpose is to determine the relation between NLR and MPV with the diagnosis and development of tolerance in children with FPIAP. Methods. In this retrospective cross-sectional study, clinical, demographic symptoms and laboratory findings of patients, monitored with FPIAP diagnosis in allergy and gastroenterology clinics, were acquired from the patient record system. Hemogram values at the time of diagnosis were compared with the values of healthy children of the same age and gender. Results. Among 59 patients diagnosed with FPIAP, males constitute 47.4% and females constitute 52.6%. MPV and platelet crit (PCT) values were significantly high when compared to the control group (n: 67) in FPIAP cases (p <0.001). Also, MPV and PCT values were significantly high in non-tolerance developing cases when compared to developing ones (p= 0.01). Conclusions. Contrary to NLR, MPV and PCT values have been considered to be good markers in predicting prognosis in cases with FPIAP since they are quick, cost effective and easy to calculate.

Frecuencia de sensibilización alimentos y aero-alergenos en pacientes recibidos en el laboratorio de Corpodiagnostica C.A. durante el periodo 2010-2011 / Frequency of sensitization for food and aero-allergens in patients reciived in a Venezuelan laboratory during 2010-2011 period

La alergia tipo I se ha definido como una reacción inmunológica adversa mediada por IgE que se produce después de una exposición repetida al alérgeno. La prevalencia de las alergias ha aumentado considerablemente en los últimos 20 años, lo que aumenta la necesidad del estudio de la respuesta a varios alérgenos. El objetivo fue evaluar la frecuencia de sensibilización a alimentos y aero-alérgenos en los pacientes referidos al Laboratorio de Corpodiagnostica C.A. durante el periodo 2010-2011. Se determinó niveles de IgE específica a 2445 pacientes, usando el método inmunoblot in vitro RIDA Allergy-screen (r-Biopharm, Alemania). La tasa de sensibilización total medida por IgE específica a alimentos fue de 30,43%, donde los alimentos más comunes fueron Leche, Queso, Trigo, Maíz y Cerdo; mientras que la tasa de sensibilización para aero-alérgenos fue de 46,16%; de los cuales los más comunes fueron los ácaros mayores y B. tropicalis. Este estudio provee de una herramienta importante para la identificación de los alérgenos alimentarios y respiratorios de mayor prevalencia en la población venezolana.

Type I allergy had been defined as an adverse immunologic reaction mediated by IgE that occurs after a repeated exposure to the allergen. The prevalence of the allergies has increased considerably in the last 20 years, thus increasing the need of study the response to several allergens. The objective was to evaluate the frecuency of foods and respiratory allerges sensitization in patients referred to Corpodiagnostica Laboratory (Caracas, Venezuela, ISO 9001:2008 certified laboratory) in the period that correspond from January 2010 to July 2011. We determinated specific IgE levels to 2445 patients, by the in vitro RIDA® Allergy-screen immunoblot method (r-biopharm®, Germany). The total sensitization rate mediated by specific IgE to food allergen was 30,43% where the foods most common were milk, cheese, wheat flour, corn and pork; while the sensitization for aero-allerges was 46,16%; the most common were the major mites and B. tropicalis. This study provides an important tool for the identification of food and aero-allergens with major prevalence in the Venezuelan population.

Identification of the major allergens of Indian scad (Decapterus russelli).

The purpose of this study was to characterize major allergens of Indian scad (Decapterus russelli) which is among the most commonly consumed fish in Malaysia. Raw and cooked extracts of the fish were prepared. Protein profiles and IgE binding patterns were produced by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting using sera from subjects with fish allergy. The major allergens of the fish were then identified by two-dimensional electrophoresis (2-DE), followed by mass spectrometry of the peptide digests. The SDS-PAGE of the raw extract revealed 27 protein fractions over a wide molecular weight range, while the cooked extract demonstrated only six protein fractions. The 1-DE immunoblotting detected 14 IgE-binding proteins, with a molecular weight range from 90 to < 6.5 kDa. Three protein fractions with molecular weights of approximately 51, 46 and 12 kDa were identified as the major allergens of this fish. The approximately 12 kDa band was a heat-resistant protein while the approximately 51 and 46 kDa proteins were sensitive to heat. The 2-DE gel profile of the raw extract demonstrated > 100 distinct protein spots and immunoblotting detected at least 10 different major IgE reactive spots with molecular masses as expected and isoelectric point (pI) values ranging from 4.0 to 7.0. A comparison of the major allergenic spot sequences of the 12 kDa proteins with known protein sequences in databases revealed extensive similarity with fish parvalbumin. In conclusion, this study demonstrated that a parvalbumin which is similar to Gad c 1 is the major allergen of Indian scad. Interestingly, we also detected heat-sensitive proteins as major allergenic components in our fish allergy patients.

A study of allergen-specific IgE antibodies in Indian patients of atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic, relapsing, pruritic dermatitis frequently associated with the hyperproduction of IgE to various allergens. Identification of these allergens is possible by various laboratory investigations. AIM: The present study was designed to assess these allergen-specific antibodies in the diagnosis of AD in the Indian context. METHODS: This prospective study comprised 50 patients of AD. The diagnosis was made clinically after satisfying Hanifin and Rajka's criteria. Serum IgE levels were estimated and specific IgE antibodies were measured for 20 food allergens and aeroallergens. RESULTS: Serum IgE was elevated in 88% of the patients. The highest elevation of mean IgE levels was seen in the 10-20 years age group. Sixty five percent of the children under the age of ten years were positive to one or more food allergens. Food allergens were more often positive in the < or = 10 years age group and specific antibodies to inhalants were seen more frequently in the older age groups. Specific antibodies to apples were found in all age groups. CONCLUSION: Antibodies against apples and hazelnuts were the more commonly seen specific antibodies in children. Incidence of positivity was much higher in children when compared to earlier studies. Identification of food allergens can be an important factor in the diagnosis of AD in children in India. Positivity to inhalant allergens in the older age groups was lower in this study. The allergen profile with regard to inhalants in Indian patients was similar to that of earlier studies.

Relevance of serum IgE estimation in allergic bronchial asthma with special reference to food allergy.

Studies suggest the importance of serum total and specific IgE in clinical evaluation of allergic manifestations. Such studies are lacking in Indian subcontinent, though a large population suffer from bronchial asthma. Here relevance of serum total and specific IgE was investigated in asthmatics with food sensitization. A total of 216 consecutive patients (mean age 31.9 years, S.D. 11.8) were screened by various diagnostic testing. Out of 216 patients, 172 were with elevated serum total IgE (201 to > 800 IU/ml). Rice elicited marked positive skin prick test reactions (SPT) in 24 (11%) asthma patients followed by black gram 22 (10%), lentil 21 (9.7%) and citrus fruits 20 (9.2%). Serum total IgE and specific IgE showed significant correlation, p = 0.005 and p = 0.001, respectively, with positive skin tests. Blinded food challenges (DBPCFC) with rice and or black gram confirmed food sensitization in 28-37% of cases. In summary, serum total IgE of 265 IU/ml or more with marked positive SPT (4 mm or more) can serve as marker for atopy and food sensitization. Specific IgE, three times of normal controls correlates well with positive DBPCFC and offers evidence for the cases of food allergy.

Murine Model of Buckwheat Allergy by Intragastric Sensitization with Fresh Buckwheat Flour Extract

Food allergies affect about 4% of the Korean population, and buckwheat allergy is one of the most severe food allergies in Korea. The purpose of the present study was to develop a murine model of IgE-mediated buckwheat hypersensitivity induced by intragastric sensitization. Young female C3H/HeJ mice were sensitized and challenged intragastricly with fresh buckwheat flour (1, 5, 25 mg/dose of proteins) mixed in cholera toxin, followed by intragastric challenge. Anaphylactic reactions, antigen-specific antibodies, splenocytes proliferation assays and cytokine productions were evaluated. Oral buckwheat challenges of sensitized mice provoked anaphylactic reactions such as severe scratch, perioral/periorbital swellings, or decreased activity. Reactions were associated with elevated levels of buckwheatspecific IgE antibodies. Splenocytes from buckwheat allergic mice exhibited significantly greater proliferative responses to buckwheat than non-allergic mice. Buckwheat-stimulated IL-4, IL-5, and INF-gamma productions were associated with elevated levels of buckwheat-specific IgE in sensitized mice. In this model, 1 mg and 5 mg dose of sensitization produced almost the same degree of Th2-directed immune response, however, a 25 mg dose showed blunted antibody responses. In conclusion, we developed IgE-mediated buckwheat allergy by intragastric sensitization and challenge, and this model could provide a good tool for future studies.

Chestnut as a Food Allergen: Identification of Major Allergens

Chestnut as a Food Allergen: Identification of Major Allergens To evaluate the clinical significance of chestnut as a food allergen in Korea, skin prick test and ELISA were done in 1,738 patients with respiratory allergies. To identify the IgE binding components, IgE-immunoblotting, 2D IgE-immunoblotting and MALDITOF were performed. To observe the effects of digestive enzymes and a boiling treatment, simulated gastric fluid (SGF) and simulated intestinal fluids (SIF) were incubated with chestnut extracts, and IgE-immunoblotting were then repeated. Skin prick test revealed that 56 (3.2%) patients showed more than 2+ of allergen to histamine ratio to chestnut. Among the 21 IgE binding components, 9 bands were found in more than 50% of the sera tested and the 24 kDa protein had the highest binding intensity. The amino acid sequence of the 24 kDa protein (pI 6.3) had homology with legume protein of oak tree. SGF, SIF and boiling treatment were able to suppress the IgE binding components. In conclusion, chestnut ingestion was shown to induce IgE mediated responses with a 3.2% sensitization rate. Twenty one IgE binding components and one new allergen (the 24 kDa protein) were identified. Digestive enzymes and boiling treatment were able to decrease the allergenic potency.

Sensibilização a alérgenos inalantes e alimentares em crianças brasileiras atópicas, pela determinação in vitro de IgE total e específica: Projeto Alergia (PROAL) / Sensitization to inhalant and food allergens in Brazilian atopic children by in vitro total and specific IgE assay: Allergy Project - PROAL

OBJETIVO: Determinar a freqüência de sensibilização a alérgenos inalantes e alimentares em crianças atendidas em serviços brasileiros de alergia. PACIENTES E MÉTODOS: IgE sérica total e específica (RAST) a alérgenos inalantes e alimentares (UniCAP® - Pharmacia) foram determinados em 457 crianças acompanhadas em serviços de alergia pediátrica e em um grupo de controles (n = 62). Resultados classe igual ou maior que 1 foram considerados positivos (R+). RESULTADOS: A freqüência de R+ foi significantemente maior entre os atópicos (361/457, 79 por cento) quando comparados aos controles (16/62, 25,8 por cento). Não houve diferenças quanto ao sexo. A prevalência de R+ entre os atópicos foi significantemente maior para todos os alérgenos avaliados. Os níveis séricos de IgE total foram significantemente mais elevados entre os atópicos com R+ quando comparados aos com R-. Comparando-se atópicos e controles, a freqüência de R+ para os principais alérgenos inalantes foi como segue: D. pteronyssinus = 66,7 versus 14,5 por cento (p < 0,05), D. farinae = 64,5 versus 17,8 por cento (p < 0,05), B. tropicalis = 55,2 versus 19,4 por cento (p < 0,05), barata = 32,8 versus 9,7 por cento (p < 0,05) e gato = 12 versus 8,1 por cento. Com os alimentos, observou-se: peixe = 29,5 versus 11,3 por cento (p < 0,05), ovo = 24,4 versus 4,8 por cento (p < 0,05), leite de vaca = 23,1 versus 3,2 por cento (p < 0,05), trigo = 20 versus 8,1 por cento (p < 0,05), amendoim = 14 versus 4,8 por cento (p < 0,05), soja = 11,8 versus 4,8 por cento (p < 0,05) e milho = 10,6 versus 4,8 por cento (p < 0,05). Segundo a idade, os R+ aos alimentares predominaram entre as crianças mais jovens, e o inverso ocorreu com os inalantes. CONCLUSÕES: Nesta população, predominou a sensibilização aos aeroalérgenos, sobretudo aos ácaros domiciliares, e os alimentos foram importantes em crianças mais jovens.

The role of food allergens in childhood asthma.

Eighty-eight patients' sera with allergen-specific IgE levels elevated only to food allergens were collected between October 1997 and March 2002 at the National Taiwan University Hospital. Thirty-three of the patients fulfilled the diagnostic criteria of asthma and were included. Most (72.7%) patients had elevated serum allergen-specific IgE levels only to one food allergen. The most common food allergens were milk and egg white. The patients with elevated soy bean-specific IgE levels had significantly higher levels of serum food allergen-specific IgE than those with either elevated milk or egg white-specific IgE levels. This study investigated some food allergen responses of asthmatic patients whose serum allergen-specific IgE levels were elevated only to food allergens. The results suggested that the allergic asthmatic response in our patients was most likely related to food rather than aeroallergens or fungal allergens.

The relevance of specific serum IgG, IgG4 and IgE in the determination of shrimp and crab allergies in Malaysian allergic rhinitis patients.

The significance of food specific serum IgG4 antibody in food allergy is unclear and this led us to investigate the relevance of specific IgG4, along with IgG and IgE antibodies to two common food allergens in Malaysia. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum antibodies in 143 allergic rhinitis patients' sera, of which 47 were from patients with clinical indication of shrimp allergy, 46 with clinical indication of crab allergy and 50 without indication to either allergy. Clinical indication of allergy was based on answers to a questionnaire or results of the skin prick test. We found that the elevation of specific IgE or IgG4 is associated with shrimp and crab allergies but elevation of specific IgG is not associated with either allergy. However, the clinical utility of elevated specific IgG and IgG4 levels is pending further investigation.

Vitamin C status in allergic children

This study was undertaken to assess vitamin C status in allergic children. Twenty-six allergic patients and 46 apparently healthy controls aged 7-16 years of both sexes were introduced. All patients were diagnosed being allergic based on their histories, physical examinations and laboratory findings. Blood samples were obtained between 09.00-11.00 to determine total serum immunoglobulin E, histamine, plasma vitamin C and complete blood cell count. Stool examinations and urinealysis were also done. Although total serum immunoglobulin E levels were significantly higher in patients than in controls, the serum histamine and plasma vitamin C levels showed no significant difference between the two groups. Surprisingly, patients with allergic dermatitis and food allergy had significantly lower plasma vitamin C levels than patients with asthma and rhinitis. Also, female patients tended to have higher plasma vitamin C but lower total serum immunoglobulin E levels compared to the male patients but none of these differences were significant. Healthy boys, on the other hand, had significantly higher plasma vitamin C than healthy girls. Our findings did not confirm the previous reports which showed decreased plasma vitamin C levels in allergic patients. We concluded that the plasma vitamin C levels in different allergies might be infuenced by such factors, such as sex, type and the stage of allergic disease, besides those affecting intake