Alergia ou tolerância ao leite de vaca: novos cut-offs
Data
2015-09-24
Autores
Franco, Jackeline Motta 
Orientadores
Sole, Dirceu Sole
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Objetivos: Estabelecer o diâmetro médio da pápula e a concentração sérica de IgE específica ao leite de vaca total (LV) e às suas frações proteicas capazes de diferenciar alérgicos de não alérgicos; após um período mínimo de seis meses, avaliar a aquisição de tolerância oral. Relacionar a história clínica sugestiva de alergia ao LV com os resultados dos testes in vivo, in vitro e o Teste de Provocação Oral (TPO) aberto. Métodos: Cento e vinte e duas crianças (mediana de idade: 17 meses) com história clínica de reações imediatas ao LV e testes cutâneos de leitura imediata (TCLI) e/ou IgE específicas para LV e/ou frações positivos foram submetidas a TPO aberto (TPO1) com LV. As crianças com TPO positivo foram reavaliadas, após um período mínimo de seis meses de exclusão dietética, por meio de novo TPO (TPO2), precedido de novos TCLI e dosagens de IgE séricas específicas. Resultados: O TPO1 foi positivo em 59,8% das crianças. Os sintomas observados foram cutâneos (52%), respiratórios (14%) e gastrintestinais (8%). Apenas um paciente apresentou anafilaxia. Entre os pacientes positivos, 56 (76,7%) deflagraram sintomas após ingestão de 0,05 ml a 5 ml de LV nos primeiros 30 minutos do procedimento. A maioria das reações foi leve (83%), controladas com anti-histamínicos orais em 40 pacientes. Não houve concordância estatisticamente significante (método Kappa) entre os sintomas iniciais relatados pelos familiares e os manifestados durante o TPO. Os níveis de IgE sérica específicas para LV e os diâmetros médios das pápulas no TCLI foram significantemente maiores nos alérgicos do que nos não alérgicos (mediana 3,39 kUA/L vs 1,16 kUA/L; 2,5 mm vs 0 mm, respectivamente). Foram construídas curvas ROC para LV total e frações com áreas acima de 0,6, consideradas discriminatórias. Os pontos de corte obtidos utilizando-se o Índice de Youden, para os níveis séricos de IgE específica para LV, alfa-lactoalbumina, beta-lactoglobulina e caseína foram 5,17 kUA/L, 0,95 kUA/L, 0,82 kUA/L, 0,72 kUA/L, respectivamente. Para os diâmetros das pápulas foram obtidas, com o Índice de Youden, medidas de 3,5 mm, 6,5 mm, 9,0 mm e 3,0 mm, respectivamente. Após seis meses, foi realizado o TPO2, e as novas mensurações séricas resultaram em valores de 0,34 kUA/L, 0,15 kUA/L, 0,43 kUA e 0,29 kUA/L para LV, alfa-lactoalbumina, beta-lactoglobulina e caseína, respectivamente, considerados não adequados. Para o diâmetro médio da pápula no TPO2, foram encontrados pontos de corte de 2,0 mm para LV, de 4,5 mm, 3,0 mm e 4,5 mm para alfa-lactoalbumina, beta- lactoglobulina e caseína, utilizando como método o Índice de Youden. Conclusão: O ponto de corte diagnóstico para os níveis séricos de IgE para LV foi 5,17 kUA/L e para o diâmetro médio da pápula, 3,5 mm. Na aquisição de tolerância, os desempenhos do diâmetro médio de pápula e do nível de IgE específica para LV e frações não foram satisfatórios. Não houve concordância estatisticamente significante entre os sintomas iniciais relatados pelos familiares e os manifestados durante o TPO.
Objectives: To estimate the mean wheal diameter and serum specific IgE levels to cow¿s milk (CM) and its protein fractions in order to differentiate allergic from nonallergic patients; after a minimum period of six months, to evaluate oral tolerance acquisition. To link the suggestive clinical history of allergy to CM with the results of in vivo and in vitro tests, as well as of the Open Oral Food Challenge (OFC). Methods: One hundred and twenty-two children (median age: 17 months) with a clinical history of immediate reactions to CM and skin prick tests (SPTs), and/or specific IgE for CM and/or positive fractions, were subjected to an open OFC (OFC1) with CM . Children positive for the OFC were reassessed after a minimum period of six months of dietary exclusion, through a new OFC (OFC2) preceded by new SPTs and doses of specific serum IgE. Results: 59.8% of the children failed the OFC 1. Elicited symptoms comprised cutaneous (52%), respiratory (14%), and gastrointestinal (8%) tracts. Only one patient presented with anaphylaxis. Among positive patients, 56 (76.7%) displayed symptoms following the ingestion of 0.05 ml to 5 mL of CM within the first 30 minutes of the procedure. Most reactions were mild (83%), controlled with oral antihistamines in 40 patients. There was no statistically significant correlation (Kappa method) between the initial symptoms reported by family members and those manifested during the OFC. The specific serum IgE levels for CM and mean wheal diameters for the SPT were significantly higher in allergic than in non-allergic patients (median 3.39 vs 1.16 KuA/L; 2.5 vs 0 mm, respectively). ROC curves were constructed for CM and fractions with areas above 0.6, considered discriminatory. The cutoff points obtained using the Youden Index for serum specific IgE to CM, alpha-lactalbumin, beta-lactoglobulin and casein were 5.17 kUA/L, 0.95 kUA/L, 0.82 kUA/L, 0.72 kUA/L, respectively. With the Youden Index, mean wheal diameter was found as 3,5 mm, 6.5 mm, 9,0 mm, and 3,0 mm, respectively. After six months, OFC2 was conducted, and the new serum measurements were found as 0.34 kUA/L, 0.15 kUA/L, 0.43 kUA and 0.29 kUA/L for CM, alpha-lactalbumin , beta-lactoglobulin and casein, respectively, considered not suitable. For the mean wheal diameter in OFC2, cutoff points were found as 2,0 mm for CM, 4,5 mm, 3,0 mm, and 4.5 mm for alpha-lactalbumin, beta-lactoglobulin and casein, using the Youden Index as a method. Conclusion: The diagnostic cutoff point for serum IgE levels for CM was 5.17 kUA/L and the mean wheal diameter, 3,5 mm. For the toleramce acquisition, the performance for mean wheal diameter and for specific IgE level for CM and fractions were not satisfactory. There was no statistically significant correlation between the initial symptoms reported by family members and those manifested during the OFC.
Objectives: To estimate the mean wheal diameter and serum specific IgE levels to cow¿s milk (CM) and its protein fractions in order to differentiate allergic from nonallergic patients; after a minimum period of six months, to evaluate oral tolerance acquisition. To link the suggestive clinical history of allergy to CM with the results of in vivo and in vitro tests, as well as of the Open Oral Food Challenge (OFC). Methods: One hundred and twenty-two children (median age: 17 months) with a clinical history of immediate reactions to CM and skin prick tests (SPTs), and/or specific IgE for CM and/or positive fractions, were subjected to an open OFC (OFC1) with CM . Children positive for the OFC were reassessed after a minimum period of six months of dietary exclusion, through a new OFC (OFC2) preceded by new SPTs and doses of specific serum IgE. Results: 59.8% of the children failed the OFC 1. Elicited symptoms comprised cutaneous (52%), respiratory (14%), and gastrointestinal (8%) tracts. Only one patient presented with anaphylaxis. Among positive patients, 56 (76.7%) displayed symptoms following the ingestion of 0.05 ml to 5 mL of CM within the first 30 minutes of the procedure. Most reactions were mild (83%), controlled with oral antihistamines in 40 patients. There was no statistically significant correlation (Kappa method) between the initial symptoms reported by family members and those manifested during the OFC. The specific serum IgE levels for CM and mean wheal diameters for the SPT were significantly higher in allergic than in non-allergic patients (median 3.39 vs 1.16 KuA/L; 2.5 vs 0 mm, respectively). ROC curves were constructed for CM and fractions with areas above 0.6, considered discriminatory. The cutoff points obtained using the Youden Index for serum specific IgE to CM, alpha-lactalbumin, beta-lactoglobulin and casein were 5.17 kUA/L, 0.95 kUA/L, 0.82 kUA/L, 0.72 kUA/L, respectively. With the Youden Index, mean wheal diameter was found as 3,5 mm, 6.5 mm, 9,0 mm, and 3,0 mm, respectively. After six months, OFC2 was conducted, and the new serum measurements were found as 0.34 kUA/L, 0.15 kUA/L, 0.43 kUA and 0.29 kUA/L for CM, alpha-lactalbumin , beta-lactoglobulin and casein, respectively, considered not suitable. For the mean wheal diameter in OFC2, cutoff points were found as 2,0 mm for CM, 4,5 mm, 3,0 mm, and 4.5 mm for alpha-lactalbumin, beta-lactoglobulin and casein, using the Youden Index as a method. Conclusion: The diagnostic cutoff point for serum IgE levels for CM was 5.17 kUA/L and the mean wheal diameter, 3,5 mm. For the toleramce acquisition, the performance for mean wheal diameter and for specific IgE level for CM and fractions were not satisfactory. There was no statistically significant correlation between the initial symptoms reported by family members and those manifested during the OFC.
Descrição
Citação
FRANCO, Jackeline Motta. Alergia ou tolerância ao leite de vaca: novos cut-offs. 2015. 125 f. Tese (Doutorado em Pediatria e Ciências Aplicadas à Pediatria) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2015.