Polimorfismo de interleucina 10 e persistência da alergia ao leite de vaca / Interleukin 10 polymorphism and cow's milk allergy persistence

Justificativa: Alergia à leite de vaca (ALV) afeta 2,5% das crianças menores de 3 anos, sendo que a maioria dos pacientes desenvolvem tolerância até 3 anos de idade. No entanto, na ALV IgE-mediada cerca de 35% desses pacientes persistem sintomáticos. O objetivo deste estudo foi determinar se polimorfismos no gene que codifica a IL-lO estariam associados à ALV persistente mediada por IgE em crianças brasileiras com cinco anos. Métodos: Neste estudo, 50 pacientes com ALV com idade de 5 anos foram avaliados, sendo 36 persistentes e 14 tolerantes. Um grupo controle composto por 224 indivíduos saudáveis foi incluído no estudo. Os critérios de diagnóstico foram: anafilaxia desencadeada pelo leite de vaca (LV) ou reação clínica imediata para o Teste Duplo Cego Placebo Controlado (DCPC). A tolerância foi definida como a ausência de resposta clínica ao DBPC ou durante a exposição acidental ao LV. Os dados utilizados na análise dos resultados clínicos e laboratoriais foram aqueles na época do diagnóstico. Todos os pacientes e os controles foram avaliados pelo PCR-RFLP para os seguintes polimorfismos de IL-lO: -3575A/T, -2849A/G, -763A/C, 592C/A e pelo PCR-SSP para o polimorfismo IL-lO -1082G/A. Resultados: Houve diferença estatisticamente significante apenas para o polimorfismo IL-l0 -1082G/A, sendo a homozigose para o alelo A estatisticamente significante comparando-se pacientes do grupo ALV total versus grupo controles (p = 0,027) e a homozigose para o alelo G entre grupo persistente versus grupo controle (p = 0,001). Conclusão: Nos pacientes avaliados, o polimorfismo de IL-lO 1082G/A foi associado ao fenótipo da ALV persistente.

Rationale: Cow's milk allergy (CMA) affects 2.5% of children under 3 years and the majority of patients develop tolerance at age 3. However, in IgE-mediate CMA about 35% of them persist symptomatic. The aim of this study is to determine if interleukin 10 (IL-l0) gene polymorphisms are associated to persistent IgE-mediated CMA in Brazilian children at age five. Methods: In this study, 50 IgE-mediated CMA patients were evaluated at age 5, being 36 persistent and 14 tolerant to cow's milk (CM). A control group with 224 healthy individuals was included. The diagnosis criteria were: anaphylaxis triggered by CM or immediate clinical reaction to double blind placebo control test (DBPCT). The tolerance was defined as the absence of clinical response to the DBPCT or during the accidental exposure to CM. The data used about clinical and laboratorial findings were from the diagnosis work up. All patients and the controls were typed by PCR-RFLP for the following IL-l0 polymorphisms: -3575A/T, -2849A/G, -763A/C, -592C/A and by SSP for -1082G/A. Results: There was differences statistically significant only for IL-lO polymorphisms -1082G/A. Homozygosis to A allele was statistically significant comparing CMA total patients with controls (p = 0.027) and homozygosis to G allele between persistent group versus control group (p = 0.001). Conclusion: In these patients evaluated the IL-lO -1082G/A polymorphism was associated to CMA persistent phenotype.

Adrenergic stimulation promotes T-wave alternans and arrhythmia inducibility in a TNF-alpha genetic mouse model of congestive heart failure.

T-wave alternans (TWA) is a proarrhythmic repolarization instability that is common in congestive heart failure (CHF). Although transgenic mice are commonly used to study the mechanisms of arrhythmogenesis in CHF, little is known about the dynamics of TWA in these species. We hypothesized that TWA is present in a TNF-alpha model of CHF and can be further promoted by adrenergic stimulation. We studied 16 TNF-alpha mice and 12 FVB controls using 1) in vivo intracardiac electrophysiological testing and 2) ambulatory telemetry during 30 min before and after an intraperitoneal injection of isoproterenol. TWA was examined using both linear and nonlinear filtering applied in the time domain. In addition, changes in the mean amplitude of the T wave and area under the T wave were computed. During intracardiac electrophysiological testing, none of the animals had TWA or inducible arrhythmias before the injection of isoproterenol. After the injection, sustained TWA and inducible ventricular tachyarrhythmias were observed in TNF-alpha mice but not in FVB mice. In ambulatory telemetry, before the isoproterenol injection, the cardiac cycle length (CL) was longer in TNF-alpha mice than in FVB mice (98 +/- 9 and 88 +/- 3 ms, P = 0.04). After the injection of isoproterenol, the CL became 8% and 6% shorter in TNF-alpha and FVB mice (P < 10(-4)); however, the 2% difference between the groups in the magnitude of CL changes was not significant. In TNF-alpha mice, the magnitude of TWA was 1.5-2 times greater than in FVB mice both before and after the isoproterenol injection. The magnitude of TWA increased significantly after the isoproterenol injection compared with the baseline in TNF-alpha mice (P = 0.003) but not in FVB mice. The mean amplitude of the T wave and area under the T wave increased 60% and 80% in FVB mice (P = 0.006 and 0.009) but not in TNF-alpha mice. In conclusion, TWA is present in a TNF-alpha model of CHF and can be further promoted by adrenergic stimulation, along with the enhanced susceptibility for ventricular arrhythmias.