Guirro Mirian, de Souza Renato Lopes, Piazza Roxane M F, Guth Beatriz E C
Department of Microbiology, Immunology, Parasitology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
Vet Immunol Immunopathol. 2013 Mar 15;152(1-2):121-5. doi: 10.1016/j.vetimm.2012.09.016. Epub 2012 Sep 26.
Enterohemorrhagic Escherichia coli (EHEC) strains can cause hemolytic uremic syndrome (HUS), a leading cause of childhood renal failure. The adhesin intimin and the secreted proteins A (EspA) and B (EspB) contribute to the occurrence of EHEC attaching and effacing lesions. In this study, immunoblot assays were performed to determine immunoglobulin G (IgG) antibodies reactive with these proteins in sera from 13 children diagnosed with HUS and in sera from 54 healthy Brazilian children. In general, high frequencies of serum IgG antibodies reactive with EspA, EspB and the conserved region of intimin were observed in both HUS patients and controls with no statistically significant differences. However, a marked difference in immune response to these proteins was observed in HUS patients compared to controls in infants less than two years of age. In addition, IgG against the variable region of intimin γ was more frequently detected in HUS patients than in children with no signs of infection (p<0.05) regardless of age, suggesting that the detection of antibodies directed to the variable region of intimin γ can be useful in serodiagnostic tests of EHEC-infected patients. The immune response against intimin and structural proteins encoded by the locus of enterocyte effacement pathogenicity island in patients with HUS has previously not been described in Brazil. The results presented here may contribute to the development of diagnostic tools and complement information concerning EHEC epidemiology in our setting.
肠出血性大肠杆菌（EHEC）菌株可导致溶血尿毒综合征（HUS），这是儿童肾衰竭的主要原因。黏附素intimin以及分泌蛋白A（EspA）和B（EspB）促成了EHEC黏附性和抹除性损伤的发生。在本研究中，进行了免疫印迹分析，以确定13名诊断为HUS的儿童血清以及54名健康巴西儿童血清中与这些蛋白发生反应的免疫球蛋白G（IgG）抗体。总体而言，在HUS患者和对照组中均观察到与EspA、EspB以及intimin保守区发生反应的血清IgG抗体的高频率，且无统计学显著差异。然而，与对照组相比，在小于两岁的婴儿HUS患者中观察到对这些蛋白的免疫反应存在显著差异。此外，无论年龄大小，HUS患者中针对intiminγ可变区的IgG检测频率均高于无感染迹象的儿童（p<0.05），这表明检测针对intiminγ可变区的抗体可用于EHEC感染患者的血清诊断测试。此前在巴西尚未描述过HUS患者针对intimin以及肠细胞抹除致病岛位点编码的结构蛋白的免疫反应。此处呈现的结果可能有助于开发诊断工具，并补充我们地区有关EHEC流行病学的信息。
