Vago A R, Andrade L O, Leite A A, d'Avila Reis D, Macedo A M, Adad S J, Tostes S, Moreira M C, Filho G B, Pena S D
Departamento de Morfologia, Instituto de Ciências Biológicas, Belo Horizonte, UFMG, Minas Gerais, Brazil.
Am J Pathol. 2000 May;156(5):1805-9. doi: 10.1016/s0002-9440(10)65052-3.
We have previously shown that a low-stringency single-specific primer-polymerase chain reaction (LSSP- PCR) is a highly sensitive and reproducible technique for the genetic profiling of Trypanosoma cruzi parasites directly in tissues from infected animals and humans. By applying LSSP-PCR to the study of the variable region of kinetoplast minicircle from T. cruzi, the intraspecific polymorphism of the kinetoplast-deoxyribonucleic acid (kDNA) sequence can be translated into individual kDNA signatures. In the present article, we report on our success using the LSSP-PCR technique in profiling the T. cruzi parasites present in the hearts of 13 patients with chagasic cardiopathy and in the esophagi of four patients (three of them with chagasic megaesophagus). In two patients, one with the cardiodigestive clinical form of Chagas disease and the other with cardiopathy and an esophageal inflammatory process, we could study both heart and esophagus and we detected distinct kDNA signatures in the two organs. This provides evidence of a differential tissue distribution of genetically diverse T. cruzi populations in chronic Chagas disease, suggesting that the genetic variability of the parasite is one of the determining factors of the clinical form of the disease.
我们之前已经表明，低严谨度单特异性引物聚合酶链反应（LSSP-PCR）是一种高度灵敏且可重复的技术，可直接对来自受感染动物和人类组织中的克氏锥虫寄生虫进行基因分型。通过将LSSP-PCR应用于克氏锥虫动基体小环可变区的研究，动基体脱氧核糖核酸（kDNA）序列的种内多态性可转化为个体kDNA特征。在本文中，我们报告了使用LSSP-PCR技术对13例恰加斯心肌病患者心脏和4例患者（其中3例患有恰加斯巨食管症）食管中的克氏锥虫寄生虫进行基因分型的成功案例。在两名患者中，一名患有恰加斯病的心脏消化系统临床类型，另一名患有心脏病和食管炎，我们对其心脏和食管都进行了研究，并在两个器官中检测到了不同的kDNA特征。这为慢性恰加斯病中基因多样的克氏锥虫群体在组织中的差异分布提供了证据，表明寄生虫的遗传变异性是该疾病临床类型的决定性因素之一。
