Heart Institute, InCor, University of São Paulo Medical School, São Paulo, Brazil.
J Heart Lung Transplant. 2011 Jul;30(7):799-804. doi: 10.1016/j.healun.2011.02.012. Epub 2011 Apr 9.
Chagas' disease reactivation (CDR) after heart transplantation is characterized by relapse of the infectious disease, with direct detection of Trypanosoma cruzi parasites in blood, cerebrospinal fluid, or tissues. CDR affecting the myocardium induces lymphocytic myocarditis and should be distinguished from acute cellular rejection in endomyocardial biopsy (EMB) specimens.
We performed retrospectively qualitative polymerase chain reaction for T cruzi DNA using 2 sets of primers targeting nuclear DNA (nDNA) or kinetoplast DNA (kDNA) in 61 EMB specimens of 11 chagasic heart transplant recipients who presented with CDR. Thirty-five EMB specimens were obtained up to 6 months before (pre-CDR group) and 26 up to 2 years after the diagnosis of CDR. The control group consisted of 6 chagasic heart transplant recipients with 18 EMB specimens who never experienced CDR.
Amplification of kDNA occurred in 8 of 35 (22.9%) EMB specimens of the pre-CDR group, in 5 of 18 (27.8%) of the control group, and in 17 of 26 (65.4%) EMB specimens obtained after the successful treatment of CDR. Amplification of nDNA occurred in 3 of 35 (8.6%) EMB specimens of the pre-CDR group, 0 of 18 (0%) of the control group, and 6 of 26 (23.1%) EMB specimens obtained after the successful treatment of CDR.
Amplification of kDNA in EMB specimens is not specific for the diagnosis of CDR, occurring also in patients with no evidence of CDR (control group). However, amplification of nDNA occurred in a few EMB specimens obtained before CDR, but in none of the control group specimens. Qualitative PCR for T cruzi DNA in EMB specimens should not be used as a criterion for cure of CDR because it can persist positive despite favorable clinical evolution of the patients.
心脏移植后恰加斯病再激活（CDR）的特征是传染病复发，血液、脑脊液或组织中直接检测到克氏锥虫寄生虫。影响心肌的 CDR 会引起淋巴细胞性心肌炎，应与心肌内膜活检（EMB）标本中的急性细胞排斥反应区分开来。
我们对 11 例发生 CDR 的恰加斯病心脏移植受者的 61 份 EMB 标本进行了核 DNA（nDNA）或动基体 DNA（kDNA）的 2 套引物的定量聚合酶链反应（PCR）。35 份 EMB 标本是在 CDR 诊断前 6 个月内（CDR 前组）获得的，26 份是在 CDR 诊断后 2 年内获得的。对照组由 6 例从未经历过 CDR 的恰加斯病心脏移植受者的 18 份 EMB 标本组成。
CDR 前组的 35 份 EMB 标本中有 8 份（22.9%）扩增 kDNA，对照组的 18 份标本中有 5 份（27.8%），CDR 成功治疗后获得的 26 份 EMB 标本中有 17 份（65.4%）扩增 kDNA。CDR 前组的 35 份 EMB 标本中有 3 份（8.6%）扩增 nDNA，对照组的 18 份标本中无（0%），CDR 成功治疗后获得的 26 份 EMB 标本中有 6 份（23.1%）扩增 nDNA。
EMB 标本中 kDNA 的扩增不能特异性诊断 CDR，也发生在无 CDR 证据的患者（对照组）中。然而，在 CDR 发生前的少数 EMB 标本中扩增了 nDNA，但对照组的标本中均未扩增。EMB 标本中克氏锥虫 DNA 的定性 PCR 不应用于 CDR 治愈的标准，因为尽管患者的临床状况良好，但它可能持续呈阳性。
