Patience C, Patton G S, Takeuchi Y, Weiss R A, McClure M O, Rydberg L, Breimer M E
Section of Virology, Institute of Cancer Research, Chester Beatty Laboratories, London, UK.
Lancet. 1998 Aug 29;352(9129):699-701. doi: 10.1016/S0140-6736(98)04369-4.
The xenotransplantation of organs and tissues, in particular those from pigs, is viewed as a means to alleviate the shortage of human donor organs and cells available for transplantation and also as a therapy for other diseases. The potential microbiological hazards of xenotransplantation have recently attracted much attention. One concern is over pig endogenous retroviruses (PERV). Until the possible consequences of infection by PERV are better understood it is unlikely that a significant number of porcine xenotransplants will proceed. However, a small number of patients have already been treated with or exposed to living porcine cells or tissue, and investigation of these patients may provide valuable information.
We took serial blood samples from two renal dialysis patients whose circulation had been linked extracorporeally to pig kidneys and tested them for pig DNA and PERV DNA by nested PCR. The patients' plasma was also tested for neutralising antibodies to two anthropotropic PERV strains.
Having established that the nested PCRs could detect single molecules of target sequence, we analysed DNA isolated from patients' peripheral blood mononuclear cells. We found no evidence of pig or PERV DNA in either patient, even in samples taken as early as 6 h after the perfusion. Furthermore, we found no evidence of seroconversion for PERV-specific antibodies.
The absence of porcine cells in the circulation of both patients, even in the samples taken soon after the perfusion experiment, suggests that any porcine cells dislodged from the kidney became rapidly sequestered from the circulation. Since cell-to-cell contact increases the efficiency of infection of PERV this removal of porcine cells may increase the risk of transmission of PERV to the xenograft recipient. We did not, however, detect indications of infection by PERV by PCR or neutralisation assay. The genetic and serological methods described here will be useful for detection of possible PERV infection in other patients.
器官和组织的异种移植，尤其是猪的器官和组织，被视为缓解可用于移植的人类供体器官和细胞短缺的一种手段，同时也被视为治疗其他疾病的一种方法。异种移植潜在的微生物危害最近引起了广泛关注。其中一个担忧是猪内源性逆转录病毒（PERV）。在更好地了解PERV感染的可能后果之前，大量的猪异种移植不太可能进行。然而，已经有少数患者接受了活猪细胞或组织的治疗或接触，对这些患者的调查可能会提供有价值的信息。
我们从两名肾透析患者身上采集了系列血样，这两名患者的循环系统已通过体外与猪肾相连，并通过巢式PCR检测其中的猪DNA和PERV DNA。还检测了患者血浆中针对两种嗜人PERV毒株的中和抗体。
在确定巢式PCR能够检测到目标序列的单分子后，我们分析了从患者外周血单个核细胞中分离的DNA。我们在两名患者中均未发现猪或PERV DNA的证据，即使是在灌注后最早6小时采集的样本中也是如此。此外，我们没有发现PERV特异性抗体血清转化的证据。
两名患者的循环系统中均未出现猪细胞，即使是在灌注实验后不久采集的样本中也是如此，这表明从肾脏脱落的任何猪细胞都迅速从循环中被隔离。由于细胞间接触会提高PERV感染的效率，这种猪细胞的清除可能会增加PERV传播给异种移植受者的风险。然而，我们通过PCR或中和试验未检测到PERV感染的迹象。本文所述的基因和血清学方法将有助于检测其他患者中可能的PERV感染。
