Abstract:
Urinary tract infections (UTI) are an important clinical problem in kidney transplant recipients (KTR). Asymptomatic bacteriuria (ASB) is frequent in these patients and often resolved by the immune system, but a significant proportion may progress to complicated UTI, which may compromise allograft function and survival. It is essential to determine the involvement of the immune system in the infectious process. Dendritic cells (DCs) are recognised as playing a pivotal role in initiating inflammatory responses capable of priming antigen-specific T cells, a crucial step in determining the fate of local inflammation. Little is known about their role in the control of UTI. In this brief communication, we report an incidental finding in a group of 16 stable KTR in which monocyte-derived dendritic cells (ModDCs), analysed by flow cytometry, were found in urine of patients with ASB and high bacterial counts >107 cfu/ml. Within this group, one patient developed pyelonephritis in the following days. These findings suggest that the immune system, in particular DCs, may be recruited during the course of a UTI and, to our knowledge, present for the first time evidence that inflammatory ModDCs can be detected in urine. Their frequency may reflect the degree of infection. This finding suggests the potential for exploring whether these cells may be useful in distinguishing between pathogenic ASB and those that can be resolved by the immune system.
摘要:
尿路感染(UTI)是肾移植受者(KTR)的重要临床问题。无症状性菌尿(ASB)在这些患者中很常见,通常由免疫系统解决。但是很大一部分可能会进展到复杂的UTI,这可能会损害同种异体移植物的功能和存活。确定免疫系统在感染过程中的参与至关重要。树突状细胞(DC)被认为在启动能够引发抗原特异性T细胞的炎症反应中起关键作用。决定局部炎症命运的关键步骤。人们对它们在控制UTI中的作用知之甚少。在这个简短的交流中,我们报告了一组16个稳定的KTR中的偶然发现,其中单核细胞衍生的树突状细胞(ModDC),通过流式细胞术分析,在ASB和高细菌计数>107cfu/ml的患者的尿液中发现。在这个群体中,一名患者在接下来的几天出现了肾盂肾炎。这些发现表明免疫系统,特别是DC,可以在UTI的过程中招募,根据我们的知识,首次有证据表明可以在尿液中检测到炎症性ModDC。它们的频率可以反映感染的程度。这一发现表明了探索这些细胞是否可用于区分致病性ASB和可由免疫系统解决的细胞的潜力。