IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy.
Department of Clinical, Surgical, Diagnostics and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy.
Int J Mol Sci. 2023 May 19;24(10):9028. doi: 10.3390/ijms24109028.
The incidence of periprosthetic joint infections (PJIs) is ~2% of total procedures and it is expected to rise due to an ageing population. Despite the large burden PJI has on both the individual and society, the immune response to the most commonly isolated pathogens, i.e., and , remains incompletely understood. In this work, we integrate the analysis of synovial fluids from patients undergoing hip and knee replacement surgery with in-vitro experimental data obtained using a newly developed platform, mimicking the environment of periprosthetic implants. We found that the presence of an implant, even in patients undergoing aseptic revisions, is sufficient to induce an immune response, which is significantly different between septic and aseptic revisions. This difference is confirmed by the presence of pro- and anti-inflammatory cytokines in synovial fluids. Moreover, we discovered that the immune response is also dependent on the type of bacteria and the topography of the implant surface. While seems to be able to hide better from the attack of the immune system when cultured on rough surfaces (indicative of uncemented prostheses), reacts differently depending on the contact surface it is exposed to. The experiments we performed in-vitro also showed a higher biofilm formation on rough surfaces compared to flat ones for both species, suggesting that the topography of the implant could influence both biofilm formation and the consequent immune response.
人工关节周围感染（PJI）的发病率约占总手术的 2%，预计随着人口老龄化，这一比例还会上升。尽管 PJI 给个人和社会带来了巨大负担，但人们对最常见的分离病原体（即 和 ）的免疫反应仍了解甚少。在这项工作中，我们整合了髋关节和膝关节置换手术患者的滑膜液分析与使用新开发的平台获得的体外实验数据，该平台模拟了人工关节周围植入物的环境。我们发现，即使在进行无菌翻修的患者中，植入物的存在也足以引起免疫反应，而这种反应在感染性和无菌性翻修之间存在显著差异。滑膜液中促炎和抗炎细胞因子的存在证实了这种差异。此外，我们还发现，免疫反应也取决于细菌的类型和植入物表面的拓扑结构。虽然 在粗糙表面（提示非骨水泥假体）上培养时似乎能更好地躲避免疫系统的攻击，但它的反应取决于其暴露的接触表面而有所不同。我们在体外进行的实验还表明，两种细菌在粗糙表面上的生物膜形成均高于在光滑表面上的生物膜形成，这表明植入物的拓扑结构可能会影响生物膜形成和随后的免疫反应。
