Department of Biology and Medical Parasitology, Wroclaw Medical University, Poland.
Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Czech Republic.
Clin Infect Dis. 2018 Sep 28;67(8):1228-1234. doi: 10.1093/cid/ciy256.
Among patients with hip joint endoprosthesis, periprosthetic osteolysis is the most common complication following primary arthroplasty, and subsequent implant loosening is the leading cause of arthroplasty revision. Causes of stability loss, though not always evident, can be mechanical, allergic, or infectious (bacterial and fungal agents) in nature. Microsporidia, widespread opportunistic fungal pathogens that infect most human tissues, are a potential infectious cause of stability loss. Infections caused by Encephalitozoon species-one of the most common microsporidial pathogens in humans-primarily localize to intestinal and respiratory tracts, but can disseminate to tissues throughout the body.
We examined 53 immunocompetent patients, 23 after revision and 30 after primary hip arthroplasty, for infection by Encephalitozoon species. Periprosthetic tissue, urine sediments, and stool samples were tested by microscopic examination and genus-specific nested polymerase chain reaction followed by genotyping.
Ten patients had Encephalitozoon-positive periprosthetic tissues, 9 (39%) after revision and 1 (3.3%) after primary hip arthroplasty. Among the tissue-positive postrevision patients, 7 had a positive urine sample and 1 had a positive stool sample. Encephalitozoon cuniculi genotype II was identified in 88.8% (16/18) of samples. Two urine samples were positive for a novel Encephalitozoon species.
Encephalitozoon cuniculi should be considered as a cause of osteolysis in hip periprosthetic tissue, leading to a loss of implant stability.
在髋关节假体患者中，假体周围骨溶解是初次关节置换术后最常见的并发症，随后的假体松动是关节翻修的主要原因。尽管稳定性丧失的原因并不总是明显，但可能是机械性、过敏性或感染性（细菌和真菌病原体）。微孢子虫是一种广泛存在的机会性真菌病原体，感染人体的大多数组织，是稳定性丧失的潜在感染原因。脑炎原虫属物种引起的感染-人类最常见的微孢子虫病原体之一-主要定位于肠道和呼吸道，但可播散到全身组织。
我们检查了 53 名免疫功能正常的患者，其中 23 名是翻修后患者，30 名是初次髋关节置换后患者，以确定是否存在脑炎原虫属物种感染。通过显微镜检查和属特异性巢式聚合酶链反应（PCR）检测，对假体周围组织、尿液沉淀物和粪便样本进行检测，然后进行基因分型。
10 名患者的假体周围组织中存在脑炎原虫属阳性，其中 9 名（39%）为翻修后患者，1 名（3.3%）为初次髋关节置换后患者。在组织阳性的翻修后患者中，7 名患者的尿液样本呈阳性，1 名患者的粪便样本呈阳性。88.8%（16/18）的样本中鉴定出脑炎原虫属 II 型。2 份尿液样本对新型脑炎原虫属呈阳性。
脑炎原虫属应被视为髋关节假体周围组织骨溶解的原因之一，导致假体稳定性丧失。
