Mendoza Leonel, Newton Joseph C
Medical Technology Program, Microbiology and Molecular Genetics, Michigan State University, East Lansing 48824-1031, USA.
Med Mycol. 2005 Sep;43(6):477-86. doi: 10.1080/13693780500279882.
Although infections caused by the straminipilan pathogen Pythium insidiosum were described in 19th century, it has been only recently that its epidemiology, immunology, treatment and other important traits were extensively studied. These studies were of paramount importance to theorize about the ecological niche for this pathogen, its host-parasite relationships, the antigens used for diagnosis, and the management of the infection using immunotherapy. P. insidiosum triggers in the infected host a T helper 2 [Th2] subset with an inflammatory reaction composed mainly of eosinophils and mast cells. These cells degranulate around the hyphal elements of P. insidiosum where a Splendore-Hoeppli-like reaction develops. In horses this reaction is so intensive that firm concretions called 'kunkers' develop. These data indicated that this pathogen might have developed an evolutionary strategy to conceal important antigens from the host immune system. Immunotherapy, a treatment approach that relies on the injection of antigens of P. insidiosum from in vitro cultures, has been successfully used in humans and horses to manage this disease. A switch from a Th2 to Th1 response is postulated as the most likely explanation of the curative properties of this approach. This review provides details on the serological, immunological, and immunotherapeutic methodologies used to diagnose and treat the infections caused by this pathogen.
尽管由卵菌纲病原体隐孢疫霉引起的感染在19世纪就有描述，但直到最近其流行病学、免疫学、治疗及其他重要特征才得到广泛研究。这些研究对于推断该病原体的生态位、宿主-寄生虫关系、用于诊断的抗原以及使用免疫疗法治疗感染至关重要。隐孢疫霉在受感染宿主中引发以嗜酸性粒细胞和肥大细胞为主的炎症反应的辅助性T细胞2（Th2）亚群。这些细胞在隐孢疫霉的菌丝周围脱颗粒，形成类似斯普伦多雷-赫普利反应。在马身上，这种反应非常强烈，会形成称为“肿块”的坚实凝块。这些数据表明，该病原体可能已经形成了一种进化策略，以向宿主免疫系统隐藏重要抗原。免疫疗法是一种依靠注射体外培养的隐孢疫霉抗原的治疗方法，已成功用于人类和马匹治疗这种疾病。从Th2反应转变为Th1反应被认为是这种方法具有治疗效果的最可能解释。本综述详细介绍了用于诊断和治疗由该病原体引起的感染的血清学、免疫学和免疫治疗方法。
