Santangelo R T, Chen S C, Sorrell T C, Wright L C
Centre for Infectious Diseases and Microbiology, University of Sydney, Westmead Hospital, Westmead, New South Wales, Australia.
Med Mycol. 2005 Jun;43(4):335-41. doi: 10.1080/13693780412331282331.
Secreted phospholipases are virulence factors of several fungi, including Cryptococcus neoformans. We describe for the first time the detection by ELISA of antibodies to cryptococcal phospholipase B in the serum of patients infected with C. neoformans or C. gattii. Sixty-nine sera from 25 patients with cryptococcosis, 23 patients with Candida infections and 26 with bacterial or viral infections were tested. The sensitivity of the ELISA in patients with cryptococcosis was 100% in immunocompetent hosts and 64.3% in immunosuppressed patients with cryptococcal meningitis. Absorbance readings were significantly higher in immunocompetent patients (P<0.001). Titres remained positive for up to 2 years. Positive results were noted in 10 episodes of invasive candidiasis, three patients colonised with Candida, and three cases of bacterial infection. Mean absorbance readings were significantly lower in patients with bacterial infection (P <0.001). We conclude that phospholipase B is produced in vivo during cryptococcal infection and that serum phospholipase B antibodies are a sensitive marker of present or past infection. Cross-reactivity of the ELISA with sera from patients with candidiasis indicates that common epitopes are present on cryptococcal and candidal phospholipase B, hence fungal phospholipase B may constitute a new therapeutic target.
分泌型磷脂酶是包括新型隐球菌在内的几种真菌的毒力因子。我们首次描述了通过酶联免疫吸附测定法（ELISA）检测新型隐球菌或格特隐球菌感染患者血清中针对隐球菌磷脂酶B的抗体。对来自25例隐球菌病患者、23例念珠菌感染患者以及26例细菌或病毒感染患者的69份血清进行了检测。该ELISA对免疫功能正常的隐球菌病患者的敏感性为100%，对免疫抑制的隐球菌性脑膜炎患者的敏感性为64.3%。免疫功能正常患者的吸光度读数显著更高（P<0.001）。抗体滴度在长达2年内保持阳性。在10例侵袭性念珠菌病、3例念珠菌定植患者以及3例细菌感染患者中检测到阳性结果。细菌感染患者的平均吸光度读数显著更低（P <0.001）。我们得出结论，在隐球菌感染期间磷脂酶B在体内产生，血清磷脂酶B抗体是当前或既往感染的敏感标志物。ELISA与念珠菌病患者血清的交叉反应表明，隐球菌和念珠菌的磷脂酶B存在共同表位，因此真菌磷脂酶B可能构成一个新的治疗靶点。
