Gómez B L, Figueroa J I, Hamilton A J, Ortiz B, Robledo M A, Hay R J, Restrepo A
Corporación para Investigaciones Biológicas, Medellín, Colombia.
J Clin Microbiol. 1997 Dec;35(12):3278-83. doi: 10.1128/jcm.35.12.3278-3283.1997.
The precise diagnosis of paracoccidioidomycosis, in most cases, is established by direct methods and indirect immunological tests. The latter method is reliant on the identification of the host's humoral responses, which are usually impaired or absent in patients with severe juvenile forms of the disease and in immunocompromised patients. Determining disease activity or assessing treatment responses by measuring antibody levels is difficult, since antibody titer may remain elevated or persist at stationary levels, even in the presence of clinical improvement. Consequently, there is a need for alternative tests aimed at the identification of circulating antigens. A modification of the standard hybridoma production method was used to raise a panel of murine monoclonal antibodies (MAbs) against the yeast form of Paracoccidioides brasiliensis. Of these, MAb PIB, directed against an 87-kDa determinant, was used to develop an inhibition ELISA (inh-ELISA) capable of detecting as little as 5.8 ng of circulating antigen per ml of serum. Sera from 46 patients with paracoccidioidomycosis or other mycoses and sera from healthy individuals were evaluated by the inh-ELISA; overall sensitivity was 80.4% (37 of 46 paracoccidioidomycosis patients tested positive), and specificity compared with that of normal controls from areas of endemicity was 81.4%. The inh-ELISA detected circulating antigen in 100% of patients with the acute form of paracoccidioidomycosis and in 83.3 and 60% of patients with the chronic multifocal and unifocal forms of paracoccidioidomycosis according to the patients' clinical presentation. These results indicate that the inh-ELISA with MAb PIB is effective in the detection of circulating antigen and that this test may be useful for monitoring responses to treatment and establishing disease prognoses.
在大多数情况下，副球孢子菌病的准确诊断是通过直接方法和间接免疫测试来确定的。后一种方法依赖于对宿主体液反应的识别，而在患有严重青少年型疾病的患者和免疫功能低下的患者中，这种反应通常受损或缺失。由于即使在临床症状改善的情况下，抗体滴度仍可能保持升高或维持在稳定水平，因此通过测量抗体水平来确定疾病活动或评估治疗反应很困难。因此，需要有旨在识别循环抗原的替代测试。采用标准杂交瘤生产方法的一种改进方法来制备一组针对巴西副球孢子菌酵母形式的鼠单克隆抗体（MAb）。其中，针对87-kDa决定簇的单克隆抗体PIB被用于开发一种抑制ELISA（inh-ELISA），该方法能够检测每毫升血清中低至5.8 ng的循环抗原。通过inh-ELISA对46例副球孢子菌病患者或其他真菌病患者的血清以及健康个体的血清进行了评估；总体敏感性为80.4%（46例副球孢子菌病患者中有37例检测呈阳性），与地方病流行区正常对照相比，特异性为81.4%。根据患者的临床表现，inh-ELISA在100%的急性副球孢子菌病患者、83.3%的慢性多灶性副球孢子菌病患者和60%的慢性单灶性副球孢子菌病患者中检测到了循环抗原。这些结果表明，使用单克隆抗体PIB的inh-ELISA在检测循环抗原方面是有效的，并且该测试可能有助于监测治疗反应和确定疾病预后。
