Dos Santos Priscila Oliveira, Rodrigues Anderson Messias, Fernandes Geisa Ferreira, da Silva Silvia Helena Marques, Burger Eva, de Camargo Zoilo Pires
Federal University of São Paulo, Department of Microbiology, Immunology and Parasitology, Cell Biology Division, São Paulo, Brazil.
Evandro Chagas Institute, Bacteriology and Mycology Division, Ananindeua, Pará, Brazil.
PLoS Negl Trop Dis. 2015 Feb 13;9(2):e0003516. doi: 10.1371/journal.pntd.0003516. eCollection 2015 Feb.
Paracoccidioidomycosis (PCM) is a life-threatening systemic disease and is a neglected public health problem in many endemic regions of Latin America. Though several diagnostic methods are available, almost all of them present with some limitations.
METHOD/PRINCIPLE FINDINGS: A latex immunoassay using sensitized latex particles (SLPs) with gp43 antigen, the immunodominant antigen of Paracoccidioides brasiliensis, or the monoclonal antibody mAb17c (anti-gp43) was evaluated for antibody or antigen detection in sera, cerebrospinal fluid (CSF), and bronchoalveolar lavage (BAL) from patients with PCM due to P. brasiliensis. The gp43-SLPs performed optimally to detect specific antibodies with high levels of sensitivity (98.46%, 95% CI 91.7-100.0), specificity (93.94%, 95% CI 87.3-97.7), and positive (91.4%) and negative (98.9%) predictive values. In addition, we propose the use of mAb17c-SLPs to detect circulating gp43, which would be particularly important in patients with immune deficiencies who fail to produce normal levels of immunoglobulins, achieving good levels of sensitivity (96.92%, 95% CI 89.3-99.6), specificity (88.89%, 95% CI 81.0-94.3), and positive (85.1%) and negative (97.8%) predictive values. Very good agreement between latex tests and double immune diffusion was observed for gp43-SLPs (k = 0.924) and mAb17c-SLPs (k = 0.850), which reinforces the usefulness of our tests for the rapid diagnosis of PCM in less than 10 minutes. Minor cross-reactivity occurred with sera from patients with other fungal infections. We successfully detected antigens and antibodies from CSF and BAL samples. In addition, the latex test was useful for monitoring PCM patients receiving therapy.
CONCLUSIONS/SIGNIFICANCE: The high diagnostic accuracy, low cost, reduced assay time, and simplicity of this new latex test offer the potential to be commercialized and makes it an attractive diagnostic assay for use not only in clinics and medical mycology laboratories, but mainly in remote locations with limited laboratory infrastructure and/or minimally trained community health workers.
副球孢子菌病(PCM)是一种危及生命的全身性疾病,在拉丁美洲的许多流行地区是一个被忽视的公共卫生问题。尽管有几种诊断方法可用,但几乎所有方法都存在一些局限性。
方法/主要发现:使用致敏乳胶颗粒(SLP)与gp43抗原(巴西副球孢子菌的免疫显性抗原)或单克隆抗体mAb17c(抗gp43)进行乳胶免疫测定,以检测巴西副球孢子菌所致PCM患者血清、脑脊液(CSF)和支气管肺泡灌洗(BAL)中的抗体或抗原。gp43-SLP在检测特异性抗体方面表现最佳,具有高灵敏度(98.46%,95%可信区间91.7 - 100.0)、特异性(93.94%,95%可信区间87.3 - 97.7)以及阳性预测值(91.4%)和阴性预测值(98.9%)。此外,我们建议使用mAb17c-SLP检测循环中的gp43,这对于免疫缺陷且无法产生正常水平免疫球蛋白的患者尤为重要,其灵敏度(96.92%,95%可信区间89.3 - 99.6)、特异性(88.89%,95%可信区间81.0 - 94.3)以及阳性预测值(85.1%)和阴性预测值(97.8%)均达到良好水平。观察到gp43-SLP(k = 0.924)和mAb17c-SLP(k = 0.850)的乳胶试验与双向免疫扩散之间具有很好的一致性,这进一步证明了我们的试验在不到10分钟内快速诊断PCM的实用性。与其他真菌感染患者的血清存在轻微交叉反应。我们成功从CSF和BAL样本中检测到抗原和抗体。此外,乳胶试验对监测接受治疗的PCM患者有用。
结论/意义:这种新的乳胶试验具有高诊断准确性、低成本、检测时间短和操作简单等优点,具有商业化潜力,不仅使其成为临床和医学真菌学实验室有吸引力的诊断方法,而且主要适用于实验室基础设施有限和/或社区卫生工作者培训不足的偏远地区。