Paula Vaz Cardoso Ludimila, Dias Ronaldo Ferreira, Freitas Aline Araújo, Hungria Emerith Mayra, Oliveira Regiane Morillas, Collovati Marco, Reed Steven G, Duthie Malcolm S, Martins Araújo Stefani Mariane
Tropical Pathology and Public Health Institute, Federal University of Goiás, 235th Street, Setor Universitário, 74605-050 Goiânia-Goiás, Brazil.
BMC Infect Dis. 2013 Oct 23;13:497. doi: 10.1186/1471-2334-13-497.
Despite efforts to eliminate leprosy as public health problem, delayed diagnosis and disabilities still occur in many countries. Leprosy diagnosis remains based on clinical manifestations and the number of clinicians with expertise in leprosy diagnosis is in decline. We have developed a new immunochromatographic test with the goal of producing a simple and rapid system that can be used, with a minimal amount of training, to provide an objective and consistent diagnosis of multibacillary leprosy.
The test immobilizes two antigens that have been recognized as excellent candidates for serologic diagnosis (the PGL-I mimetic, ND-O, and LID-1), on a nitrocellulose membrane. This allows the detection of specific IgM and IgG antibodies within 20 minutes of the addition of patient sera. Furthermore, we coupled the NDO-LID® rapid tests with a new cell phone-based test reader platform (Smart Reader®) to provide objective interpretation that was both quantifiable and consistent.
Direct comparison of serologic responses indicated that the rapid test detected a greater proportion of leprosy patients than a lab-based PGL-I ELISA. While positive responses were detected by PGL-I ELISA in 83.3% of multibacillary patients and 15.4% of paucibacillary patients, these numbers were increased to 87% and 21.2%, respectively, when a combination of the NDO-LID® test and Smart Reader® was used. Among multibacillary leprosy the sensitivity of NDO-LID® test assessed by Smart Reader® was 87% (95% CI, 79.2-92.7%) and the specificity was 96.1% (95% CI, 91.7- 98.6%). The positive predictive value and the negative predictive value of NDO-LID® tests were 94% (95% CI, 87.4-97.8%) and 91.4% (95% CI, 85.9-95.2%), respectively.
The widespread provision of rapid diagnostic tests to facilitate the diagnosis or prognosis of multibacillary leprosy could impact on leprosy control programs by aiding early detection, directing appropriate treatment and potentially interrupting Mycobacterium leprae transmission.
尽管各国努力将麻风作为公共卫生问题消除，但在许多国家仍存在诊断延迟和残疾现象。麻风诊断仍基于临床表现，且具备麻风诊断专业知识的临床医生数量正在减少。我们开发了一种新的免疫层析检测方法，目标是打造一个简单快速的系统，经过最少的培训即可使用，以对多菌型麻风进行客观且一致的诊断。
该检测方法将两种已被确认为血清学诊断优秀候选抗原（PGL-I模拟物ND-O和LID-1）固定在硝酸纤维素膜上。这使得在加入患者血清后20分钟内就能检测到特异性IgM和IgG抗体。此外，我们将NDO-LID®快速检测与一个基于手机的新型检测读数器平台（智能读数器®）相结合，以提供可量化且一致的客观解读。
血清学反应的直接比较表明，与基于实验室的PGL-I ELISA相比，该快速检测能检测出更大比例的麻风患者。PGL-I ELISA在83.3%的多菌型患者和15.4%的少菌型患者中检测到阳性反应，而当使用NDO-LID®检测和智能读数器®组合时，这些数字分别增至87%和21.2%。在多菌型麻风患者中，通过智能读数器®评估的NDO-LID®检测灵敏度为87%（95%置信区间，79.2 - 92.7%），特异性为96.1%（95%置信区间，91.7 - 98.6%）。NDO-LID®检测的阳性预测值和阴性预测值分别为94%（95%置信区间，87.4 - 97.8%）和91.4%（95%置信区间，85.9 - 95.2%）。
广泛提供快速诊断检测以促进多菌型麻风的诊断或预后评估，可通过帮助早期发现、指导适当治疗并可能阻断麻风分枝杆菌传播，对麻风控制项目产生影响。
