Almeida I C, Covas D T, Soussumi L M, Travassos L R
Discipline of Cellular Biology, Federal University of São Paulo, Brazil.
Transfusion. 1997 Aug;37(8):850-7. doi: 10.1046/j.1537-2995.1997.37897424410.x.
Chagas' disease is transmitted to man either by the bite of insects harboring Trypanosoma cruzi or by the transfusion of blood from infected donors. The conventional serologic testing as presently used in blood banks in South America is unsatisfactory, because of a high number of inconclusive and false-positive results. Other methods such as polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) with recombinant antigens have been proposed, but inherent difficulties have so far precluded their adoption in the large-scale screening required by blood banks.
A highly sensitive and specific chemiluminescent ELISA using a purified trypomastigote glycoconjugate antigen and a complex epimastigote antigen was devised for the diagnosis of active T. cruzi infection.
Chemiluminescent ELISA was 100-percent sensitive in the diagnosis of 100 cases of confirmed Chagas' disease. Inconclusive results and false-positive reactions were eliminated in a panel of 115 sera. The specificity of the chemiluminescent ELISA was 100 percent with a purified trypomastigote glycoconjugate antigen and 99.7 percent with a complex epimastigote antigen when applied to 1000 normal human sera and 288 heterologous sera from patients with other infections, including leishmaniasis, and vaccinated individuals.
The chemiluminescent ELISAs provide a test that is highly sensitive (purified trypomastigote glycoconjugate and complex epimastigote antigens) and specific (purified trypomastigote glycoconjugate antigen) for Chagas' disease diagnosis. It can be used in blood bank screening and to monitor the treatment of patients undergoing chemotherapy.
恰加斯病可通过携带克氏锥虫的昆虫叮咬或受感染供血者的输血传播给人类。由于南美洲血库目前使用的传统血清学检测存在大量不确定和假阳性结果，因此并不令人满意。虽然有人提出了其他方法，如聚合酶链反应和使用重组抗原的酶联免疫吸附测定（ELISA），但由于存在固有困难，这些方法至今未能被血库大规模筛查所采用。
设计了一种使用纯化的锥鞭毛体糖缀合物抗原和复杂的前鞭毛体抗原的高灵敏度和特异性化学发光ELISA，用于诊断克氏锥虫的活动性感染。
化学发光ELISA在诊断100例确诊的恰加斯病时灵敏度为100%。在一组115份血清中消除了不确定结果和假阳性反应。当应用于1000份正常人血清以及288份来自其他感染（包括利什曼病）患者和接种疫苗个体的异种血清时，使用纯化的锥鞭毛体糖缀合物抗原的化学发光ELISA特异性为100%，使用复杂的前鞭毛体抗原的特异性为99.7%。
化学发光ELISA提供了一种对恰加斯病诊断具有高灵敏度（纯化的锥鞭毛体糖缀合物和复杂的前鞭毛体抗原）和特异性（纯化的锥鞭毛体糖缀合物抗原）的检测方法。它可用于血库筛查以及监测接受化疗患者的治疗情况。
