Identification of a Western Blot Pattern for the Specific Diagnosis of Trypanosoma cruzi Infection in Human Sera

Abstract

Abstract. A Western blot (WB) method using a lysate from Trypanosoma cruzi (Maracay strain) epimastigotes was evaluated. Serum samples from 37 patients with confirmed Chagas disease (cohort I), 27 Spanish patients with visceral leishmaniasis caused by Leishmania infantum (cohort II), and 28 Colombian patients with cutaneous leishmaniasis caused by L. panamensis and negative serology for Chagas disease (cohort III) were tested. The negative controls were 55 healthy seronegative subjects for T. cruzi and Leishmania; 28 of the negative controls were from a region endemic for Chagas disease and Leishmania (cohort IV), and 27 of the negative controls were from a non-endemic area for Leishmania and T. cruzi (cohort V). A homogeneous standard band pattern consisting of six antigenic bands corresponding to 28, 32, 38, 39, 40, and 48 kDa was recognized simultaneously for all Chagasic patients' sera. Sera from Leishmania-infected patients showed a heterogeneous band pattern that was easily differentiated from the pattern of patients with Chagas disease. WB with T. cruzi epimastigote antigen is an efficient method for diagnosis and may be used as an alternative to confirm T. cruzi and detect cross-reactivity with Leishmania.

Congenital Transmission of Trypanosoma cruzi in Non-Endemic Areas: Evaluation of a Screening Program in a Tertiary Care Hospital in Barcelona, Spain

“…In the absence of a reference gold standard test to confirm the diagnosis, we performed a qualitative immunological method (in-house Western blot) as has been suggested for serological confirmation by other authors. 15,16 In the case of a positive result in this test, the individual was considered infected to offer to the newborn the best diagnostic option.…”

Serological Diagnosis of Chronic Chagas Disease: Is It Time for a Change?

“…Samples with positive results for both assays were included in panel I, and sera with negative results were included in panel II. Samples with discordant results by these techniques were included in panel III, and they were tested by an in-house WB based on lysate T. cruzi epimastigotes, as described elsewhere (19). The final interpretation of panel III samples was based on results coinciding in two out of the three techniques performed; thus, 11 were considered negative and one was considered positive.…”

“…These samples had discordant results for ELISAc and ELISAr and were also tested by Western blotting (WB) (19) in order to get the final interpretation (11 considered negative and 1 positive). Clinical and epidemiological data were also considered for the selection.…”

“…There are two types of serological techniques for the detection of anti-T. cruzi antibodies: conventional tests using a whole-parasite antigen, and nonconventional tests based on recombinant antigens (17,18). Cross-reactivity, especially in conventional assays, is a particular problem for the serological diagnosis of Chagas disease in regions where leishmaniasis also occurs (15,19). Although numerous assays are available for diagnosing Chagas disease, no single test is considered the reference standard (19)(20)(21).…”

Tropical Diseases Screening in Immigrant Patients with Human Immunodeficiency Virus Infection in Spain

“…All discordant serum samples were tested by using an in-house Western blotting method with a lysate from Trypanosoma cruzi epimastigotes. 9 When a positive result was obtained, chest radiograph, electrocardiogram, echocardiogram, esophagogram, and barium enema were performed and specific treatment was offered.…”