Torres-Gutiérrez E, Barrios-Palacios D, Ruiz-Hernández AL, Cabrera-Bravo M, Guevara-Gómez Y, Rojas-Wastavino G, Salazar-Schettino PM, Bucio-Torres MI

Language: Spanish
References: 14
Page: 6-13
PDF size: 352.02 Kb.

ABSTRACT

Introduction: Conventional serology was used for the detection of Trypanosoma cruzi infection, with diverse sensitivity and specificity results. Due to the number of samples with doubtful results, it is necessary to develop additional confirmation tests such as the immunoblot. Objective: The aim of this study was identify major immunogenic proteins of T. cruzi isolate and establish criteria for immunoblot positivity with diagnostic purposes. Methods: Immunoblot initial standardization was performed, determining optimal concentrations of antigen, serum, and second antibody. Thirty-five positive and thirty negative sera were assayed to evaluate different criteria of positivity and determine which provides greater sensitivity and specificity. Results: Immunoblot of T. cruzi positive sera shared a rich pattern of components with molecular weights between 10-250 kDa. Twelve components had a recognition rate higher than 50%, of which the polypeptides of 27, 32, 34, and 38 kDa were close to 100%. Of the positivity criteria evaluated, the recognition of the components of 27 and 32 kDa provided sensitivity and specificity of 100%. Discussion: The Immunoblot is suitable for confirmation of infection by T. cruzi, so it is strongly recommended for confirmation and discrimination of discordant cases.

REFERENCES

1. UNAM, Facultad de Medicina, OPS. Manual para el Diagnóstico de la Infección por Trypanosoma cruzi. México: OPS/OMS; 2006 .

2. Reiche EM, Cavazzana M, Okamura H, Tagata EC, Jankevicius SI, Jankevicius JV. Evaluation of the western blot in the confirmatory serologic diagnosis of Chagas’ disease. Am J Trop Med Hyg. 1998;59(5): 750-6.

3. World Health Organization. Reporte sobre la Enfermedad de Chagas. Argentina; 2007. [Internet] Disponible en: http://http//whqlibdoc.who.int/ hq/2007/TDR_SWG_09_spa.pdf.

4. Sánchez B, Monteón V, Reyes PA, Espinoza B. Standardization of micro- enzyme-linked immunosorbent assay (ELISA) and Western blot for detection of Trypanosoma cruzi antibodies using extracts from Mexican strains as antigens. Arch Med Res. 2001;32(5):382-8.

5. Rangel-Flores H, Sánchez B, Mendoza-Duarte J, et al. Serologic and parasitologic demonstration of Trypanosoma cruzi infections in an urban area of central Mexico: correlation with electrocardiographic alterations. Am J Trop Med Hyg. 2001;65(6):887-95.

6. Bucio MI, Cabrera M, Segura EL, Zenteno E, Salazar-Schettino PM. Identification of immunodominant antigens in Mexican strains of Trypanosoma cruzi. Immunol Invest. 1999;28(4):257-68.

7. Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970;227(5259):680-5.

8. Towbin H, Staehelin T, Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci USA. 1979;76(9):4350-4.

9. Teixeira MG, Borges-Pereira J, Netizert E, Souza ML, Peralta JM. Development and evaluation of an enzyme linked immunotransfer blot technique for serodiagnosis of Chagas’ disease. Trop Med Parasitol. 1994; 45(4):308-12.

10. O’Daly JA, Carrasco H, Fernandez V, Rodríguez MB. Comparison of chagasic and non-chagasic myocardiopathies by ELISA and immunoblotting with antigens of Trypanosoma cruzi and Trypanosoma rangeli. Acta Tropica. 1994;56(4):265-87.

11. De Lima Rivero AR, Farías Tamoy MN, Tortolero Leal E, Navarro Aguilera MC, Contreras Alvarez VT. Partial purification and use of Trypanosoma cruzi glycosidic fractions for Chagas disease diagnosis. Acta Cient Venez. 2001;52(4):235-47.

12. Nogueira N, Chaplan S, Tydings JD, Unkeless J, Cohn Z. Trypanosoma cruzi. Surface antigens of blood and culture forms. J Exp Med. 1981 Mar 1;153(3):629-39.

13. Scharfstein J, Rodrigues M, Alves C, de Souza W, Previato J. Trypanosoma cruzi: description of a highly purified surface antigen defined by human antibodies. J Immunol. 1983;131(2):972-6.

14. Silber AM, Mancipar IS, Roodvelt C, Cabeza Meckert P, Laguens R, Marcipara AJ. Trypanosoma cruzi: identification of a galactose-binding protein that binds to cell surface of human erythrocytes and is involved in cell invasion by the parasite. Exp Parasitol. 2002;100(4):217-25.