Novels antigens of Leishmania (viannia) braziliensis as candidates for the inmmunodiagnosis of American Tegumentary Leishmaniasis

BRACAMONTE ME, CAJAL S, BIVONA AE, HOYOS C, JUAREZ M, PORTELLI M, CZENTNER L, ACUÑA L, UNCOS R, RAMOS F, SÁNCHEZ NEGRETE O, CIMINO R, BASOMBRÍO MA, BELLOMIO A, MALCHIODI EL, NASSER J, BARROSO P, CAZORLA SI, MARCO DJ

Congreso; 6th World Congress on Leishmaniasis; 2017

American tegumentary leishmaniasis (ATL) is endemic in ten provinces of Argentina. Leishmania (Viannia) braziliensis is the main causative agent in this area. Its diagnosis remains as challenge, despite the advances in the development of the molecular methods.Our main goal is to improve the diagnostic performance of ATL developing ELISA techniques with four recombinant antigens from a local strain of L. (V.) braziliensis expressed in bacterial systems: HATLbAg1 (MW: 49.76 kDa), HATLbAg2(MM 94.25), HAT-LbAg3 (MM 40.29), HAT-LbAg4 (MW: 34.9 kDa), or a soluble extract-enriched with membrane proteins of promastigotes of the same strain (ESM). Serum samples from 215 patients diagnosed as ATL cases by a combination of parasitological methods, PCR, Montenegro skin test, and clinical- Epidemiological criteria were included in this study. On the other hand, the absence of disease was represented by a set of 212 sera, from patients diagnosed as No ATL cases, seropositive for Chagas disease (CH), toxoplasmosis or syphilis, and donor subjects from LTA non-endemic areas.The estimated general sensitivities and specificities were 70.71 and 72.88% for HAT-LbAg1; 68.32 and 28.79% for HAT-LbAg2; 68.37 and 47.62% for HAT-LbAg3; 69.9 and 96.97% for HAT-LbAg4, while for the ESM they reached 91.27% and 66.23%, respectively.The specificities increase significantly when patients with Chagas disease are excluded. Importantly, HAT-LbAg4 and ESM ELISAs presented a relatively high diagnostic performance comparing with the parasitological and molecular methods currently used in the ATL diagnosis in the country. These results led us to proposed HAT-LbAg4 and ESM ELISAs as promising techniques for a multi-method diagnosis of this pathology