Performance of different Trypanosoma cruzi antigens in the diagnosis of Chagas disease in patients with American cutaneous leishmaniasis from a co-endemic region in Argentina

OBJECTIVE To determine the ability of recombinant antigens to detect cases of infection with Trypanosoma cruzi among cases of infection with Leishmania spp. by serological methods. METHODS Sera from 41 patients infected with Leishmania spp. were evaluated with ELISA using single (FRA, CP1 and TSSAVI) or pooled (commercial Rec-ELISA) recombinant proteins or homogenate antigens (commercial H-ELISA). As there is no gold standard antigen to discriminate Chagas disease from leishmaniasis, the correlation of results between defined antigens and the homogenate was made with Kappa Index (KI), the level of correlation considered being used as a criterion of specificity. RESULTS Single recombinant antigens and Rec-ELISA showed good correlation (KI>0.8). A low correlation (KI<0.66) was observed between the results from single recombinant antigens or the commercial recombinant kit and H-ELISA. CONCLUSIONS The highly correlated results between T.cruzi single or pooled recombinant proteins are indicative of the usefulness of recombinant antigens for Chagas diagnosis. Our results also indicate that in the city of Oran in Argentina, between 12% and 17% of patients with leishmaniasis are also infected with Chagas disease. The high KI values between TSSAVI and the other recombinant proteins suggest that in these patients, the infection may be caused by T.cruzi II and/or V and/or VI lineages.