The increased presence of repetitive motifs in the KDDR-plus recombinant protein, a kinesin-derived antigen from < i > Leishmania infantum < /i > , improves the diagnostic performance of serological tests for human and canine visceral leishmaniasis

by Williane Fernanda Siqueira, Agostinho Gon çalves Viana, João Luís Reis Cunha, Leticia Mansur Rosa, Lilian Lacerda Bueno, Daniella Castanheira Bartholomeu, Mariana Santos Cardoso, Ricardo Toshio Fujiwara Visceral leishmaniasis (VL) is caused by protozoa belonging to theLeishmania donovani complex and is considered the most serious and fatal form among the different types of leishmaniasis, if not early diagnosed and treated. Among the measures of disease control stand out the management of infected dogs and the early diagnosis and appropriate treatment of human cases. Several antigens have been characterized for use in the VL diagnosis, among them are the recombinant kinesin-derived antigens fromL.infantum, as rK39 and rKDDR. The main difference between these antigens is the size of the non-repetitive kinesin region and the number of repetitions of the 39 amino acid degenerate motif (6.5 and 8.5 repeats in rK39 and rKDDR, respectively). This repetitive region has a high antigenicity score. To evaluate the effect of increasing the number of repeats on diagnostic performance, we designed the rKDDR-plus antigen, containing 15.3 repeats of the 39 amino acid degenerate motif, besides the absence of the non-repetitive portion fromL.infantum kinesin. Its performance was evaluated by enzyme-linked immunosorbent assay (ELISA) and rapid immunochromatographic test (ICT), and compared with the kinesin-derived antigens (rKDDR and rK39). In ELISA with human sera, all recombinant antig...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research