Padronização de um iELISA com emprego da proteína recombinante p26 do vírus da anemia infecciosa equina produzida em Pichia pastoris

Abstract

Equine infectious anemia (EIA ) is a difficult control disease, characterized by a wide variety of clinical signs that appear in recurring and dynamic cycles. According with Brazilian law, positive animals in the agar gel immunodiffusion (AGID) must be sacrificed, therefore, there is a dependency relationship between diagnosis and disease control. For reasons related with peculiar characteristics of the infection and immune response EIA, this test may not be able to detect newly infected animals. Considering that the IDGA has a decisive role in the fate of the animal tested, we study the possibility of complementing the diagnostic with the ELISA. In this context, in a previous study, we developed the recombinant protein p26 (rp26) from VAIE, produced in yeast Pichia pastoris, aiming their use as antigens in immunoassays . The purpose of the current study was to test this antigen in AGID, ELISA and Western blot, standardize an indirect ELISA (iELISA) using the rp26 protein from equine infectious anemia virus (EIAV) as antigen, and also compare it with the pattern test. In all these immunoassays was identified the functionality of the RP26 antigen. After analyzing 101 AGID - positive sera from animals and 704 AGID - negative at the new iELISA, was observed excellent concordance (kappa=0,9) between tests. The cutoff point (15%) was selected by observing the distribution of the relative values of the optical densities of the samples IDGA -positive and negative. The relative sensitivity and specificity were 97 % and 97,9 %, respectively. The excellent results using the rp26 as antigen in iELISA enables the consideration of a new alternative diagnostic for EIA.