Immunodominant Molecules for the Immunodiagnosis of Strongyloides stercoralis Infection

Abstract

This study aimed to identify immunodominant molecules with potential for S. stercoralis infection immunodiagnosis. Serum samples were tested by an IgG-ELISA using Strongyloides venezuelensis soluble (AgS) and membrane (AgM) antigens, and its protein fractions (<100 and >100 kDa). Proteins were tested by one- and two-dimensional (2D) gel immunoblotting. The ELISA results showed sensitivities, ranging from 82.3 to 85.3 %, while specificities ranged from 60.0 to 93.3 %. Cross-reactivities were observed with sera from individuals infected with other helminths. Immunoreactive protein bands were revealed by Western blotting using both antigens, and a band with molecular weight around 140 kDa of AgS showed 100 % sensitivity and specificity, without cross-reactivity. The 2D immunoblotting revealed 7 spots in the 140 kDa protein with the S. stercoralis pool of serums. The pre-selection of Strongyloides immunodominant proteins that are highly specific and free from cross-reactions is essential for the production of recombinant antigens for the immunodiagnosis of strongyloidiasis.