Usefulness of concanavalin-A non-binding fraction of Strongyloides venezuelensis larvae to detect IgG and IgA in human strongyloidiasis

• DOI: 10.1016/j.diagmicrobio.2011.01.016
• Publication Date: 2011-04-22T13:09:41Z
• Authors: Henrique Tomaz Go...; Vanessa da Silva ...; Jair Pereira Cunh...; Marlene Tiduko Ueta; Julia Maria Costa...
• Keywords: Microbiology (medical); 0301 basic medicine; Antibodies, Helminth; Chemical Fractionation; Sensitivity and Specificity; 03 medical and health sciences; Strongyloides; Concanavalin A; Animals; Humans; Glycoproteins; Immunoassay; Serodiagnosis; Clinical Laboratory Techniques; Immunoglobulin A; Infectious Diseases; ROC Curve; Antigens, Helminth; Immunoglobulin G; Larva; Strongyloidiasis; Parasitology; Strongyloides stercoralis; Protein Binding

Glycosylated components from Strongyloides have an important role in parasite establishment and host recognition of these substances. Considering the sugar-binding capacity of lectins, such as concanavalin-A (Con-A), IgG and IgA detection in serum samples from strongyloidiasis patients was tested using different antigenic preparations. The total saline extract (SE) of Strongyloides venezuelensis filariform larvae was fractionated in Con-A column to obtain Con-A unbound (Con-A UF) and Con-A bound (Con-A BF) fractions. Sensitivity (Se), specificity (Sp), area under the ROC curve (AUC), likelihood ratio (LR), and correlation coefficients were calculated. Con-A UF showed the highest diagnostic parameters for IgG detection (Se 95.0%, Sp 92.5%, AUC 0.99, LR 12.7) and high correlation (r = 0.700) with SE. Con-A fractions did not clearly demonstrate any usefulness for IgA detection. In conclusion, the results obtained demonstrate that Con-A UF is an important source of specific peptides efficient to detect IgG in strongyloidiasis immunodiagnosis.