Potential immunological markers for diagnosis and therapeutic assessment of toxocariasis

• Published in: Revista do Instituto de Medicina Tropical de São Paulo Vol. 53; no. 2; pp. 61 - 65
• Main Authors: Rubinsky-Elefant, Guita, Hoshino-Shimizu, Sumie, Jacob, Cristina Miuki Abe, Sanchez, Maria Carmen Arroyo, Ferreira, Antonio Walter
• Format: Journal Article
• Language: English
• Published: Brazil Instituto de Medicina Tropical de Sao Paulo 01-03-2011; Instituto de Medicina Tropical; Universidade de São Paulo (USP)
• Subjects: Animals; Anthelmintics - therapeutic use; Antibodies, Helminth - blood; Antigens, Helminth; Biomarkers - blood; Blotting, Western; Chemotherapy; Child; Child, Preschool; Enzyme-Linked Immunosorbent Assay; Follow-Up Studies; Helminth Proteins; Humans; Immunoblot assay; Immunoglobulin isotypes; Immunoglobulins - blood; Infant; Sensitivity and Specificity; Thiabendazole - therapeutic use; Toxocara canis - immunology; Toxocariasis; Toxocariasis - diagnosis; Toxocariasis - drug therapy; TROPICAL MEDICINE; Toxocariasis; Immunoblot assay; Immunoglobulin isotypes; Chemotherapy
• ISSN: 0036-4665; 1678-9946; 1678-9946; 0036-4665
• DOI: 10.1590/S0036-46652011000200001

In human toxocariasis, there are few approaches using immunological markers for diagnosis and therapeutic assessment. An immunoblot (IB) assay using excretory-secretory Toxocara canis antigen was standardized for monitoring IgG, IgE and IgA antibodies in 27 children with toxocariasis (23 visceral, three mixed visceral and ocular, and one ocular form) for 22-116 months after chemotherapy. IB sensitivity was 100% for IgG antibodies to bands of molecular weight 29-38, 48-54, 95-116, 121-162, >205 kDa, 80.8% for IgE to 29-38, 48-54, 95-121, > 205 kDa, and 65.4% for IgA to 29-38, 48-54, 81-93 kDa. Candidates for diagnostic markers should be IgG antibodies to bands of low molecular weight (29-38 and 48-54 kDa). One group of patients presented the same antibody reactivity to all bands throughout the follow-up study; in the other group, antibodies decayed partially or completely to some or all bands, but these changes were not correlated with time after chemotherapy. Candidates for monitoring patients after chemotherapy may be IgG antibodies to > 205 kDa fractions, IgA to 29-38, 48-54, 81-93 kDa and IgE to 95-121 kDa. Further identification of antigen epitopes related to these markers will allow the development of sensitive and specific immunoassays for the diagnosis and therapeutic assessment of toxocariasis.