IgG subclass responses in a longitudinal study of canine visceral leishmaniasis

• Published in: Veterinary immunology and immunopathology Vol. 91; no. 3; pp. 161 - 168
• Main Authors: Quinnell, R.J., Courtenay, O., Garcez, L.M., Kaye, P.M., Shaw, M.A., Dye, C., Day, M.J.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.02.2003
• Subjects: Animals; Antibodies, Protozoan - classification; Antibodies, Protozoan - immunology; Dog; Dog Diseases - immunology; Dogs; Female; IgG subclass antibodies; Immunoglobulin G - blood; Immunoglobulin G - classification; Immunoglobulin G - immunology; Leishmania infantum; Leishmania infantum - immunology; Leishmaniasis, Visceral - immunology; Leishmaniasis, Visceral - veterinary; Longitudinal Studies; Male; Time Factors; Up-Regulation; Dog; Leishmania infantum; IgG subclass antibodies
• ISSN: 0165-2427; 1873-2534
• DOI: 10.1016/S0165-2427(02)00311-2

Visceral leishmaniasis (VL), caused by Leishmania infantum, is an important disease of domestic dogs. Here, we present data on the IgG subclass antibody response to crude L. infantum antigen in a cohort of naturally infected Brazilian dogs. Specific IgG1–IgG4 responses could be detected in 98, 58, 70 and 82%, respectively of 57 dogs that were seropositive for specific IgG. Levels of all IgG subclasses were strongly inter-correlated. Levels of all IgG subclasses increased at the time of seroconversion, before reaching a plateau after several months. Levels of all IgG subclasses were higher in sick dogs than healthy dogs, and levels of all except IgG2 were higher in parasite-positive (by PCR) than parasite-negative dogs. However, levels of IgG2 relative to IgG1 were lower in sick or parasite-positive dogs compared to healthy or parasite-negative infected dogs. In contrast to previous studies, the results suggest that canine VL is associated with upregulation of specific antibody of all IgG subclasses, particularly IgG1, IgG3 and IgG4.