Korean J Parasitol.  2009 Dec;47(4):409-412. 10.3347/kjp.2009.47.4.409.

Antigenemia and Specific IgM and IgG Antibody Responses in Rabbits Infected with Toxoplasma gondii

• Quan JH
• Hassan HA
• Cha GH
• Shin DW
• Lee YH

• KMID: 1720646
• DOI: http://doi.org/10.3347/kjp.2009.47.4.409

Abstract

In this experiment, the correlation between antigenemia and specific antibody responses in Toxoplasma gondii-infected rabbits was assessed. We injected 1,000 T. gondii tachyzoites (RH) subcutaneously into 5 rabbits. Parasitemia, circulating antigens, and IgM and IgG antibody titers in blood were tested by ELISA and immunoblot. For detection of parasitemia, mice were injected with blood from rabbits infected with T. gondii and mice died between days 2 and 10 post-infection (PI). Circulating antigens were detected early on day 2 PI, and the titers increased from day 4 PI and peaked on day 12 PI. Anti-Toxoplasma IgM antibody titers increased on day 6 PI and peaked on days 14-16 PI. IgG was detected from day 10 PI, and the titers increased continuously during the experiment. The antigenic protein patterns differed during the infection period, and the number of bands increased with ongoing infection by the immunoblot analysis. These result indicated that Toxoplasma circulating antigens during acute toxoplasmosis are closely related to the presence of parasites in blood. Also, the circulating antigen levels were closely correlated with IgM titers, but not with IgG titers. Therefore, co-detection of circulating antigens with IgM antibodies may improve the reliability of the diagnosis of acute toxoplasmosis.

Keyword

Toxoplasma gondii; rabbit; antigenemia; parasitemia; antibody

MeSH Terms

Animals
Antibodies, Protozoan/*blood
Antigens, Protozoan/*blood
Enzyme-Linked Immunosorbent Assay/methods
Immunoblotting/methods
Immunoglobulin G/*blood
Immunoglobulin M/*blood
Mice
Parasitemia
Rabbits
Time Factors
Toxoplasma/*immunology
Toxoplasmosis, Animal/*immunology/parasitology