Immunoglobulin M (IgM)-glycoinositolphospholipid enzyme-linked immunosorbent assay: an immunoenzymatic assay for discrimination between patients with acute toxoplasmosis and those with persistent parasite-specific IgM antibodies.
In the present study we developed an enzyme-linked immunosorbent assay (ELISA) to measure immunoglobulin M (IgM) specific for glycoinositolphospholipids (GIPL) derived from tachyzoite membrane (IgM-GIPL ELISA). The sensitivity and specificity of the assay were compared with those of commercially available Toxoplasma-specific IgM serological tests, namely, immunofluorescence assay (IFA) with fixed tachyzoites and capture ELISA employing tachyzoite extracts. Our results show that all patients with acute toxoplasmosis, as determined by clinical data and conventional serological tests, were also positive by the IgM-GIPL ELISA. Interestingly, many patients that were classified as indeterminate, who had IgG with high avidity but positive results in the IgM-specific IFA and capture ELISA, were negative by the IgM-GIPL ELISA. Finally, we tested the sera from patients with rheumatoid arthritis and various parasitic infections and found no evidence of false positives in the IgM-GIPL ELISA.
Giraldo
Mónica
M
Department of Biochemistry and Immunology-UFMG, 31270-901 Belo Horizonte, Brazil.
Portela
Ricardo W D
RW
Snege
Mirian
M
Leser
Paulo G
PG
Camargo
Mário E
ME
Mineo
José Roberto
JR
Gazzinelli
Ricardo T
RT
D000208:Acute Disease; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology; D000918:Antibody Specificity; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006017:Glycolipids / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood* / Q000276:immunology; D010743:Phospholipids / Q000276:immunology*; D014122:Toxoplasma / Q000254:growth & development / Q000276:immunology*; D014123:Toxoplasmosis / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology
D000913:Antibodies, Protozoan; D006017:Glycolipids; D007075:Immunoglobulin M; D010743:Phospholipids