Comparison of methods for estimation of Toxoplasma gondii-specific antibody production in the aqueous humor of cats.
Intraocular production of Toxoplasma gondii-specific antibody in cats has been estimated by comparing the ratio of T gondii-specific antibody in aqueous humor and serum with the ratio of total immunoglobulins in serum and aqueous humor (Goldmann-Witmer coefficient; aqueous antibody coefficient; C value). It has been proposed that in human beings, comparison of the ratio of T gondii-specific antibody in aqueous humor and serum with the ratio of antibodies against a nonocular pathogen in serum and aqueous humor is more accurate than methods using total immunoglobulin quantification. We developed an ELISA for detection of calicivirus-specific antibodies in the serum and aqueous humor of cats. By evaluating calicivirus-specific antibody concentrations in the aqueous humor of healthy and diseased cats, calicivirus was assessed as a nonintraocular pathogen. The ratio of T gondii-specific antibodies in the aqueous humor and serum and the ratio of calicivirus-specific antibodies in serum and aqueous humor were evaluated as a means of estimating intraocular T gondii-specific antibody production. A field strain of feline calicivirus was isolated, cultured, and purified. A calicivirus-specific IgG ELISA was developed for detection of feline calicivirus-specific IgG in serum and aqueous humor. Calicivirus-specific IgG was measured in the serum and aqueous humor from 3 groups of control cats. Results suggested that calicivirus is a nonintraocular pathogen in cats and that calicivirus IgG detected in aqueous humor is attributable to leakage across a damaged blood-ocular barrier.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis* / Q000096:biosynthesis / Q000097:blood; D000914:Antibodies, Viral / Q000032:analysis / Q000097:blood; D000917:Antibody Formation; D000918:Antibody Specificity; D001082:Aqueous Humor / Q000276:immunology*; D002139:Caliciviridae / Q000276:immunology; D002371:Cat Diseases; D002415:Cats; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000096:biosynthesis / Q000097:blood; D014122:Toxoplasma / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000097:blood / Q000276:immunology*; D014605:Uveitis / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*
D000913:Antibodies, Protozoan; D000914:Antibodies, Viral; D007074:Immunoglobulin G