Difference between intraocular and erum antibody repone in patient with ocular toxoplamoi Original Reearch Article

PURPOE: To invetigate the antigen pecificity of the intraocular anti–Toxoplama gondii antibody repone in patient with ocular toxoplamoi. METHOD: Paired ocular fluid and erum ample were collected from 13 patient with active ocular toxoplamoi. erum IgM anti–T. gondii antibodie were teted to ditinguih recently-acquired from chronic infection. Anti–T. gondii IgG pecificity wa analyzed by immunoblotting uing a crude T. gondii extract. REULT: Two of the 13 patient teted were IgM poitive and conidered to have acquired ocular toxoplamoi. The antibody pecificity in ocular fluid and erum of thee two patient wa imilar, wherea in the patient with preumed chronic dieae, marked difference could be oberved. Mot ocular fluid ample contained antibodie that tained a 28-kD antigen more intenely than did antibodie from paired erum ample. Uing aborption and elution experiment, we demontrated that thi 28-kD protein wa identical to the GRA-2 antigen, which i expreed in both the tachyzoite and the bradyzoite tage of the paraite. CONCLUION: Our reult how that the intraocular T. gondii antibody repone of patient with recurrent ocular toxoplamoi differ from the ytemic repone. Thi finding may have implication for our undertanding of the immunopathogenei of ocular toxoplamoi and could be employed to improve diagnoi of the dieae.