Lacrimal secretory IgA in active posterior uveitis induced by Toxoplasma gondii

Anti-Toxoplasma gondii secretory IgA in tears of patients with ocular toxoplasmosis: immunodiagnostic validation by ELISA

“…Consistent with previous reports (Schellini et al 1993, Sebben et al 1995, Lynch et al 2004, APUPT tends to occur more frequently in younger individuals; in this study, 45.5% of cases were between 10-30 years. This is an important aspect, since the disease leads to longterm morbidity when scars appear in the macula (Lynch et al 2008).…”

“…Secretory IgA (sIgA) is the dominant antibody in tears and together with lysozyme and lymphocytes in the lachrymal film forms the first ocular defensive barrier. Lynch et al (2004) have found that there was strong association between the levels of sIgA in individuals presenting the clinical picture consistent with gold standard ocular toxoplasmosis. The test showed 84% sensitivity and 78% specificity, compared to individuals without ocular disease or symptomatology of toxoplasmosis.…”

“…Crude T. gondii extract preparation -This was done according to Lynch et al 2004. RH strain tachyzoites were collected from the mouse peritoneal cavity on the 3rd day after infection with 0.01 M PBS (pH 7.2), pelleted at 800 g, sieved through a filter with a 3-µm pore size and washed twice.…”

“…sIgA was determined by the ELISA capture method as described by Lynch et al (2004). Briefly, 5.1 µg/mL of T. gondii crude antigen were diluted in 50 mM carbonate bicarbonate buffer (pH 9.0), immobilised in microplate wells for 3 h and then blocked with skimmed milk for 3 h at 18ºC.…”

“…Patients with an active retinochoroidal lesion adjacent to a characteristic healed lesion, e.g., scars delimited with pigmented edges, with one or more foci, can be characterised as having a gold standard lesion (Lynch et al 2004, Garweg 2005. Some authors have shown that the acquired form of the disease presents an aggressive clinical picture and an absence of old scars (Montoya & Remington 1996, Holland 2003.…”