Increased frequency of anti-retina antibodies in asymptomatic patients with chronic t. gondii infection

Abstract

PURPOSE:To search for anti-retina antibodies that serve as markers for eye disease in uveitis.MATERIALS AND METHODS:Stored sera from patients with uveitis, ocular toxoplasmosis (n = 30) and non-infectious, immune-mediated uveitis (n = 50) and from asymptomatic individuals who were positive (n = 250) and negative (n = 250) for anti-Toxoplasma antibodies were tested. Serum anti-retina IgG was detected by an optimized ELISA using a solid-phase whole human retina extract, bovine S-antigen or interphotoreceptor retinoid-binding protein.RESULTS:Uveitis patients showed a higher mean reactivity to whole human retina extract, interphotoreceptor retinoid-binding protein and S-antigen in comparison to the asymptomatic population. These findings were independent of the uveitis origin and allowed the determination of the lower anti-retina antibody cut-off for the three antigens. Asymptomatic anti-Toxoplasma serum-positive individuals showed a higher frequency of anti-human whole retina extract antibodies in comparison to asymptomatic anti-Toxoplasma serum-negative patients. The bovine S-antigen and interphotoreceptor retinoid-binding protein ELISAs also showed a higher mean reactivity in the uveitis groups compared to the asymptomatic group, but the observed reactivities were lower and overlapped without discrimination.CONCLUSION:We detected higher levels of anti-retina antibodies in uveitis patients and in a small fraction of asymptomatic patients with chronic toxoplasmosis. The presence of anti-retina antibodies in sera might be a marker of eye disease in asymptomatic patients, especially when whole human retina extract is used in a solid-phase ELISA.

Prevalence and clinical impact of antiretinal antibodies in uveitis

“…; Cursino et al. ). In several animal models with monkeys and rats, vaccination with retinal S‐antigen induced an ocular disease similar to human uveoretinitis (Faure et al.…”

“…; Cursino et al. ). As the aforementioned studies usually lacked clinical data and information on laboratory techniques, the exact comparison with previous results is not possible.…”

Environmental Microbes and Uveitis: Is Microbial Exposure Always Bad?

“…For example, rabbits infected with Toxoplasma gondii show antibodies for S‐Ag and retinal peptide‐35 . Similarly, autoantibodies to the human retinal extract have been demonstrated in patients affected with chronic toxoplasmosis showing no apparent symptoms . Likewise, antibodies to retinal Gal‐1 and S‐Ag were found to be elevated in patients with toxoplasmic retinochoroiditis .…”

Autoantibodies Against Ubiquitous and Confined Antigens in Patients With Ocular, Neuro-Ophthalmic and Congenital Cerebral Toxoplasmosis

“…Besides the damage caused by the parasite and the inflammatory response against it, an immune response triggered against autoantigens could be occurring and aggravating the clinical signs. In fact, several works related to OT and autoimmunity have been published, particularly on detection of antibodies or autoreactive lymphocytes using retinal extracts or isolated antigens -like rhodopsin or S antigen-in humans and rodent or lagomorph experimental models (15)(16)(17)(18)(19)(20)(21)(22)(23). Nevertheless, there is no consensus about the role of these responses as a cause or exacerbation of the eye disease; neither there is agreement on the mechanism of autoimmunity elicitation, i.e.…”