We describe 16 cases of ocular and, in some patients, associated CNS toxoplasmosis in AIDS patients. T gondii is commonly associated with infection in the immunocompromised host. The lesions are most often seen in the CNS and eyes; involvement in the brain, heart, lung, liver, spleen, and lymph nodes may be observed. CNS involvement by toxoplasmosis may be an initial manifestation of AIDS and may be associated with discrete or diffuse lesions. CT scan and MR imaging may demonstrate a multitude of lesions often displaying the characteristic ring-shaped enhancement after contrast injection. Ocular involvement by toxoplasmosis, though less common than CNS involvement, is characterized by several features. These may be manifested as single or multifocal retinal lesions in one or both eyes or massive areas of retinal necrosis. Invariably these lesions are unassociated with a pre-existing retinochoroidal scar suggesting that the lesions are a manifestation of acquired rather than congenital disease. Presence of IgM antibodies may support this observation although antibody levels in AIDS patients may not reflect the magnitude of disease. Vitreous reaction is often minimal. Anterior uveitis has been reported in one case. Treatment of the ocular infection with pyrimethamine, clindamycin and sulfadiazine is effective in over 75% of patients. Once resolution of the ocular infection is observed, maintenance therapy is continued as relapses occur in the absence of treatment. Corticosteroid treatment is unnecessary and its use has been associated with the development of CMV retinitis. Other retinal infections in AIDS patients which should be considered in the differential diagnosis include CMV, herpetic-associated ARN and syphilis. Concomitant CMV and toxoplasmosis in the same eye have been seen. (+info)
Intraocular in vivo immunofluorescence. A new technique for visualizing structures of the ocular fundus.
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A new noninvasive technique for observing structures in the living eye has been developed: the technique is based on intravenous application of specific antibodies, labeled with fluorescein. The immunologically marked substructures of the fundus of the eye, the only transparent organ in mammals, are photographed directly using high speed film. Combined with a digital image processor to enhance low contrast contours, this technique can be used for diagnostic purposes, as shown in rabbits with experimental toxoplasmic chorioretinitis. (+info)
Anti-gamma-enolase autoimmune retinopathy manifesting in early childhood.
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Viral isolation and systemic immune responses after intracameral inoculation of herpes simplex virus type 1 in Igh-1-disparate congenic murine strains.
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Igh-1-disparate congenic murine strains differ in their susceptibility to develop contralateral chorioretinitis after intracameral (AC) inoculation with Herpes simplex virus type 1 (HSV-1): 75% of BALB/cByJ (Igh-1a) and 5% of C.B-17 (Igh-1b) develop necrotizing chorioretinitis. To determine the mechanism of influence of host genetics on development of contralateral chorioretinitis, the authors did viral isolation studies in contralateral eyes, determined in vivo and in vitro T-cell responses, and HSV-antibody levels at various times after AC inoculation of BALB/cByJ and C.B-17 mice with HSV-1. Viral isolation was similar in both mouse strains (P less than 0.2). Similarities in systemic immune responses included suppressed delayed-type hypersensitivity responses 5 days, cytotoxic T-lymphocyte and lymphocyte proliferation responses 8 days, and viral neutralizing antibody titers 5 days postinoculation (PI). Differences in systemic immune responses included: (1) delayed-type hypersensitivity responses were not suppressed in C.B-17 mice (P greater than 0.1) and were hyperactive in BALB/cByJ mice (P less than 0.025) 10 days PI and (2) HSV-neutralizing antibody production was higher in C.B-17 mice 10 days PI. These data suggest that the mere presence of HSV-1 in the uninoculated eye is insufficient for the development of chorioretinitis. Virus-specific delayed-type hypersensitivity reactions might be involved in the pathogenesis of retinitis in BALB/cByJ mice; and virus-neutralizing antibodies and suppressed HSV-specific delayed-type hypersensitivity reactions might be instrumental in the protection enjoyed by C.B-17 mice. (+info)
Diagnostic approach to ocular toxoplasmosis.
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