CONGENITAL TOXOPLASMOSIS ASSOCIATED WITH TRACTIONAL RETINAL DETACHMENT

PURPOSE

We report a case of congenital toxoplasmosis associated with retinal detachment.

METHODS

A 9-month-old white boy presented a unilateral tractional retina detachment associated with congenital toxoplasmosis retinochoroiditis.

RESULTS

The diagnosis is supported by positive IgG (>400) for toxoplasmosis and intracranial calcification on magnetic resonance imaging, along with positive family history of Toxoplasma infection in the mother.

CONCLUSION

Tractional retinal detachment is an infrequent and unconventional presentation of congenital Toxoplasma infection. Inflammatory interference with normal sequence of vitreous development may explain pathogenesis of tractional retinal detachments in the setting of congenital ocular toxoplasmosis.

Clinical and Biological Factors Associated With Recurrences of Severe Toxoplasmic Retinochoroiditis Confirmed by Aqueous Humor Analysis

PURPOSE

To investigate clinical and biological factors influencing recurrences of severe toxoplasmic retinochoroiditis (TRC) confirmed by aqueous humor analysis.

DESIGN

Retrospective case series.

METHODS

Retrospective analysis of 87 subjects with severe TRC, proven by positive Goldmann-Witmer coefficient (GWC), Toxoplasma gondii (T. gondii) immunoblot, or T. gondii-specific polymerase chain reaction (PCR) in aqueous humor. Cases with immunosuppression or retinal scars without previous recorded episode were excluded. Time-dependent, clinical, treatment-related, and biological factors were explored by univariate and multivariate shared frailty survival analyses.

RESULTS

Among 44 included subjects (age, 40.4 ± 17.6 years; follow-up, 8.3 ± 2.7 years), 22 presented recurrences. There was 0.11 recurrence/patient/year and mean disease-free interval was 5.0 ± 2.9 years. The risk of recurrence was higher immediately after an episode (P < .0001). Among recurrent cases, the risk of multiple recurrences was higher when the first recurrence occurred after longer disease-free intervals (P = .046). In univariate analysis, the recurrence risk declined with higher number of intense bands on aqueous T. gondii immunoblot (P = .006), and increased when venous vasculitis was present initially (P = .019). Multivariate analysis confirmed that eyes with more intense bands on immunoblot had fewer recurrences (P = .041). There was a near-significant risk elevation after pyrimethamine/azithromycin treatment (P = .078 and P = .054, univariate and multivariate). Intravenous corticosteroid administration, oral corticosteroid administration, aqueous GWC, and T. gondii PCR did not influence recurrences (P = .12, P = .10, P = .39, and P = .96, respectively).

CONCLUSIONS

Recurrences of severe TRC are not random and may be influenced by clinical and biological factors possibly related to blood-retinal barrier alterations. These results may contribute to identifying biomarkers for TRC reactivation.

Birdshot Retinochoroidopathy: Prognostic Factors of Long-term Visual Outcome

PURPOSE

To determine the prognostic factors of long-term visual outcome in birdshot retinochoroidopathy (BRC).

METHODS

Design: Retrospective case series. Study Population: Successive HLA-A29+ BRC patients whose latest visit was between May and August 2013 at a single tertiary center (Pitié-Salpétrière Hospital, Paris).

OBSERVATION PROCEDURE

Endpoint visual status (remission or deterioration) was determined for each patient based on clinical and ancillary data from the latest visit including optical coherence tomography (OCT), automated visual field (AVF), and angiograms. Main Outcome Measure: Epidemiologic, clinical, OCT, AVF, angiographic, and electrophysiological data at baseline were correlated to final visual status.

RESULTS

Fifty-five patients were included. Mean observation period was 8 years (range: 0.6-23 years). Mean disease duration was 9.8 years (range: 1.2-32.7 years). Female-to-male sex ratio was 1.6:1. Factors of good visual prognosis (remission vs deterioration) included at baseline: late age of disease onset (49.5 vs 45 years, P = .05), presence of vitreous inflammatory reactions >2+ (35.9% vs 6.2%, P = .04), vascular leakage on fluorescein angiograms (FA) (44.4% vs 12.5%, P = .03), absence of macular pigment epithelium atrophy on FA (88.9% vs 62.5%, P = .05), and presence of macular edema on OCT (33.3% vs 6.2%, P = .04). Preserved electrooculography light peak and Arden ratio (P = .06) and presence of choroidal spots on infracyanine green angiograms (80.0% vs 53.3%, P = .08) seemed associated with the best prognoses.

CONCLUSION

This study suggests a series of prognostic factors of long-term visual outcome in BRC. Keeping in mind the insidious evolution of the disease, knowledge of such prognostic factors should help tailor the treatment and monitoring of birdshot patients.

Secretion of interleukin-17 by CD8+ T cells expressing CD146 (MCAM)

Interleukin-17 (IL-17) has been associated with the pathogenesis of numerous autoimmune diseases. CD4+ T cells secreting IL-17 are termed Th17 cells. CD8+ T cells, designated Tc17 cells, are also capable of secreting IL-17. Here we describe a population of Tc17 cells characterized by the expression of surface CD146, an endothelial adhesion molecule. These cells display signatures of a human Tc17 genotype and phenotype. Circulating CD8+CD146+ T cells are present in low levels in healthy adults. Elevations in CD8+CD146+ T cells are found in Behcet's disease and birdshot retinochoroidopathy, which have been reported to have HLA class I associations. Sarcoidosis does not have a class I association and displays an increase in CD4+ CD146+ T cells but not in CD8+CD146+ T cells. CD146 on these cells may facilitate their ability to bind to, and migrate through, endothelium, as has been reported for CD4+CD146+ T cells.

Spectral optical coherence tomography findings in patients with ocular toxoplasmosis and active satellite lesions (MINAS Report 1)

PURPOSE

To characterize the active retinochoroiditis lesion observed in patients with the classic clinical presentation of ocular toxoplasmosis (OT) utilizing spectral optical coherence tomography (SOCT).

METHODS

Twenty-four patients with OT and satellite lesions underwent standardized ophthalmologic examination and multimodal fundus imaging. The SOCT findings observed at presentation were described.

RESULTS

The mean age of the fourteen (58.3%) women and ten (41.7%) men was 27.6 years. The mean LogMAR ETDRS best-corrected visual acuity was 0.58 (Snellen equivalent, 20/80(+1) ). On SOCT evaluation, the posterior hyaloid was diffusely thickened in 23 (95.8%) of 24 eyes, increased hyper-reflective signals in the vitreous were observed in 18 (75.0%), and vitreal spherical hyper-reflective depositions were observed in 12 (50.0%) eyes. In all patients, at the active OT lesion site, the inner retinal layers were abnormally hyper-reflective with full-thickness disorganization of the retinal reflective layers (smudge effect); associated choriocapillaris/choroidal optical shadowing was observed in 22 (91.7%) eyes. The retina was thickened in 22 (91.7%) eyes, the retinal pigment epithelium-Bruch membrane reflective complex was focally increased or contained focal splits in 16 (66.7%) eyes and the choroid appeared thickened in 17 (70.8%) eyes. Disorganization of the outer retinal highly reflective layers adjacent to the active OT lesion was observed in all eyes.

CONCLUSION

Full-thickness disorganization of the retinal reflective layers, generally associated with some degree of posterior optical shadowing, was observed in the active OT lesion in all patients. The posterior hyaloid was often thickened and, adjacent to the OT lesion, the outer retina was consistently altered.

Anti-γ-enolase autoimmune retinopathy manifesting in early childhood

OBJECTIVE

To describe the clinical, molecular, and serologic findings of a case in which autoimmune retinopathy and early-onset heritable retinal degeneration were both considered in the differential diagnosis.

METHODS

A 3-year-old girl had clinical findings suggestive of a childhood-onset retinal degeneration. Samples of DNA and serum were collected. The coding regions of 11 genes associated with Leber congenital amaurosis were sequenced. The patient's serum reactivity to soluble and insoluble fractions of human retinal protein was compared with that of healthy control subjects (n = 32), patients with inflammatory eye disease (n = 80), and patients with molecularly confirmed retinal degenerations (n = 11). Two-dimensional gel electrophoresis and mass spectrometry were used to identify a protein that corresponded to a reactive band on Western blot.

RESULTS

No plausible disease-causing mutations were identified in any of the retinal disease genes tested. However, the patient's serum showed reactivity to a single retinal antigen of approximately 47 kDa. Two-dimensional gel electrophoresis and mass spectrometry revealed the major reactive species to be neuron-specific enolase (NSE). Autoantibodies targeting NSE were not observed in any healthy control subjects or patients with inflammatory eye disease. However, anti-NSE activity was found in 1 child with molecularly confirmed Leber congenital amaurosis.

CONCLUSION

This patient's clinical and laboratory findings coupled with the recently discovered role of anti-NSE antibodies in canine autoimmune retinopathy suggest that autoantibodies targeting NSE are involved in the pathogenesis of her disease.

CLINICAL RELEVANCE

Infection or inflammation within the retina early in life may lead to an autoimmune phenocopy of early-onset inherited retinal degeneration.

[Toxoplasmic central chorioretinitis]

Toxoplasma gondii is the most frequent cause of chorioretinitis in immunocompetent patients. This paper highlights the case of a 15 years old girl, an immunocompetent patient, with an active chorioretinal focus in the LE and a chorioretinal scar in the RE. Serologically, the IgG antiToxoplasma titre is increased, but the IgM antibodies are negative. It is the bilateral character of the lesions and the serology found that make this case special.

Immunity and Toxoplasma retinochoroiditis

Toxoplasma infection accounts for up to 50% of all cases of posterior uveitis worldwide. In this review the control of Toxoplasma infection generally, and specific in the eye, by the immune system is discussed.

The antitoxoplasma gondii antibodies incidence to the different ocular diseases patients cases of human ocular toxoplasmosis infections in Romania

Toxoplasmosis is an anthropo-zoonosis widely spread around the earth, whose ocular complications are very frequent and are often a first sign of infestation. This is a retrospective statistic research based on the clinical survey and periodic control of a lot of 135 patients with toxoplasmosis, out of which 90 presented ocular toxoplasmosis.

Severe Reactive Ischemic Posterior Segment Inflammation in Acanthamoeba Keratitis

OBJECTIVE

To describe a newly recognized clinical syndrome in Acanthamoeba keratitis consisting of severe reactive ischemic posterior segment vascular inflammation.

DESIGN

Noncomparative, retrospective, single-institution observational case series.

PARTICIPANTS

Five eyes of 5 patients with Acanthamoeba keratitis.

METHODS

A retrospective review of the records of patients diagnosed with Acanthamoeba keratitis between January 1, 1995, and December 1, 2005, was conducted to identify those who underwent eventual enucleation. Five enucleated eyes of 118 eyes with Acanthamoeba keratitis were identified.

MAIN OUTCOME MEASURES

History, clinical examination results, available laboratory study results, and histopathologic examination results.

RESULTS

Histopathologic examination showed Acanthamoeba cysts in the cornea in 4 eyes, whereas it failed to demonstrate amebic cysts or trophozoites in the posterior segment of all eyes studied and unexpectedly revealed chronic chorioretinal inflammation with perivascular lymphocytic infiltration and diffuse neuroretinal ischemia in 4 of 5 eyes. Retinal artery thrombosis was present in 3 of the 4 involved eyes, and central retinal artery and vein thrombosis was found in 1 eye. Hematologic studies in 3 patients showed abnormal anticardiolipin antibody levels in 1 patient and factor V Leiden deficiency in another.

CONCLUSIONS

Prolonged Acanthamoeba keratitis can result in a severe sterile ischemic posterior segment inflammation that is potentially blinding, especially in patients with underlying hypercoagulation disorders.

Screening by ophthalmoscopy for Toxoplasma retinochoroiditis in Colombia

PURPOSE

To measure the prevalence of toxoplasmic retinal scars in a young universitary population.

DESIGN

Observational cohort study.

METHODS

The study was performed at the "Universidad del Quindío," Armenia (Colombia), from November to December 2005. Indirect ocular funduscopy by ophthalmologists was performed in students, teachers, and administrative staff between 18 and 45 years of age without previous ocular pathology. The diagnostic criteria were based on the observation of typical funduscopic lesions and the detection of positive immunoglobulin (Ig) G anti-Toxoplasma antibodies.

RESULTS

From a total of 200 people, 12 (6%) had inactive retinochoroidal scars. Two of them had visual acuity of <20/200 and one of 20/70. Enzyme-Linked Immunosorbent Assay (ELISA) IgG and IgM anti-Toxoplasma was performed in nine patients, all of whom were positive for IgG and one for IgM.

CONCLUSIONS

A relatively high prevalence of retinochoroidal scars (6%) was detected in a young universitary population in Colombia.

[Ophthalmic manifestation in icterus--hemorrhagic leptospirosis]

We present the case of a 19-year-old male, admitted in the Ophthalmology Clinic for Macular Chorioretinitis, hemorrhagic form. Laboratory findings shown high titres of icterus-hemorrhages leptospirosis.

Birdshot chorioretinopathy

PURPOSE OF REVIEW

Birdshot chorioretinopathy is the disease with the strongest link to a human leukocyte antigen class I allele. Current research aims at understanding its immunogenetic mechanisms, focusing on the A29 allele, its subtypes, and on other loci of the human leukocyte antigen region. Research criteria can be applied to define birdshot chorioretinopathy. Its heterogeneous presentations and its multiple consequences on visual function are being delineated.

RECENT FINDINGS

HLA-A*2902 is the most frequent subtype in Caucasians and in patients with birdshot chorioretinopathy. The condition has also been observed, however, in a few HLA-A*2901 Caucasian patients, but remains absent or extremely rare in Asia where HLA-A*2901 is the most prevalent subtype. Birdshot chorioretinopathy affects visual acuity, color vision, contrast sensitivity or visual field and pigmentation of birdshot spots could be a marker of disease severity. Electroretinography has been used to monitor the course of the disease; abnormalities may be due to altered outer retinal function or to inner retinal dysfunction. Various therapeutic regimens have been tested and most studies confirm that corticosteroids alone are not a sustainable treatment for patients with birdshot chorioretinopathy.

SUMMARY

Progress has been made in understanding the spectrum of manifestations of birdshot chorioretinopathy. The disease remains of unknown cause and many decisions regarding the management of patients are still empirical.

Reactivation of toxoplasma retinochoroiditis under atovaquone therapy in an immunocompetent patient

PURPOSE

To report a case of toxoplasma retinochoroiditis reactivation in an immunocompetent patient under atovaquone therapy.

METHODS

Case report.

RESULTS

A healthy woman with a history of bilateral toxoplasma retinochoroiditis since childhood presented with a reactivation of toxoplasma retinochoroiditis. Because earlier treatment regimens had either produced intolerable side effects and/or were deemed ineffective for the prevention of reactivation, the patient was started on atovaquone suspension (750 mg three times a day). After initial regression of the lesion and still under atovaquone therapy, the patient presented again five weeks later with worsened best-corrected visual acuity. Examination showed that the lesion had expanded again and more cells were present in the vitreous.

CONCLUSIONS

To our knowledge, this is the first report of a reactivation of toxoplasma retinochoroiditis in an immunocompetent patient under atovaquone therapy, possibly indicating tachyzoite resistance to atovaquone.

Cytomegalovirus antibodies in tear fluid of patients with retinitis

The diagnosis of cytomegalovirus retinitis (CMV-R) is difficult and usually based on clinical criteria or invasive diagnostic procedures. The purpose of this study was to investigate a possible association between CMV-R and specific anti-CMV antibodies in tears. Paired tear and serum samples were obtained from 96 individuals, which included 20 children with congenital CMV infection and chorioretinitis, 56 adults with retinitis with clinical signs suggestive of viral infection, and 20 healthy control subjects, and were tested for CMV antibodies using ELISA. The prevalence of anti-CMV antibodies in tears was found to be 80% (16/20) in children, 35% (20/56) in adults, and 5% (1/20) in control subjects. Furthermore, high antibody levels were detected in 35% (7/20) of children and 10.7% (6/56) of adults with retinitis, and were not found in control subjects. There was a strong association between high tear levels of anti-CMV antibodies and active ocular infection. No correlations were found between tear and serum antibodies. ELISA sensitivity was 80% and specificity 95%. Further studies are needed to compare the tear and intraocular levels of CMV-specific antibodies in patients with retinitis to find out if CMV antibody testing in tear fluid could substitute for more invasive diagnostic procedures.

Birdshot Chorioretinopathy

Birdshot chorioretinopathy is a well-known, yet poorly understood, form of posterior uveitis, characterized by multiple, distinctive, hypopigmented choroidal lesions, and strongly associated with human leukocyte antigen (HLA)-A29. We reviewed all English language publications regarding birdshot chorioretinopathy and performed analyses of combined patient data taken from these articles. The mean age at presentation was 53 years, with a slight female predominance (54.1%). At least 95.7% of reported patients have been HLA-A29-positive. Blurring of vision and floaters are the most prevalent presenting complaints, even in patients with visual acuity of 20/20 or better in both eyes. Birdshot chorioretinopathy is a slowly progressive disease with profound dysfunction of vision that may not be reflected in Snellen visual acuity. Two or more lines of Snellen visual acuity were lost in approximately 20% of eyes over a median follow-up of 3.5 years; macular edema was the most common cause of reduced visual acuity. Overall, patients had a slow decline in visual acuity, despite the fact that nearly all were treated with anti-inflammatory therapies. Final visual acuity in the better eye was 20/40 or better in 75.1% of patients and 20/200 or worse in 9.8% of patients. Oral corticosteroids and cyclosporine were the most commonly used medications. Using a regression model, patients in the literature that have been treated with cyclosporine alone had better final visual acuity than patients treated with oral corticosteroids alone. Further study is needed to determine the optimal methods for treating and monitoring patients with birdshot chorioretinopathy.

[Toxocara canis central chorioretinitis]

This issue presents the case of a patient which presents monolateral chorioretinitis caused by Toxocara canis.

[Toxoplasmic retinochoroiditis reactivated in the puberty]

By a clinical-infectious and ophthalmologic examination that includes serologic studies, we found that 17 cases of retinochoroiditis reactivated in the puberty.

Comparison of enzyme-linked immunosorbent assay, immunoblotting, and PCR for diagnosis of toxoplasmic chorioretinitis

Ocular toxoplasmosis is the major cause of posterior uvetis in European populations. The clinical diagnosis of toxoplasmic chorioretinitis is based upon ophthalmoscopic findings, which are often but not always typical. Laboratory testing is therefore important to confirm the etiology of the disease. In the present 2-year prospective study, the relative diagnostic sensitivities of the three analytical techniques (enzyme-linked immunosorbent assay [ELISA], immunoblotting, and PCR) were compared by using a group of patients (n = 19) with suspected ocular toxoplasmosis. The relative specificities of the three techniques were assessed by including two control groups of patients: one with nontoxoplasmic and noninflammatory ocular disease (n = 48) and the other with nontoxoplasmic and inflammatory ocular disease (n = 20). All 19 of the clinically suspect patients had serological evidence of exposure to Toxoplasma gondii: 17 had been previously infected, and 2 had current infection. The analysis of paired aqueous humor and serum samples by ELISA and immunoblotting revealed the local production of specific antibodies of the immunoglobulin G type in 63% (12 of 19) and 53% (10 of 19) of patients, respectively. PCR analysis of aqueous humor samples confirmed the presence of T. gondii DNA in 28% (5 of 18) of cases. When combined, ELISA, immunoblotting, and PCR findings confirmed the toxoplasmic origin of retinal lesions in 83% (15 of 18) of patients. The relative specificities of the three techniques were 89% for ELISA and immunoblotting and 100% for PCR.

[Birdshot retinochoroidopathy]

Birdshot retinochoroidopathy is a rare, chronic, bilateral, posterior uveitis with a distinctive clinical presentation and a strong genetic association. Middle aged white people of northern European extraction are most commonly. The pathogenesis is unknown, but HLA-A29 positivity appears to confer predisposition and retinal autoimmunity seems to play a role. Clinically, there are patches of postequatorial choroidal and retinal pigment epithelial depigmentation, vitreal cells, macular and disc edema, and venous sheathing. This review provides an updated summary of the current state of knowledge about birdshot retinochoroidopathy. It includes results of visual field and electrophysiological tests.

Retinochoroiditis associated with congenital toxoplasmosis in children: IgG antibody profiles demonstrating the synthesis of local antibodies

PURPOSE

Retinochoroiditis is generally diagnosed after the first year of life and the association with congenital toxoplasmosis presents a diagnostic dilemma. The detection of local intraocular specific antibodies could be useful for diagnosis.

METHODS

We studied six patients (mean age 7 +/- 5 years) with retinochoroiditis which appeared after the first year of life. Aqueous and serum were analysed by immunoblotting for anti T. gondii IgG to diagnose toxoplasmosis.

RESULTS

All serum samples were positive only for anti T. gondii IgG. The retinochoroiditis was active in three patients and inactive in the others. Immunoblot analysis of serum and aqueous from the patients with active lesions showed IgG versus the specific antigen of T. gondii. In the patients with inactive lesions the pattern was the same in the two compartments. In active forms, aqueous and serum Western blot patterns differed in proteins lower than 16kDa and higher than 116kDa: in aqueous the findings were typically positive for 30kDa.

CONCLUSIONS

Aqueous humour analysis by the Western blot technique may be useful in the diagnosis of congenital toxoplasmosis. In the present small series, we nevertheless detected different patterns for inactive and active retinochoroiditis, confirming the diagnosis in the latter. Aqueous humour paracentesis may be indicated in a child with active retinochoroiditis with unusual clinical features, appearing after the first year of life, and with no clinical or serological evidence of congenital infection.

Birdshot retinochoroidopathy: immunopathogenesis, evaluation, and treatment

Birdshot retinochoroidopathy (BSR) is a bilateral posterior uveitis. A putative organ-specific autoimmune disease, it is strongly associated with the HLA-A29 allele, and understanding the immunopathogenesis of BSR is of great interest. The clinical features include minimal anterior uveitis, vitritis, retinal vasculitis, cystoid macular edema, and distinctive hypopigmented choroidal lesions. Findings on electrophysiology studies and angiography have implications for understanding the pathophysiology of the disease, and may be useful for following the course of BSR and the response to therapy in individual patients. The decision to initiate therapy can be difficult, but corticosteroids and immunosuppressive agents are often used.

Transforming growth factor-beta expression in human retinal pigment epithelial cells is enhanced by Toxoplasma gondii: a possible role in the immunopathogenesis of retinochoroiditis

Retinochoroiditis caused by Toxoplasma gondii infection results in inflammation and necrosis of the retina. We have used human retinal pigment epithelial cultures (HRPE) as an in vitro model to investigate the role of TGF-beta in T. gondii-induced retinochoroiditis. RT-PCR analyses showed enhanced steady state levels of TGF-beta1 and TGF-beta2 mRNA in T. gondii-infected HRPE. Uninfected HRPE secrete TGF-beta1 in a latent form while 10-30% of the secreted TGF-beta2 was in the active form. T. gondii infection induced a significant increase (P < 0.01) in total TGF-beta1 and TGF-beta2 secretion by HRPE. In addition, soluble extracts of T. gondii (ST) stimulated secretion of both TGF-beta1 and TGF-beta2 significantly (P < 0.01). Interestingly, T. gondii infection as well as ST of the parasites completely inhibited secretion of the active form of TGF-beta2. Studies evaluating the effect of TGF-beta on T. gondii replication in HRPE revealed that TGF-beta enhanced parasite replication. The interactions between host retinal cells and T. gondii may play an active role in the pathogenesis of retinochoroiditis.

Birdshot retinochoroiditis: long term follow-up of a chronically progressive disease

PURPOSE

To determine the long-term course of birdshot retinochoroiditis by reviewing patient records from The University of Iowa Hospitals and Clinics.

DESIGN

A descriptive case series.

METHODS

We conducted a retrospective review of 19 patients seen at The University of Iowa for birdshot retinochoroiditis. Inclusion criteria were set before review. Goldmann perimetry isopters were converted to an area measurement in steradians and the I2e and I4e isopters were evaluated at each time point. The visual acuity, electroretinography (ERG), and visual field findings were compared to the clinical appearance of the fundus.

RESULTS

Follow-up ranged from one visit to 220 months. Of the 14 patients who were tested, all were HLA-A29-positive. Seven patients were followed for >or=60 months. Eleven patients were followed for >or=30 months. The initial visual acuity was 20/50 or better in 36 of 38 eyes and 20/60 and 20/80 in the remaining two. Visual acuity was worse than 20/50 in three of 22 eyes followed for more than 30 months. Visual field data demonstrated progressive loss of area for either the I4e or I2e isopters in six of seven patients who were followed for >or=60 months. Multiple ERGs were performed over time on eight of 19 patients; seven of eight patients demonstrated progressive loss of electrophysiologic indices.

CONCLUSION

Retinal function in birdshot retinochoroiditis deteriorated progressively over a period of years despite stable visual acuity. Late in the course of disease, visual acuity may be lost due to chorioretinal atrophy in the posterior pole. Visual acuity alone is not an adequate parameter with which to monitor disease activity and may falsely suggest that a patient is stable or doing well. Intermittent treatment of the inflammatory exacerbations did not prevent progressive visual loss. Other treatment strategies such as prolonged corticosteroid or immunosuppressive treatment should be investigated for patients with birdshot retinochoroiditis.

Rapid progressive subacute sclerosing panencephalitis in a 2-year-old child with congenital athyreosis

We present the unique case of a 2-year-old girl with congenital athyreosis who acquired primary measles virus infection at the age of 18 months, coincidentally with an Epstein-Barr virus infection. First neurologic symptoms of subacute sclerosing panencephalitis appeared 5 months later, and the girl died within 6 months after a rapid progressive illness. Factors possibly predisposing to this extraordinary disease course-primary measles virus infection at an early age and lack of evidence for immunodeficiency-are discussed.

Toxoplasma gondii infection induces gene expression and secretion of interleukin 1 (IL-1), IL-6, granulocyte-macrophage colony-stimulating factor, and intercellular adhesion molecule 1 by human retinal pigment epithelial cells

We have used human retinal pigment epithelial (HRPE) cultures to investigate the primary cellular responses of retinal resident cells to intracellular Toxoplasma gondii replication. At 4 days postinoculation, when all of the cells were infected, the secretion of interleukin 1beta (IL-1beta), IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), and intercellular adhesion molecule 1 (ICAM-1) was augmented by 23-, 10-, 8-, and 5-fold, respectively, over the control. Northern and reverse transcriptase PCR analyses showed significant upregulation of steady-state levels of mRNA for IL-1beta, IL-6, GM-CSF, and ICAM-1. The secretion of these molecules by HRPE cells may play a critical immunoregulatory role in the pathophysiological processes associated with T. gondii-induced retinochoroiditis.

Detection of specific immunoglobulin E during maternal, fetal, and congenital toxoplasmosis

Toxoplasma immunoglobulin E (IgE) antibodies in 664 serum samples were evaluated by using an immunocapture method with a suspension of tachyzoites prepared in the laboratory in order to evaluate its usefulness in the diagnosis of acute Toxoplasma gondii infection during pregnancy, congenital infection, and progressive toxoplasmosis. IgE antibodies were never detected in sera from seronegative women, from patients with chronic toxoplasma infection, or from infants without congenital toxoplasmosis. In contrast, they were detected in 86.6% of patients with toxoplasmic seroconversion, and compared with IgA and IgM, the short kinetics of IgE was useful to date the infection precisely. For the diagnosis of congenital toxoplasmosis, specific IgE detected was less frequently than IgM or IgA (25 versus 67.3%), but its detection during follow-up of children may be interesting, reflecting an immunological rebound. Finally, IgE was detected early and persisted longer in progressive toxoplasmosis with cervical adenopathies, so it was also a good marker of the evolution of toxoplasma infection.

Experimental reproduction of viral chorioretinitis in kangaroos

OBJECTIVE

To investigate whether preparations containing Wallal and/or Warrego viruses could cause disease when inoculated subcutaneously into captive kangaroos.

DESIGN AND PROCEDURE

Four groups of two kangaroos, seronegative to both Wallal and Warrego virus, were each inoculated with wild Wallal virus, cultured Wallal virus, wild Warrego virus, or wild Warrego virus followed by wild Wallal virus after 3 weeks. A single uninoculated animal served as a control. Animals were monitored weekly under anaesthesia, examined ophthalmoscopically (including fundic photography), and samples collected for haematological and serum biochemical analysis, virus isolation, PCR and serological examination for antibodies against Wallal and Warrego viruses. Animals inoculated with cultured Wallal virus were killed at week 10, and remaining kangaroos were reinoculated with cultured Wallal virus at week 12.

RESULTS

Virus was isolated from the blood of two kangaroos 2 weeks after inoculation with Wallal virus preparations, and from a third kangaroo 2 weeks after reinoculation. By 3 weeks after inoculation, all kangaroos given Wallal virus preparations had seroconverted to Wallal virus and one had seroconverted to Warrego virus. Fundic changes were detected in the three viraemic kangaroos 4 or more weeks after inoculation, and lesions were present in the eye and brain typical of those seen in field cases of chorioretinitis. No other kangaroos had lesions. Wallal virus was identified by PCR and immunohistochemical analysis in the retina of one affected animal and orbivirus-like particles were seen by electron microscopy in the remains of retinal cells.

CONCLUSION

The condition of chorioretinitis was reproduced in three of eight kangaroos by inoculation with preparations containing Wallal virus.

[Experimental autoimmune uveitis. Characterization of retina infiltrating cells]

The chronic model of murine EAU induced by interphotoreceptor retinoid binding protein represents a disease similar to clinical chorioretinitis. In this study we characterized the kinetics of retina infiltrating T-cells, macrophages and expression of the adhesion molecules ICAM-1 and ICAM-2.

METHODS

B10.A mice were immunized subcutaneously with IRBP, and the eyes were analyzed on days 10, 18, 24 and 28. The infiltrating cells were characterized by mAbs recognizing T-cell receptors (TCR) Vss6 and Vss8, T-cell markers, macrophages and ICAM-1 and ICAM-2.

RESULTS

While CD8+ T-cells and ICAM-2 were detectable from day 10 (retina is intact) until day 28, CD4+ T-cells, macrophages and ICAM-1 appear with the onset of retinal destruction. Starting at day 10 the dominating TCR was Vss6; Vss8 was noticed from day 18 on.

CONCLUSION

CD8+ T-cells infiltrating the intact retina and stimulating the expression of high endothelial venules (HEVs) could be responsible for the onset of uveitis.

Pathogenesis of toxoplasmic retinochoroiditis

The protozoan parasite Toxoplasma gondii is an important cause of ocular disease both in immunosuppressed and immunocompetent individuals. Non-ocular infections are not usually serious in otherwise healthy adults. In contrast, toxoplasmic retinochoroiditis is a progressive, recurring disease that can cause severe morbidity. Here, Fiona Roberts and Rima McLeod review the demography, pathology and clinical findings of this disease. They discuss mechanisms of retinal destruction and disease recurrences, and the local immunological response at this immune-privileged site.

Local production of IgG and IgG subclasses in the aqueous humor of patients with Fuchs heterochromic cyclitis, herpetic uveitis and toxoplasmic chorioretinitis

Changes in local immunity are important when considering the physiopathology of uveitis. The aim of this study was to measure IgG and IgG subclass concentrations in the serum and the AH of patients with three different types of uveitis and to determine for each of them the presence of a local production of IgG in the intra-ocular compartment. This investigation was extended to IgG subclasses. Serum and AH of 46 patients, including 11 with Fuchs heterochromic cyclitis (FHC), 13 with toxoplasmic chorioretinitis, 11 with herpetic uveitis and 11 with senile cataract (taken as controls) were analyzed by ELISA for IgG and IgG subclasses. Three quotients (r1, IgG/albumin in serum; r2, IgG/albumin in AH; and R, r2/r1) were calculated in order to estimate the local synthesis (LS) of IgG and each IgG subclass. In AH of patients with herpetic uveitis, a concomitant and significant increase of all IgG subclasses as well as albumin (with no significant increase of r2 or R) was observed. This finding was interpreted as an indirect consequence of major damage to the blood-aqueous barrier. In patients with FHC, a significant increase of r2 and R involving only the IgG1 subclass was observed, indicating the existence of LS of IgG1 in the majority of these patients. In the AH of patients with toxoplasmic chorioretinitis, no significant modification of IgG subclass or albumin concentrations was observed when compared to controls. In conclusion, it would seem interesting to consider measurement of IgG and IgG subclasses and calculation of the coefficients r1, r2 and R for a better evaluation of the local immunological processes observed in different types of uveitis.

Peripheral multifocal chorioretinitis with panuveitis: clinical and immunogenetic characterization in older patients

BACKGROUND

The etiology of peripheral multifocal chorioretinitis with panuveitis (MCP) is unclear. Characteristic signs of MCP are punched-out, white chorioretinal lesions of the lower fundus periphery, chronic smoldering chorioretinal inflammation, vitritis, and mild inflammation of the anterior chamber. In this retrospective study we investigated clinical and immunogenetic abnormalities in MCP in older patients.

PATIENTS AND METHODS

20 patients (18 women, 2 men), median age 70.5 years, were investigated clinically by ophthalmologists and were typed for HLA class I antigens using the standard microlymphocytotoxicity test. Typing for HLA-DR antigens was performed by polymerase chain reaction with sequence-specific primers (PCR-SSP). The HLA controls consisted of healthy people (108 for HLA class I, 114 for HLA class II).

RESULTS

MCP was bilateral in 18 patients. Disease-related symptoms were present for 8 months (median) before diagnosis. The main presenting symptoms or findings were glaucoma (in 11 patients), visual loss (7), iritis (5), and vitritis (2). Anterior segment changes were frequently seen: keratitic precipitates (32 eyes), anterior chamber cells (25 eyes), aqueous flare (26 eyes), posterior synechiae (22 eyes), secondary glaucoma (15 eyes), and iris neovascularization (8 eyes). All patients had vitritis and typical chorioretinal fundus lesions. Fourteen patients developed cystoid macular edema (bilateral in seven cases). Subretinal neovascularization occurred in three patients. Although systemic medication was given to 17 patients and surgical treatment was performed in 25 eyes, improvement in vision was found in only 6 eyes, but 18 eyes deteriorated markedly (median 5 lines) during follow-up (median 24.5 months). Immunogenetically significant reduced frequencies of HLA-B7 and HLA-DR1 were found; also HLD-DR15(2) was reduced. However, several alleles were increased in MCP, although not significantly: HLA-A31; HLA-B57, HLA-B62; HLA-Cw3, HLA-Cw6; HLA-DR4, HLA-DR7, and HLA-DR8.

CONCLUSIONS

MCP is clinically and immunogenetically open to speculation. The present diagnosis and treatment of MCP are insufficient. Further DNA typing methods should clarify, whether HLA-DQ antigens are associated with the disease.

[Analysis of aqueous humor in intraocular toxoplasmosis]

BACKGROUND

Despite many clinical examinations and laboratory tests, the cause of uveitis is very often not discovered. The examination of local intraocular antibody production is a valuable additional diagnostic means.

PATIENTS AND METHODS

Aqueous humor was obtained from 46 eyes with severe uveitis: retinochorioiditis (n = 27), intermediate uveitis (n = 11), iridocyclitis (n = 5), and panuveitis (3). With the enzyme-linked immunosorbent assay (ELISA) the antibodies against Toxoplasma gondii were measured in aqueous humor and serum and the intraocular antibody production was calculated by the formation of an antibody index (AI). As the AI values are corrected for possible polyspecific immune response, the AI index is more sensitive than the Goldmann-Witmer index.

RESULTS

An intraocular antibody synthesis against T. gondii could be confirmed in 20 eyes. The serum antibody concentration against T. gondii was in the reference range in 45 patients and only one patient had a very high increase of antibodies. In nine of 20 eyes, intraocular synthesis of antibodies against T. gondii was unexpected due to the lack of clinical evidence.

CONCLUSIONS

The aqueous humor analysis is more reliable than the proof of serum antibodies, and it helps to increase the number of eyes with uveitis in which a specific therapy can be established.

Elevated interleukin 6 activity in aqueous humor of cats with uveitis

The purpose of this study was to assess the role of interleukin 6 (IL-6) in feline uveitis by measuring IL-6 activity in the serum and aqueous humor of cats. Serum and aqueous humor was collected from clinically normal, random source cats (n = 10); clinically normal, specific-pathogen free cats experimentally inoculated with Toxoplasma gondii strain ME49 and sampled sequentially for 20 months (n = 4); and client-owned cats with uveitis (n = 27). Interleukin 6 activity was measured in each sample. Client-owned cats with uveitis were also evaluated for evidence of present or prior exposure to T. gondii, feline leukemia virus, feline immunodeficiency virus, and feline coronaviruses. Interleukin 6 activity was non-detectable or low in serum from cats of each group. Interleukin 6 activity was not detected in aqueous humor of clinically normal cats. Interleukin 6 activity was detected in 22/27 (81.5%) aqueous humor samples from cats with uveitis, with a range of 28.9 U ml(-1)-15702.9 U ml(-1) (mean = 1911.9 U ml[-1], SD = 3946.7 U ml[-1]). Serologic evidence of exposure to T gondii, feline immunodeficiency virus, feline leukemia virus, or a coronavirus was present in 21/27 (77.8%) cats with uveitis. Interleukin 6 was detected in the aqueous humor of 18/21 (85.7%) and 3/6 (50%) of the cats with and without serologic evidence of exposure to one to the infectious diseases, respectively. Statistically significant increases in mean IL-6 activity in aqueous humor were found for cats with any evidence of infection with T. gondii, for cats with T. gondii antigen in aqueous humor and for cats with coronavirus antibody titers > or = 1:100. Aqueous humor IL-6 activity was greater than corresponding serum IL-6 activity in 21/27 cats. These results show that IL-6 is produced intraocularly in some cats with uveitis and that IL-6 may be a mediator of uveitis in cats.

T-cell subsets and T-cell receptor V beta utilization by Igh-1-congenic mice in herpetic retinal necrosis

BACKGROUND

After unilateral anterior chamber (AC) inoculation with herpes simplex virus type 1 (HSV-1), C.B-17 and BALB/c congenic mice, which differ only in a limited region around the lgh-1 locus on chromosome 12, show a striking difference in susceptibility to development of encephalitis and contralateral necrotizing chorioretinitis.

METHODS

After AC inoculation with HSV-1 (KOS), C.B-17 and BALB/c mice were followed up for the clinical signs of encephalitis and chorioretinitis. At different time points following inoculation, lymphocytes isolated from the spleen were triple-stained with antibodies directed against CD4 or CD8, IL-2R, and various V beta T-cell receptor (TCR) subsets, and were analyzed by flow cytometry.

RESULTS

These lgh-1-disparate congenic mice showed differences in the time course of splenic V beta T-cell receptor (TCR) usage in both CD4+, IL-2R+ and CD8+, IL-2R+ T cells. By day 1 post infection (p.i.), C.B-17 mice showed an increase of V beta 8 and V beta 9 TCR by both CD4+, IL-2R+ and CD8+, IL-2R+ splenic T cells. Susceptible BALB/c mice delayed the increase of splenic V beta 8 and V beta 9 TCR by CD4+, IL-2R+ T cells, which was noted by day 4 p.i. Furthermore, in BALB/c mice the usage of V beta 9 by CD8+ cells was increased by day 6 p.i.

CONCLUSIONS

Our findings indicate that early preferential splenic usage of a restricted repertoire of TCR occurs after ocular inoculation with HSV-1 in resistant C.B-17 mice. Such preferential TCR usage by activated T cells may prevent viral replication in the brain and contralateral eye and may be linked to protection from development of encephalitis and destructive herpesmediated ocular inflammation.

Toxoplasmic chorioretinitis in the setting of acute acquired toxoplasmosis

Ocular toxoplasmosis is considered to be the most commonly recognized cause of chorioretinitis in the United States. It is commonly believed that the majority of cases of acute toxoplasmic chorioretinitis involving adults in the United States are late sequelae of congenital infection and that the condition is rarely associated with acute postnatally acquired infection. We report here the clinical and serological test findings for 22 adults with acute toxoplasmic chorioretinitis that occurred in the setting of acute postnatally acquired toxoplasmosis. The initial serum specimen from each adult yielded an acute toxoplasmic serological profile, on the basis of the following positive results: 95.5%, Sabin-Feldman dye test [titer of > or = 1:1,024]; 95.5%, IgM ELISA; 90.9%, IgA ELISA; 77.3%, IgE ELISA; 95.5%, IgE immunosorbent agglutination assay; and 86.4%, differential agglutination (AC/HS) test (acute pattern). Detection of IgA or IgE antibodies or an acute pattern in the AC/HS test was particularly helpful in diagnosis for those patients whose ELISA IgM titers at presentation were negative or lowly positive. Thus, acute toxoplasmic chorioretinitis occurring with a recently acquired Toxoplasma gondii infection would appear to be more common in the United States than previously recognized, and a toxoplasmic serological profile is useful in diagnosing this entity.

Three HLA-A29 positive patients with uveitis

We evaluated the ocular symptomatology in 3 HLA-A29 positive patients with uveitis. In two patients we saw bilateral flecked fundus lesions known as birdshot retinochoroidopathy. One patient with an idiopathic vasculitis had no depigmented fundus flecks. The differences and similarities in these 3 patients are described.

[A case of toxoplasmic chorioretinitis and meningoencephalitis in an immunocompetent adult]

A 71-year-old man who presented with toxoplasmic chorioretinitis and meningoencephalitis is reported. He had been healthy and immunologically normal. Initially, he complained of blurring of vision without headache, nor fever. Neurological examinations revealed papilledema, nuchal rigidity, and disorientation. Fluorescent angiography of the ocular fundi disclosed hyperfluorescent leaks suggesting chrioretinitis. His EEG had dysrhythmic slow alpha wave with some theta slowing. CSF studies showed pleocytosis up to 80/mm3; the cells were predominantly lymphocytes. The titers of toxoplasma antibody in the serum and CSF were prominently increased. Toxoplasmosis was highly suspected and he was treated with predinsolone, acetylspiramycin, and pyrimethamine. After the treatment, ophthalmologic and neurological symptoms improved, and the laboratory findings including the titers of toxoplasma antibody in the serum and CSF were also improved. Recently, toxoplasmosis associated with neurological complications as an opportunistic infection is a serious problem in the immunocompromised hosts, especially in AIDS, but this infection is rare in immunologically normal adults. Our case and some other reports may suggest a chance of developing toxoplasmic meningoencephalitis even in healthy individuals. We have to think of the possibility of toxoplasmosis in the immunocompetent hosts when they are presenting with chorioretinitis and meningoencephalitis.

Immunomodulation of experimental autoimmune uveoretinitis: a model of tolerance induction with retinal antigens

Experimental autoimmune uveoretinitis (EAU) is a CD4+ T-lymphocyte mediated inflammation of the uveal tract and retina. As a model of human posterior uveitis it permits further understanding of the underlying immunopathogenesis of uveitis. It also allows for preclinical trials of immunosuppressive therapies and in vivo assessment of alternative strategies for immunointervention. This review highlights possible immunostrategic modalities which prevent the initiation or perpetuation of the immune response, and in particular reports on the novel effect of intranasal induction of tolerance with retinal antigens, prior to immunisation with retinal antigens. The mechanisms and potential application of this 'natural' method of immunosuppression in the treatment of autoimmune disease are discussed.

T lymphocyte effector mechanisms in the retina in posterior uveitis

Loss of vision in posterior uveitis is often the consequence of chronic retinal oedema and immune-mediated damage to the retinal parenchyma. Research in other putative autoimmune diseases such as rheumatoid arthritis, and in animal models of autoimmune disease, has uncovered a number of mechanisms which may contribute to the development of inflammatory disease within the eye. With recent developments in specific anti-cytokine therapy an understanding of these mechanisms, most of which are cytokine-mediated, is essential in order to plan more effective therapeutic strategies. In this paper we review recent research investigating the functional characteristics of the T cells which are recruited into the retina in experimental autoimmune uveoretinitis, including activation status, antigen-specific proliferation in vitro and cytokine mRNA production in the inflamed retina.

Necrotizing chorioretinitis in mice inoculated with herpes simplex virus type 1 with or without glycoprotein C: anterior chamber-associated immune deviation does not persist

BALB/c mice developed contralateral necrotizing retinitis following intracameral inoculation with herpes simplex virus type 1 (HSV-1). The animals showed a positive delayed-type hypersensitivity (DTH) response at 10 days postinoculation, indicating that the anterior chamber-associated immune deviation was transient after HSV-1 inoculation. Since glycoprotein C (gC) of HSV-1 is a major immunogen, we examined DTH and the antibody response induced by a gC-deficient strain TN-1 and compared them with those induced by the recombinant gC-positive mutants. We found that gC was not required for DTH reaction, and that gC was neither necessary for nor protective against the contralateral retinal necrosis. Serial lymphocyte subset analyses of the draining lymph nodes revealed an absolute increase of B cells, CD4-positive T cells, and CD8-positive T cells. CD4-positive T cells but not CD8-positive T cells increased in the contralateral eyes during the inflammation and necrosis. The coincident emergence of the positive DTH and contralateral retinal necrosis of HSV-1-inoculated mice, together with the presence of CD4-positive cells in the retina, indicated that CD4-positive T cells responsible for DTH induction may participate in the retinal necrosis.

[Diagnostic and predictive importance of the blast transformation test and basophil activation test in retinal vasculitis]

22 patients suffering from Birdshot retinochoroidopathy (10), idiopathic vasculitis (6) and Behcet disease (6) and treated by cyclosporine were tested at regular intervals during 11 to 38 months by the lymphocyte stimulation test (LST) and basophil degranulation test (HBDT) with S retinal antigen. These two tests were found frequently positive especially during acute inflammation for the LST. However HBDT was positive in all the patients before relapse of acute inflammation which is in favor of its predictive value and its involvement in the triggering of inflammation at the basophiles or at the local mast cell level.