Clinical manifestations and visual outcomes associated with ocular toxoplasmosis in a Brazilian population.

Ocular toxoplasmosis is the leading cause of posterior uveitis worldwide. We conducted an observational study of 262 consecutive individuals (n = 344 eyes) with ocular toxoplasmosis who were followed over a 34-month period. Most subjects were T. gondii IgG + /IgM- (n = 242; 92.4%; 317 eyes), and 140 eyes (40.7%) had active lesions. For eyes in which retinal lesions were active at recruitment and best-corrected visual acuity (BCVA) could be measured (n = 133), 21.0% (n = 28) remained blind (BCVA below 20/400) after inflammation resolved. In these eyes, atypical ocular toxoplasmosis (OR 4.99; 95% CI 1.14-22.85; p = 0.0330), macular lesion (OR 9.95; 95% CI 2.45-47.15; p = 0.0019) and any complication (OR 10.26; 95% CI 3.82-30.67; p < 0.0001) were associated with BCVA below 20/200. For eyes with only inactive lesions at recruitment and BCVA measured (n = 178), 28.1% (n = 50) were blind. In these eyes, having at least one lesion larger than one disc-diameter (OR 6.30; 95% CI 2.28-22.46; p = 0.0013) and macular lesion (OR 5.69; 95% CI 2.53-13.54; p < 0.0001) were associated with BCVA below 20/200. Older age (OR 1.02; 95% CI 1.00-1.05; p = 0.0493) and active disease at presentation (OR 4.74; 95% CI 1.95-12.91; p = 0.0011) were associated with recurrences. Additional clinical attention should be directed towards patients with risk factors for poor visual outcome.

Successful multi-modality approach in management of human leukocyte antigen-B27 associated fulminant panuveitis - rare presentation.

Objective: To report a multimodality approach in the management of human leukocyte antigen B27 (HLA-B27) associated fulminant posterior uveitis, an uncommon presentation, with good visual and anatomical recovery. Methods: A 33-year-old young male presented with HLA-B27 associated severe posterior uveitis, which is a relatively uncommon presentation. The patient had severe vitritis with papillitis, which was sequentially and stepwise managed with oral steroids, pars plana vitrectomy, immunosuppressive agents and sustained release intravitreal steroid implant. Results: The patient had a good recovery of vision with complete resolution of inflammation and without any long-term complication. Conclusion: HLAB27 positivity can be associated with an uncommon presentation of fulminant posterior uveitis that requires a judicious and stepwise multimodality approach in its management, and can have a good visual and anatomical outcome as demonstrated in our case.

High-dose intravenous steroid pulse therapy in ocular involvement of Behcet's disease: a pilot double-blind controlled study.

AIM: To evaluate the efficacy of intravenous high-dose pulses of methylprednisolone (IVPM) for treatment of ocular involvement in Behcet's disease (BD). METHOD: In a double-blind control study, we randomized BD patients with posterior uveitis (PU) and/or retinal vasculitis (RV) into two groups. They received either IVPM (1000 mg methylprednisolone) or placebo for 3 consecutive days. Both groups received combination therapy with IV cyclophosphamide, azathioprine and prednisolone for 6 months. Visual acuity (VA), Disease Activity Index (DAI) based on the inflammatory state of each section of each eye, total inflammatory (TIAI) and adjusted DAI (TADAI) for each patient were calculated. The comparisons were done by paired t- and Mann-Whitney U-test. RESULTS: Seventeen patients in each group completed the treatment. The mean VA improved from 0.5 to 0.8 (P < 0.000001) for the study and from 0.6 to 0.7 (P < 0.02) for the placebo group. The difference was significant (P = 0.01). The comparison showed no significant difference regarding DAI improvement in other items (P > 0.2): PU, 1.9 to 0.5 (P < 0.0006) versus 2.3 to 0.8 (P < 0.0002); RV: 4.0 to 1.1 (P < 0.0004) versus 3.1 to 1.1 (P < 0.0005); TIAI: 23 to 5.7 (P < 0.0002) versus 24.8 to 8.4 (P < 0.003); TADAI: 24.1 to 7.3 (P < 0.0002) versus 25.9 to 7.9 (P < 0.004). We had one flare in the study versus seven in the placebo group (P < 0.005). CONCLUSION: Adding high-dose intravenous steroid pulse therapy to conventional combination therapy for severe ocular lesions of BD may cause better improvement on VA and fewer flares during the first 6 months of treatment.

LYN- and AIRE-mediated tolerance checkpoint defects synergize to trigger organ-specific autoimmunity.

Studies of the genetic factors associated with human autoimmune disease suggest a multigenic origin of susceptibility; however, how these factors interact and through which tolerance pathways they operate generally remain to be defined. One key checkpoint occurs through the activity of the autoimmune regulator AIRE, which promotes central T cell tolerance. Recent reports have described a variety of dominant-negative AIRE mutations that likely contribute to human autoimmunity to a greater extent than previously thought. In families with these mutations, the penetrance of autoimmunity is incomplete, suggesting that other checkpoints play a role in preventing autoimmunity. Here, we tested whether a defect in LYN, an inhibitory protein tyrosine kinase that is implicated in systemic autoimmunity, could combine with an Aire mutation to provoke organ-specific autoimmunity. Indeed, mice with a dominant-negative allele of Aire and deficiency in LYN spontaneously developed organ-specific autoimmunity in the eye. We further determined that a small pool of retinal protein-specific T cells escaped thymic deletion as a result of the hypomorphic Aire function and that these cells also escaped peripheral tolerance in the presence of LYN-deficient dendritic cells, leading to highly destructive autoimmune attack. These findings demonstrate how 2 distinct tolerance pathways can synergize to unleash autoimmunity and have implications for the genetic susceptibility of autoimmune disease.

In-vivo immunofluorescent imaging in cases of posterior uveitis.

In-vitro immunofluorescent assays/imaging are routinely used methods of detecting antigens. The ability to perform ocular angiography to study the choroidal and retinal vasculature in real time provides us with a unique opportunity to perform real time in-vivo immunofluorescent imaging. This unique combination of in-vivo immunofluorescent imaging and live imaging of choroidal and retinal circulation can help detect antigens of infective organisms in-vivo to diagnose causative infective aetiology in cases of choroiditis/retinitis. The following paper describes the basic designing of such an imaging platform.

Characterization of a New Epitope of IRBP That Induces Moderate to Severe Uveoretinitis in Mice With H-2b Haplotype.

PURPOSE: Experimental autoimmune uveitis (EAU) induced in mice using the retinal antigen interphotoreceptor retinoid binding protein (IRBP) is an animal model for posterior uveitis in humans. However, EAU induced by native IRBP protein or its widely used epitope amino acid residues 1 to 20 of human IRBP (hIRBP1-20) is inconsistent, often showing low scores and incidence. We found an urgent need to identify a better pathogenic epitope for the C57BL/6 strain. METHODS: Mice were immunized with uveitogenic peptides or with native bovine IRBP. Clinical and histological disease and associated immunological responses were evaluated. Truncated and substituted peptides, as well as bioinformatic analyses, were used to identify critical major histocompatibility complex (MHC)/T cell receptor (TCR) contact residues and the minimal core epitope. RESULTS: The new uveitogenic epitope of IRBP, amino acid residues 651 to 670 of human IRBP (LAQGAYRTAVDLESLASQLT [hIRBP651-670]) is uveitogenic for mice of the H-2b haplotype and elicits EAU with a higher severity and incidence in C57BL/6 mice than the previously characterized hIRBP1-20 epitope. Using truncated and substituted peptides, as well as bioinformatic analysis, we identified the critical contact residues with MHC/TCR and defined the minimal core epitope. This made it possible to design MHC tetramers and use them to detect epitope-specific T cells in the uveitic eye and in lymphoid organs of hIRBP651-670-immunized mice. CONCLUSIONS: Data suggest that hIRBP651-670 is an epitope naturally processed from a conserved region of native IRBP, potentially explaining its relatively high uveitogenicity. This epitope should be useful for basic and preclinical studies of uveitis in the C57BL/6 model and gives access to genetically engineered mice available on this background.

Retinal involvement in uveitis associated with Hodgkin disease.

PURPOSE: To describe a patient with Hodgkin disease with posterior uveitis who also had a thinning of the retina and an antiretinal autoantibody in his serum. METHODS: Our patient was a 58-year-old man who had been diagnosed with Hodgkin disease. He had a complete ophthalmologic examination including fluorescein angiography, electroretinography, perimetry, and spectral-domain optical coherence tomography. A search for antiretinal antibodies in the serum was made by Western blot analysis, and the retinal sites reactive to the antibodies were determined by immunohistochemistry. RESULTS: The ocular signs were mild cellular infiltration in the anterior chamber and vitreous, and small, round chorioretinal lesions in the peripheral retina. The electroretinograms were slightly reduced. Small ring-like scotomas were detected in the Goldmann visual fields. An antiretina-specific 116-kDa antibody was detected in the serum by Western blot analysis, and the antibody reacted with the ganglion cell and inner nuclear layers of mice retinas. Although the visual acuities were maintained for over eight years, the macular thickness measured in the spectral-domain optical coherence tomography images was reduced. CONCLUSION: The presence of an antiretinal autoantibody, granulomatous uveitis, and retinal thinning in a patient with Hodgkin disease suggests that the patient had a granulomatous uveitis associated with Hodgkin disease or lymphoma-associated uveitis with retinal involvement.

Clinical manifestations of cytomegalovirus-associated posterior uveitis and panuveitis in patients without human immunodeficiency virus infection.

IMPORTANCE: Little attention has been paid to clinical features of cytomegalovirus (CMV) infections in individuals without human immunodeficiency virus (HIV). OBJECTIVE: To describe the clinical manifestations and comorbidities of patients without HIV infection who have CMV-associated posterior uveitis or panuveitis. DESIGN AND SETTING: Retrospective observational case series in an academic research setting. PARTICIPANTS: The medical records were reviewed of 18 patients (22 affected eyes) diagnosed as having posterior uveitis or panuveitis who had aqueous positive for CMV by polymerase chain reaction techniques. MAIN OUTCOME MEASURES: Demographic data, clinical manifestations, and associated systemic diseases were recorded. RESULTS: Ocular features included focal hemorrhagic retinitis (n = 13) and peripheral retinal necrosis (n = 7). Two eyes had no focal retinal lesions but manifested vasculitis and vitritis. All patients exhibited vitreous inflammation. Inflammatory reactions in anterior segments developed in 14 of 22 eyes (64%). Retinal vasculitis was observed in 16 of 22 eyes (73%) and included mostly arteries (in 13 of 16 eyes [81%]). Eleven of 18 patients were taking immunosuppressive medications (5 for hematologic malignant diseases, 4 for systemic autoimmune diseases, and 2 following organ transplants). One additional patient was diagnosed as having non-Hodgkin lymphoma 3 months after the onset of CMV-associated panuveitis, and another patient had primary immunodeficiency disorder. Of the remaining 5 patients, 2 had diabetes mellitus, and 3 had no associated systemic diseases and exhibited no evidence of immune deficiency. CONCLUSIONS AND RELEVANCE: Cytomegalovirus-associated infections of posterior eye segments can develop in patients without HIV infection who have compromised immune function of variable severity but may occur also in individuals who have no evidence of immune insufficiency. Cytomegalovirus infections located in posterior eye segments in patients without HIV infection caused intraocular inflammatory reaction in all cases and demonstrated more variable clinical presentation than classic CMV retinitis observed in patients with HIV infection.

Effects of systemic and intravitreal TNF-α inhibition in experimental autoimmune uveoretinitis.

PURPOSE: To investigate the effect of systemic or local TNF-α inhibition with etanercept on experimental autoimmune uveoretinitis (EAU). METHODS: EAU was induced by immunizing B10.RIII mice with IRBPp161-180 or by adoptively transferring uveitogenic splenocytes. Mice received systemic or local treatment with etanercept in the afferent or efferent phase. For systemic treatment, mice were injected intraperitoneally. For local treatment, etanercept was injected intravitreally or subconjunctivally. Control mice received PBS. EAU scores were determined histologically. Splenic cells were assessed for [(3)H]thymidine incorporation. ELISA was performed to measure levels of cytokines produced by splenocytes. Vitreous cavity-associated immune deviation (VCAID) was induced by intravitreally injecting ovalbumin and evaluated by measuring DTH reaction. RESULTS: After systemic treatment with etanercept in the afferent phase, EAU disease scores, IRBP-specific cell proliferation, and production of Th1, Th2, and Th17 cytokines were reduced. EAU also improved after intravitreal etanercept treatment in the afferent phase, with unaltered IRBP-specific proliferation, reduced IFN-γ, but increased IL-6 and IL-10 secretion. VCAID induction was impaired after intravitreal etanercept treatment. No amelioration of EAU or reduction in IRBP-specific cell response was found after systemic or intravitreal treatment in the efferent phase or after subconjunctival treatment. After adoptive transfer, etanercept- and PBS-treated recipients showed similar disease severity and antigen-specific proliferation of splenocytes. CONCLUSIONS: It can be concluded that TNF-α participates mainly in the immunopathology in the induction phase of EAU. The mechanism of action underlying EAU improvement may be different for local and systemic etanercept treatment.

Everolimus improves experimental autoimmune uveoretinitis.

The efficacy and action mechanism of everolimus in the treatment of experimental autoimmune uveoretinitis (EAU) was analyzed. Disease was induced in B10.RIII mice by immunization with human interphotoreceptor-retinoid-binding protein peptide 161-180 (hIRBPp161-180). Everolimus was administered by oral gavage (5 mg/kg/d) beginning either two days before or 14 days after immunization. Everolimus significantly reduced the histopathological uveitis score compared to sham-treated mice. To examine the effect on the antigen-specific immune response, proliferation ([(3)H]-thymidine test) and delayed-type hypersensitivity (DTH) response were measured. Furthermore, content of T-helper-1, -2, and -17 cytokines were analyzed intraocularly (Bead Array) and in cell culture supernatants from splenocytes (sandwich ELISA). To study the effect on the humoral immune response the presence of antigen-specific serum antibodies was tested (indirect ELISA). The DTH, the humoral immune response, the proliferation of splenocytes and the intraocular Th1, Th2, Th17 cytokine content and in vitro production of Th1 and Th17 cytokines were impaired after everolimus treatment. The study of CD4+CD25+FoxP3+ regulatory T cells (T(reg)) in peripheral blood, draining lymph nodes, and spleen by flow cytometry showed an increased number of splenic T(reg) in mice of the everolimus therapy group. Furthermore the T(reg) of these mice had a higher suppressive capacity than cells from sham-treated mice. These results indicate that the immunosuppressive effect of everolimus on EAU was associated with the suppression of pathogenic effector responses and induction of regulatory T cells.

Interleukin 17A as an effective target for anti-inflammatory and antiparasitic treatment of toxoplasmic uveitis.

BACKGROUND: Toxoplasmosis is the most common cause of posterior uveitis in immunocompetent subjects. The requirement of limiting both parasite multiplication and tissue destruction suggests that the balance between T-helper (Th) 17 and T-regulatory cells is an important factor in toxoplasmosis-induced retinal damage. METHODS: In a prospective clinical study of acute ocular toxoplasmosis, we assessed the cytokine pattern in aqueous humors of 10 affected patients. To determine the immunological mechanisms, we evaluated intraocular inflammation, parasite load, and immunological responses using messenger RNA and protein levels in a mouse model. Anti-interleukin 17A (IL-17A) monoclonal antibodies (mAbs) were administered with the parasite to evaluate the role of IL-17A. RESULTS: Severe ocular inflammation and cytokine patterns comparable to human cases were observed, including IL-17A production. Neutralizing IL-17A decreased intraocular inflammation and parasite load in mice. Detailed studies revealed up-regulation of T-regulatory and Th1 pathways. When interferon γ (IFN-γ) was neutralized concomitantly, the parasite multiplication rate was partially restored. CONCLUSIONS: Local IL-17A production by resident cells plays a central role in the pathology of ocular toxoplasmosis. The balance between Th17 and Th1 responses (especially IFN-γ) is crucial for the outcome of infection. This data reveals new in vivo therapeutic approaches by repressing inflammatory pathways using intravitreal injection of IL-17A mAbs.

An age-adjusted seroprevalence study of Toxoplasma antibody in a Malaysian ophthalmology unit.

Toxoplasma gondii is a public health risk in developing countries, especially those located in the tropics. Widespread infection may inflict a substantial burden on state resources, as patients can develop severe neurological defects and ocular diseases that result in lifelong loss of economic independence. We tested sera for IgG antibody from 493 eye patients in Malaysia. Overall age-adjusted seroprevalence was estimated to be 25% (95% CI: [21%, 29%]). We found approximately equal age-adjusted seroprevalence in Chinese (31%; 95% CI: [25%, 38%]) and Malays (29%; 95% CI: [21%, 36%]), followed by Indians (19%; 95% CI: [13%, 25%]). A logistic regression of the odds for T. gondii seroprevalence against age, gender, ethnicity and the occurrence of six types of ocular diseases showed that only age and ethnicity were significant predictors. The odds for T. gondii seroprevalence were 2.7 (95% CI for OR: [1.9, 4.0]) times higher for a patient twice as old as the other, with ethnicity held constant. In Malays, we estimated the odds for T. gondii seroprevalence to be 2.9 (95% CI for OR: [1.8, 4.5]) times higher compared to non-Malays, with age held constant. Previous studies of T. gondii seroprevalence in Malaysia did not explicitly adjust for age, rendering comparisons difficult. Our study highlights the need to adopt a more rigorous epidemiological approach in monitoring T. gondii seroprevalence in Malaysia.

HLA-A29 and birdshot chorioretinopathy.

Birdshot chorioretinopathy primarily affects patients of European descent. At least 96%, if not all patients, are HLA-A29 carriers. HLA-A*29:01 and HLA-A*29:02, the two main subtypes of HLA-A29, differ only by a single mutation. In the general population HLA-A*29:02 is most frequent in whites, while HLA-A*29:01 is more frequent in Asians. The differential distribution of HLA-A*29:01 and HLA-A*29:02 has been actively debated as an explanation for the selective development of the disease in patients of European descent, but is no longer a valid argument. Another factor, probably not HLA linked, is either protective in Asians and in Africans or, conversely, triggers an autoimmune reactivity that is possibly present in whites and absent in Asians and in Africans. HLA-A*29:02 transgenic mice in which a spontaneous posterior uveitis is observed after 6 months of age provide further evidence that the HLA-A29 molecule plays a role in the pathogenesis of the disease.

Long-term remission of ocular and extraocular manifestations in Behçet's disease using infliximab.

OBJECTIVES: To investigate the long-term effect of infliximab on ocular and extraocular manifestations in patients with Behçet's disease. METHODS: Seven patients with active Behçet's disease and treated with infliximab at Aichi Medical University Hospital for more than 18 months were included in the study. We evaluated visual acuity, the average number of uveitis attacks involving the posterior segment, and general disease activity every 2 months. The Behçet's Disease Current Activity Form (BDCAF) was used for an overall index of disease activity. Anti-infliximab antibody levels were examined in the patients' sera. RESULTS: The follow-up period after initial introduction of infliximab ranged from 19 to 40 months (mean ± SD, 32 ± 8.7 months). The number of infliximab infusions ranged from 12 to 24 (19 ± 4.4). By the 2-month follow-up, the frequency of uveitis attacks involving the posterior segment and the BDCAF scores were significantly improved compared to the 2 months before introducing infliximab. Anti-infliximab antibodies were detected in the sera of all examined patients. CONCLUSIONS: Significant long-term improvement in both the frequency of uveitis attacks involving the posterior segment and overall disease activity was provided by the administration of infliximab to patients suffering from Behçet's disease, despite the presence of anti-infliximab antibodies.

Real-time polymerase chain reaction and intraocular antibody production for the diagnosis of viral versus toxoplasmic infectious posterior uveitis.

PURPOSE: The aim of this work was to determine the diagnostic performance of real-time polymerase chain reaction (RT-PCR) and to assess intraocular specific antibody secretion (Goldmann-Witmer coefficient) on samples from patients with signs of posterior uveitis presumably of infectious origin and to target the use of these two biologic tests in the diagnostic of Toxoplasma/viral Herpesviridae posterior uveitis by the consideration of clinical behavior and delay of intraocular sampling. METHODS: Aqueous humour and/or vitreous fluid were collected from patients suspected of having posterior uveitis of infectious origin at presentation (140 samples). The diagnosis was confirmed by quantification of antibodies with the Goldmann-Witmer coefficient (GWC) and for detection of Herpesviridae and Toxoplasma gondii genomes with RT-PCR. Forty-one patients had final diagnosis of uveitis of non-Toxoplasma/non-viral origin and 35 among them constituted the control group. The main outcome measures were sensitivity, specificity, and positive and negative predictive values (PPV and NPV). RESULTS: When pre-intraocular testing indication was compared with final diagnosis, GWC was a more sensitive and specific method than RT-PCR, and was successful in detecting T. gondii, especially if the patient is immunocompetent and the testing is carried out later in the disease course, up to 15 months. For viral Herpesviridae uveitis, the sensitivity and PPV of PCR evaluation was higher than detected with GWC with respectively 46% compared with 20% for sensitivity and 85% versus 60% for PPV. In either viral retinitis or toxoplasmosis infection, RT-PCR results were positive from 24 h, although GWC was not significant until 1 week after the onset of signs. In toxoplasmosis patients, positive RT-PCR results were statistically correlated with the chorioretinitis area (more than three disc areas; p = 0.002), with the age older than 50 (p = 0.0034) and with a clinical anterior inflammation (Tyndall ≥1/2+) and panuveitis; (p = 0.0001). CONCLUSIONS: For the diagnosis of viral or toxoplasmosis-associated intraocular inflammation, the usefulness of laboratory diagnosis tools (RT-PCR and GWC) depends on parameters other than the sensitivity of the tests. Certain patient characteristics such as the age of the patients, immune status, duration since the onset of symptoms, retinitis area, predominant site and extent of inflammation within the eye should orientate the rational for the choice of laboratory testing in analysis of intraocular fluids.

Seroreactivity against aqueous-soluble and detergent-soluble retinal proteins in posterior uveitis.

OBJECTIVE: To characterize the seroreactivity against retinal proteins in patients with posterior uveitis, retinal disease of noninflammatory origin, and healthy controls. METHODS: Patients with posterior uveitis (n = 47), molecularly confirmed photoreceptor degenerations (n = 11), and healthy controls (n = 33) received dilated fundus examinations at the University of Iowa. Aqueous-soluble and detergent-soluble fractions of human retina were separated by gel electrophoresis and transferred to polyvinylidene fluoride membranes. Membranes were probed with patient serum samples to detect IgG, IgA, and IgM human antibodies that react with retinal antigens. The number of bands detected by Western blot was counted, and their molecular weights were determined. RESULTS: Antibodies recognizing retinal proteins were found in healthy controls, in patients with posterior uveitis, and in patients with molecularly confirmed heritable retinal degenerations. In healthy controls, 42% of individuals had circulating autoantibodies that recognized retinal proteins. Healthy controls had a low odds ratio of serum reactivity to soluble antigens (0.7; 95% confidence interval [CI], 0.4-1.2). Patients with inflammatory retinal diseases and inherited retinal diseases had 4.89 (95% CI, 2.25-10.64; P < .001) and 2.71 (95% CI, 1.19-6.16; P = .02) times more activity against soluble retinal antigens compared with controls. CONCLUSIONS: Healthy control patients exhibited a significantly higher level of background autoantibody activity against retinal proteins than previously reported. Antibody activity in healthy controls was primarily directed against membrane-bound retinal proteins, whereas in patients with pathologic retinal conditions, antibodies targeting nonmembrane-bound retinal proteins predominate.

[Intravitreal implants: drug carriers and carriers of hope?]. / Intravitreale Implantate: Wirkstoff- und "Hoffnungsträger"?

Immunosuppressive agents are used for the therapy of noninfectious uveitis if intraocular quiescence and freedom from recurrences are not achievable with oral steroids at a low dosage. Partially, severe side effects are tolerated to preserve visual acuity even if the disease is limited to the eyes. Because of this a therapy would be desirable which is highly effective, limited to the eyes and with few side effects. For this fluocinolone acetonide and dexamethasone drug delivery systems were developed. Dexamethasone implants were already approved for the therapy of retinal vein occlusions and are used successfully. Diabetic macular edema would be another possible indication for dexamethasone implants.

Neutrophil-dominant experimental autoimmune uveitis in CC-chemokine receptor 2 knockout mice.

PURPOSE: Murine experimental autoimmune uveitis (EAU) is an animal model of human uveitis. It has been demonstrated that ocular-infiltrating macrophages are crucial for EAU induction, and monocyte chemoattractant protein-1 (MCP-1) was actually upregulated in the eye. CC chemokine receptor-2 (CCR2) is the receptor of MCP-1, and macrophages fail to recruit particular lesions in CCR2 knockout (KO) mice. To confirm the role of macrophages in EAU, we examined EAU in CCR2 KO mice. METHODS: CCR2 KO mice and wild-type (WT) mice that had the same genetic background were immunized with human interphotoreceptor retinoid-binding protein peptide 1-20 emulsified in complete Freund's adjuvant. At multiple time-points, EAU severity was evaluated based on microscopic fundus observation and histological examination. To examine the phenotype of retinal-infiltrating cells, single cells were prepared from the eye and analysed by flow cytometry. RESULTS: In WT mice, EAU was induced at the peak of day 16 and marked macrophage infiltration was observed. Although macrophages failed to be recruited into the eye in CCR2 KO mice, severe uveitis was induced unexpectedly. Flow cytometry and histology revealed that most of the infiltrating cells were neutrophils. We also compared the intraocular chemokine concentrations between WT mice and KO mice. Two CXC chemokine (monokine induced by interferon-γ and interferon-γ-inducible protein-10) were upregulated in KO mice. CONCLUSION: Interphotoreceptor retinoid-binding protein peptide immunization caused neutrophil-dominant uveitis in CCR2 KO mice. In the absence of macrophages, neutrophils can be alternatively recruited and can cause tissue damage.

Contribution of anti-Hsp70.1 IgG antibody levels to the diagnostic certainty of clinically suspected ocular toxoplasmosis.

PURPOSE: Laboratory diagnosis of ocular toxoplasmosis, the major cause of posterior uveitis worldwide, can be improved. Heat shock protein (Hsp) 70 is involved in cellular infection by Toxoplasma gondii but also in the immune response to this parasite. The authors postulate that infected patients may exhibit serum IgG anti-Hsp70.1 antibodies and that determining the presence of these antibodies could improve the diagnosis of suspected ocular toxoplasmosis. METHODS: This retrospective case-control study included 26 laboratory-confirmed cases of ocular toxoplasmosis (group A), 41 clinically suspected cases (group B), and 67 currently healthy blood donors who were chronically infected with T. gondii (group C). Laboratory and clinical data were analyzed according to the ocular presentation and Goldmann-Witmer's coefficient. Serum and aqueous humor were sampled at the time of uveitis. Serum anti-Hsp70.1 antibody levels were obtained by ELISA. The probability of ocular toxoplasmosis was estimated by a logistic regression analysis that combined data from serum IgG anti-Hsp70.1 and aqueous-humor IgG anti-T. gondii antibody levels. RESULTS: Serum IgG anti-Hsp70.1 antibody levels were significantly increased in groups A and B when compared to the levels in control group C (P ≤ 0.0034). These levels correlated with the retinal lesion size (r = 0.301; P < 0.0349). Logistic probability and anti-Hsp70.1 antibodies in sera confirmed that 10 of 23 cases in group B were true ocular toxoplasmosis. CONCLUSIONS: Anti-Hsp70 may play a role in the immunopathogenesis of ocular Toxoplasma infection. This study showed that the anti-Hsp70.1 antibody and the logistic probability test can confirm clinically suspected ocular toxoplasmosis.

The monocyte chemokine receptor CX3CR1 does not play a significant role in the pathogenesis of experimental autoimmune uveoretinitis.

PURPOSE: To examine the role of the monocyte chemokine receptor CX(3)CR1 in experimental autoimmune uveoretinitis (EAU). METHODS: EAU was induced in naive WT, Cx(3)cr1(gfp/+), and Cx(3)cr1(gfp/gfp) C57Bl/6 mice or chimeric mice. Ocular disease severity was graded by histologic analysis of resin sections. In addition, immunohistochemistry and confocal microscopy were performed on retinal whole mounts to characterize the monocytic infiltrate and changes in retinal microglia. To determine the relative roles of resident and blood-borne monocyte-derived cells in the active phase of uveoretinitis, EAU was induced 4 weeks after transplantation in chimeric mice (Cx(3)cr1(gfp/gfp)→WT and Cx(3)cr1(gfp/+)→WT), and analysis was performed at days 14, 16, 21, and 28 after immunization. RESULTS: After EAU induction, disease scores were not significantly different in WT, Cx(3)cr1(gfp/+), and Cx(3)cr1(gfp/gfp) mice. Chimeric studies revealed both donor- and host-derived monocyte-derived cells in the inner retinal layers during early EAU; however, it was donor monocytic cells that infiltrated the photoreceptors, the site of the target antigen. The absence of CX(3)CR1 did not impede the ability of monocyte-derived cells from Cx(3)cr1(gfp/gfp) donor mice to infiltrate during the peak of EAU. CONCLUSIONS: The lack of CX(3)CR1 on monocyte-derived cells does not significantly influence the onset or severity of EAU. In addition, chimeric studies revealed that it is primarily blood-derived monocytes that mediate photoreceptor damage in the effector phase of EAU, and this process is not CX(3)CR1 dependent.