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.

Inner Retinal Microvasculature Damage Correlates With Outer Retinal Disruption During Remission in Behçet's Posterior Uveitis by Optical Coherence Tomography Angiography.

Purpose: To quantify the inner retinal vascular changes that occur in the superficial and deep layers in patients with Behçet's disease (BD) in remission using optical coherence tomography angiography (OCTA) and to evaluate the associations with outer retinal structure. Methods: Nineteen eyes from 19 patients with BD in remission were enrolled, including 10 eyes with less than five ocular attacks (n < 5) and nine eyes with five or more attacks (n ≥ 5). The foveal avascular zone (FAZ) and global and regional vessel density (VD) in both layers were compared between BD eyes and normal eyes. Their outer retinal structure, including integrity of the ellipsoid zone (EZ), interdigitation zone (IZ), and outer retinal layer thickness were evaluated. Associations between the inner retinal vasculature and outer retinal disruption were sought. Results: Compared to normal eyes, except for the nasal region, all deep capillary VD values were lower in the BD groups, especially in the inferior region. In the superficial layer, the VD differences between groups were larger in capillaries than in small vessels. The FAZ in the n ≥ 5 group was larger than that in normal and the n < 5 groups in the deep layer. Greater disruption of EZ and IZ was correlated with decreasing global and regional deep capillary VD. Conclusions: BD Patients in remission had significant changes in the inner retinal vasculature that corresponded to the outer retinal disruption. Quantitative measurement by OCTA and algorithm might be useful for evaluation of the vasculature and pathologic changes in BD.

QUANTITATIVE ANALYSIS OF STRUCTURAL ALTERATIONS IN THE CHOROID OF PATIENTS WITH ACTIVE BEHÇET UVEITIS.

PURPOSE: To quantitatively analyze in vivo morphology of subfoveal choroid during an acute attack of Behçet uveitis. METHODS: In this prospective study, 28 patients with Behçet uveitis of ≤4-year duration, and 28 control subjects underwent enhanced depth imaging optical coherence tomography. A novel custom software was used to calculate choroidal stroma-to-choroidal vessel lumen ratio. Subfoveal choroidal thickness was measured at fovea and 750 µm nasal, temporal, superior, and inferior to fovea. Patients underwent fluorescein angiography and indocyanine green angiography. Receiver operating characteristic curve and area under the curve were computed for central foveal thickness. The eye with a higher Behçet disease ocular attack score 24 was studied. The main outcome measures were choroidal stroma-to-choroidal vessel lumen ratio and choroidal thickness. RESULTS: The mean total Behçet disease ocular attack score 24, fluorescein angiography, and indocyanine green angiography scores were 7.42 ± 4.10, 17.42 ± 6.03, and 0.66 ± 0.73, respectively. Choroidal stroma-to-choroidal vessel lumen ratio was significantly higher in patients (0.413 ± 0.056 vs. 0.351 ± 0.063, P = 0.003). There were no significant differences in subfoveal choroidal thickness between patients and control subjects. Choroidal stroma-to-choroidal vessel lumen ratio correlated with retinal vascular staining and leakage score of fluorescein angiography (r = 0.300, P = 0.036). Central foveal thickness was significantly increased in patients (352.750 ± 107.134 µm vs. 263.500 ± 20.819 µm, P < 0.001). Central foveal thickness showed significant correlations with logarithm of minimum angle of resolution vision, Behçet disease ocular attack score 24, total fluorescein angiography score, retinal vascular staining and/or leakage and capillary leakage scores of fluorescein angiography, and total indocyanine green angiography score. At 275 µm cutoff, diagnostic sensitivity and specificity of central foveal thickness for acute Behçet uveitis were 89% and 72%, respectively (area under the curve = 0.902; 95% CI = 0.826-0.978, P < 0.001). CONCLUSION: There was choroidal stromal expansion which was not associated with thickening of the choroid. Central foveal thickness may be used as a noninvasive measure to assess inflammatory activity in early Behçet uveitis.

Dexamethasone implants in paediatric patients with noninfectious intermediate or posterior uveitis: first prospective exploratory case series.

BACKGROUND: To evaluate the efficacy and safety of dexamethasone (DEX) implants in paediatric patients with noninfectious intermediate or posterior uveitis. METHODS: Prospective single center exploratory case series. Children and adolescents, 6 to 17 years old, with a vitreous haze score of ≥1.5+ or cystoid macular edema (CME) of >300 µm were enrolled. Vitreous haze score at month 2 was chosen as primary endpoint. Best corrected visual acuity (BCVA), central retinal thickness (CRT) and concomitant medication at month 6 were defined as secondary endpoints. Intraocular pressure (IOP) and cataract formation were determined as safety endpoints. RESULTS: Three out of 6 eligible patients participated in the case series. At month 2, vitreous haze was reduced from a score of 1.5+ to 0.5+ and 0 and BCVA improved by ≥3 lines, ≥4 lines and ≥2 lines of Early Treatment of Diabetic Retinopathy (ETDRS)-letters, respectively. Visual acuity gain was accompanied by a CRT reduction of -186 µm and -83 µm in the first and third patient, in whom CME was the indication for DEX implantation. A reduction of concomitant medication was achieved in 1 patient. IOP increase was seen in all 3 patients, but could be treated sufficiently with primarily IOP lowering medications and without need for glaucoma surgery. Cataract progression did not occur. CONCLUSIONS: DEX implants led to an improvement in all endpoints, especially BCVA. This study confirms that IOP rises may also occur in the paediatric population and should be monitored and treated appropriately. TRIAL REGISTRATION: European Union Drug Regulating Authorities Clinical Trials (EudraCT)- nr: 2013-000541-39.

Viral Retinopathy in Experimental Models of Zika Infection.

Purpose: Emerging evidence has shown that both congenital and adult Zika virus (ZIKV) infection can cause eye diseases. The goals of the current study were to explore mechanisms and pathophysiology of ZIKV-induced eye defects. Methods: Wild-type or A129 interferon type I receptor-deficient mice were infected by either FSS13025 or Mex1-7 strain of ZIKV. Retinal histopathology was measured at different time points after infection. The presence of viral RNA and protein in the retina was determined by in situ hybridization and immunofluorescence staining, respectively. Growth curves of ZIKV in permissive retinal cells were assessed in cultured retinal pigment epithelial (RPE) and Müller glial cells. Results: ZIKV-infected mice developed a spectrum of ocular pathologies that affected multiple layers of the retina. A primary target of ZIKV in the eye was Müller glial cells, which displayed decreased neurotrophic function and increased expression of proinflammatory cytokines after infection. ZIKV also infected RPE; and both the RPE and Müller cells expressed viral entry receptors TYRO3 and AXL. Retinitis, focal retinal degeneration, and ganglion cell loss were observed after the clearance of viral particles. Conclusions: Our data suggest that ZIKV can infect infant eyes with immature blood-retinal barrier and cause structural damages to the retina. The ocular findings in microcephalic infants may not be solely caused by ZIKV-induced impairment of neurodevelopment.

Detection of mild papilloedema in posterior uveitis using spectral domain optical coherence tomography.

OBJECTIVE: To compare two methods for diagnosing mild papilloedema (PO) using peripapillary total retinal (PTR) and retinal nerve fibre layer (RNFL) thickness measurement by spectral domain optical coherence tomography (OCT) in patients suffering from posterior uveitis. METHODS: 17 eyes in 17 patients with PO caused by posterior uveitis, 15 eyes in 15 patients with uveitis but with no PO based on slit lamp analysis were studied. High-quality OCT fundus images were analysed and graded by three masked observers using the Modified Frisén Scale. Eyes with PO were divided into two subgroups: mild (n=15) and moderate-severe PO (n=2). Two measurement methods were evaluated and compared: RNFL and PTR thickness measurements centred on the optic disc. Thickness values were calculated overall and for each quadrant and compared between groups. The main outcome measures were RNFL and PTR thickness, and thickness variation between control and affected patients for both protocols. RESULTS: Average RNFL and PTR thickness in the moderate-severe PO, mild PO and control groups were 274.5±54.45 µm, 134±31.69 µm, 97.4±14.43 µm and 722.25±29.34 µm, 437.53±84.47 µm, 327.8±25.92 µm, respectively. Mild PO differed from the control groups according to both the RNLF (p=0.0006) and the PTR (p=0.0002) measurements. The average thickness variation between control and mild PO was significantly different between RNFL and PTR measurements: 36.6 µm vs 109.73 µm (p<0.0001), respectively. CONCLUSIONS: PTR thickness measurement increases the sensitivity of detection of mild PO and could be useful for diagnosing and monitoring papillitis. A new protocol should be developed to measure PTR in the same 3.5 mm disc as the RNFL measurement.

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.

Development and evaluation of dexamethasone nanomicelles with potential for treating posterior uveitis after topical application.

PURPOSE: This study aims at the development and preliminary evaluation of dexamethasone nanomicelles for treating posterior uveitis. Nanomicelles were formulated using polyoxyl 40 stearate (P40S) and polysorbate 80 (P80), which are approved by the FDA for ocular use. METHODS: Dexamethasone nanomicelles were prepared and characterized for critical micellar concentration, solubility of dexamethasone, particle size, surface charge, morphology, in vitro drug release, clarity, stability, filtration efficiency, and sterility. Ocular tolerance and the tissue drug distribution of dexamethasone were assessed in rabbits after single and multiple topical administration. RESULTS: Dexamethasone nanomicelles (0.1% w/v) were successfully developed and characterized with an optimized composition of P40S/P80=7/3 by weight. The mean diameter of blank and drug-loaded nanomicelles was 13.3±0.4 and 14.5±0.4 nm, respectively. Transmission electron microscopy images revealed the spherical structure of nanomicelles. Nanomicelles were found to be stable with respect to clarity, size and drug content at 4°C and 25°C for up to 6 months. No irritation or redness was observed in the treated eyes as compared with the untreated control rabbit eyes. Therapeutic concentrations of dexamethasone were observed in the retina and choroid after single and multiple topical application in rabbits. CONCLUSION: In conclusion, the nanomicelles of P40S and P80 could efficiently solubilize 0.1% dexamethasone in their cores. The results also indicate that mixed nanomicelles could be utilized as a potential delivery system for delivering dexamethasone to treat the back of the eye diseases such as posterior uveitis after topical application.

The role of fundus autofluorescence imaging in the study of the course of posterior uveitis disorders.

BACKGROUND: To evaluate the correlation of fundus autofluorescence (FAF) with indocyanine green angiography (ICGA) in patients with various posterior uveitis disorders. METHODS: Interventional case series including 23 eyes of 15 patients with diagnosis of a specific type of retinochoroiditis, such as acute posterior multifocal placoid pigment epitheliopathy (APMPPE), serpiginous-like choroiditis, multifocal choroiditis (MFC), Harada disease, and syphilitic retinochoroiditis. Also, some cases with undefined retinochoroiditis were included. FAF and ICGA were performed and correlated at baseline and during follow-up after treatment. RESULTS: In ICGA, early hypofluorescence was found to be the hallmark of acute choroidal inflammation, resolving in later stages and remaining in the late phase in areas with retinal pigment epithelium (RPE) damage. Poorly defined hyperautofluorescent areas correlated with acute choroidal lesions. Hypoautofluorescent delineation suggested the initiation of RPE healing processes, correlating well with the late phase of ICGA and delineating the RPE damage. Early hyperautofluorescence with late hypofluorescence in ICGA indicated the presence of primary RPE involvement. CONCLUSION: FAF contributes to the interpretation of RPE disease and may be a useful tool for the follow-up of progressive inflammatory disorders. Comparative evaluation of FAF and ICGA allows a characterization of the sequence of inflammatory events and the level of tissue affected.

Chronic herpes simplex virus type 2 encephalitis associated with posterior uveitis.

We report on a patient with chronic herpes simplex virus-2 encephalitis who was characteristic for concomitantly having chronic or recurrent posterior uveitis. A 66-year-old immunocompetent man suffering from a 6-month refractory posterior uveitis developed a 1-month history of impaired short-term memory and orientation. Brain MRI demonstrated hyperintense lesions in the right parietal lobe in diffusion and fluid attenuated inversion recovery (FLAIR) sequences. Cerebrospinal fluid (CSF) examination showed mild pleocytosis and increased protein concentration. Quantitative PCR for HSV-2 DNA was positive in CSF. Treated with acyclovir, his cognitive functions gradually improved and the posterior uveitis was cured. Clinicians must be aware that HSV-2 should be considered in the aetiological investigation of chronic encephalitis in an immunocompetent patient. HSV-2 is well known for its ability to cause unilateral chronic or recurrent posterior uveitis. Therefore, posterior uveitis should be considered as an associated feature of HSV-2 encephalitis.

[Wide-field fundus autofluorescence in non-infectious posterior uveitis]. / Weitwinkelfundusautofluoreszenz bei nichtinfektiöser Uveitis posterior.

BACKGROUND: Posterior uveitis comprises a heterogeneous group of diseases with inflammatory alterations of the posterior fundus and is a common cause of visual impairment and blindness. The goal of this study was to evaluate the diagnostic value of wide-field fundus autofluorescence (FAF) in patients with non-infectious posterior uveitis and chorioretinal alterations. MATERIAL AND METHODS: In this study 73 eyes from 51 patients were included. Best-corrected visual acuity, wide-field color and FAF images achieved by a wide-field scanning laser opththalmoscope (SLO, Optomap P200Tx, Optos PLC, Dunfermline UK) and a full ophthalmological examination were obtained from each patient. A systematic analysis of chorioretinal alterations detected with FAF and color images was conducted followed by the evaluation of the diagnostic information of wide-field FAF compared to the clinical finding and wide-field color images. RESULTS: Of the 73 eyes included in the study 52 showed peripheral alterations. In 32 cases wide-field FAF images revealed a greater number and more extensive chorioretinal alterations than the corresponding wide-field color images of the posterior fundus. CONCLUSIONS: In this study wide-field FAF images showed more chorioretinal alterations than seen in funduscopy or in color SLO images. Therefore, wide-field FAF images offer important additional information for detection and documentation of peripheral and central chorioretinal alterations.

[Intravitreal ranibizumab in the treatment of subretinal neovascularization in a case of punctate inner choroidopathy]. / Ranibizumab intravítreo en el tratamiento de membrana neovascular subretiniana en un caso de coroidopatía puntata interna.

CASE REPORT: We report the case of a 28-year old woman suffering loss of visual acuity in her left eye, who presented an image suggestive of a subretinal neovascular membrane in her left eye, and bilateral retinal lesions compatible with punctate inner choroidopathy (PIC). She was treated with intravitreal ranibizumab obtaining excellent results. DISCUSSION: The differential diagnosis must be made between PIC and the rest of "white dot syndromes" and the presumed ocular histoplasmosis syndrome (POHS). Antiangiogenic drugs may be a good alternative for the treatment of such diseases when they develop a subretinal neovascular membrane.

Treatment of acute posterior uveitis in a porcine model by injection of triamcinolone acetonide into the suprachoroidal space using microneedles.

PURPOSE: To evaluate the effect of triamcinolone acetonide (TA) administered into the suprachoroidal space (SCS) using a microneedle and compare it with intravitreal (IVT) TA injections in a porcine model of acute posterior segment inflammation. MATERIALS: An IVT injection of balanced salt solution (BSS) or lipopolysaccharide (LPS) was followed 24 hours later with an injection of 0.2 mg or 2.0 mg of TA into the SCS or IVT. The SCS was accessed using microneedles in a minimally invasive procedure. Ocular inflammatory scores and IOP measurements were collected daily, whereas electroretinography, optical coherence tomography, and wide-field ocular fundus photography was performed on -1, 0, and 3 days after treatment. Aqueous and vitreous humor cell counts and protein levels and histopathology were also compared. RESULTS: Delivery of TA to the SCS using microneedles was simple, effective, and not associated with adverse effects or toxicity. SCS injection of low (0.2 mg) and high doses (2.0 mg) of TA was as effective in reducing acute inflammation in the ocular posterior segment as high-dose IVT injection. Low-dose SCS TA was also effective in reducing inflammation; however, low-dose IVT TA was not. CONCLUSIONS: Results from this study suggest that 0.2 mg and 2.0 mg of SCS TA was as effective in reducing inflammation as 2.0 mg IVT TA injection in a model of acute posterior segment inflammation. There were no adverse effects, increased IOP, or evidence of procedural or drug toxicity following injection of TA into the SCS in porcine eyes.

Mean platelet volume does not seem to relate to thrombosis or posterior uveitis in Behçet's disease.

Behçet's disease (BD) is a chronic inflammatory disorder in which thrombosis and posterior ocular involvement occur in about 30% of patients, whose ethiology is unknown. It has not been established whether mean platelet volume (MPV), a marker of platelet activation, is involved in the pathogenesis of thrombotic events and posterior uveitis in these patients. We aimed to analyze whether there are differences in MPV in BD patients when compared with controls and its relation with the presence of thrombosis and posterior uveitis. We determined MPV and platelet count, along with C-reactive protein (CRP) and cardiovascular risk factors (because of their influence on MPV) in 89 BD patients (of which 24 had thrombosis and 23 had posterior uveitis) and 89 sex- and age-matched healthy controls. BD patients showed statistically higher MPV than controls: 10.98 ± 1.19 fL vs. 10.60 ± 1.21 fL (P = 0.044) and higher CRP: 5.9 ± 8.9 mg/L vs. 1.4 ± 1.7 mg/L (P = 0.001). The percentage of hyperlipemia and diabetes was higher in cases than in controls (P = 0.032, P = 0.013, respectively). No differences in MPV were observed when comparing: patients with and without thrombosis: 11.8 ± 1.27 fL vs. 10.94 ± 1.28 fL (P = 0.654); with and without posterior uveitis: 10.76 ± 1.18 fL vs. 11.03 ± 1.30 fL P = 0.398; with CRP and cardiovascular risk factors (P > 0.05). MPV correlated negatively with platelet count (r = -308, P < 0.01), but not with CRP (r = -0.22, P = 0.772). MPV seems to relate to neither thrombosis nor posterior uveitis in BD patients.

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.

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.

A promising therapeutic approach for treatment of posterior uveitis: recombinant T cell receptor ligand protects Lewis rats from acute and recurrent experimental autoimmune uveitis.

INTRODUCTION: Chronic autoimmune uveitis is a major cause of vision loss from intraocular inflammation in humans. In this study we report that a recombinant TCR ligand (RTL220) composed of the alpha1 and beta1 domains of MHC class II molecules linked to the uveitogenic interphotoreceptor retinoid-binding protein (IRBP) 1177-1191 peptide is effective in the suppression of acute and recurrent experimental autoimmune uveitis (EAU). MATERIAL AND METHODS: EAU was induced with IRBP1177-1191 peptide or by adoptive transfer of specific T cells in Lewis rats. The rats received 5 doses of RTL220 subcutaneously every other day starting at the onset of clinic signs of EAU. RESULTS: The administration of RTL220 resulted in a delayed onset and a significant amelioration of the disease severity at clinical levels and showed protection of the retina from inflammatory damage at histological levels. In treatment of recurrent EAU, RTL220 administrated at the first or second onset of clinical disease significantly inhibited EAU, modulated immune responses and provided protection from relapses of uveitis. The systemic and local proinflammatory cytokines were significantly reduced, including IL-17. There was local and systemic increase in IL-10 and reduction in the expression of the proinflammatory chemokines CCL2, CCL3 and CCL5. CONCLUSIONS: Our studies demonstrate a successful treatment of acute and recurrent EAU with RTL220, which effectively suppressed the recurrence of inflammation and reversed clinical and histological EAU by altering cytokine and chemokine expression. These findings strongly support a possible clinical application of this novel class of peptide/MHC class II drugs for patients with autoimmune uveitis.

Treatment of experimental autoimmune uveoretinitis with intravitreal injection of tacrolimus (FK506) encapsulated in liposomes.

PURPOSE. To evaluate the effects of intravitreal injection of liposomes encapsulating tacrolimus (FK506) on experimental autoimmune uveoretinitis (EAU) in Lewis rats. METHODS. Liposomes containing tacrolimus were prepared by reverse-phase evaporation vesicles. EAU was induced in Lewis rats by subcutaneous injection of interphotoreceptor retinoid-binding protein R16 peptide emulsified in adjuvant. Ten days later, rats were intravitreally injected with saline, tacrolimus, tacrolimus-loaded liposomes, or unloaded liposomes. Clinical signs of inflammation and ocular histologic sections were observed and graded. Retinal function was evaluated by electroretinography (ERG). Tacrolimus concentration was determined in the vitreous body and serum by ELISA. Ocular biodistribution of rhodamine-conjugated liposomes containing tacrolimus (tacrolimus-Rh-lip) was analyzed with a laser scanning confocal microscope. To evaluate the systemic effect of intravitreally injected tacrolimus, delayed-type hypersensitivity (DTH) and lymphocyte proliferation assay (LPA) responses were detected. RESULTS. Treatment of EAU with intravitreal injection of liposomal tacrolimus significantly reduced intraocular inflammation and markedly inhibited the development of EAU, as determined in clinical and histopathologic analyses. No toxic effects could be detected as evaluated by ERG. The concentration of tacrolimus in ocular fluids remained for as long as 14 days after liposomal injection of tacrolimus. Confocal microscopy showed a transretinal distribution of the liposomal particles. DTH and LPA responses were not impaired in liposomal tacrolimus-treated rats. CONCLUSIONS. Intravitreal injection of liposomal tacrolimus was highly effective in suppressing the process of EAU without any side effects on retinal function or systemic cellular immunity. This treatment may represent a new option for the management of intraocular inflammation.

Evaluation of experimental autoimmune uveitis in mice treated with FTY720.

PURPOSE: FTY720 (fingolimod) is an immunomodulatory drug capable of preventing T-cell migration to inflammatory sites by binding to and subsequently downregulating the expression of sphingosine-1 phosphate receptor 1 (S1P(1)) leading in turn to T-cell retention in lymphoid organs. Additional effects of FTY720 by increasing functional activity of regulatory T cells have recently been demonstrated, raising the conversion of conventional T cells into regulatory T cells and affecting the sequestration of regulatory T cells in normal mice. In this study, the action of FTY720 in the ocular autoimmune model in mice was investigated. METHODS: Mice were immunized with 161-180 peptide and pertussis toxin and were treated with 1 mg/kg/d FTY720 by gavage (7-21 days postimmunization [dpi]) or left untreated. Spleen cells, harvested 21 dpi, were cultured and assayed for cytokine production. Draining lymph node, spleen, and eye cells 21 dpi were assayed for quantification of T-cell populations. Disease severity was evaluated by histologic examination of the enucleated eyes at 21 and 49 dpi. In addition, anti-IRBP antibodies were analyzed by ELISA. RESULTS: FTY720 was effective in suppressing the experimental autoimmune uveitis score. Although there was a reduction in the number of eye-infiltrating cells, FTY did not prevent Treg accumulation at this site. FTY720 leads to a significant increase of CD4(+)IFN-gamma(+) and CD4(+)Foxp3(+) cell percentages in lymph nodes, suggesting that this site could be the source of Treg cells found in the eye. CONCLUSIONS: The data showed that treatment in vivo with FTY720 was able to suppress EAU in mice. These results are indicative of the possible therapeutic use of FTY720 in ocular autoimmune processes.