Pegaptanib sodium for macular edema secondary to central retinal vein occlusion.

OBJECTIVES: To assess the safety and efficacy of intravitreous pegaptanib sodium for the treatment of macular edema following central retinal vein occlusion (CRVO). DESIGN: This dose-ranging, double-masked, multicenter, phase 2 trial included subjects with CRVO for 6 months' or less duration randomly assigned (1:1:1) to receive pegaptanib sodium or sham injections every 6 weeks for 24 weeks (0.3 mg and 1 mg, n=33; sham, n=32). MAIN OUTCOME MEASURE: Visual acuity at week 30. RESULTS: In the primary analysis at week 30, 12 of 33 (36%) subjects treated with 0.3 mg of pegaptanib sodium and 13 of 33 (39%) treated with 1 mg gained 15 or more letters from baseline vs 9 of 32 (28%) sham-treated subjects (P= .48 for 0.3 mg and P= .35 for 1 mg of pegaptanib sodium vs sham). In secondary analyses, subjects treated with pegaptanib sodium were less likely to lose 15 or more letters (9% and 6%; 0.3-mg and 1-mg pegaptanib sodium groups, respectively) compared with sham-treated eyes (31%; P= .03 for 0.3 mg and P= .01 for 1 mg of pegaptanib sodium vs sham) and showed greater improvement in mean visual acuity (+7.1 and +9.9, respectively, vs -3.2 letters with sham; P= .09 for 0.3 mg and P= .02 for 1 mg of pegaptanib sodium vs sham). By week 1, the mean central retinal thickness decreased in the 0.3-mg and 1-mg pegaptanib sodium groups by 269 microm and 210 microm, respectively, vs 5 microm with sham (P< .001). CONCLUSIONS: Based on this 30-week study, intravitreous pegaptanib sodium appears to provide visual and anatomical benefits in the treatment of macular edema following CRVO. APPLICATION TO CLINICAL PRACTICE: Benefits accrued with intravitreous pegaptanib sodium treatment of macular edema following CRVO suggest a role for vascular endothelial growth factor in the pathogenesis of this condition. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00088283.

Intravitreal methotrexate resistance in a patient with primary intraocular lymphoma.

PURPOSE: To describe the clinical course of a patient with multiple recurrences of primary intraocular lymphoma (PIOL). DESIGN: Interventional case report, METHODS: Retrospective chart review. RESULTS: A 57-year-old female treated with multiple intravitreal methotrexate injections became refractory to intravitreal methotrexate after a year. Lymphoma cells evaluated using immunocytochemistry and confocal microscopy showed aberrant multidrug resistance-related protein (MRP) and decreased reduced folate carrier (RFC) and folate binding protein (FBP) expression compared to PIOL cells from another patient clinically responsive to methotrexate. CONCLUSIONS: This case suggests that alterations in the transport of methotrexate across the cell membrane might contribute to resistance following repeated intravitreal injections.

A double-masked, randomized study to investigate the safety and efficacy of daclizumab to treat the ocular complications related to Behçet's disease.

PURPOSE: To investigate the safety and efficacy of daclizumab (Zenapax, humanized anti-Tac, HAT) in controlling the ocular manifestations of Behçet's disease. DESIGN: Randomized, placebo-controlled, double-masked clinical trial. PARTICIPANTS: Seventeen participants with Behçet's disease experiencing at least two prior ocular attacks and requiring treatment with immunosuppressive agents for the ocular complications of Behçet's disease. METHODS: Participants received either intravenous placebo or daclizumab (1 mg/kg) infusions every two weeks for six weeks, then every four weeks while continuing their standard immunosuppressive regimens. If clinically indicated, tapering of the standard immunosuppressive medications was allowed after six months of study enrollment. Complete ocular and physical examinations and an adverse event assessment were performed at baseline and prior to each study infusion. MAIN OUTCOME MEASURES: Primary safety endpoints were the development of a life-threatening complication or a severe opportunistic infection. Primary efficacy outcomes were the number of ocular attacks and an assessment of systemic immunosuppressive medications required during the study, including the ability to taper concomitant immunosuppressive therapy. RESULTS: Nine participants randomized to daclizumab and eight to placebo were followed monthly. Follow-up ranged from one to 34 months, with a median follow-up of 15 months. Two participants randomized to daclizumab discontinued study therapy prior to the end of the study for personal reasons. No participant experienced a safety endpoint, and visual acuity remained stable in all participants during the course of the study. Ten participants (six daclizumab, four placebo) experienced ocular attacks requiring therapy. The median ocular attack rate during the study was greater in the daclizumab arm than the placebo arm (median 1.27 vs. 0.17 attacks/year, respectively). Participants in the placebo arm also experienced a greater reduction in the immunosuppressive medication score compared to participants receiving daclizumab (median -4.0 vs. -1.0, respectively). CONCLUSIONS: The observed results in the placebo group demonstrate that careful follow-up and treatment with standard combination immunosuppressive therapy can be effective for the management of the ocular complications of Behçet's disease. In our small study, there was no suggestion that daclizumab was beneficial in comparison with placebo. However, the low observed attack rate limited our ability to make a definitive treatment group comparison.

Progressive outer retinal necrosis in the era of highly active antiretroviral therapy: successful management with intravitreal injections and monitoring with quantitative PCR.

BACKGROUND: Progressive outer retinal necrosis (PORN) is an ocular disease in individuals with AIDS and is associated with substantial morbidity. The optimal management of PORN and its clinical course in the HAART era is unclear. OBJECTIVE: We report a case of successfully managed PORN that provides insight into the monitoring and treatment of this disease. STUDY DESIGN: Intravitreal injections and intravenous therapy targeted towards varicella zoster virus (VZV) were used to treat PORN. HAART was initiated for HIV-1 therapy. Serial PCR for VZV was performed on aqueous humor to monitor the clinical course. RESULTS: The presence of VZV DNA from aqueous humor correlated with clinical exacerbations of disease. Initiation of twice weekly intravitreal injections with dual antiviral drugs appeared to be an important therapeutic intervention that resulted in remission of PORN. Secondary prophylaxis against VZV was successfully withdrawn after HAART induced partial immune recovery. CONCLUSION: In addition to aggressive therapy with intravitreal injections, HAART and quantitative measurements of VZV DNA from aqueous humor have important roles in the management of PORN. A multidisciplinary approach involving specialists in infectious diseases, ophthalmology, and clinical microbiology will improve the chances for successful long-term outcomes.

Hypergammaglobulinemia and corneal opacities in patients with human T-cell lymphotrophic virus type-1.

PURPOSE: To investigate the relationship between serum immunoglobulin levels and corneal opacities in a cohort of patients with human T-cell lymphotrophic virus type-1 (HTLV-1). DESIGN: Retrospective case series. METHODS: Complete ophthalmologic examination was performed on 44 patients with HTLV-1 infection (25 patients with adult T-cell leukemia/lymphoma [ATL], 18 patients with HTLV-1 that was associated myelopathy/tropical spastic paraparesis [HAM/TSP], and one patient who was asymptomatic). Corneal opacities were described by shape, size, color, and location. Serum immunoglobulin (Ig) levels (IgG, IgM, and IgA) were measured by nephelometry. RESULTS: Corneal opacities were identified in 15 of 25 patients (60%) with ATL and five of 18 patients (28%) with HAM/TSP. The prevalence of corneal opacities was associated statistically with elevated IgG level (P = .023) in patients with ATL, but not in patients with HAM/TSP (P > .99). CONCLUSION: Although the mechanism remains unclear, hypergammaglobulinemia is associated with the development of the corneal opacities in patients of African descent with ATL.

Detection of the bcl-2 t(14;18) translocation and proto-oncogene expression in primary intraocular lymphoma.

PURPOSE: Primary intraocular lymphoma (PIOL) is a diffuse large B cell lymphoma that initially infiltrates the retina, vitreous, or optic nerve head, with or without central nervous system involvement. This study examined the expression of the bcl-2 t(14;18) translocation, the bcl-10 gene, and high expression of bcl-6 mRNA in PIOL cells. METHODS: Microdissection and PCR analysis were used to examine vitreous specimens in patients with PIOL for the presence of bcl-2 t(14;18) translocations, the bcl-10 gene, and expression of bcl-6 mRNA. A medical record review was also conducted to determine whether the bcl-2 t(14;18) translocation correlated with prognosis. RESULTS: Forty of 72 (55%) PIOL patients expressed the bcl-2 t(14;18) translocation at the major breakpoint region. Fifteen of 68 (22%) patients expressed the translocation at the minor cluster region. The bcl-10 gene was detected in 6 of 26 (23%) patients, whereas 4 of 4 (100%) PIOL patients expressed higher levels of bcl-6 mRNA compared with inflammatory lymphocytes. An analysis of clinical outcome in 23 PIOL patients revealed no significant association between bcl-2 t(14;18) translocations and survival or relapse. However, patients with the translocation were significantly younger. CONCLUSIONS: PIOL has unique molecular patterns of bcl-2, bcl-10, and bcl-6 when compared with other systemic lymphomas. This study lays the foundation for future studies aimed at exploring the genotypic classification of PIOL based on the quantitative molecular framework of gene expression profiling, with the goal of providing useful adjuncts to the pathologic diagnosis of this complex disease.

Primary testicular and intraocular lymphomas: two case reports and a review of the literature.

Testicular lymphoma is a rare neoplasm of the testis that is most commonly seen in older patients. It metastasizes preferentially to extranodal sites, including the skin, central nervous system, Waldeyer ring, contralateral testis, and lung. Two case reports of patients with a history of testicular lymphoma who developed involvement of the vitreous and retina are presented. These are interesting cases as the testis, central nervous system, and eye are all immune privileged organs, which may account for occurrence of disease in these sites. Histopathologic examination of diagnostic vitrectomy specimens from both cases showed atypical lymphoid cells with immunoglobulin heavy chain (IgH) gene rearrangements, consistent with the diagnosis of intraocular B-cell lymphoma. The results of a literature review of all reports of ocular involvement with testicular lymphoma are discussed. Patients with testicular lymphoma are at risk for relapse, particularly in the central nervous system. Clinicians should be suspicious for intraocular lymphoma in patients with a history of testicular lymphoma who present with vitritis or retinal lesions.

Gamma interferon assay as an alternative to PPD skin testing in selected patients with granulomatous intraocular inflammatory disease.

BACKGROUND: To evaluate the QuantiFERON-TB test (gamma interferon assay), approved by the Centers for Disease Control and Prevention for the detection of latent tuberculosis (LTB), in patients who potentially may require immunosuppressive therapy for ocular inflammatory disease. METHODS: Blood samples from 12 consecutive patients with granulomatous ocular inflammatory disease were evaluated first with the purified protein derivative (PPD) skin test and then with the QuantiFERON-TB test (11 of 12 patients, 1 declined). The results of the 2 tests in both U.S.- and non-U.S.-born patients were compared with their Bacillus Calmette-Guérin (BCG) vaccination status and chest x-rays. RESULTS: In our small series there was a high degree of concordance between the QuantiFERON-TB assay and the PPD skin test. INTERPRETATION: The QuantiFERON-TB test did not demonstrate intrinsic merit over PPD skin testing for screening for LTB in selected patients when immunosuppressive therapy is considered. The confounding effect of BCG vaccination renders interpretation of both tests difficult. Early reports suggest the second-generation tests that are now available may hold promise for use in the uveitis clinic and should be formally evaluated.

Initial evaluation of subcutaneous daclizumab treatments for noninfectious uveitis: a multicenter noncomparative interventional case series.

PURPOSE: To assess the feasibility of a study design that may determine whether subcutaneous administration of the interleukin-2 receptor antibody daclizumab can safely reduce the dependence on standard systemic corticosteroids or other immunosuppressive regimens in patients with sight-threatening, noninfectious intermediate uveitis, posterior uveitis, or panuveitis. DESIGN: Prospective, multicenter, nonrandomized, noncomparative, open-label interventional trial. PARTICIPANTS: Fifteen patients, 5 each at 3 clinical centers, with noninfectious intermediate, posterior, or panuveitis, who require a currently stable immunosuppression regimen of systemic corticosteroids and/or other systemic treatments to control noninfectious intraocular inflammation. METHODS: After enrollment and baseline ophthalmic evaluations, 2 induction treatments were given 2 weeks apart using subcutaneous (SC) daclizumab at 2 mg/kg. Subcutaneous daclizumab maintenance treatments were then continued every 2 weeks at 1 mg/kg for 6 months. The initial immunosuppression load was tapered over 8 to 12 weeks in a staggered fashion beginning with the first induction treatment. Safety evaluations were performed at each treatment visit, with a primary efficacy evaluation at 12 weeks and a repeat efficacy evaluation at 26 weeks. MAIN OUTCOME MEASURES: Best-corrected visual acuity (Early Treatment of Diabetic Retinopathy Study [ETDRS] method) with a concurrent taper of concomitant systemic immunosuppression medication load (tabulated by use of a weighted scoring system) was assessed; target for success was defined as a 50% or greater reduction in concomitant immunosuppression load by 12 weeks while maintaining visual acuity within 5 ETDRS letters of baseline. Ocular inflammation was assessed at each visit with standardized grading scales. RESULTS: Ten of 15 patients (67%) receiving SC daclizumab treatments every other week successfully achieved the primary efficacy end point of reducing their concomitant immunosuppression load by at least 50% while maintaining their baseline visual acuity at 12 and 26 weeks. Subcutaneous daclizumab injections were well tolerated with no serious adverse events observed during the 6 months of treatments, although 3 patients experienced possibly related, nonserious adverse events. CONCLUSIONS: Subcutaneous daclizumab induction treatments at 2 mg/kg followed by 1 mg/kg maintenance treatments every other week seems safe and, in most cases, may reduce the concomitant immunosuppressive load required to treat noninfectious uveitis for 12 to 26 weeks.

Serpiginous choroiditis.

Serpiginous choroiditis is a rare, usually bilateral, chronic, progressive, recurrent inflammation of the choroid, retinal pigment epithelium, and choriocapillaris of unknown etiology. Based on clinical presentation, it can be classified into 1) peripapillary, 2) macular, and 3) ampiginous types. The clinical course, regardless of the presentation, is progressive with multiple recurrences leading to potentially significant visual loss. Visual outcome is directly related to the involvement of the para-fovea and fovea by the lesions or secondary choroidal neovascularization. The histological findings of the lesions are atrophy of the choriocapillaris, retinal pigment epithelium and photoreceptor cells, and moderate diffuse lymphocytic infiltrates throughout the choroid. Multiple etiologies including autoimmunity, infection, vasculopathy, and degeneration were proposed but none is well supported by clinical and laboratory evidence. Fluorescein and indocyanine green angiography have been useful in the assessment of the extent and the activity of lesions. Due to the insidious and progressive clinical course, an assessment of treatment outcomes needs long term follow-up. Currently, treatment with immunosuppressive and alkylating agents have shown possible efficacy in small case series. Larger clinical studies and interventional trials are required to further our understanding of the pathogenesis, etiology, and for the evaluation of treatment strategies.

Bilateral uveitis in a patient with autoimmune lymphoproliferative syndrome.

PURPOSE: We report a case of autoimmune lymphoproliferative syndrome (ALPS) presenting with bilateral uveitis. DESIGN: Observational case report. METHODS: Review of case record, serum and aqueous IL-10 and IL-6 cytokine results, and immunosuppressive treatment of a patient with a mutation in the gene encoding Fas. RESULTS: Control of the intermediate uveitis required sustained doses of topical and periocular corticosteroids as well as systemic cyclosporine. The serum IL-10 level was elevated, as commonly seen in ALPS, but the aqueous IL-10 was not. CONCLUSIONS: Despite a Th2 immune predominance in ALPS, uveitis, a Th1-mediated disease, may still manifest in these patients. The pathogenesis of uveitis in ALPS may differ from that of the systemic disease overall. Long-term follow-up is required for patients with uveitis associated with ALPS.

Waldenström's macroglobulinemia-associated retinopathy.

OBJECTIVE: To report the clinical, electrophysiologic, and immunopathologic findings in a patient with progressive retinal degeneration associated with Waldenström's macroglobulinemia. DESIGN: Case report with immunohistochemical studies. METHODS: A 46-year-old female with elevated serum immunoglobulin M (IgM) levels complained of photophobia and photopsias. Complete ophthalmic examinations including electrophysiologic testing and hematologic evaluations were performed over a 3-year period. Immunohistochemical studies to determine the presence of serum antiretinal antibodies were evaluated using confocal microscopy. RESULTS: Examination of the patient's fundus remained normal, although there was deterioration in her visual acuity, visual field, and electroretinogram over the follow-up period. Waldenström's macroglobulinemia was diagnosed by bone marrow biopsy. Indirect immunohistochemistry revealed reactivity of the patient's serum against the photoreceptor-connecting cilium. CONCLUSION: The paraneoplastic retinopathy associated with Waldenström's macroglobulinemia in this patient is presumed to result from antibodies of the IgM subtype reacting to proteins in the retinal photoreceptors.

Ocular manifestations of human T-cell lymphotropic virus type 1 infection.

PURPOSE OF REVIEW: Human T-cell lymphotropic virus type 1 (HTLV-1) infection is endemic in Japan, the Caribbean islands, and parts of Central Africa and South America. Known ophthalmic manifestations of HTLV-1 include malignant infiltrates in patients with adult T-cell leukemia/lymphoma, retinal degeneration, neuroophthalmic disorders, and keratoconjunctivitis sicca in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis, and HTLV-1-associated uveitis. This report reviews the recent developments and ocular findings reported in patients with HTLV-1-related diseases. RECENT FINDINGS: Most of the knowledge of the ocular manifestations of HTLV-1 comes from southwestern Japan, which has the highest incidence of infection worldwide. During the past few years, however, ocular disease associated with HTLV-1 has been described in patients from other endemic areas genetically distinct and geographically distant from Japan. The most interesting of these was the recognition of corneal pathology in Brazilian and Caribbean patients with HTLV-1 that have not been described in Japanese patients. Other developments include the use of molecular techniques in the diagnostic evaluation of ocular tissues from HTLV-1 patients, and clinical studies demonstrating choroidal involvement by indocyanine green angiography in patients with HTLV-1-associated uveitis, and suggesting that retinal vasculitis unresponsive to corticosteroid therapy maybe a poor prognostic sign. SUMMARY: The spectrum of ocular disease related to HTLV-1 continues to expand. Routine evaluation of HTLV-1-infected patients is important because immune-mediated or neoplastic ocular involvement may occur during the disease course. Genetic and environmental factors may play a role in the ocular manifestations of HTLV-1 in different populations.

Effect of sex hormones on experimental autoimmune uveoretinitis (EAU).

PURPOSE: Sex hormones have been associated with the prevalence, susceptibility, and severity of autoimmune disease. Although the exact mechanism is unknown, sex hormones are reported to influence cytokine production, specifically by affecting the balance of Th1 and Th2 effector cells. We evaluated the effect of estrogen, progesterone, and testosterone in autoimmune uveoretinitis (EAU), a rodent model of human ocular autoimmune disease. METHODS: Lewis rats implanted with either beta-estradiol (estrogen), 5-dihydrotestosterone (5-DHT), norgestrel (progesterone), or estrogen plus progesterone were immunized with the retinal antigen interphotoreceptor retinoid binding protein (IRBP) peptide. Evaluation of EAU was based on histology of the eyes and measurement of peripheral immunological responses of DTH and lymphocyte proliferation to S-antigen. Quantitative RT-PCR was used to measure IFN-gamma and IL-10 mRNA in the eyes. RESULTS: In female rats 5-DHT significantly decreased, estrogen slightly enhanced, but progesterone or estrogen + progesterone did not affect EAU. In contrast, in male rats 5-DHT slightly decreased, estrogen moderately decreased, progesterone did not effect, but, estrogen + progesterone slightly decreased EAU. The results correlated with the ocular levels of Th1 (IFN-gamma) and Th2 (IL-10) cytokine messengers. CONCLUSION: The data support the hypothesis that sex hormones may affect autoimmune diseases by inducing changes in the cytokine balance. This suggests that sex hormone therapy could be considered as an adjunct to anti-inflammatory agents to treat ocular autoimmune diseases in humans.

Humanized anti-interleukin-2 (IL-2) receptor alpha therapy: long-term results in uveitis patients and preliminary safety and activity data for establishing parameters for subcutaneous administration.

Therapy for severe uveitis is frequently long-term immunosuppression using systemic corticosteroids and cytotoxic agents, but side effects make long-term therapy difficult. A long-term (>4 year) Phase I/II single armed interventional study using intravenous anti-IL-2 receptor alpha treatments (daclizumab) and a short-term Phase II study evaluating the use of a subcutaneous daclizumab formulation were conducted. Patients were tapered off their systemic immunosuppressive therapy and received daclizumab infusions or subcutaneous injections at intervals varying from 2 to 6 weeks. In the long-term study, seven of ten enrolled patients were tapered from their original immunosuppressive medications and maintained exclusively on repeated daclizumab infusions for control of their uveitis for over 4 years. No patient was permanently removed from therapy for an adverse event ascribed to the medication. The use of 6-week infusion intervals led to recurrence of uveitis, while 2- to 4-week intervals did not. Only one patient developed measurable anti-daclizumab antibodies but this disappeared when subcutaneous therapy was begun. In the short-term study, four of the five patients receiving the subcutaneous formulation met the study endpoints for success within the first 12 weeks. All five were successful by 26 weeks. These studies provide preliminary evidence that regularly administered long-term daclizumab therapy can be given in lieu of standard immunosuppression for years to treat severe uveitis and that subcutaneously administered daclizumab appeared to be a clinically viable treatment strategy. These studies suggest that anti-IL-2 receptor blockade could be useful in the treatment of Th1-mediated autoimmune conditions.

Mycophenolate mofetil for the treatment of scleritis.

PURPOSE: To evaluate the usefulness of mycophenolate mofetil (MMF) (CellCept, Roche, Nutley, NJ), an antimetabolite immunosuppressant with a selective antiproliferative effect on T and B lymphocytes, for the treatment of scleritis. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Eight patients with scleritis treated with MMF in a tertiary referral center. METHODS: Review of the clinical records of patients evaluated at the National Eye Institute and prescribed MMF for the treatment of scleritis. MAIN OUTCOME MEASURES: Control of scleral inflammation, the ability to taper prednisone or other immunosuppressive medications, and adverse events were recorded for each patient. Mycophenolate mofetil was determined to be an effective steroid-sparing agent if the daily prednisone dosage could be reduced by 50% or more and was determined to be an effective adjunctive immunosuppressive agent if the scleral inflammation was controlled in patients with active scleritis. RESULTS: Four patients with diffuse anterior scleritis, two with necrotizing scleritis with inflammation, one with nodular anterior scleritis, and one with nodular anterior and posterior scleritis, were identified. Mycophenolate mofetil administration was initiated as a steroid-sparing agent in 4 patients with controlled scleritis and as an additional immunosuppressive agent in 4 patients with active scleritis receiving concomitant treatment with prednisone and cyclosporine or methotrexate. In 3 of the 4 patients started on MMF as a steroid-sparing agent, the scleritis remained controlled while the prednisone dosage was tapered by more than 50%. One of the patients started on MMF as a steroid-sparing agent had recurrent scleritis, and each of the patients with active scleritis continued to have persistent scleral inflammation requiring additional immunosuppressive therapy. Adverse effects recorded in 4 of the 8 patients included a rash, gastrointestinal symptoms, paresthesias, and laboratory evidence of hepatotoxicity and renal toxicity. CONCLUSIONS: Although MMF maybe be useful as a steroid-sparing agent, it was not effective as an adjunctive immunosuppressive agent in patients with active scleritis in our small, tertiary referral series. The adverse effects encountered with the use of MMF in this study cannot be attributed conclusively to MMF and are more likely complications of the multiagent systemic immunosuppressive therapy required for the treatment of recalcitrant scleritis.

Expression of glucocorticoid induced TNF receptor family related protein (GITR) on peripheral T cells from normal human donors and patients with non-infectious uveitis.

The expression of the glucocorticoid induced TNF receptor family related gene (GITR) in subsets of T lymphocytes from human peripheral blood was studied. In normal human peripheral blood mononuclear cells, GITR expression on the resting CD4+ T cells was low but markedly increased after activation. The percentage of GITR+ T cells in the CD4+CD25+ T cell subpopulation (15.1%) was significantly higher than that in the CD4+CD25- T cell subpopulation (5.2%, P<0.01), suggesting a preferential co-expression of GITR with CD25. In a group of patients with non-infectious uveitis, a proposed T helper cell mediated autoimmune ocular disease, the GITR expression on the CD4+ T cells in both the active patients (34.5%) and the inactive patients (19.6%) was significantly higher as compared to that in the normal donors (10.7%; P<0.01 vs. active, P<0.05 vs. inactive). This increased GITR expression in T cells was only seen in the CD4 positive T helper cell subpopulation but not in the CD4 negative T cell subpopulation. GITR expression on the CD4+ T cells decreased when the patients became clinically quiescent. Therefore, GITR is an activation marker for the CD4+ T cells and preferentially co-expressed with CD25 on the CD4+ T cells in human peripheral blood. Its expression correlates with the clinical course of non-infectious uveitis.