Expression of ocular autoantigens in the mouse thymus

PURPOSE. The occurrence of eye diseases of autoimmune nature, as well as experimental models of these diseases, has been attributed to the sequestration of ocular antigens from the immune system, that prevents the development of tolerance against these antigens. Here, we tested this assertion by examining whether transcripts of certain ocular antigens are constitutively expressed in the thymus, the site of central tolerance induction.

METHOD

RNA was isolated from the eyes and thymi of two mouse strains and analyzed for the expression of genes encoding four retinal and three lens proteins by reverse transcribed-polymerase chain reaction. Southern blot and DNA sequence analyses.

RESULTS

We detected gene transcripts of S-Antigen (S-Ag), interphotoreceptor retinoid-binding protein, opsin, recoverin, lens major intrinsic protein (MIP), alphaA-, alphaA(-ins)- and gamma-crystallins in the thymi of BALB/c and FVB/N mouse strains. DNA sequence analysis of the thymic MIP and S-Ag transcripts confirmed their identity to the lens and retinal proteins, respectively.

CONCLUSIONS

Our results reveal that transcripts of several ocular-specific proteins are expressed in the thymus and suggest that the commonly held view that ocular-specific antigens are sequestered from the immune system should be modified.

Phakic patients with cystoid macular edema, retinal periphlebitis, and vitreous inflammation

OBJECTIVE

To characterize a group of phakic patients with idiopathic intermediate uveitis as defined by vitritis, cystoid macular edema, and retinal periphlebitis.

DESIGN

Cross-sectional study.

PARTICIPANTS

Nineteen phakic patients (35 eyes) with vitreous inflammation, cystoid macular edema, and/or retinal periphlebitis of unknown cause.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Best-corrected final visual acuities, standardized clinical examinations, photographic and fluorescein angiographic evaluations, and class I and II HLA analysis on all 19 patients.

RESULTS

Fifteen of the 19 patients were women. The mean age was 38 years, the mean follow-up was 104 months, and the mean duration of symptoms was 154 months. All 35 affected eyes had significant vitritis; 21 eyes (60%) had cystoid macular edema, 21 eyes (60%) had retinal periphlebitis. The median initial visual acuity was 20/30. The median final visual acuity was 20/20 with 32 (91%) of 35 eyes having 20/40 or better visual acuity at the final visit. No patient developed "snow-banks" or evidence of systemic disease, including multiple sclerosis or sarcoidosis, during the follow-up period. There were no statistically significant HLA associations in these patients compared with controls from another study from Iowa, but the Iowa phakic patients with cystoid macular edema did differ from the Iowa patients with pars-planitis at loci HLA-B8, HLA-B51, and HLA-DR2.

CONCLUSIONS

We describe a disease entity of idiopathic intermediate uveitis that affects primarily young to middle-aged women and usually causes bilateral vitritis, cystoid macular edema, and retinal periphlebitis. Most patients retained good vision over a prolonged follow-up period. Multiple sequential examinations and HLA associations suggest that these conditions are distinct from other syndromes of intermediate uveitis, particularly parsplanitis.

Discontinuation of maintenance therapy in patients with quiescent cytomegalovirus retinitis and elevated CD4+ counts

OBJECTIVE

To determine whether maintenance therapy can be discontinued safety in patients with quiescent cytomegalovirus retinitis (CMVR) and increased CD4+ counts after treatment with highly active antiretroviral therapy (HAART).

DESIGN

A prospective observational case series.

PARTICIPANTS

Eight human immunodeficiency virus (HIV)-positive patients with quiescent CMVR who were taking HAART and had CD4+ counts above 100 cells/microliter elected to discontinue anti-CMV maintenance treatment.

INTERVENTION

Biweekly-to-monthly indirect ophthalmoscopy and fundus photographs, monthly-to-quarterly CD4+ counts, and quarterly HIV viral loads were ordered.

MAIN OUTCOME MEASURES

Twelve previously affected eyes were examined for evidence of recurrent retinitis, which was defined as any retinal whitening, border opacification, or expansion of areas of retinal pigment epithelial (RPE) atrophy greater than 750 microns. Four previously unaffected fellow eyes were observed for new CMVR.

RESULTS

There was no reactivation or progression of retinitis in any patient during the mean follow-up interval of 11.4 months (range, 3-16 months). No previously unaffected eye developed CMVR. CD4+ remained elevated in all patients (range, 70-725; mean, 255). The HIV viral load ranged from undetectable to 139,000 copies.

CONCLUSION

Discontinuation of maintenance therapy may be considered in patients with HAART-induced elevated CD4+ counts above 100 cells/microliter, prolonged relapse-free intervals during the reconstitution period before CD4+ counts rise above 100 cells/microliter, and completely quiescent retinitis characterized by RPE scarring only. Reduced risks of drug toxicity and drug-resistant organisms are potential benefits. Close observation for evidence of recurrent retinitis is indicated.

A novel murine model of allergic conjunctivitis

Allergic conjunctivitis affects over 40 million patients per year in the United States. Here we present the first murine model that incorporates the clinical, cellular, and humoral parameters of allergic conjunctivitis, including a ragweed-induced Th2-type cytokine production by lymphocytes. SWR/J mice were immunized with short ragweed pollen in aluminum hydroxide. Ten days after immunization, allergic conjunctivitis was induced by one topical application of ragweed pollen onto the eye. Immediate response was characterized by chemosis, redness of the conjuctiva, and lid edema. Histopathology and immunohistochemistry showed dense conjunctival infiltration with polymorphonuclear leukocytes, macrophages, and CD4+ T lymphocytes. In addition, ragweed-specific IgG1 and IgE serum levels were significantly higher in immunized animals, and high levels of IL-4 and IL-5 were detected in supernatants from ragweed-activated lymphocytes. This reproducible model is a well-suited instrument for testing the pathophysiology and future therapies of allergic conjunctivitis.

A phase I/II study of the protease inhibitor ritonavir in children with human immunodeficiency virus infection

BACKGROUND

Ritonavir, a potent antiretroviral protease inhibitor, has been approved for the treatment of adults and children with human immunodeficiency virus (HIV) infection. In a phase I/II study, we assessed the safety, tolerability, and pharmacokinetic profile of the oral solution of ritonavir in HIV-infected children and studied the preliminary antiviral and clinical effects.

METHODS

HIV-infected children between 6 months and 18 years of age were eligible. Four dose levels of ritonavir oral solution (250, 300, 350, and 400 mg/m given every 12 hours) were evaluated in two age groups (</=2 years, >2 years). Ritonavir was administered alone for the first 12 weeks and then in combination with zidovudine and/or didanosine. Clinical and laboratory parameters were monitored every 2 to 4 weeks.

RESULTS

A total of 48 children (median age, 7.7 years; range, 0.5 to 14.4 years) were included in this analysis. Dose-related nausea, diarrhea, and abdominal pain were the most common toxicities and resulted in discontinuation of ritonavir in 7 children. Ritonavir was well absorbed at all dose levels, and plasma concentrations reached a peak 2 to 4 hours after a dose. CD4 cells counts increased by a median of 79 cells/mm3 after 4 weeks of monotherapy and were maintained throughout the study. Plasma HIV RNA decreased by 1 to 2 log10 copies/mL within 4 to 8 weeks of ritonavir monotherapy, and this level was sustained in patients enrolled at the highest dose level of 400 mg/m for the 24-week period.

CONCLUSIONS

The oral solution of ritonavir has potent antiretroviral activity as a single agent and is relatively well tolerated by children when administered alone or in combination with zidovudine or didanosine.

Topical liposome-encapsulated FK506 for the treatment of endotoxin-induced uveitis

PURPOSE

Liposome preparations of FK506 improve the penetration of topically administered drug into the aqueous humor. The purpose of the experiment was to compare topically administered highdose oil-dissolved FK506 (OD-FK506) and low-dose liposome-bound FK506 (LB-506) for the treatment of endotoxin-induced uveitis (EIU).

METHODS

Endotoxin-induced uveitis was produced in female Lewis rats with Salmonella typhimurium endotoxin. Four hours prior to endotoxin injection, one eye received 20 mul eyedrops every four hours containing either high-dose OD-FK506 at 3 mg/ml (N = 20), low-dose LB-FK506 at 0.16 mg/ml (N = 19), prednisolone acetate 1% (N = 20), or empty liposomes (N = 20). Eyes were enucleated 24 hours after endotoxin injection and inflammatory cells were counted on histologic sections by two masked observers.

RESULTS

The mean number of infiltrating inflammatory cells per section +/- S.E.M. was 127.8 +/- 20.1, 76.8 +/- 16.7, 75.0 +/- 19.1, and 3.6 +/- 0.4 for animals treated with empty liposomes, LB-FK506, OD-FK506, and prednisolone acetate, respectively. The difference in inflammation between the empty liposome controls and the LB-FK506- and OD-FK506-treated animals was statistically significant (p = 0.03 and p = 0.02, respectively). The difference in inflammation between the high-dose OD-FK506- and low-dose LB-FK506-treated animals was not statistically significant (0 = 0.94).

CONCLUSION

In this study, low-dose LB-FK506 and high-dose (OD-FK506) were both effective in inhibiting EIU. Higher concentrations of LB-FK506 are being developed and should augment the therapeutic effect of topical FK506.

Apoptosis in patients with posterior uveitis

BACKGROUND

Apoptosis plays a part in the pathogenesis of autoimmune diseases.

OBJECTIVE

To investigate the expression of apoptotic markers in the eyes of patients with uveitis.

METHODS

With the use of immunohistochemical and in situ apoptotic detection techniques, apoptotic molecules (Fas or Fas ligand [FasL]) and nuclear DNA fragmentation were examined in 8 enucleated eyes with Behçet's disease (1), sarcoidosis (1), subretinal fibrosis and uveitis (1), sympathetic ophthalmia (4), and the Vogt-Koyanagi-Harada syndrome (1); in 5 chorioretinal biopsy specimens with acute retinal necrosis (2), multifocal choroiditis (1), sarcoidosis (1), and subretinal fibrosis and uveitis (1); and in 3 normal control eyes.

RESULTS

Fas and FasL were constitutively expressed in the normal human retina, but they were expressed much less in the choroid. Increased expression of Fas and FasL was found in the retina, chorioretinal scar, and choroidal granulomas in uveitic eyes. However, Fas and FasL expression was absent in the biopsy specimens with acute retinal necrosis, and little Fas or FasL was noted on infiltrating lymphocytes. DNA fragmentation was also identified in eyes with chorioretinal scar and gliosis.

CONCLUSIONS

Apoptosis occurs in uveitic eyes and may play a regulatory role in limiting ocular inflammation. In uveitic eyes, a dysregulation of the Fas-FasL apoptotic pathway may lead to gliosis and fibrosis.

Effect of gallium nitrate on experimental autoimmune uveitis

Gallium nitrate (GN) has been shown to inhibit T cell-mediated inflammatory disease. The purpose of our study was to test the effect of gallium nitrate (GN) on experimental autoimmune uveitis (EAU). Experimental autoimmune uveitis was induced in male Lewis rats immunized with retinal S-antigen. Rats received subcutaneous injections of GN or saline one day prior to immunization and 1, 4, 7, 10, 13, 16, and 19 days after immunization. Ocular inflammation was graded clinically and histologically by masked observers, and in vitro assays of cell-mediated and humoral immunity were performed. GN significantly inhibited the development of EAU graded clinically (P = 0.001) and histologically (P = 0.002). Treatment with GN also resulted in a small (30-41%) decrease in the lymphocyte responses to retinal S-Antigen and a small (12-37%) reduction in antibody production to S-antigen. These data show that GN suppresses the development of EAU, and inhibits both lymphocyte proliferative responses to antigen and antibody production.

Ocular immunopathology of Behçet's disease

A patient developed progressive, severe, recurrent bilateral iridocyclitis, retinal vasculitis, and hemorrhagic infarction of the retina that led to blindness despite immunosuppressive therapy. Histopathology of an enucleated blind and painful eye revealed marked nongranulomatous uveitis with a predominantly CD4+ T-lymphocytic infiltration, as well as B-cell and plasma cell aggregation. Extensive expression of adhesion molecules on vascular endothelial cells were found. This finding suggests that adhesion molecules play an important role in the vasculitic process, the trademark of Behçet's disease. The ocular pathology and the therapeutic approach to Behçet's disease are briefly reviewed.

Association of interleukin 10 in the vitreous and cerebrospinal fluid and primary central nervous system lymphoma

BACKGROUND

Diagnosis of primary central nervous system lymphoma (PCNSL) is usually made by identifying malignant lymphocytes in the brain, cerebrospinal fluid (CSF), or vitreous. However, these cells are few and friable, and misdiagnosis can occur, even in properly prepared specimens. Recent data suggest that levels of interleukin 10 (IL-10) are elevated in the serum and vitreous of patients with non-Hodgkin lymphoma; levels of interleukin 6 (IL-6) are elevated in the vitreous of patients with intraocular inflammation unrelated to a malignant neoplasm. We investigated whether PCNSL involving the vitreous or CSF is associated with elevated ratios of IL-10 to IL-6.

PATIENTS

Vitreous specimens were obtained from 5 patients with PCNSL involving the eye and from 13 control patients with intraocular inflammation not related to a malignant neoplasm; CSF specimens were obtained from 11 patients with PCNSL.

RESULTS

Levels of IL-10 exceeded those of IL-6 in all 5 patients with intraocular lymphoma but in none of the 13 patients with uveitis (P < .001). In patients with PCNSL, levels of IL-10 exceeded those of IL-6 in 6 of 11 CSF samples with malignant cells compared with 7 of 53 samples without malignant cells (P = .01). The calculated odds ratio (OR) suggests that the risk for malignant involvement of the CSF is about 8 times higher when IL-10 levels exceed IL-6 levels.

METHODS

Levels of IL-10 and IL-6 were determined by enzyme-linked immunosorbent assay in both vitreous and CSF specimens.

CONCLUSIONS

The occurrence of PCNSL in the eye was strongly associated with elevated vitreous levels of IL-10 relative to levels of IL-6. Moreover, among patients with diagnosed PCNSL, malignant cells were significantly more likely to be present in CSF when levels of IL-10 exceeded those of IL-6.

Elevation of laser flare photometry in patients with cytomegalovirus retinitis and AIDS

PURPOSE

To investigate an alteration of the blood-ocular barriers by laser flare photometry in patients with acquired immunodeficiency syndrome (AIDS) diagnosed with cytomegalovirus retinitis.

METHODS

Serial laser flare photometry measurements from 31 eyes of 31 patients with AIDS and newly diagnosed cytomegalovirus retinitis were compared with measurements from 31 control patients with AIDS but without documented eye disease. Location and extent of retinitis, presence of visual symptoms, and CD4 lymphocyte counts were also compared with laser flare photometry readings.

RESULTS

Laser flare readings (mean +/- SE) were significantly higher in eyes with (13.0 +/- 1.5 photon counts per msec) than without cytomegalovirus retinitis (4.9 +/- 0.3 photon counts per msec) (P < .001). Lesions within the arcade vessels resulted in significantly higher laser flare photometry readings (17.3 +/- 2.5 photon counts per msec) compared with peripheral retinitis (9.8 +/- 1.5 photon counts per msec) (P = .01). A significant correlation was found between area of involvement of peripheral retinitis and laser flare photometry readings (P = .008). Readings in patients without cytomegalovirus retinitis increased significantly 10 months after the first measurement (9.5 +/- 1.9 photon counts per msec) (P = .04). Readings in patients with cytomegalovirus remained elevated 3 months after successful treatment of retinitis (12.3 +/- 2.3 photon counts per msec) (P = .6).

CONCLUSIONS

Laser flare photometry readings are significantly elevated in eyes with cytomegalovirus retinitis, suggesting a breakdown of the blood-ocular barriers. Increasing laser flare photometry readings over time in patients without known ocular disease suggests that HIV infection may cause progressive breakdown of the blood-ocular barrier.

Treatment of uveitis by oral administration of retinal antigens: results of a phase I/II randomized masked trial

PURPOSE

To evaluate the effect and safety of the oral administration of retinal antigens as a treatment of ocular inflammation.

METHODS

In a phase I/II randomized masked trial, patients with endogenous uveitis who were dependent on immunosuppressive agents were randomly assigned to receive either retinal S antigen alone (10 patients), retinal S antigen and a mixture of soluble retinal antigens (10 patients), a mixture of soluble retinal antigens alone (10 patients), or placebo (15 patients). An attempt was then made to taper patients completely off their standard immunosuppressive therapy over an 8 week period. The primary study endpoint was time to ocular inflammatory attack. The secondary study endpoint was the ability to taper patients completely off their immunosuppressive or cytotoxic medication within 8 weeks.

RESULTS

Time to development of the main study endpoint was not statistically significantly different for any of the four treatment groups. However, the group receiving the purified S antigen alone appeared to be tapered off their immunosuppressive medication more successfully compared with patients given placebo (P = .08), whereas all the other groups appeared to do worse than did those receiving placebo. No toxic effects attributable to any treatment were observed.

CONCLUSIONS

This phase I/II study is the first to test the use of orally administered S antigen in the treatment of uveitis. Although not statistically significant, patients given S antigen were more likely to be tapered off their chronically administered systemic immunosuppressive therapy than were the other groups tested.

Immunologic mechanisms of uveitis. New targets for immunomodulation

The uvea consists of the choroid, ciliary body, and iris, and inflammation of the uveal tract is termed uveitis. Nevertheless, uveitis is commonly used to more generally describe intraocular inflammation involving not only the uvea, but also the retina, vitreous, and sclera. Fifty years ago, infectious organisms such as syphilis and tuberculosis were thought to be the cause of most forms of uveitis. Since that time, many causes of uveitis have been described as infectious and noninfectious. Scientists have shown that the immune response plays a critical role in the development of infectious and noninfectious forms of the disease. With a more detailed understanding of the immune mechanisms leading to the development of uveitis, we are now able to develop new therapeutic approaches based on targeting various components of the immune response.

Blocking both E-selectin and P-selectin inhibits endotoxin-induced leukocyte infiltration into the eye

The initial contact between leukocytes and the vascular endothelium at sites of inflammation is mediated by selectins. The purpose of this study was to investigate the role of the two selectins expressed on the vascular endothelium, E-selectin and P-selectin, in the pathogenesis of endotoxin-induced uveitis. Endotoxin-induced uveitis was produced in female C3H/HeN mice using Salmonella typhimurium endotoxin injected into one hind footpad. At the time of endotoxin injection mice were treated with an intraperitoneal injection of a monoclonal antibody against E-selectin or P-selectin, a combination of both anti-selectin antibodies, or isotype-matched control antibodies. In a second set of experiments, antibody treatment was administered 6 hr after endotoxin injection, when inflammatory cells are already entering the eye. Ocular inflammation was graded histologically by a masked observer. When administered at the time of endotoxin injection, anti-P-selectin antibody decreased ocular inflammation by 37% compared to control animals (P = 0.05). There was no statistical decrease in ocular inflammation in animals treated with anti-E-selectin antibody. The combination of anti-P-selectin and anti-E-selectin antibodies decreased infiltrating inflammatory cells by 61% (P < 0.01). When treatment was delayed until 6 hr after endotoxin injection, the combination of anti-P-selectin and anti-E-selectin antibodies again decreased ocular inflammation by 60% (P < 0.01). Immunohistochemical staining showed decreased ICAM-1 expression in the eyes of animals treated with the combination of anti-P-and anti-E-selectin antibodies. Blocking both P-selectin and E-selectin resulted in a significant decrease in endotoxin-induced intraocular inflammation.

Permissive recognition of immunodominant determinants of the retinal S-antigen in different rat strains, primates and humans

The majority of antigenic peptides exhibit restriction in their interaction with the MHC molecules on antigen-presenting cells of different haplotypes. Certain peptides, however, are "permissive': they bind strongly to different MHC molecules and are selected as the immunodominant epitopes by animals using these MHC gene products. Here we show for the first time that several peptides from four regions of the sequence of human S-antigen (H-SAg), a retinal-specific protein, demonstrate high levels of permissiveness. Each of these peptides was found to be immunodominant in at least some of four inbred rat strains and five cynomolgus monkeys, immunized with whole H-SAg. Moreover, some of these peptides were recognized by lymphocytes from four normal controls and four patients with uveitis who responded against the H-SAg molecule. On the other hand, the permissive peptides stimulated marginal or no response in cultures of Lewis rats injected with adjuvant alone, or rat and human cell lines specific to other antigens, thus demonstrating that these peptides do not carry any non-specific mitogenic activity. One peptide, 29, which was found immunodominant in the monkeys, the uveitis patients and Lewis rats, is highly immunopathogenic in this rat strain. No good correlation between immunodominance and immunopathogenicity was found with other H-SAg peptides. The finding of cross-species permissiveness among peptides of H-SAg and similar observations with myelin proteins suggest that permissiveness could be quite prevalent among peptides of immunopathogenic antigens.

Association of thyroid disease with retinitis pigmentosa and gyrate atrophy

PURPOSE

To compare the prevalence of thyroid disease in patients with retinitis pigmentosa, in patients with gyrate atrophy of the choroid and retina, and in patients with no history of ocular disease.

METHOD

Forty-four patients with retinitis pigmentosa, 34 patients with gyrate atrophy, and 30 normal control patients with no ocular disease were evaluated in a case-control study for the presence of thyroid disease.

RESULTS

Thyroid disease was diagnosed in six of 44 patients with retinitis pigmentosa and seven of 34 patients with gyrate atrophy but in only one of 30 control patients. Compared with control patients, the odds ratio for the occurrence of thyroid disease was 6.2 for patients with retinitis pigmentosa and 12.7 for patients with gyrate atrophy.

CONCLUSION

These data suggest an increased occurrence of thyroid disease in patients with retinitis pigmentosa and gyrate atrophy.

Topical cyclosporine inhibits mast cell-mediated conjunctivitis

PURPOSE

Allergic conjunctivitis is a common condition caused by a mast cell-mediated hypersensitivity reaction to immunoglobulin E-bound allergens. The purpose of this study was to investigate the effect of topical cyclosporine A on the development of mast cell-mediated conjunctivitis in mice.

METHODS

Allergic conjunctivitis was induced in C57BL/6 mice by topical applications of compound 48/80, a mast cell degranulating agent. In two separate experiments, mice were treated with topical cyclosporine A (0.05%, 0.2%, or 0.4%), prednisolone acetate 1%, or phosphate-buffered saline. Twenty-four hours after compound 48/80 instillation, the number of neutrophils, eosinophils, lymphocytes, macrophages, and the number of preserved goblet cells and undegranulated mast cells in the conjunctiva were counted by a masked observer.

RESULTS

In both experiments, treatment with all three doses of cyclosporine A resulted in a statistically significant reduction in the number of infiltrating neutrophils and eosinophils compared to saline-treated controls. There was no significant difference in the treatment effect of cyclosporine and prednisolone acetate. In addition, there was increased preservation of goblet cells in the cyclosporine A-treated animals. Immunohistochemical staining showed a reduction in infiltrating lymphocytes and a smaller reduction in infiltrating macrophages in animals treated with cyclosporine compared to saline-treated controls.

CONCLUSIONS

Topical cyclosporine A was effective in inhibiting the development of mast cell-mediated allergic conjunctivitis in mice. This study suggests that topical cyclosporine A may be effective in treating allergic conjunctivitis in humans.

Advances in the management of AIDS-related cytomegalovirus retinitis

Cytomegalovirus (CMV) retinitis, a common complication of the acquired immunodeficiency syndrome (AIDS), is increasing in frequency as patients infected with the human immunodeficiency virus (HIV) live longer. In recent years, the lifetime risk for CMV disease in HIV-infected persons has increased from 24.9% to 44.9%. Cytomegalovirus retinitis is usually diagnosed clinically: Almost all patients are CMV seropositive and have CD4+ counts less than 50 cells/mm3. Specific diagnostic tests that use antigen detection or quantitation of circulating nucleic acid to detect CMV are being developed, but they have not been validated for routine clinical use. Such tests would help predict disease, diagnose acute retinitis, and monitor therapy. Therapy with systemic agents, including intravenous ganciclovir, intravenous foscarnet, and intravenous cidofovir, is effective. However, it is cumbersome, costly, and associated with considerable toxicity, therapy encouraging investigation of other therapeutic approaches. Intravitreous injections with antiviral agents are effective, but the short half-life of available agents makes these injections inconvenient. Intraocular implants that slowly release ganciclovir have been effective for both acute therapy and long-term maintenance, but they need to be directly compared with intravenous and oral regimens to determine which regimen will optimally maximize convenience, preserve vision, and improve survival. Cytomegalovirus retinitis could be prevented by improved antiretroviral therapies or by immune-based therapies that would prolong the time during which patients remain immunocompetent. Once patients become immunologically susceptible to CMV end-organ disease (when their CD4+ counts decrease to < 50 cells/ mm3), specific chemotherapy with oral ganciclovir is promising, but the cost, inconvenience, toxicity, and conflicting reports of efficacy associated with this strategy mean that it needs careful assessment before it can be considered standard treatment. Management of CMV retinitis is on the verge of major changes. In the next few years, improvements in diagnostic, therapeutic, and preventive tools should reduce morbidity and mortality from this disease.

A randomized, masked, cross-over trial of acetazolamide for cystoid macular edema in patients with uveitis

PURPOSE

To study the effect of acetazolamide on cystoid macular edema in patients with uveitis.

METHODS

Forty patients with chronic intermediate, posterior, or panuveitis associated cystoid macular edema were randomized into a masked, cross-over trial comparing acetazolamide versus placebo. Patients received an initial 4-week course of either acetazolamide or placebo (course A) followed by a 4-week washout period. They then received a 4-week course of the opposite study medication (course B). Primary endpoints included area of cystoid macular edema measured on late-phase views of fluorescein angiography and visual acuity.

RESULTS

Thirty-seven patients completed the trial and were available for analysis; 17 (46%) were randomized to receive acetazolamide and 20 (54%) to receive placebo during course A. Acetazolamide resulted in a 0.5-disc area (25%) decrease in cystoid macular edema over that of placebo (P = 0.01; estimated treatment effect = -0.5 disc areas; 95% confidence interval, -0.9 to -0.1). However, there was no statistically significant effect of acetazolamide on visual acuity (P = 0.61; estimated treatment effect = 0.6 letters; 95% confidence interval, -2 to 3).

CONCLUSIONS

A 4-week course of acetazolamide therapy results in a statistically significant but small decrease in cystoid macular edema in patients with chronic uveitis, and does not improve visual acuity. In contrast to previous studies in the literature, acetazolamide may have a more limited clinical benefit in patients with long-standing cystoid macular edema associated with chronic uveitis.

IL-12 inhibits endotoxin-induced inflammation in the eye

Interleukin-12 (IL-12) is a heterodimeric cytokine that induces interferon (IFN)-gamma production and an increased generation of Th1 cells. Both IL-12 and IL-12 antagonists are being studied for the treatment of allergic reactions, autoimmune disease and malignancy. The goal of the present experiments was to examine the importance of IL-12 in endotoxin-induced ocular inflammation. The number of inflammatory cells infiltrating eyes with endotoxin-induced uveitis (EIU) was significantly increased in animals treated with intraperitoneal anti-IL-12 antibody when compared to control animals, but there was no difference in infiltrating inflammatory cells in the eyes of animals treated with IL-12 when compared to controls. In contrast, intraocular injection of IL-12 significantly inhibited the development of endotoxin-induced intraocular inflammation. The infiltrating inflammatory cells were reduced in the eyes of animals receiving intraocular IL-12 when compared to controls. Cytokine analysis of the aqueous humor obtained from eyes with EIU showed increased levels of IFN-gamma and decreased levels of IL-6 in eyes receiving intraocular IL-12. These data show that IL-12 has an inhibitory effect on endotoxin-induced inflammation in the eye and suggest that IL-12 can have an immunoregulatory function in some forms of inflammatory disease.

Primary retinal vasculitis. Systemic associations and diagnostic evaluation

BACKGROUND

Inflammation of the retinal vasculature without an infectious etiology, systemic disease association, or concomitant ocular disease is termed primary retinal vasculitis, and can result in severe and permanent vision loss. Patients with primary retinal vasculitis usually are subjected to an extensive but unrewarding diagnostic evaluation. This study was undertaken to determine the value of such a diagnostic workup, and to determine whether systemic diseases develop in these patients during the course of their illness.

METHODS

The clinical records of 25 patients seen between 1984 and 1994 with the referring diagnosis of primary retinal vasculitis were reviewed retrospectively. Recorded data included patient age, sex, race, medical history, medications, visual acuity, extent of retinal disease, and the results of their diagnostic evaluations.

RESULTS

On presentation, none of the patients had an underlying systemic disease attributable as the cause of their retinal vasculitis. Review of systems was suggestive of an underlying systemic disease in 1 of 25 patients. Diagnostic evaluation in this patient showed a positive antinuclear antibody value and a double-stranded DNA, suggestive of systemic lupus erythematosus. Subsequently, systemic lupus erythematosus was diagnosed based on the development of other diagnostic criteria. The review of systems was not suggestive of an underlying systemic disease in 24 of 25 patients. False-positive diagnostic test results were obtained in 5 (20.8%) of these 24 patients. No underlying systemic disease associated with the patients' retinal vasculitis subsequently developed in any of these five patients (mean follow-up, 4 years).

CONCLUSION

Few diagnostic tests should be ordered in patients with retinal vasculitis in the absence of a medical history suggestive of underlying systemic disease.

Compound 48/80-induced conjunctivitis in the mouse: kinetics, susceptibility, and mechanism

A mouse model of conjunctivitis has been developed by topical application of compound 48/80 (C48/80), an agent that triggers mast cell degranulation. We examined the responsiveness of C57BL/6, C3H/HeN, and ASW/J mouse strains to C48/80 stimulation, and of a mutant strain with mast cell depletion (WBB6F1/J and its sham control). Conjunctivae were collected and examined histopathologically at 15 min and 1,6,24,48 and 72 h after topical C48/80 administration. Conjunctival inflammation developed in all strains, although the severity varied. The conjunctivitis was characterized clinically by irritation, discharge, erythema, and chemosis. Pathology showed conjunctival infiltration with neutrophils, macrophages, CD4+ T lymphocytes, and a few eosinophils. Degranulation of mast cells and evacuation of goblet cells were also observed. Late-phase inflammatory reactions peaked 6-24 h after C48/80 administration and resolved by 48-72 h. WBB6F1/J mice had much less inflammation than their sham controls. In conclusion, topical C48/80 induced a conjunctival inflammatory response similar to allergen-induced conjunctivitis. The depletion of mast cells significantly reduced the inflammation. This model which consistently mimics the clinical signs and histopathological processes of allergic conjunctivitis in humans, is practical and reliable for the evaluation of new anti-allergic medications and for the investigation of conjunctival cellular responses in the allergic inflammatory cascade.

Intraocular inflammatory disease (uveitis) and the use of oral tolerance: a status report

Intraocular inflammatory disease, or uveitis, is a disorder that mostly affects children and young adults. It is the cause of about 10% of the severe visual handicap in the United States. Many of the severe, sight-threatening uveitic conditions are thought to be driven by putative autoimmune mechanisms, often with high-dose oral prednisone use as treatment, along with cytotoxic agents, antimetabolites, and cyclosporine adjunctively. The feeding of the uveitogenic retinal S-Ag to rats immunized with the same antigen resulted in clinical protection. A pilot study in which two patients, one with pars planitis and the other with Behcet's disease, were fed with the retinal S-Ag resulted in these patients' immunosuppressive medication being decreased and/or stopped. The trial also provided us with information concerning dosage and expected immune responses. A randomized, masked study looking at the effect of feeding retinal antigens to uveitis patients is ongoing.

Human lymphocyte responses against epitopes of a self antigen: a follow-up at different time points

This study was aimed at examining the changes that may occur with time in the lymphocyte responses of an individual against peptide determinants of self antigens. Peripheral blood lymphocytes were collected from the same donor at seven different time points during a 10-month period and tested for their proliferative responses against whole human S-antigen and 40 overlapping peptides derived from the sequence of this uveitogenic retinal protein. Lymphocytes collected at different dates varied in their responsiveness to all tested antigens, as well as in the pattern of their response against individual peptides. The latter variability was expressed by differences in the hierarchical order of the most stimulatory peptides for lymphocytes collected at the seven time points. Despite the variability in their stimulatory capacity, six of the peptides exhibited their immunodominance by eliciting proliferation in lymphocytes collected at all time points. Our results thus indicate that data collected from a single sample of blood may be insufficient to accurately assess the level of cellular response to autologous antigens.

Combined intravenous ganciclovir and foscarnet for children with recurrent cytomegalovirus retinitis

PURPOSE

Children with the acquired immune deficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis may not complain of symptoms despite the presence of advanced sight-threatening disease. Although little data exist regarding CMV retinitis in this population, the treatment of this disease may be difficult because of frequent, extensive recurrences after reduction of drug dose from induction to maintenance levels. The authors reported the results of the use of combined ganciclovir and foscarnet for treatment of recurrent CMV retinitis in three children with AIDS.

METHODS

Three children with recurrent CMV retinitis were treated with combined ganciclovir and foscarnet administered intravenously. All patients initially received induction dosages of ganciclovir followed by maintenance therapy, at which time they experienced reactivation of their disease. The dosing regimen for induction with the combined therapy was foscarnet (60 mg/kg every 8 hours) and ganciclovir (5 mg/kg daily for 3 weeks). Maintenance with combined therapy consisted of foscarnet (90 mg/ kg daily) and ganciclovir (5 mg/kg daily).

RESULTS

All patients showed complete healing of the retinitis during the first 3 weeks of combined therapy. Median survival after initiation of combined therapy was 15 weeks (range, 12-33 weeks). None of the children experienced reactivation of CMV retinitis during combined therapy with ganciclovir and foscarnet. Combined therapy was well tolerated in all patients without major side effects. No patient required discontinuation or interruption of either drug during combined therapy.

CONCLUSION

Children with recurrent CMV retinitis may not report visual symptoms, which can delay therapeutic intervention. Therefore, recurrent disease in children should be treated aggressively to avoid potentially devastating visual loss. A combination of ganciclovir and foscarnet appears to be a safe and effective therapeutic option for treatment of recurrent CMV retinitis in children with AIDS. This approach causes no additional toxic reactions and may provide improved long-term control of recurrent CMV retinitis in children.

Endotoxin induced uveitis in the mouse: susceptibility and genetic control

Endotoxin induced uveitis in the mouse provides a useful animal model for acute anterior uveitis in humans. We have investigated the susceptibility of endotoxin-induced uveitis among various mouse strains, and have examined the relationship between genetic background and the resultant inflammatory response to endotoxin. We studied ten strains with differing major histocompatibility-2 genes, lipopolysaccharide response gene, and strains with mast cell depletion and its sham control. Anterior uveitis was induced by injecting 300 micrograms of Salmonella typhimurium endotoxin into one hind footpad. Mice were then killed 8, 12, 16, 20, 24, 48 and 72 hr after endotoxin injection, and vertical sections of the eyes through the pupil-optic nerve axis were evaluated for ocular inflammation. C3H/HeN mice developed severe uveitis. In contrast, C3H/HeJ mice (lipopolysaccharide response gene-) did not develop uveitis even though it has the same genetic background and shares the same major histocompatibility-2 haplotype with C3H/HeN mice (lipopolysaccharide response gene+). The strain that was mast-cell deficient (W/Wv) developed minimal uveitis; however, W/+ mice, with mast cells, developed more inflammation at 48 and 72 hr after endotoxin injection. C3H.SW and FVB/N mice also developed severe uveitis, and BALB/C, CBA/J, and B10.A developed mild uveitis. In conclusion, there is a wide variation in the magnitude and susceptibility to endotoxin among mouse strains. Multiple factors appear to influence this variability, including non-histocompatibility-2 genetic background, the lipopolysaccharide response gene, and the presence of mast cells.

Interleukin-10 in the vitreous of patients with primary intraocular lymphoma

PURPOSE

To find an accurate and simple method to diagnose primary intraocular lymphoma.

METHODS

We prospectively analyzed concentrations of interleukin-10, interleukin-1, interleukin-2, interleukin-4, and interleukin-6 in vitrectomy specimens from three patients with primary intraocular lymphoma and five patients with uveitis by enzyme-linked immunosorbent assay.

RESULTS

Interleukin-10 in the vitreous was detected in patients with primary intraocular lymphoma. Interleukin-10 levels correlated with clinical activity and the number of malignant cells.

CONCLUSION

Concentrations of interleukin-10 in the vitreous may be a helpful clue to both clinicians and pathologists in diagnosing primary intraocular lymphoma.

The relationship between visual acuity and functioning and well-being among diabetics

Given the enormous recent interest in functional capabilities related to vision, the goal of this study was to examine the relationship of standard clinical measures of vision (e.g. Snellen acuity) to functioning and well-being. The association between Snellen visual acuity, Amsler grid distortion and presence of diabetic retinopathy with self-reported functioning and well-being (SF-36) were examined in a sample of 327 diabetics from the Medical Outcomes Study (MOS). There was little or no correlation between Snellen visual acuity, Amsler grid distortion or diabetic retinopathy and functioning and well-being (i.e. SF-36 scales). Maximum product-moment correlation was 0.15 with worst eye visual acuity, 0.13 with best eye visual acuity, 0.08 with presence of retinopathy, and 0.10 with Amsler grid distortion. Analysis of variance revealed that visual acuity (both best and worst eye) was statistically related only to the physical function scale; no other exam measure was related to any other SF-36 scale score. Snellen visual acuity, Amsler distortion and diabetic retinopathy correlate weakly with patient self-reported functioning and well-being. Thus, the information provided by functioning and well-being measures is complementary to that of standard clinical measures of visual ability.

Monoclonal antibodies against CD54 (ICAM-1) and CD11a (LFA-1) prevent and inhibit endotoxin-induced uveitis

We studied the effect of monoclonal antibodies (mAbs) against CD54 (intercellular adhesion molecule-1; ICAM-1) and CD11a (lymphocyte function-associated antigen-1; LFA-1) on the prevention and treatment of endotoxin-induced uveitis (EIU). When treated at the time of endotoxin injection the mean number of inflammatory cells infiltrating the eye +/- S.E.M. on histologic sections was 469.2 +/- 51.9 for controls, 13.8 +/- 2.6 for rats receiving anti-ICAM-1 mAb (P < 0.0001), and 195.8 +/- 48.8 for rats receiving anti-LFA-1 mAb (P = 0.0003). When treated after the start of inflammatory disease, the mean number of infiltrating inflammatory cells +/- S.E.M. was 273.0 +/- 30.7 for controls, 6.4 +/- 1.7 for rats receiving anti-ICAM-1 mAb (P < 0.0001), and 54.2 +/- 7.6 for rats receiving anti-LFA-1 mAb (P < 0.0001). The mean number of cells per milliliter of aqueous humor +/- S.E.M. was 1867.6 +/- 321.8 for controls, 21.7 +/- 5.3 for rats receiving anti-ICAM-1 mAb (P < 0.0001), and 295.1 +/- 71.2 for rats receiving anti-LFA-1 mAb (P < 0.0001). MAbs against ICAM-1 and LFA-1 significantly inhibited the development of EIU and were effective in treating clinically evident ocular inflammatory disease.

32 cases of sympathetic ophthalmia. A retrospective study at the National Eye Institute, Bethesda, Md., from 1982 to 1992

OBJECTIVE

To examine the relationship between visual outcome and the clinical management of patients with sympathetic ophthalmia.

METHODS

Thirty-two patients with sympathetic ophthalmia who were seen at the National Eye Institute, Bethesda, Md, between 1982 and 1992, were retrospectively reviewed.

RESULTS

There were equal numbers of males and females. Sympathetic ophthalmia occurred after trauma in 23 patients and surgery in nine patients. Sixteen of the 32 patients had a final visual acuity of 20/40 or better; 10 patients had a visual acuity worse than 20/200. Good visual outcome was associated with early and aggressive treatment with corticosteroids, sometimes in combination with other immunosuppressive agents. Poor visual acuity was associated with glaucoma, chorioretinal scars in the macula, and persistent uncontrolled inflammation.

CONCLUSION

Prompt and aggressive use of antiinflammatory therapy can improve the visual outcome of patients with sympathetic ophthalmia.

Effects of topical FK506 on endotoxin-induced uveitis (EIU) in the Lewis rat

FK506 is a macrolide antibiotic and a potent immunosuppressant. To investigate the effect of topical FK506 on acute ocular inflammation, we evaluated its action on the development of endotoxin-induced uveitis (EIU). At two different concentrations of 0.05% and 0.3%, topical FK506 was applied to Lewis rats with EIU. In aqueous, the mean number of inflammatory cells per microliter +/- SEM was 2,389 +/- 1,277, 1,571 +/- 1,562, 898 +/- 882, and 69 +/- 152 for rats treated with vehicle alone, 0.05%, 0.3% FK506, and 1% prednisolone acetate. The median of histological grades was 2, 1.5, 0.8, and 0.5 for animals treated with these 4 different regimens respectively. Analysis of aqueous protein showed a small reduction in FK506-treated animals. Mean blood levels of FK506 were low in rats treated with topical FK506 (0.05%, 0.84 ng/ml; 0.3%, 2.0 ng/ml) suggesting that its therapeutic effect was not secondary to the systemic absorption of the drug. Although FK506 is not as effective as prednisolone, 0.3% FK506 produced significant decreases in the mean aqueous inflammatory cell number and histological inflammatory score as compared to control vehicle alone. We conclude that topical FK506 can suppress EIU in a dose-dependent fashion and may be an alternative medication for patients with anterior uveitis and contra-indication to topical steroid.

The diagnosis and management of uveitis

The diagnosis and management of uveitis is complicated and challenging. The protean signs and symptoms seen in patients with uveitis may lead to a diagnostic dilemma. A carefully taken history with particular attention to demographic factors and meticulous physical examination are crucial to guiding diagnostic testing. Tailoring the diagnostic approach in patients with uveitis frequently yields useful data in contrast to blanketing every possible uveitic entity. It is also important to distinguish among various aetiologies, including infectious and neoplastic causes which may respond to specific therapy. Medical treatment of noninfectious uveitis must have clear objectives including reduction of inflammation, relief of symptoms and restoration of visual functioning. Familiarity with possible symptoms and signs of adverse drug reactions is essential early in the course of treatment so that their effects may be minimised. Appropriate therapy of presumed autoimmune uveitis is based on disease severity, presence or absence of bilateral disease and the health status of the patient.

Intraocular inflammation in transgenic mice expressing a foreign antigen in their lens a preliminary report

Lens-induced uveitis can be elicited in experimental animals by immunization with lens antigens, followed by puncture of the lens capsule. The animal disease, that serves as a model for the human disease (also known as phacoanaphylactic endophthalmitis), has been shown to be mediated by antibodies against the lens antigens. Here the authors report on a new disease model for lens-induced uveitis which is cell-mediated. This experimental disease is induced in transgenic (Tg) mice that express hen egg lysozyme (HEL) in their lens. Eyes of these mice show disrupted lens, but no inflammation. On the other hand, severe inflammation develops in eyes of these Tg mice following intraperitoneal injection of lymphocytes from syngeneic wildtype donors sensitized against HEL. Furthermore, the recipient mice exhibit intense cellular immunity but no antibodies against HEL.

A clinicopathologic report of the retinal lesions associated with didanosine

Didanosine, a purine analogue with antiretroviral activity, is used in the treatment of human immunodeficiency virus disease. Associated toxic effects of didanosine include pancreatitis, peripheral neuropathy, and retinopathy. The retinal lesions associated with didanosine therapy were studied in a 6-year-old girl with acquired immunodeficiency syndrome. Gross examination disclosed multiple well-circumscribed depigmented lesions in the midperipheral retina. Microscopic examination of these lesions showed multiple areas of retinal pigment epithelial (RPE) loss, some surrounded by areas of hypertrophy or hypopigmentation of the RPE. Partial loss of the choriocapillaris and neurosensory retina were also noted in areas of diseased RPE. Transmission electron microscopy showed numerous membranous lamellar inclusions and cytoplasmic bodies in the RPE cells. These data show that didanosine primarily affects the RPE and that the choriocapillaris and overlying neurosensory retina are also dystrophic in areas of RPE loss.

Combined cyclosporine and corticosteroid therapy for sight-threatening uveitis in Behçet's disease

Behçet's disease is a multisystem disorder that may cause profound ocular inflammation and blindness. We reviewed 19 patients with severe ocular Behçet's disease treated with combined cyclosporine and corticosteroid therapy. Previous treatment with corticosteroids alone failed to control the uveitis in all patients. Ten patients were given cyclosporine therapy alone (mean dosage, 8.6 mg/kg of body weight per day), and nine patients were given lower dosages of cyclosporine (mean dosage, 6.2 mg/kg of body weight per day) in combination with prednisone (mean dosage, 29.4 mg per day). The mean follow-up on therapy was 51 months. After three months of therapy, a trend toward greater improvement in visual acuity was noted in patients treated with combined cyclosporine and prednisone compared to those receiving cyclosporine alone (17.8 letters vs 10.2 letters, P = .2379), but after one year little difference was observed in the improvement between the two groups (5.8 letters vs 3.3 letters, P = .7984). However, a trend toward greater renal toxicity was seen in patients treated with cyclosporine alone after both three months and one year of therapy. Because of either a suboptimal therapeutic response or adverse effects, all patients treated with cyclosporine alone at baseline had prednisone added to their regimen after a mean time of 23.5 months. Overall, visual acuity remained stable or improved in 28 of 37 eyes (75.7%) over the course of therapy. These data suggest that combined cyclosporine and prednisone therapy is an effective treatment for Behçet's uveitis and may be less toxic than therapy with cyclosporine alone. A prospective, randomized trial with a larger sample size is needed to provide definitive data.

Experimental melanin-protein-induced uveitis in the Lewis rat. Immunopathologic processes

PURPOSE

To study the immunopathology of experimental melanin-protein-induced uveitis in the Lewis rat.

METHODS

Rats were immunized with bovine ocular melanin protein. The kinetics of experimental melanin-protein-induced uveitis was studied by clinical examination and immunopathology. Cellular and humoral responses were evaluated by lymphocyte proliferation, delayed-type hypersensitivity, and agglutination. After clinical disease subsided, recurrent experimental uveitis was induced with a low-dose footpad injection of lipopolysaccharide.

RESULTS

Experimental melanin-protein-induced uveitis was characterized by bilateral uveal infiltration mainly with lymphocytes and monocytes. Delayed-type hypersensitivity, lymphocyte proliferation, and agglutination to bovine ocular melanin protein were positive. Expressions of major histocompatibility complex class II and intercellular adhesion molecule-1 were observed before ocular infiltration. The predominantly infiltrating cells were CD4+ lymphocytes. Experimental melanin-protein-induced uveitis subsided within 1 month, spontaneously recurred within 1 week in approximately one quarter of the rats, and was inducible in most rats with 5 micrograms of lipopolysaccharide confirmed by histopathology.

CONCLUSIONS

Experimental melanin-protein-induced uveitis is a T-cell-mediated autoimmune uveitis, resembling noninfectious recurrent iridocyclitis and choroiditis in humans.

Treatment of autoimmune uveitis

The number of effective drugs for the treatment of autoimmune uveitis has greatly increased over the past 40 years. Many patients previously condemned to blindness can now be successfully treated with new immunosuppressive agents. New targets of the immune system, such as cell adhesion molecules, may offer novel therapeutic approaches for the treatment of inflammatory disease. However, since the catholicon for uveitis is not yet available, the search for new antiinflammatory therapy continues.

Expression of cell adhesion molecules in corneal graft failure

Corneal graft failure is frequently mediated by uncontrolled inflammatory disease. We studied the expression of cell adhesion molecules in seven penetrating keratoplasty specimens with graft failure and in a normal eye bank cornea using immunohistochemical staining and monoclonal antibodies against intercellular adhesion molecule-1 (ICAM-1, CD54), lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and major histocompatibility complex (MHC) class II antigen (HLA-DR). ICAM-1 and HLA-DR were expressed on keratocytes and the corneal endothelium in six of the seven specimens. ICAM-1 expression was strongest in the corneas with the most severe inflammation (corneal allograft rejection and severe intraocular inflammation). LFA-1 is a counter-receptor for ICAM-1, and infiltration with leukocytes expressing either the alpha or beta chain of LFA-1 was found in areas of ICAM-1 expression in four of the seven corneas. In contrast, E-selectin was expressed in the stroma in only two specimens, and VCAM-1 in one specimen. Expression of cell adhesion molecules or MHC class II antigen were not detected in the normal eye bank cornea. These data suggest that ICAM-1 expression may play an important role in the development of corneal graft failure. Furthermore, monoclonal antibodies to block ICAM-1 or its ligands may inhibit the development of corneal inflammation.

A pilot study of sequential therapy with zidovudine plus acyclovir, dideoxyinosine, and dideoxycytidine in patients with severe human immunodeficiency virus infection

A pilot study was initiated to explore a sequential combination antiretroviral regimen in 21 patients with AIDS or advanced human immunodeficiency virus (HIV) infection, who had received little or no prior anti-HIV therapy. The mean entry CD4 cell count was 184/mm3. Patients received 3-week cycles consisting of zidovudine plus acyclovir, dideoxyinosine, and dideoxycytidine for 1 week each. Overall, the regimen was well tolerated for up to 3 years. The principal toxicities were anemia, nausea, and vomiting; 1 patient developed retinal lesions. The mean CD4 cell count reached a peak of 64 cells/mm3 above baseline at week 8 (P = .005 compared to baseline) and remained above baseline for > 40 weeks. Patients also gained weight and had decreases in serum HIV p24 antigen. Eight patients developed opportunistic infections or tumors. Only 4 patients died during 3 years of follow-up. This regimen appears to be generally tolerable and to have anti-HIV activity. Additional studies will be needed, however, to learn how to best combine the available agents in patients with HIV infection.

The paradoxical effect of tumor necrosis factor alpha (TNF-alpha) in endotoxin-induced uveitis

PURPOSE

To investigate the role of TNF-alpha in endotoxin-induced uveitis (EIU) in mice.

METHODS

To neutralize TNF-alpha activity, mice were pretreated with either repeated injections of this cytokine or a single injection of antibody against it. The mice were then injected intraperitoneally with 500 micrograms endotoxin, to induce lethal septic shock, or into the footpad with 200 micrograms to induce EIU.

RESULTS

Although both pretreatments conferred protection against the systemic toxic effects of LPS, TNF-resistant mice and mice treated with anti-TNF-alpha antibody demonstrated an exacerbation of EIU when compared to control animals.

CONCLUSIONS

Unlike its apparent participation in the systemic effect of endotoxin, TNF-alpha is not directly involved in the pathogenesis of EIU and may even protect against the inflammatory processes of this disease.

Intraocular lymphoma. Clinical and histopathologic diagnosis

BACKGROUND

Intraocular lymphoma is associated with significant morbidity and mortality, but early diagnosis and treatment may improve prognosis.

METHODS

The diagnostic features of 12 cases of intraocular lymphoma diagnosed at the National Eye Institute between 1984 and 1992 were retrospectively reviewed.

RESULTS

A pathologic diagnosis of large B-cell lymphoma was made on vitrectomy specimens in ten patients, cerebral spinal fluid in one, and on an enucleation specimen in one. The mean time from onset of symptoms to diagnosis was 21.4 months (range, 1-66 months). All 12 patients were given a final diagnosis of non-Hodgkin's lymphoma of the central nervous system (NHL-CNS), based on the epidemiology, pathology, and clinical course of their tumors. Although an initial vitrectomy was negative for malignant cells in three of ten patients, a repeat vitrectomy specimen subsequently showed intraocular lymphoma. Results of examination of the cerebrospinal fluid (CSF) showed malignant cells in 5 of 11 patients, although malignant cells were only identified after repeat examination of additional samples of CSF in three of these patients. Malignant cells often are difficult to identify, and an experienced cytopathologist was critical in making the correct diagnosis. In addition, corticosteroids are lympholytic to the lymphoma cells, and they appeared to decrease the viability of tumor cells obtained in samples of vitreous and CSF.

CONCLUSION

The prompt, appropriate handling of specimens and review by an experienced cytopathologist are critical to the diagnosis of intraocular lymphoma. Malignant cells often are present in the cerebral spinal fluid at the time that ocular lymphoma is diagnosed. Nevertheless, multiple vitrectomies and lumbar punctures may be necessary before the correct diagnosis is made.