Antigen-specificity of antiretinal antibodies in patients with noninfectious uveitis

Repurposing of rituximab biosimilars to treat B cell mediated autoimmune diseases

Rituximab, the first monoclonal antibody approved for the treatment of lymphoma, eventually became one of the most popular and versatile drugs ever in terms of clinical application and revenue. Since its patent expiration, and consequently, the loss of exclusivity of the original biologic, its repurposing as an off-label drug has increased dramatically, propelled by the development and commercialization of its many biosimilars. Currently, rituximab is prescribed worldwide to treat a vast range of autoimmune diseases mediated by B cells. Here, we present a comprehensive overview of rituximab repurposing in 115 autoimmune diseases across 17 medical specialties, sourced from over 1530 publications. Our work highlights the extent of its off-label use and clinical benefits, underlining the success of rituximab repurposing for both common and orphan immune-related diseases. We discuss the scientific mechanism associated with its clinical efficacy and provide additional indications for which rituximab could be investigated. Our study presents rituximab as a flagship example of drug repurposing owing to its central role in targeting cluster of differentiate 20 positive (CD20) B cells in 115 autoimmune diseases.

Anti-retinal Antibodies in Sarcoidosis

PURPOSE

To measure, characterize, and evaluate the clinical significance of anti-retinal antibodies in patients with sarcoid uveitis.

SUBJECTS/METHODS

Prospective study of anti-retinal antibodies in 45 patients with biopsy-proven sarcoidosis (25 with and 20 without uveitis). Results were compared with patients with confirmed infectious uveitis (n = 40) and non-infectious uveitis (n = 40).

RESULTS

Among sarcoidosis patients, anti-retinal antibodies were positive in 23/25 patients with uveitis and in 15/20 without uveitis [P = ns]. The most common antigens recognized were carbonic anhydrase II (14/23) and α-enolase (6/23). Anti-carbonic anhydrase II autoantibodies were infrequently detected in sarcoidosis patients without uveitis (2 out 15, P < .001), in patients with infectious uveitis (1 out 18, P < .001), and in patients with non-infectious uveitis (8 out 37, P < .001).

CONCLUSIONS

Anti-retinal antibodies recognizing carbonic anhydrase II are common in sarcoid uveitis. Although not fully sensitive and specific, they might be a useful non-invasive diagnostic tool for the diagnosis of sarcoid uveitis.

Serum Autoantibodies in Patients with Dry and Wet Age-Related Macular Degeneration

BACKGROUND

To assess the serum autoantibody profile in patients with dry and exudative age-related macular degeneration compared with healthy volunteers to detect potential biomarkers, e.g., markers for progression of the disease.

MATERIALS AND METHODS

IgG Immunoreactivities were compared in patients suffering from dry age-related macular degeneration (AMD) (n = 20), patients with treatment-naive exudative AMD (n = 29) and healthy volunteers (n = 21). Serum was analysed by customized antigen microarrays containing 61 antigens. The statistical analysis was performed by univariate and multivariate analysis of variance, predictive data-mining methods and artificial neuronal networks were used to detect specific autoantibody patterns.

RESULTS

The immunoreactivities of dry and wet AMD patients were significantly different from each other and from controls. One of the most prominently changed reactivity was against alpha-synuclein (p ≤ 0.0034), which is known from other neurodegenerative diseases. Furthermore, reactivities against glyceraldehyde-3-phosphat-dehydrogenase (p ≤ 0.031) and Annexin V (p ≤ 0.034), which performs a major role in apoptotic processes, were significantly changed. Some immunoreacitvities were antithetic regulated in wet and dry-AMD, such as Vesicle transport-related protein (VTI-B).

CONCLUSIONS

Comparison of autoantibody profiles in patients with dry and wet AMD revealed significantly altered immunoreactivities against proteins particularly found in immunological diseases, further neurodegenerative, apoptotic and autoimmune markers could be observed. A validation study has to explore if these antibody pattern can help to understand the underlying differences in pathogenesis, evaluate their prognostic value and if those could be possibly useful as additional therapeutic targets.

Birdshot chorioretinopathy in an HLA-A29 positive Asian patient

Purpose

To present a case of birdshot chorioretinopathy (BCR) in a Chinese patient with HLA-A29 positivity.

Observations

A 45-year-old Chinese female presented at a tertiary Ophthalmology Clinic with complaints of frequent headaches as well as blurred vision, photophobia, and pressure in the left eye (OS). The patient had a significant ocular history of left orbital cavernous hemangioma status post lateral orbitotomy and resection. Uncorrected visual acuity was 20/20 in the right eye (OD) and 20/40 in OS (pinhole 20/30). Funduscopic examination demonstrated optic disc edema, left eye worse than right eye, and vascular tortuosity in both eyes (OU). Late phase fluorescein angiography (FA) showed extensive perivascular and optic disc leakage and peripheral capillary leakage in OU. Laboratory evaluations were positive for human leukocyte antigen-A29 (HLA-A29). The patient was started on 40 mg prednisone daily; mycophenolate mofetil 500 mg twice daily was subsequently added.At the 3-month consultation visit to the Uveitis Clinic, dilated funduscopic examination revealed 1+ vitreous cells and improved optic disc edema in OU. FA showed improved vascular and optic disc leakage in OS but worsened leakage in OD. At this point, indocyanine green angiography (ICGA) was ordered which revealed hypocyanescent lesions throughout the choroid that were centered on the optic disc, supporting and confirming the diagnosis of BCR.

Conclusions and Importance

The index patient is the first reported case of BCR in an HLA-A29 positive Asian patient.

Antireconverin antibodies in ocular chronic graft versus host disease: A new cause of nonparaneoplasic autoimmune retinopathy

INTRODUCTION

A case of a 48-year-old male with a nonparaneoplasic autoinmune retinopathy (nPAIR) due to chronic graft versus host disease (GVHD) after an allogenic stem cell transplantation (ASCT) is described.

CASE REPORT

The patient developed a bilateral rapidly progressive loss of visual acuity with bilateral optic disc edema and bilateral cystoid macular edema (CME) in the funduscopy, a ring scotoma in the visual field (VF) and photoreceptors dysfunction in the electroretinogram (ERG) 210 days after the ASCT. After ruling out other causes, the suspicion of autoimmune retinopathy (AIR) led to the study of antirecoverin antibodies which resulted positive. The exclusion of neoplasia discarded diagnosis of paraneoplasic autoinmune retinopathy (PAIR) and the temporal relationship with BMT led to the diagnosis of nonparaneoplasic autoinmune retinopathy (nPAIR) due to chronic graft versus host disease (GVHD). Oral corticosteroids led to resolution of the CME.

CONCLUSIONS

Diagnosis of AIR requires a high index of suspicion based on the typical findings on visual field, optical coherence tomography (OCT) and ERG, which force requesting antirecoverin antibodies. However, diagnosis is often delayed because of the need to exclude other causes. Knowing typical symptoms and signs in for a quick action is important because an earlier diagnosis and treatment will improve visual prognosis since the loss of vision already established is irrecoverable. To our knowledge, this is the first reported case in the literature of nPAIR with CME and optic disc edema due to GVHS after ASCT.

Interphotoreceptor Retinoid-Binding Protein (IRBP) in Retinal Health and Disease

Interphotoreceptor retinoid-binding protein (IRBP), also known as retinol binding protein 3 (RBP3), is a lipophilic glycoprotein specifically secreted by photoreceptors. Enriched in the interphotoreceptor matrix (IPM) and recycled by the retinal pigment epithelium (RPE), IRBP is essential for the vision of all vertebrates as it facilitates the transfer of retinoids in the visual cycle. It also helps to transport lipids between the RPE and photoreceptors. The thiol-dependent antioxidant activity of IRBP maintains the delicate redox balance in the normal retina. Thus, its dysfunction is suspected to play a role in many retinal diseases. We have reviewed here the latest research on IRBP in both retinal health and disease, including the function and regulation of IRBP under retinal stress in both animal models and the human retina. We have also explored the therapeutic potential of targeting IRBP in retinal diseases. Although some technical barriers remain, it is possible that manipulating the expression of IRBP in the retina will rescue or prevent photoreceptor degeneration in many retinal diseases.

Anti-recoverin antibodies indicate fundus abnormalities in systemic lupus erythematosus

OBJECTIVES

Lupus fundus abnormalities are a sight-threatening complication of systemic lupus erythematosus (SLE) and its pathogenesis remains to be studied. The aim of this study was to assess the clinical characteristics associated with the presence of anti-recoverin antibodies in patients with SLE, especially those with fundus abnormalities.

METHODS

Seventy-six participants were enrolled, including 21 patients with fundus abnormalities (fundus group), 30 patients without fundus abnormalities (non-fundus group) and 25 healthy individuals. Serum anti-recoverin antibody levels were measured using enzyme-linked immunosorbent assay, and clinical and laboratory data were obtained from medical records.

RESULTS

Compared with the non-fundus group, the fundus group had a higher incidence of hematuria (p < 0.05). The Systemic Erythematosus Disease Activity Index (SLEDAI) score in the fundus group was significantly higher than the non-fundus group (21.48 ± 8.06 versus 10.80 ± 5.74, p < 0.001). The levels of serum anti-recoverin antibodies in the fundus group were significantly higher than the non-fundus group (p = 0.029) or the healthy control group (p = 0.011). Anti-recoverin-negative and -positive patients differed on a number of clinical parameters, including incidence of fever, rash, antinuclear antibody, anti-dsDNA antibody, erythrocyte sedimentation rate, immunoglobulin G, complement C3 and complement C4. The average SLEDAI score of anti-recoverin-positive patients was significantly higher than anti-recoverin-negative patients (17.73 ± 8.11 versus 12.56 ± 8.37, p < 0.05).

CONCLUSIONS

Anti-recoverin antibodies were related to higher disease activities in SLE, especially those with fundus abnormalities, suggesting that anti-recoverin antibodies may play an important role in the pathogenesis of fundus abnormalities in SLE.

Immune Cell Infiltration into the Eye Is Controlled by IL-10 in Recoverin-Induced Autoimmune Retinopathy

Autoimmune retinopathy (AIR) is a treatable condition that manifests in acute and progressive vision loss in patients. It has recently been determined that AIR is associated with an imbalance of T_H1 versus regulatory T cell immunity toward the retinal protein, recoverin. This study describes a new murine model to understand the immunopathology of AIR and its association with T cell responses toward recoverin. Immunization of C57BL/6 mice with recoverin resulted in ocular inflammation including infiltration of CD4⁺ and CD8⁺ T lymphocytes, B cells, and CD11b⁺Ly6C⁺ inflammatory monocytes in the eyes. Production of IFN-γ and IL-17 from T cells was exacerbated in IL-10 knockout (KO) mice and kinetics of disease development was accelerated. Infiltration of T cells and inflammatory monocytes into the eyes dramatically increased in recoverin-immunized IL-10 KO mice. An immunodominant peptide of recoverin, AG-16, was capable of inducing disease in IL-10 KO mice and resulted in expansion of AG-16 tetramer-specific CD4⁺ T cells in lymphoid organs and eyes. Adoptive transfer of recoverin-stimulated cells into naive mice was sufficient to induce AIR, and immunization of B cell-deficient mice led to a milder form of the disease. This model supports the hypothesis that recoverin-specific T cell responses are major drivers of AIR pathogenesis and that IL-10 is an important factor in protection.