Cytokines and immunopathogenesis of intraocular posterior segment inflammation

PR1P ameliorates neurodegeneration through activation of VEGF signaling pathway and remodeling of the extracellular environment

Neurodegenerative diseases affect millions of people worldwide. Optic neuropathies are the most commonly occurring neurodegenerative diseases, characterized by progressive retinal ganglion cell (RGC) degeneration. We recently reported that Prominin-1, a protein found on the surface of stem cells, interacts with VEGF and enhances its activity. VEGF is known to have various protective roles in the nervous system. Subsequently, we have developed a 12-mer peptide derived from Prominin-1, named PR1P, and investigated its effects on neuronal survival of damaged RGCs in a rat model of optic nerve crush (ONC). PR1P prevented RGC apoptosis resulting in improvement of retinal function in the rat ONC model. PR1P treatment significantly increased phosphorylation of ERK and AKT and expression its downstream proteins c-fos and Egr-1 in the retina. Additionally, PR1P beneficially increased the MMP-9/TIMP-1 ratio and promoted glial activation in the retina of ONC rats. Thus, PR1P displayed neuroprotective effects through enhanced VEGF-driven neuronal survival and reconstruction of the extracellular environment in ONC model. Our data indicate that PR1P may be a promising new clinical candidate for the treatment of neurodegenerative diseases.

Long-term results of pars plana vitrectomy as an anti-inflammatory therapy of pediatric intermediate uveitis resistant to standard medical treatment

PURPOSE

To evaluate the efficacy of pars plana vitrectomy (PPV) as an anti-inflammatory therapy in pediatric recurrent intermediate uveitis.

METHODS

A retrospective study evaluated the long-term results of PPV indicated for intermediate uveitis with a mean observation period of 10.3 years (range 7-15.6 years) in 6 children (mean age 8 years, range 6-12 years). Pars plana vitrectomy was performed on 10 eyes in the standard manner and was initiated by vitreous sampling for laboratory examination. Data recorded were perioperative or postoperative vitrectomy complications, anatomic and functional results of PPV, and preoperative and postoperative best-corrected Snellen visual acuity.

RESULTS

No perioperative or postoperative complications were observed. Bacteriologic, virologic, mycotic, and cytologic analysis of the vitreous was negative in all tested children. Five eyes were subsequently operated on for posterior subcapsular cataracts. An average preoperative visual acuity of 0.32 improved to an average postoperative visual acuity of 0.8.

CONCLUSIONS

In the case of systemic immunosuppressive treatment failure in pediatric uveitis, particularly in eyes with cystoid macular edema, we recommend PPV relatively early.

Cytokines and Biologics in non-infectious autoimmune uveitis: bench to bedside

Intraocular inflammatory eye disease is one of the important causes of ocular morbidity. Even though the prevalence of uveitis is less common in relation to diabetic retinopathy, glaucoma or age related macular degeneration, the complexity and heterogeneity of the disease makes it more unique. Putative uveitogenic retinal antigens incite innate immunity by the process of antigen mimicry and have been shown to be associated in patients with intraocular inflammatory disease by numerous experimental studies. Laboratory diagnostic tools to aid the etiologic association in intraocular inflammatory disease have evolved over the last two decades and we are entering into an era of molecular diagnostic tests. Sophisticated novel technologies such as multiplex bead assays to assess biological signatures have revolutionized the management of complex refractory uveitis. Nevertheless, there is still a long way to go to establish the causal relationship between these biomarkers and specific uveitic entities. Experimental studies have shown the supreme role of infliximab in the management of Behcet's disease. Despite significant experimental and case control studies, the deficiency of randomized clinical trials using these biologic agents has handicapped us in exploring them as a front line therapy in severe refractory uveitis. Studies still need to answer the safety of these potentially life threatening drugs in a selected group of patients and determine when to commence and for how long the treatment has to be given. This review article covers some basic concepts of cytokines in uveitis and their potential application for therapy in refractory uveitis.

Biologic response modifiers in retinal vasculitis

Intraocular inflammation is an important cause of blindness both in the developing and developed world. Corticosteroids play a pivotal role in the treatment of intraocular inflammation. Lately, therapy by immunosuppression has taken the center stage for patients with severe intraocular inflammation. However, the side effects of immunosuppressive drugs are oncogenic, infectious, and hematological. Recently, biologic response modifiers specifically targeting suppression of the immune effector responses have revolutionized the treatment of intraocular inflammation. Anti-tumour necrosis factor agents are etanercept, infliximab, and adalimumab. Newer drugs include certolizumab and golimumab. Infliximab has been found to be superior to corticosteroids in treating retinal vasculitis. Anti-interlenkin therapies include rituximab, daclizumab, anakinra, tocilizumab and secukinumab. Rituximab has been proven to be quite effective. Other biologics used are interferons and abatacept. However, there are several limitations and side effects associated with their use.

Recent developments in the treatment of uveitis: an update

The management of complex uveitis is often based around the use of oral corticosteroids. To spare the side effects of corticosteroids, second-line oral immunosuppressant drugs are used. Newer systemic immunosuppressive drugs, including biologics, and locally delivered treatments are being evaluated. This article reviews current conventional treatments, discusses their limitations and evaluates newer treatment strategies. Current theories about the pathogenesis of uveitis and potential targets for treatment are discussed in this context. We are still in search of a low-risk, where possible, locally delivered and targeted treatment for uveitis.

Vitreous fluid biomarkers

Interactions between cells and the network of secreted proteins are associated with the ocular disease. In most cases, clinical appearcance is sufficiently diagnostic. However, in cases of nonspecific or atypical clinical presentation, diagnostic sampling of vitreous fluid can aid diagnosis and treatment for ocular disease. Progresses in the basic sciences, particularly molecular biology, and advances in surgical instrumentation have greatly enhanced the diagnostic armamentarium. These developments also have led to a better understanding of the pathophysiological processes involved in ocular diseases and have prompted evolution of new therapeutic modalities. In this chapter, we review techniques for vitreous fluid sampling and biomarker quantitation thereof. The molecular biology of bioactive vitreous fluid factors is also discussed with respect to their clinical involvement in the development of ocular disease.

Cytokines and chemokines in uveitis: is there a correlation with clinical phenotype?

Uveitis is a general term for intraocular inflammation and includes a large number of clinical phenotypes. As a group of disorders, it is responsible for 10% of all registered blind patients under the age of 65 years. Immune-mediated uveitis may be associated with a systemic disease or may be localized to the eye. The pro-inflammatory cytokines interleukin (IL)-1beta, IL-2, IL-6, interferon-gamma and tumor necrosis factor-alpha have all been detected within the ocular fluids or tissues in the inflamed eye together with others, such as IL-4, IL-5, IL-10 and transforming growth factor-beta. The chemokines IL-8, monocyte chemoattractant protein-1, macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and fractalkine are also thought to be involved in the associated inflammatory response. There have been a number of studies in recent years investigating cytokine profiles in different forms of uveitis with a view to determining what cytokines are important in the inflamed eye. This review attempts to present the current state of knowledge from in vitro and in vivo research on the inflammatory cytokines in intraocular inflammatory diseases.

Vitrectomy for juvenile uveitis: prognostic factors for the long-term functional outcome

PURPOSE

This study evaluated the long-term effect of pars plana vitrectomy (PPV) in children and adolescents with chronic uveitis on visual function, anatomical outcome, and the requirement of systemic treatment. Further, predictive preoperative factors associated with a beneficial visual outcome were assessed.

METHODS

Retrospective review of 29 eyes of 23 consecutive paediatric and juvenile patients below 20 years of age with chronic uveitis who underwent a PPV for visually significant opacities in 25 eyes, vitreous haemorrhage in three eyes, and retinal detachment in one eye. The clinical diagnosis was chronic intermediate uveitis in 22 eyes and retinal vasculitis of different origin in seven eyes.

RESULTS

LogMAR visual acuity improved from an average of 0.91 to 0.33 (P<0.001). Cystoid macular oedema (CME) was significantly reduced in eight of 10 eyes postoperatively (P=0.021). In the multiple regression analysis, a low preoperative logMAR visual acuity and the presence of a CME had a negative influence on the final logMAR visual acuity. Furthermore, the appearance of chronic uveitis relapses was significantly reduced from 15 eyes before to seven eyes after surgery (P=0.042).

CONCLUSIONS

PPV has a beneficial effect on the course and the complications of chronic uveitis in paediatric and juvenile patients with respect to the anatomical and visual outcome. Preoperative logMAR visual acuity and clinically significant CME were the most accurate predictors for the functional outcome.