Cytokines in proliferative vitreoretinopathy

This study determined the presence of interleukin 1 (IL-1), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF alpha), tumour necrosis factor beta (TNF beta), interferon gamma (IFN gamma), transforming growth factor beta 2 (TGF beta 2) and fibroblast proliferation activity (FPA) in vitreous aspirates from eyes undergoing vitrectomy for the treatment of retinal detachment complicated by proliferative vitreoretinopathy (PVR) or uncomplicated retinal detachment (RD). Cadaveric vitreous from normal subjects were used as controls. The results showed that IL-1 and IL-6 predominated in vitreous from eyes with PVR or RD, and that concentrations of IL-6 greater than 20 pg/ml were more frequently found in PVR than in RD (p = 0.031) or control specimens (p = 0.006). Low levels of TNF alpha were observed in 4/18 eyes with PVR, 1/15 eyes with RD and 1/15 control vitreous, and small concentrations of TNF alpha were seen in 3/18 eyes with PVR, 1/15 eyes with RD and 2/15 control vitreous. IFN gamma was detected in 12/18 eyes with PVR, but only in 5/15 eyes with RD (p = 0.048) and 6/15 control specimens. TGF beta 2 was present in all vitreous samples at concentrations ranging from 100 to 4,500 pg/ml with no significant differences among the three groups. Control vitreous possessed the greatest FPA when compared with vitreous from eyes with PVR (p = 0.031) or RD (p = 0.048). These observations provide further evidence that cytokine-mediated pathways of inflammation are involved in the pathogenesis of PVR and point to the possible involvement of IL-1, IL-6 and IFN gamma in cellular interactions leading to chronicity.

Proliferative vitreoretinopathy. Lymphocytes in epiretinal membranes

BACKGROUND

To investigate the potential contribution of inflammatory and immune-mediated processes contributing to the pathogenesis of proliferative vitreoretinopathy (PVR), an immunohistochemical study was undertaken to characterize the infiltrating inflammatory cells in epiretinal membranes surgically removed from the eyes of patients with PVR.

METHODS

Twenty-one epiretinal membranes obtained surgically from eyes with PVR complicating rhegmatogenous retinal detachment were studied immunohistochemically using the ABC technique and a panel of monoclonal and polyclonal antibodies.

RESULTS

T lymphocytes were found in 18 of the 21 specimens and generally constituted a small percentage of the total cell number. CD4+ T cells were found in 14 of the 18 membranes containing T cells. Three of six frozen membranes contained T cells that were positive for the interleukin-2 receptor. In 5 of 16 membranes studied, cells positive for the macrophage/monocyte marker were found. No B lymphocytes or neutrophils were identified, and there were no deposits of complement or immunoglobulins. Positive staining for the class II MHC antigen HLA-DR was found in 7 of the 21 membranes, a result that was more consistent in frozen than in fixed tissues.

CONCLUSION

The study suggests that T lymphocytes are present in PVR epiretinal membranes and may be activated. These cells have the potential to play a role in the pathobiology of PVR.

Expression of mRNA coding for TNF alpha, IL-1 beta and IL-6 by cells infiltrating retinal membranes

BACKGROUND

Cellular mechanisms of inflammation are thought to be involved in the pathogenesis of proliferative vitreoretinopathy, and cytokines, which are products of cell activation, are known to play an important role in the development and maintainance of inflammatory reactions. It was the aim of this work to investigate the presence of cells expressing cytokine mRNA within retinal membranes.

METHODS

The presence of mRNA coding for the cytokines interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF alpha) was investigated in 19 epiretinal membranes obtained from eyes undergoing vitrectomy for the treatment of retinal detachment complicated by proliferative vitreoretinopathy.

RESULTS

Cells expressing mRNA for IL-1 beta were observed in 7 membranes, cells positive for IL-6 mRNA were seen in 12 membranes, and cells exhibiting mRNA for TNF alpha were present in 9 specimens. Only three membranes contained cells expressing mRNA for all the cytokines investigated. Four membranes possessed positive cells for IL-6 and TNF alpha, two contained cells expressing mRNA for IL-6 and IL-1 beta, and two others exhibited cells expressing mRNA for TNF alpha and IL-1 beta. Five membranes contained IL-6 mRNA-positive cells only, whilst two exhibited cells expressing mRNA for IL-1 beta or TNF alpha only.

CONCLUSION

The present findings indicate that cellular activation may occur during the development of PVR, and suggest that these cytokines may be locally produced by cells infiltrating epiretinal membranes. The presence of IL-1 beta, IL-6 and TNF alpha mRNA-positive cells within retinal membranes provides further evidence of a pathogenic role of these cytokines in proliferative vitreoretinopathy.

Further characterization of epiretinal membranes in human massive periretinal proliferation

Periretinal membranes obtained at vitrectomy from three patients with massive periretinal proliferation were examined by immunofluorescence and electron microscopy. Immunofluorescent staining on fresh frozen sections showed positive stain with glial fibrillary acidic protein and a weaker stain with antibodies to actin, PBM-1 and laminin. Staining was negative for antibodies to actin, PBM-1 and laminin. Staining was negative for antibodies of collagen types I, III and IV. Electron microscopy revealed abundant glial cells arranged in a tubulo-acinar configuration with junctional complexes, apical microvillous processes and 9-10 nm cytoplasmic filaments.

Clinical and molecular markers in retinal detachment-From hyperreflective points to stem cells and inflammation

PURPOSE

Retinal detachment (RD) is one of the most frequently diagnosed ophthalmologic conditions requiring prompt surgical intervention. Combination of proper surgical technique and new diagnostic markers, both clinical and molecular, can help improve the diagnosis and prognosis of RD treatment.

METHODS

12 patients with rhegmatogenous RD (rRD) were included into the study after obtaining patient consent and Regional Ethical Approval (average age: 58.1 ± 17.4 years). OCT was performed before and after 23G vitrectomy for RD. Pure subretinal fluid (SRF) was collected during surgery and analyzed by protein array profiling on a panel of 105 inflammatory cytokines (Human XL Cytokine Array), while the effect of SRF upon human macrophages-driven phagocytosis of apoptotic retinal pigment epithelial (RPE) cells ex vivo was quantified by flow cytometry. Immunohistochemistry (IHC) of retinectomized tissue due to PVR caused by RD was performed to determine presence of markers for microglial cells (CD34), macrophages and activated microglia (CD68), regulator of the immune response to infection (NFkB), progenitor and stem cell marker (Sox2), pluripotency marker (Oct4) and intermediate filament markers (GFAP and Nestin).

RESULTS

OCT of fresh RD patients contained pre-operatively hyper reflective points (HRPs) at the detached neuroretina border and proximal to the RPE layer-their size and number decreased following successful reattachment surgery. IHC of the retinectomized tissue from detached retina due to severe PVR showed presence of cell conglomerates at the detached neuroretina border which were positive for CD68, NFkB, Sox2 and GFAP, less positive for CD47 and Nestin and negative for Oct4 and CD34. The SRF contained at least 37 cytokines with higher, and 4 cytokine with lower concentration compared to that in vitreous from non-RD pathology; when used as conditional medium to human macrophages ex vivo, the SRF doubled their capacity for engulfing dying RPEs.

CONCLUSIONS

Fresh RD can be hallmarked by presence of HRPs at the detached neuroretina border on OCT; the HRPs decrease in size and number after successful reattachment surgery, and likely resemble the macrophage conglomerates seen by IHC. The neuroretina in RD contains progenitor/stem-like cells and signs of inflammatory reaction, while the SRF contains inflammatory cytokines and other factors which increase the ability of professional phagocytes to engulf dying RPE, or for that matter, other dying cells in the retina.

Immunoreactive opsin content in subretinal fluid from patients with rhegmatogenous retinal detachments

We determined the immunoreactive opsin content in the subretinal fluid from 16 patients with rhegmatogenous retinal detachment by enzyme-linked immunosorbent assay. The opsin content decreased, with the duration of the detachment, but there was no correlation between opsin content and the age of the patient or the extent of the retinal detachment.

Immunoglobulins in paired specimens of vitreous and subretinal fluids from patients with rhegmatogenous retinal detachment

Evidence suggests that there is a net movement of fluid through the retinal break in eyes with rhegmatogenous retinal detachment, this net movement being directed from the vitreous humour into the subretinal space. However, it remains uncertain how much fluid exchange occurs in both directions across such breaks. The concentration ratios of IgG/IgM or IgA/IgM, derived from assay of immunoglobulins in vitreous humour, subretinal fluid, and serum from a group of 19 such patients, suggest a lack of free, two-directional, fluid movement across the retinal break. Furthermore the IgG/IgM ratios for the two intraocular fluids were significantly greater than that of serum, this suggesting that these intraocular fluids are formed, at least in part, by a selective transduction of serum.

Histopathological and immunohistochemical findings associated with a null mutation in the Norrie disease gene

PURPOSE

To determine the clinical, histopathological, and immunohistochemical ocular changes associated with a null mutation in the Norrie disease protein (NDP) gene.

METHODS

Tissue from a six-month-old boy with bilateral retrolental membranes and retinal detachment was obtained during vitreoretinal surgery. Histological sections were stained immunohistochemically with specific antibodies. No eye diseases with severe visual impairment or blindness were reported in the parents and their families. The NDP gene was analyzed by standard molecular genetic methods.

RESULTS

A severe reduction in the number of retinal ganglion cells and a largely disarranged and hypoplastic inner nuclear layer were visible in the tissue specimen. Areas of the tissue with advanced pathology displayed massive fibrovascular proliferation in the vitreous cavity. Shrinkage and traction resulted in folding and detachment of the outer retina. Immunohistochemical reactivity for MIB(1) antigen demonstrated many proliferating cells in the vitreous, but no proliferative activity in the neuroretina. Retinal neurons showed a high grade of differentiation and expressed uniformly neuron-specific enolase and synaptophysin. A 1-base pair insertion (544/545insA) in the NDP gene was found in the affected boy. This mutation predicts a 'functional null-allele' due to a shift in the reading frame and, thus, a premature termination of mRNA translation after 55 instead of 133 amino acids.

CONCLUSIONS

Loss of function of the NDP gene causes marked hypoplasia of the inner retinal cell layers and fibrovascular proliferation in the vitreous cavity, leading to retinal folding and detachment. The NDP therefore seems to play a critical role in terminal differentiation of the inner retinal cell layers and establishment and maintaining of anti-proliferative cellular interactions in the vitreous.

Production of specific retinal S antigen antibodies in patients with retinal detachment

One hundred patients with retinal detachment (61 primary operations and 39 reoperations) were studied for titers of autoantibodies to human retinal S antigen using the enzyme-linked immunosorbent assay technique (ELISA). There was no statistically significant difference when comparing the group of patients with primary retinal detachment with the control group. However, a statistically significant increase in anti-S titers was recorded when a comparison was made between the group of reoperated patients and the control group (chi 2, P less than 0.001) and between the group of reoperated subjects and the group of patients operated on for the first time (chi 2, P less than 0.005).

Retinal detachment and HLA typing

105 patients with retinal detachment were HLA types and divided into hyperopic, emmetropic and myopic groups. None of these different groups showed a statistically significant correlation with any of the HLA antigens. For the patient group as a whole, there was a slightly significant correlation with HLA-B8 at the corrected p level of 0.05.

CONGENITAL TOXOPLASMOSIS ASSOCIATED WITH TRACTIONAL RETINAL DETACHMENT

PURPOSE

We report a case of congenital toxoplasmosis associated with retinal detachment.

METHODS

A 9-month-old white boy presented a unilateral tractional retina detachment associated with congenital toxoplasmosis retinochoroiditis.

RESULTS

The diagnosis is supported by positive IgG (>400) for toxoplasmosis and intracranial calcification on magnetic resonance imaging, along with positive family history of Toxoplasma infection in the mother.

CONCLUSION

Tractional retinal detachment is an infrequent and unconventional presentation of congenital Toxoplasma infection. Inflammatory interference with normal sequence of vitreous development may explain pathogenesis of tractional retinal detachments in the setting of congenital ocular toxoplasmosis.

[Antinuclear antibodies (ANA) in inflammatory eye diseases]

The occurrence of antinuclear antibodies was investigated in patients with chronic open-angle glaucoma, senile cataract and retinal detachment, using the indirect immunofluorescence technique. The values obtained were the same as those for a normal population. Additionally, the presence and titer levels of ANA were tested in patients with endogenous uveitis, papillitis and optic neuritis. Our results suggest that ANA do not occur more frequently in these conditions.

Effects of retinal detachment surgery on protein C antigen level

BACKGROUND

The purpose of the study was to evaluate perioperative changes in protein C antigen (PC Ag) in patients undergoing retinal detachment surgery under general or local anesthesia.

MATERIAL AND METHODS

Prospective study of 39 patients: 27 patients, 14 male, 13 female, age from 15 to 78 (mean: 50.8, SD=18.6), undergoing retinal detachment surgery (encirclement with scleral buckling) performed under general anesthesia (group A), and 12 patients, 5 male, 7 female, age from 25 to 78 (mean: 52.9, SD=19.2), operated under local anesthesia (group B). Patients with venous or arterial disease or other factors which could affect the evaluated parameters were excluded from the study. Blood samples were collected from the cubital vein one day before surgery, immediately after induction of anesthesia but before surgery, immediately after the completion of the operation but before the termination of anesthesia, and after surgery (on the 1st and 4th day). The PC Ag concentration was measured in the citrate plasma of the patients studied, utilizing a commercially available enzyme-linked immunosorbent assay.

RESULTS

In both groups, the pattern of changes in perioperative PC antigen was similar. A trend towards moderately lower intraoperative levels of PC Ag could be observed. In both groups, PC Ag concentration increased on the first postoperative day, but a significant change was noted only in general anesthesia group.

CONCLUSIONS

Retinal detachment surgery evokes a less than statistically significant decrease in intraoperative PC antigen levels in systemic circulation, and these changes are not affected by the type of anesthesia. An increase in PC Ag was observed on the 1st postoperative day, but this was statistically significant only in the general anesthesia group.

[Behcet disease -- case report]

Behçet's Disease is a chronic, systemic, relapsing disease, an occlusive vasculitis which is immune complex mediated. Ocular involvement is usually bilateral, often asymmetric, associated with the loss of visual functions. This case presentation is a way to reveal an uncommon debut and evolution of the pathology using diagnostic criteria for Behçet's Disease.