Deisy V. Bula

Identification of Chlamydia pneumoniae within human choroidal neovascular membranes secondary to age-related macular degeneration.

Age-related macular degeneration (AMD) is a leading cause of blindness in the United States, and increasing evidence suggests that it is an inflammatory disease. The prokaryotic obligate intracellular pathogen Chlamydia pneumoniae is emerging as a novel risk factor in cardiovascular disease, and recent sero-epidemiological data suggest that C. pneumoniae infection is also associated with AMD. In this study, we examined choroidal neovascular membrane (CNV) tissue from patients with neovascular AMD for the presence of C. pneumoniae and determined whether the pathogen can dysregulate the function of key cell types in ways that can cause neovascular AMD. Nine CNV removed from patients with neovascular AMD were examined for the presence of C. pneumoniae by immunohistochemistry (IHC) and polymerase chain reaction (PCR); in addition, we performed PCR on nine non-AMD eyes, and IHC on five non-AMD CNV, seven non-AMD eyes, and one internal limiting membrane specimen. Finally, human monocyte-derived macrophages and retinal pigment epithelial (RPE) cells were exposed to C. pneumoniae and assayed in vitro for the production of pro-angiogenic immunomodulators (VEGF, IL-8, and MCP-1). C. pneumoniae was detected in four of nine AMD CNV by IHC and two of nine AMD CNV by PCR, induced VEGF production by human macrophages, and increased production of IL-8 and MCP-1 by RPE cells. In contrast, none of the 22 non-AMD specimens showed evidence for C. pneumoniae. These data indicate that a pathogen capable of inducing chronic inflammation and pro-angiogenic cytokines can be detected in some AMD CNV, and suggest that infection may contribute to the pathogenesis of AMD.

Inhibition of Hsp90 attenuates inflammation in endotoxin-induced uveitis

Heat shock protein (Hsp) 90 inhibitors, such as 17‐allylamino‐17‐demethoxy‐geldanamycin (17‐AAG), constitute promising novel therapeutic agents. We investigated the anti‐inflammatory activity of 17‐AAG in endotoxin‐induced uveitis (EIU) in rats. After the induction of EIU with a footpad injection of lipopolysaccharide (LPS), female Lewis rats received a single intraperitoneal. (i.p.) injection of 17‐AAG or vehicle. Twenty‐four hours later, the retinas were extracted and assayed for leukocyte adhesion; blood‐retinal barrier breakdown;VEGF, TNF‐α, IL‐1β, and CD14 protein levels;NF‐κB and HIF‐1α activity;hsp90 and 70 levels and expression and phosphorylation of the tight junction proteins ZO‐1 and occludin. 17‐AAG treatment significantly suppressed the LPS‐induced increase in retinal leukocyte adhesion;vascular leakage; NF‐KB, HIF‐1α, p38, and PI‐3K activity;and VEGF, TNF‐α, and IL‐1β levels. 17‐AAG also suppressed phos‐phorylation of ZO‐1 and occludin by inhibiting their association with p38 and PI‐3K Although 17‐AAG treatment did not reduce the LPS‐induced increase in total CD14 levels in leukocytes, it significantly decreased membrane CD14 levels. These data suggest that Hsp90 inhibition suppresses several cardinal manifestations of endotoxin‐induced uveitis in the rat. 17‐AAG has demonstrated a favorable safety profile in clinical trials in cancer patients and represents a promising therapeutic agent for the treatment of inflammatory eye diseases.–Poulaki V., Iliaki, E., Mitsiades, N., Mitsiades, C. S., Paulus, Y. M., Bula, D. V., Gragoudas, E. S., Miller J. W. Inhibition of Hsp90 attenuates inflammation in endotoxin‐induced uveitis. FASEB J. 21, 2113–2123 (2007)

Amino-acid levels in subretinal and vitreous fluid of patients with retinal detachment

PurposeTo compare the concentration of amino acids in subretinal and vitreous fluid of patients with primary rhegmatogenous retinal detachment to that of control vitreous.MethodsThis prospective, observational study measured amino-acid levels in subretinal fluid of patients undergoing scleral buckle placement (n=20) and vitreous fluid in patients undergoing pars plana vitrectomy (n=5) for primary retinal detachment. Vitreous fluid from patients undergoing vitrectomy for macular hole (n=7) or epiretinal membrane (n=3) served as a control. Subretinal fluid and control vitreous were analysed using high-pressure liquid chromatography. Retinal detachment vitreous was analysed using capillary electrophoresis-laser-induced fluorescence.ResultsMean levels of glutamate (27.0±1.7 μM), aspartate (4.1±4.0 μM), and glycine (44.1±31.0 μM) in subretinal fluid and glutamate (13.4±11.9 μM) in the vitreous were significantly elevated in retinal detachment compared to control vitreous. A significant, positive association was observed between levels of aspartate and glutamate in subretinal fluid (Spearmans correlation coefficient: 0.74, P<0.01). Mean arginine levels did not differ significantly between subretinal fluid and control vitreous. Levels of alanine, tyrosine, valine, isoleucine, leucine, and phenylalanine were significantly lower in subretinal fluid compared to control vitreous (all P<0.01).ConclusionsGlutamate levels in subretinal fluid and vitreous of patients with primary retinal detachment is significantly elevated in comparison to control vitreous. This finding lends further support to the hypothesis that elevated glutamate levels may result from ischaemia of the outer retina secondary to retinal detachment.

Bilateral Candida albicans endophthalmitis associated with an infected deep venous thrombus

BackgroundTo describe the clinical and histopathologic findings in a patient with bilateral Candida albicans endophthalmitis due to an infected deep venous thrombus.CaseA 43-year-old patient with bilateral Candida albicans endophthalmitis due to an infected central venous thrombus. The patient’s ophthalmology and hospital charts were reviewed. Histopathologic sections of the Candida albicans retinal granuloma were examined under light microscopy.ObservationsOur patient had multiple blood cultures positive for Candida albicans owing to an infected subclavicular venous thrombosis. Bilateral Candida albicans endophthalmitis was diagnosed. Bilateral vitrectomy and membrane peeling for macular traction retinal detachments were performed. In the right eye, a large retinal granuloma was excised during surgery to adequately relieve traction on the macula. Vision improved in both eyes after surgery. Histopathologic findings revealed branching hyphae surrounded by giant cells, endothelial cell-lined vascular channels, and inflammatory cells.ConclusionsThis is the first report of an infected deep venous thrombosis causing bilateral endogenous endophthalmitis. Appropriate management of these patients requires clear differentiation between endogenous chorioretinitis and endophthalmitis. Patients with documented fungemia should have a dilated fundus examination on a regular basis until complete clearance of the infection. Jpn J Ophthalmol 2004;48:30–33

Apoptosis in Diabetic Fibrovascular Membranes After Panretinal Photocoagulation

A more complete understanding of the role of apoptosis in the regression of diabetic neovasculature following laser panretinal photocoagulation (PRP) will both elucidate the treatments therapeutic mechanism and potentially lead to novel treatments for neovascularization associated with proliferative diabetic retinopathy that target apoptotic pathways. Pars plana vitrectomy with fibrovascular membrane delamination was performed on five patients with proliferative diabetic retinopathy, with four having received previous PRP treatment and one no previous laser treatment. Using in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, propidium iodide and hematoxylin-eosin staining, apoptotic cells were identified in the excised membranes. The authors found evidence of cells undergoing apoptosis in all of the excised membranes, with increasing amounts of preoperative PRP associated with an increased number of apoptotic cells per millimeter of membrane. The preliminary data suggest that the decrease in ambient mitogen, initiated by PRP treatment, activates apoptosis in diabetic fibrovascular membranes.