Machine Learning Approach for Intraocular Disease Prediction Based on Aqueous Humor Immune Mediator Profiles.

PURPOSE: Various immune mediators have crucial roles in the pathogenesis of intraocular diseases. Machine learning can be used to automatically select and weigh various predictors to develop models maximizing predictive power. However, these techniques have not yet been applied extensively in studies focused on intraocular diseases. We evaluated whether 5 machine learning algorithms applied to the data of immune-mediator levels in aqueous humor can predict the actual diagnoses of 17 selected intraocular diseases and identified which immune mediators drive the predictive power of a machine learning model. DESIGN: Cross-sectional study. PARTICIPANTS: Five hundred twelve eyes with diagnoses from among 17 intraocular diseases. METHODS: Aqueous humor samples were collected, and the concentrations of 28 immune mediators were determined using a cytometric bead array. Each immune mediator was ranked according to its importance using 5 machine learning algorithms. Stratified k-fold cross-validation was used in evaluation of algorithms with the dataset divided into training and test datasets. MAIN OUTCOME MEASURES: The algorithms were evaluated in terms of precision, recall, accuracy, F-score, area under the receiver operating characteristic curve, area under the precision-recall curve, and mean decrease in Gini index. RESULTS: Among the 5 machine learning models, random forest (RF) yielded the highest classification accuracy in multiclass differentiation of 17 intraocular diseases. The RF prediction models for vitreoretinal lymphoma, acute retinal necrosis, endophthalmitis, rhegmatogenous retinal detachment, and primary open-angle glaucoma achieved the highest classification accuracy, precision, and recall. Random forest recognized vitreoretinal lymphoma, acute retinal necrosis, endophthalmitis, rhegmatogenous retinal detachment, and primary open-angle glaucoma with the top 5 F-scores. The 3 highest-ranking relevant immune mediators were interleukin (IL)-10, interferon-γ-inducible protein (IP)-10, and angiogenin for prediction of vitreoretinal lymphoma; monokine induced by interferon γ, interferon γ, and IP-10 for acute retinal necrosis; and IL-6, granulocyte colony-stimulating factor, and IL-8 for endophthalmitis. CONCLUSIONS: Random forest algorithms based on 28 immune mediators in aqueous humor successfully predicted the diagnosis of vitreoretinal lymphoma, acute retinal necrosis, and endophthalmitis. Overall, the findings of the present study contribute to increased knowledge on new biomarkers that potentially can facilitate diagnosis of intraocular diseases in the future.

Cytokines and Chemokines Involved in Acute Retinal Necrosis.

Purpose: To investigate which cytokines and chemokines are involved in the immunopathogenesis of acute retinal necrosis (ARN), and whether cytokine profiles are associated with clinical manifestations, such as visual outcome. Methods: Serum and aqueous humor (AH) samples of 19 patients with ARN were analyzed by multiplex immunoassay. Infectious controls consisted of 18 patients with rubella virus-associated Fuchs' uveitis and 20 patients with ocular toxoplasmosis all confirmed by intraocular fluid analyses. The control group consisted of seven paired AH and serum samples from seven noninflammatory control patients with age-related cataract. In each sample, 4 anti-inflammatory, 12 proinflammatory, 2 vascular, and 4 other immune mediators were measured. In addition, various clinical characteristics were assessed. Results: In ARN, 10 of the 22 mediators, including most proinflammatory and vascular mediators such as IL-6, IL-8, IL-18, MIF, MCP-1, Eotaxin, IP-10, IL-15, sICAM-1, and sVCAM-1, were significantly elevated when compared to all controls. In addition, one anti-inflammatory mediator (IL-10) was significantly elevated in ARN as compared to the controls. No association was found between the time of sampling and the extent and levels of immune mediator expression. Conclusions: The pathogenesis of ARN is characterized by the presence of predominantly proinflammatory cytokines and chemokines with high expression levels as compared to other infectious causes of uveitis. There are no indications for an obvious Th-1 or Th-17 pathway. The combined data suggest that immune mediator expression is related to severity of disease, which is more fulminant in ARN, rather than to a specific uveitis entity.

Valacyclovir as Initial Treatment for Acute Retinal Necrosis: A Pharmacokinetic Modeling and Simulation Study.

PURPOSE: Acute retinal necrosis (ARN) is a feared complication of infectious retinitis most commonly caused by varicella zoster virus (VZV). We performed a pharmacokinetic modeling and simulation study by integrating the existing understanding of physiology with previously published data to evaluate the vitreal penetration of oral valacyclovir for the treatment of ARN, under various dosing scenarios. METHOD: We compared different oral valacyclovir dosing regimens with intravenous acyclovir. The vitreous compartment was modeled as a peripheral compartment, and paired serum and vitreal acyclovir concentrations were obtained from previously published data of adult patients with ARN undergoing vitrectomy. The efficacy threshold for vitreal acyclovir concentrations was based on the previously reported IC50 values for VZV. RESULTS: Based on the minimum vitreal acyclovir concentrations (Cmin) relative to the mean IC50 for VZV, valacyclovir 1.5 g every 8 hours performed similarly to intravenous acyclovir 700 mg every 8 hours, with the minimum concentration (Cmin) exceeding the mean IC50 after the second dose. In contrast, the standard dosing regimen for herpes zoster, valacyclovir 1 g every 8 hours, performed inferiorly to the intravenous acyclovir regimen throughout the dosing interval. CONCLUSIONS: Modeling and simulation data support oral valacyclovir for the treatment of ARN, although the required dosing exceeds the recommended FDA dose size for herpes zoster.

Necrosis retiniana aguda bilateral en el anciano por varicela zóster / Bilateral acute retinal necrosis due to varicella zóster virus in an elderly patient

CASO CLÍNICO: Presentamos a un paciente de 77 años, con un cuadro de necrosis retiniana aguda con afectación bilateral; la reacción en cadena de la polimerasa (PCR) de la muestra de humor acuoso fue positiva al virus de varicela zóster. En su evolución desarrolla vasculitis de Kyrieleis al mes de inicio del tratamiento y con el análisis por PCR negativo. DISCUSIÓN: La PCR es un método rápido, con una sensibilidad y especificidad del 97%. La actuación debe ser urgente por la rapidez de la progresión. El famciclovir oral es buena alternativa por su mejor biodisponibilidad

CASE REPORT: The case is reported of acute retinal necrosis with bilateral involvement due to Varicella Zoster virus in a 77 year-old man. Polymerase chain reaction (PCR) of aqueous humor was positive for Varicella Zoster virus (VZV). He developed a Kyrieleis’ vasculitis a month after the starting treatment, when the PCR analysis was negative. DISCUSSION: PCR is a quick and safe technique, with a high sensitivity and specificity of 97%, useful to diagnose and monitor the viral activity. The intervention must be urgent, due to the dramatically rapid evolution. Oral famciclovir oral is good alternative owing to its bioavailability

Angiogenesis: molecular mechanisms of activation, promotion and maintenance.

The formation of new blood vessels is a fundamental process that occurs during embryonic and post-natal development but also in a number of pathologies ranging from cancer to chronic inflammatory disease. The molecular regulations of this process are complex since they require signalling that modifies both the quantity and the quality of the vasculature. Many players have been characterized and there are many more still to come. In this article I will review basic concepts and some of the major regulatory pathways and there implication in physiological and pathological angiogenesis.

Cytokine profile in aqueous humor and sera of patients with infectious or noninfectious uveitis.

PURPOSE: To determine the cytokine expression profile at the protein level in aqueous humor (AqH) and sera of patients with uveitis. METHODS: Patients with various clinical entities of strictly diagnosed infectious or noninfectious uveitis were tested. AqH and sera were collected from patients with uveitis. AqH was also collected during surgery from patients with cataract, as control specimens. Interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-2, -4, -5, and -10 were measured from nondiluted samples simultaneously, with microparticle-based flow cytometric analysis. RESULTS: In AqH IFN-gamma was the most abundant cytokine in both infectious (mean, 3240.5 pg/mL) and noninfectious (mean, 115.6 pg/mL) uveitis, and IL-10 was the second (mean, 402.1 pg/mL, infectious uveitis; 7.5 pg/mL, noninfectious uveitis). The expression level of other cytokines in AqH was generally higher in infectious uveitis than in noninfectious uveitis, but the levels were lower than that of IL-10. There was no remarkable difference, however, in the cytokine expression pattern in AqH of the different clinical entities of uveitis. Sera from patients with noninfectious uveitis contained IFN-gamma (mean, 45.0 pg/mL), but the other serum cytokines in both types of uveitis were low or under the detectable level. CONCLUSIONS: IFN-gamma is the most abundant cytokine in infectious and noninfectious uveitis, with a remarkable difference between the two groups. The data suggest that cytokines in AqH of infectious uveitis are locally produced, whereas in noninfectious uveitis, IFN-gamma is produced both in the eye and the peripheral blood.

Cytokine profiles and inflammatory cells during HSV-1-induced acute retinal necrosis.

PURPOSE: To investigate infiltrating cells, cytokines, and kinetics of cytokine expression during acute retinal necrosis (ARN) in the uninoculated eye after inoculation of herpes simplex virus (HSV)-1 into the anterior chamber of one eye of BALB/c mice. METHODS: At different time points after inoculation of 2 x 10(4) plaque-forming units (PFU) HSV-1 (KOS strain) or an equivalent volume of Vero cell extract in cell culture medium, the uninoculated eyes were enucleated. RT-PCRs for TNFalpha, IFNgamma, and IL-4 and immunohistochemical staining were performed to identify infiltrating cells and cytokines. Cytometric bead array was used to measure the levels of TNFalpha, IFNgamma, and IL-4 protein. RESULTS: CD4(+) T cells, F4/80(+) macrophages, Gr-1(+) polymorphonuclear cells (PMNs), and CD19(+) B cells were detected in the uninoculated eye of virus-infected mice. Furthermore, RPE65(+) retinal pigment epithelial (RPE) cells and activated Muller cells were also detected in the ARN lesion. TNFalpha, IFNgamma, and IL-4 mRNA and protein were upregulated during the evolution of ARN in HSV-1-infected contralateral eyes compared with levels in control subjects. Immunohistochemistry revealed that cytokines were produced by infiltrating cells as well as by resident retinal cells. CONCLUSIONS: The results of these studies support the idea that T cells and cytokines are actively involved in HSV-1 retinitis. They also suggest that PMNs, B cells, and/or macrophages, as well as resident retinal cells, such as RPE and activated Muller cells, also play a role in the pathogenesis of HSV-1 retinitis.

DNA microarray analysis of the uninoculated eye following anterior chamber inoculation of HSV-1.

PURPOSE: To use DNA microarray to analyze the expression patterns of genes in the uninoculated eye following uniocular anterior chamber inoculation of HSV-1. METHODS: On Day 9 following inoculation of 2 x 10( 4) PFU of HSV-1 (KOS strain) or an equivalent volume of tissue culture medium into one anterior chamber of BALB/c mice, the uninoculated eyes were enucleated, pooled, and total RNA was isolated. cDNA was synthesized from the total RNA. The gene expression patterns were inferred based on the hybridization intensities of the probes on the cDNA array. The hybridization signals were globally normalized and filtered. The data were analyzed using hierarchical and gene tree clustering algorithms. Additional uninoculated eyes collected on Day 9 p.i. were stained for F4/80 and CD19. RESULTS: Compared with the uninoculated eye of control mice, 3800 genes were upregulated at least twofold in the contralateral eye of HSV-1-infected mice. Among the 10 most upregulated genes, T cell-specific protein, MHC II antigen A, and MHC II k region locus 2 were upregulated 179-, 164-, and 162-fold, respectively. Ten T-cell receptor-related genes, 61 cytokine and chemokine genes, and 16 MHC genes were upregulated. Furthermore, 11 immunoglobulin and B cell genes and 11 macrophage-related genes were also upregulated. F4/80+ and CD19+ cells were observed on Day 9 p.i. CONCLUSIONS: The DNA microarray results support the idea that T cells and immunomodulatory factors (cytokines, chemokines) are likely to be involved in HSV-1 retinitis. These results also suggest that B cells and/or macrophages play a role in the pathogenesis of HSV-1 retinitis.

Interferon gamma expression and clinical features in patients with acute retinal necrosis syndrome.

BACKGROUND: Interferon gamma (IFN-gamma) has been reported to play an important role during virus infections. The purpose of this study was to examine the relationship between IFN-gamma expression and the clinical course of patients with acute retinal necrosis syndrome (ARN) associated with the varicella-zoster virus (VZV). METHODS: Six patients with ARN were studied. The aqueous and/or vitreous were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay during the follow-up period. The presence of VZV genome was also determined by PCR. The results were correlated with the clinical data and features and compared with patients with other ocular diseases. RESULTS: A statistically significant higher level of IFN-gamma was detected in the aqueous and/or vitreous in eyes with ARN than in eyes with other ocular diseases. A statistically significant positive correlation was observed between the level of IFN-gamma in the vitreous and the final visual acuity. IFN-gamma was reduced to undetectable levels within 30 days after the initial eye symptoms. Three of five patients had severe inflammation initially, and the visual acuity gradually recovered with the disappearance of VZV and higher levels of IFN-gamma. Conversely, the other 2 patients showed mild inflammation, had a slow decrease of visual acuity with persistent VZV, and lower levels of IFN-gamma expression. CONCLUSION: Our results suggest that IFN-gamma may be one of the factors that plays an important role in the clinical course of VZV-associated ARN.

[Expression of the varicella zoster virus thymidine kinase and cytokines in patients with acute retinal necrosis syndrome].

PURPOSE: Acute retinal necrosis (ARN) is caused by varicella zoster virus (VZV) infection. In this study, we investigated the activity of this virus and expressions of some cytokines. PATIENTS AND METHODS: The expression of VZV thymidine kinase and some cytokines were investigated by reverse transcriptase-polymerase chain reaction (RT-PCR) in 9 eyes of 8 patients with ARN. RESULTS: Thymidine kinase expression was observed in all samples except one. Several cytokines, such as interferon (IFN) gamma, tumor necrosis factor (TNF) alpha, interleukin (IL)-1 beta, IL-6, and transforming growth factor (TGF) beta 1 were observed in the samples. Among these cytokines, a statistically significant expression of IFN gamma was observed in the samples of ARN, when compared to those of proliferative vitreoretinopathy (PVR) or other uveitis. The expression of IFN gamma also decreased during successive follow-ups. CONCLUSION: These cytokines may play an important role in the immune response in ARN.

Analysis of immunoregulatory cytokines in ocular fluid samples from patients with uveitis.

PURPOSE: To investigate the T-helper cell cytokine profiles in two well-defined clinical uveitis entities caused by an infectious mechanism. METHODS: Cytokines (interleukin [IL]-2, IL-4, IL-6, IL-10, and interferon [IFN]-gamma) were measured in ocular fluid samples obtained from patients with herpes simplex- or varicella-zoster virus-induced acute retinal necrosis (ARN; n = 17) and toxoplasma chorioretinitis (n = 27) using enzyme-linked immunosorbent assay techniques. The data were compared with data for 51 control samples taken during cataract surgery (n = 10), vitrectomy in diabetic retinopathy (n = 10), eye bank eyes (n = 10) and with samples from patients with "autoimmune" uveitis (n = 21). RESULTS: Interleukin-6 was detected in 44 of 51 control samples and 43 of 44 eyes of patients with uveitis. The highest levels in the control samples were detected in 9 of 10 vitreous samples from patients with diabetic retinopathy (mean, 648 pg/ml). In 8 of 10 samples taken from patients during cataract surgery and in 7 of 10 eye bank eyes the amount of IL-6 was significantly lower (mean, 10 pg/ml and 136 pg/ml, respectively). Interleukin-6 levels in patients with ARN (mean, 1436 pg/ml) were significantly higher than in those with toxoplasma chorioretinitis (mean, 272 pg/ml). Interleukin-2 was detected in one of the samples from patients with toxoplasma chorioretinitis (1105 pg/ml) and in three samples from the control subjects suffering from Fuchs' heterochromic anterior uveitis (mean, 752 pg/ml). No IL-4 (<2 pg/ml) was detected either in patient or control samples. Interferon-gamma could be detected in 7 of 17 ARN patients (range, 277-3483 pg/ml), in 13 of 27 samples from patients with toxoplasma chorioretinitis (range, 12-250 pg/ml), and in 1 of 21 of the samples from control subjects with uveitis (31 pg/ml) but was absent in nonuveitic control samples. Interleukin-10 was detected in 10 of 17 ARN patients (range, 29-3927 pg/ml), in 13 of 27 samples from patients with toxoplasma chorioretinitis (range, 4-67 pg/ml), and in only 3 of 51 control samples (6 pg/ml, 16 pg/ml, and 20 pg/ml). CONCLUSIONS: Various immunoregulatory cytokines (IL-6, IL-10, and IFN-gamma) were detected in ocular fluid samples from patients with uveitis. A separate role for either a T-helper type 1 or T-helper type 2 response in the pathogenesis of clinical uveitis could not be proven.

T-cell subsets and T-cell receptor V beta utilization by Igh-1-congenic mice in herpetic retinal necrosis.

BACKGROUND: After unilateral anterior chamber (AC) inoculation with herpes simplex virus type 1 (HSV-1), C.B-17 and BALB/c congenic mice, which differ only in a limited region around the lgh-1 locus on chromosome 12, show a striking difference in susceptibility to development of encephalitis and contralateral necrotizing chorioretinitis. METHODS: After AC inoculation with HSV-1 (KOS), C.B-17 and BALB/c mice were followed up for the clinical signs of encephalitis and chorioretinitis. At different time points following inoculation, lymphocytes isolated from the spleen were triple-stained with antibodies directed against CD4 or CD8, IL-2R, and various V beta T-cell receptor (TCR) subsets, and were analyzed by flow cytometry. RESULTS: These lgh-1-disparate congenic mice showed differences in the time course of splenic V beta T-cell receptor (TCR) usage in both CD4+, IL-2R+ and CD8+, IL-2R+ T cells. By day 1 post infection (p.i.), C.B-17 mice showed an increase of V beta 8 and V beta 9 TCR by both CD4+, IL-2R+ and CD8+, IL-2R+ splenic T cells. Susceptible BALB/c mice delayed the increase of splenic V beta 8 and V beta 9 TCR by CD4+, IL-2R+ T cells, which was noted by day 4 p.i. Furthermore, in BALB/c mice the usage of V beta 9 by CD8+ cells was increased by day 6 p.i. CONCLUSIONS: Our findings indicate that early preferential splenic usage of a restricted repertoire of TCR occurs after ocular inoculation with HSV-1 in resistant C.B-17 mice. Such preferential TCR usage by activated T cells may prevent viral replication in the brain and contralateral eye and may be linked to protection from development of encephalitis and destructive herpesmediated ocular inflammation.