Aqueous immune mediators in malignant uveal melanomas in comparison to benign pigmented intraocular tumors

Expression of GNAQ, BAP1, SF3B1, and EIF1AX Proteins in the Aqueous Humor of Eyes Affected by Uveal Melanoma

Purpose

The purpose of this study was to quantify specific aqueous humor (AH) proteins in eyes affected by posterior uveal melanoma (UM).

Methods

Thirty-six eyes affected by primary UM were included. Tumor thickness and largest basal diameter were specific clinical characteristics. Tumors were staged with the American Joint Commission on Cancer Eighth Edition (AJCC) classification. During the brachytherapy (Iodine-125) surgical procedure, both the AH sample collection and the 25-gauge transscleral fine needle aspiration biopsy (FNAB) were performed. AH samples were analyzed by immunoprecipitation and SDS PAGE techniques to quantify GNAQ, BAP1, SF3B1, and EIF1AX proteins. Cytologic material underwent fluorescence in situ hybridization for chromosome 3. The AH of 36 healthy eyes was used as the control group. Cluster analysis of groups was also performed.

Results

Compared with the control group, significantly higher protein levels of: GNAQ (P = 0.02), BAP1 (P = 0.01), and SF3B1 (P = 0.02) were detected in eyes with UM. Cluster analysis of UM group revealed 2 clusters, one showing higher expression of GNAQ and BAP1 protein and one of EIF1AX protein. Moreover, the 2 clusters corresponded with the chromosome 3 status of UM.

Conclusions

Specific and selected proteins may be detected in the AH of eyes affected by UM. These findings confirm the possibilities provided by AH analysis in UM.

Variability of Replicates of Intraocular Inflammatory Biomarkers in Ocular Fluid Samples Analyzed with Multiplex Assays

Purpose

Certain factors such as instrumental and sample processing errors may contribute to variability of ocular biofluid samples when they are run as replicates with multiplex assays. There is a paucity of literature on the variability of replicates in multiplex assays. This study aims to evaluate whether there is significant variability in replicate analyses of multiplex assays.

Methods

A total of 152 human ocular biofluid samples (51 aqueous humor and 101 vitreous) were collected and assayed for 27 cytokine biomarker concentrations (pg/mL). Samples were evaluated as replicates (duplicate analysis) at four different time points. Statistical methods including paired samples t-test, 3-way ANOVA, intraclass correlation coefficient (ICC; <0.5-0.75=poor-moderate, 0.75->0.90 =good-excellent reliability), and coefficients of variation (CV) were employed to evaluate for statistical significance, with Bonferroni corrected P=0.002.

Results

Among the 4104 biomarker replicate assays for aqueous humor and vitreous, two analytes (PDGF-BB and IL-7) had a statistically significant difference between the sampled concentrations of the replicates in vitreous samples (mean (diff)=2.05, P<0.001, mean (diff)=1.56, P<0.001, respectively). Majority of the ICC values fell within the good-excellent range (86% of samples) with a minority falling in the poor-moderate range (14% of samples). More variability was noted in the vitreous humour, with five analytes (IL-2, IL-10, IL-12(p70), IL-13, IL-17) demonstrating an average ICC of less than 0.5. The CV calculated for each set of replicates suggested that 93% of replicates had an acceptable level of quantitative assay variability (CV<20%).

Conclusion

This study demonstrates that the analysis of most biomarkers in ocular fluids may not require the use of replicates. However, certain analytes such as PDGF-BB and IL-7 may require the use of replicates to ensure reliable results. Caution should be taken when applying these findings to other laboratory settings as our study was conducted by an experienced technician using a standardized protocol. In less standardized settings, replicates may be required in order to ensure accuracy of results. These findings may guide researchers with the design of their studies on ophthalmic biomarker analysis.

Genetic and Epigenetic Features of Uveal Melanoma-An Overview and Clinical Implications

Uveal melanoma (UM) is rare, but it is the most common primary intraocular malignancy among adults. This review represents the molecular, genetic, and immunobiological mechanisms involved in UM carcinogenesis and progression, as well as data about the association of chromosomal changes, genetic mutations, selective proteins, and biochemical biomarkers with the clinical implications of UM. Genetic analysis has the potential to identify patients with a high risk of UM metastasis, enabling management that is more effective and allowing for the follow-up of patients. Advancements in molecular characterization of UM offer opportunities to develop targeted therapeutic strategies by focusing on relevant signaling pathways. Changes in miRNA expression could be useful in the diagnosis and prognosis of UM, due to unique miRNA profiles in melanoma cells or tissue and its association with metastasis. Although liver function tests do not provide enough data on the prognosis of UM, due to the high frequency of liver metastasis, liver function tests (LFTs) might be useful indicators; however, the absence of rising LFT values cannot lead to the exclusion of liver metastases. Molecular analysis of tumor tissue will allow us to identify patients with the added benefit of new therapeutic agents and provide a better insight into melanoma pathogenesis and its biological behavior.

Investigating Vitreous Cytokines in Choroidal Melanoma

Due to the close relationship between the vitreous and posterior eye layers, the microenvironment of these layers can affect the composition of the vitreous. Molecular analysis of the vitreous may therefore provide important insights into the pathogenesis of chorioretinal diseases. In this study, vitreous cytokines (n = 41) were evaluated to gain further insights into the tumor microenvironment in uveal melanoma (UM) arising from the choroid (CM). Cytokine levels were measured using a bead-based multiplex immunoassay panel in vitreous samples obtained from 32 eyes, including 18 with CM and 14 controls. Median fluorescence intensity values were extracted and used as relative quantification of the cytokine abundance. Vitreous cytokine levels were compared between the CM and non-CM groups and between different prognostic categories within the CM group (classified as having low or high metastatic risk using tumor biopsy-based gene expression profiling). Correlations between vitreous cytokine levels and tumor dimensions were also evaluated. Our analysis revealed twenty-six vitreous cytokines significantly upregulated in CM-affected eyes compared to the control eyes. Within the CM group, six vitreous cytokines showed altered levels (five upregulated and one downregulated) in eyes with high- vs. low-risk tumors. Levels of these six plus several other cytokines showed correlations with the tumor dimensions. In conclusion, our study has uncovered several UM-relevant vitreous cytokines, worthy of follow-up in larger studies as potential candidates for liquid biopsy-based biomarker development and/or new therapeutic targeting.

Proteomics in uveal melanoma

PURPOSE OF REVIEW

This article reviews the latest proteomic research on uveal melanoma.

RECENT FINDINGS

Proteomic analysis of uveal melanoma cell lines and tissue specimens has improved our understanding of the pathophysiology of uveal melanoma and helped identify potential prognostic biomarkers. Circulating proteins in patient serum may aid in the surveillance of metastatic disease. The proteomes of aqueous and vitreous biopsy specimens may provide safer biomarkers for metastatic risk and candidate therapeutic targets in uveal melanoma. Proteomic analysis has the potential to benefit patient outcomes by improving diagnosis, prognostication, surveillance, and treatment of uveal melanoma.

SUMMARY

These recent findings demonstrate that proteomic analysis is an important area of research to better understand the pathophysiology of uveal melanoma and improve the personalized management of our patients.

Aflibercept for Radiation Maculopathy (ARM Study): Year-2 Extension of a Prospective Clinical Study

Purpose:

This work describes the 2-year results of the Aflibercept for Radiation Maculopathy (ARM) randomized clinical study that evaluated intravitreal vascular endothelial growth factor antagonist therapy in radiation maculopathy delivering aflibercept using a second-year collapsed, every-6-weeks, treat-and-adjust interval.

Methods:

Forty patients were enrolled in an institutional review board–approved clinical trial and randomly assigned to aflibercept treatment via 1 of 2 regimens: fixed, every-6-week treatment or variable, treat-and-adjust therapy centered around 6 weeks. All patients had a diagnosis of treated uveal melanoma with documented tumor control, and they had visually compromising radiation maculopathy. At conclusion of year 1, the first 30 patients were offered a collapsed single-arm variable of an every-6-weeks treat-and-adjust aflibercept injection schedule for an additional treatment year.

Results:

Baseline best-corrected visual acuity (BCVA) was 20/63 at ARM study entry 20/62 at the institution of the year-2 extension. At ARM study entry baseline, spectral domain–optical coherence tomography mean central retinal thickness was 432 µm and was 294 µm at the same institution. At the 2-year study’s conclusion, 76.7% (23 of 30) of eyes were better than 20/50, and only 6.7% (2 of 30) ended with a BCVA below 20/200. Final mean BCVA was 20/62 and final mean spectral domain–optical coherence tomography central retinal thickness was 286 µm, but as in year 1, this reduction in number of injections was not statistically significant.

Conclusions:

Aflibercept is effective in treating radiation maculopathy with maintained visual acuity at 2 years but continues to require an ongoing treatment approach to stabilize radiation maculopathy.

Clinicopathologic analysis of 32 ciliary body tumors

PURPOSE

To describe the demographic profile, clinical and histopathologic features, and treatment of ciliary body tumors.

STUDY DESIGN

Retrospective, observational case series.

METHODS

Thirty-two patients (32 eyes) with ciliary body tumors diagnosed histopathologically at Tokyo Medical University Hospital between 1994 and 2017 were retrospectively reviewed.

RESULTS

The patients' mean age at diagnosis was 45.4 ± 17.0 (range, 14-87) years. Ten of the patients were male, and 22, female. Twenty-four cases (75%) were benign tumors, comprising 9 melanocytomas, 7 adenomas, 4 mesectodermal leiomyomas, 2 leiomyomas, and 2 other tumors; and 8 cases (25%) were malignant tumors, comprising 6 melanomas and 2 low-grade adenocarcinomas. Local resection of the tumor was performed in 20 patients, including 3 cases of melanoma and 2 cases of adenocarcinoma. Enucleation was initially performed in 3 cases of melanoma, 1 case of melanocytoma with iris melanoma, and 2 cases of benign tumors difficult to differentiate clinically from melanoma. In the 17 patients who underwent local resection and were followed for at least 3 years, the outcome was best-corrected visual acuity better than 0.1 logMAR in 8 patients (47%), but hand motions in 2 patients (12%).

CONCLUSIONS

Melanocytoma and adenoma of the ciliary epithelium were the major ciliary body tumors found in this study. Management of ciliary body tumors with accurate clinical diagnosis remains challenging because of the anatomic characteristics and clinical similarities to melanoma in the majority of the cases.

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.

UVEAL MELANOMA BIOPSY A REVIEW

In intraocular tumors, diagnosis is usually based on clinical examination and imaging without the need for invasive surgery or tissue sampling. The diagnosis can be confirmed by biopsy, however, in the case of intraocular malignancy, the biopsy is considered controversial. Due to the development of uveal melanoma cytogenetic prognostics and the progression in generalised uveal melanoma treatment, intraocular melanoma biopsy is becoming increasingly important. Diagnostic biopsy of intraocular tumors is indicated in cases of diagnostic uncertainty for findings with conflicting non-invasive test results and for small melanocyte lesions. Tumor prognostic biopsy is performed to obtain a tissue sample for tumor cytogenetic testing, which can help to determine the prognosis and specific metastatic risk of the patient. For anterior segment tumors, anterior chamber fluid sampling, thin-needle iris biopsy, punch biopsy, surgical biopsy or biopsy using vitrectomy may be used. For posterior segment tumors, procedures include transscleral or transretinal thin-needle biopsy, vitrectomy-assisted biopsy, punch biopsy, endoresection or transscleral exoresection. Complications of intraocular melanoma biopsy include too small or non-valuable sample collection, intra-tumoral heterogeneity, intra-ocular trauma and induction of intraocular or extraocular tumor dissemination.

In vivo intraocular biomarkers: Changes of aqueous humor cytokines and chemokines in patients affected by uveal melanoma

Inflammatory, angiogenic, and immune processes have been associated with uveal melanoma (UM). The aim of the present study was to evaluate the presence of some specific aqueous humor (AH) soluble biomarkers in eyes affected by UM. Thirty-five eyes affected by primary UM and 35 control eyes, scheduled for cataract surgery, underwent full ophthalmic examination and AH sampling at time of surgery (brachytherapy or cataract surgery, respectively). AH samples were analyzed by means of ELISA, to detect the concentration of selected cytokines, chemokines, and growth factors. Compared with the control group, higher levels of IL-6 (P = .049), IL-8 (P = .006), RANTES (P = .008), EGF (P = .032), bFGF (P = .016), MIF (P = .007), and MCP (P = .020) were detected in eyes with UM. VEGF concentration between the two groups was statistically borderline (P = .058). Comparison between clinical characteristics and cytokine concentrations showed a positive correlation between tumor thickness and IL-8 (P = .032), and degree of serous retinal detachment and IL-6 (P = .021). UM is characterized by the presence of retinal neuroinflammatory, angiogenic, and immune biomarkers in AH. The proteomic analysis of AH could characterize UM microenvironment, allowing to better understand its pathophysiology.

Aqueous Humor Biomarkers Identify Three Prognostic Groups in Uveal Melanoma

Purpose

To investigate whether we can identify different patterns of inflammation in the aqueous humor of a uveal melanoma (UM)-containing eye, and whether these are related to prognosis.

Methods

Ninety samples of aqueous humor from UM-containing eyes were analyzed using a high-throughput multiplex immunoassay that enables simultaneous analysis of 92 predefined protein biomarkers. Cytokine expression was compared to clinical and histopathological characteristics. Cluster analysis was performed, after which the clusters were compared with clinical and histopathological tumor characteristics.

Results

Cluster analysis revealed three distinct clusters, with one cluster showing hardly any inflammatory cytokines, one showing intermediate levels, and one showing a high expression of inflammation-related biomarkers. Significant differences between the clusters were seen with regard to patient age (P = 0.008), tumor prominence (P = 0.001), ciliary body involvement (P < 0.001), American Joint Committee on Cancer (AJCC) stage (P < 0.001), monosomy of chromosome 3 (P = 0.03), and gain of chromosome 8q (P = 0.04), with the cluster with a highest cytokine expression having the worst prognostic markers. Especially apoptosis-related cytokines were differentially expressed.

Conclusions

Analysis of cytokines in the aqueous humor shows distinct differences between aqueous humor samples and allocates these samples into three different prognostic tumor clusters. Especially large tumors with ciliary body involvement and monosomy 3 were associated with many cytokines, especially apoptosis-related cytokines. The presence of these cytokines in the aqueous humor may play a role in the lack of effective antitumor immune responses.

Aflibercept for Radiation Maculopathy Study: A Prospective, Randomized Clinical Study

PURPOSE

To evaluate 2 treatment approaches to intravitreal vascular endothelial growth factor antagonist therapy in radiation maculopathy comparing aflibercept delivered by either a 6-week treatment interval or treat-and-adjust interval.

DESIGN

Randomized, prospective clinical trial.

METHODS

Forty consecutive patients were enrolled in an institutional review board-approved clinical trial and randomized to aflibercept treatment via 1 of 2 regimens: (1) fixed, every-6-weeks treatment or (2) variable, treat-and-adjust treatment centered around 6 weeks. All patients had a diagnosis of treated uveal melanoma with documented tumor control. All patients showed visually compromising radiation maculopathy confirmed by a decline in best-corrected visual acuity (BCVA) and spectral-domain (SD) OCT documentation of radiation maculopathy.

MAIN OUTCOME MEASURES

Best-corrected visual acuity and SD OCT central retinal thickness at 1 year.

RESULTS

Thirty-nine of 40 patients completed the trial (97.5%) with 1 year of follow-up. Baseline study entry BCVA was 20/63 and was maintained at 20/62 at study conclusion at 60 weeks (1 year). At baseline, SD OCT mean central retinal thickness was 432 μm and improved to 294 μm at 60 weeks (P < 0.02). At the study conclusion, 42.5% of eyes (17/40) showed better than 20/50 BCVA, and only 5% of eyes (2/40) showed a BCVA worse than 20/200. In the every-6-weeks interval treatment arm, patients received 9 injections, whereas in the treat-and-adjust study arm, patients received 8.4 injections (P = 0.88, not significant). One patient experienced an inflammatory response after aflibercept injection, but this did not occur again for this patient, nor for any other study injections (1/400 injections [0.0025%]). No patients demonstrated endophthalmitis or metastatic disease or died during the study window.

CONCLUSIONS

Aflibercept seems to limit vision loss associated with radiation maculopathy. In this randomized, prospective clinical study, no difference was found between a fixed 6-week treatment interval and a variable treat-and-adjust interval because virtually all patients required treatment every 6 weeks and were not able to extend. Remarkably, almost half of all treated patients maintained BCVA of 20/50 or better throughout 1 year of treatment. Aflibercept is effective in treating radiation maculopathy, but requires an ongoing treatment approach.