Diagnostic Value of Genetic Mutation Analysis and Mutation Profiling of cfDNA in Intraocular Fluid for Vitreoretinal Lymphoma

Objective Vitreoretinal lymphoma (VRL) is a rare but aggressive masquerade syndrome, with challenging diagnosis. Since the tumor-related genetic mutation analysis based on cell-free DNA (cfDNA) are underutilized in ocular oncology, we aimed to test the VRL diagnostic value of cfDNA genetic mutation analysis using intraocular fluid (IOF) samples and to identify its mutation profile. Subjects Seventeen VRL and 6 uveitis patients from Zhongshan Ophthalmic Centre were selected as training group, and 5 VRL and 5 uveitis patients from Beijing Chaoyang Hospital were selected as validation group. Methods The medical records and genetic mutation analysis using a panel containing 446 tumor-related genes of included patients were retrospectively reviewed. We analyzed the mutation profile, and identified the molecular subtypes and subdivisions of B-cell differentiation pathways of our VRL patients. Main outcomes The cfDNA genetic mutations detected in IOF. Results The VRL patients from the training group exhibited abundant cfDNA mutations in IOF (sensitivity 100%), while only 2 out of 6 uveitis patients were positive (specificity 67%). However, the number of cfDNA mutations observed in VRL patients was higher than that of uveitis patients. The mutation-positive patients from the validation group were diagnosed with VRL while the mutation-negative patients were diagnosed with uveitis (sensitivity and specificity 100%). VRL patients were characterized by the high mutation frequencies of PIM1, MYD88, CD79B, ETV6 , and IRF4 . Conclusions The genetic mutation analysis of IOF samples represents a feasible diagnosis method for VRL with 100% sensitivity; it could track genetic profiles; thus, revealing genetic heterogeneity of VRL. Statement of translational relevance The anterior chamber paracentesis and diagnostic vitrectomy have been widely used in ophthalmic clinics, as they are less invasive sampling techniques for liquid biopsies. Genetic mutation analysis of cell-free DNA (cfDNA) of intraocular fluid using a panel containing 446 targeted genes represents a feasible method with 100% sensitivity for vitreoretinal lymphoma (VRL) diagnosis. Furthermore, it can address cytological diagnostic issues including limited cellular yield, cell lysis associated with the fragile nature of lymphoma cells, and high risks associated with retinal tissue biopsies. Furthermore, it allows for genetic profile tracking, having the potential to reveal genetic heterogeneity and molecular characteristics of VRL in the future