Single B-Cell Genomic Analyses Differentiate Vitreoretinal Lymphoma from Chronic Inflammation

Area of Science:

• Ophthalmology
• Hematology
• Genomics

Background:

• Distinguishing vitreoretinal lymphoma (VRL) from chronic inflammation is critical for appropriate patient management.
• Current diagnostic methods may not always provide definitive differentiation.

Purpose of the Study:

• To evaluate the utility of single B-cell genomic analysis from vitreous fluid for differentiating VRL from chronic inflammation.
• To identify key genomic features, including immunoglobulin heavy chain (IGH) and MYD88^L265P mutations, and copy number profiles, for diagnostic purposes.

Main Methods:

• Retrospective analysis of vitreous biopsies from patients with VRL and chronic inflammation.
• Single B-cell isolation using the DEPArray NxT system.
• Genomic analysis including IGH gene rearrangement, MYD88^L265P mutation detection, and genome-wide copy number profiling.

Main Results:

• Significantly higher frequencies of dominant IGH and MYD88^L265P mutations were observed in VRL patients compared to those with chronic inflammation.
• Single-cell analysis revealed clonal B-cell populations and characteristic copy number aberrations in VRL cases, including a BCL2/JH translocation.
• Copy number profiles showed high similarity within patients with VRL but no common genome-wide signatures across different VRL patients.

Conclusions:

• Single B-cell genomic characterization of IGH, MYD88^L265P mutation, and copy number profiles is a viable method for VRL diagnosis.
• These proof-of-concept findings in a small cohort warrant further investigation in larger patient populations.