A Comprehensive Analysis of Rhoa Mutation Positive and Negative Angioimmunoblastic T-Cell Lymphomas By Targeted Deep Sequencing, Expression Profiling, and Single Cell Digital Image Analysis

Angioimmunoblastic T-cell lymphoma is a uniquely aggressive mature T-cell neoplasm. In recent years, recurrent genetic mutations in RHOA, TET2, DNMT3A and IDH2 have been identified which characterize this disease. However, a deep molecular study assessing both DNA mutations and RNA expression profile, combined with digital image analysis is lacking.

We designed a study to assess the significance of molecular and morphologic features by high resolution digital image analysis in cases of AITL. Eighteen separate tissues from ten patients with AITL were identified and analyzed in this study.

Our results confirm recurrent mutations in RHOA, TET2, DNMT3A, and IDH2, and demonstrate increased DNA mutations in coding, promoter and CTCF binding sites in RHOA mutated AITLs versus RHOA non-mutated cases as well as increased overall survival in RHOA mutated patients. In addition, single cell computational digital image analysis morphologically characterized RHOA mutated AITL cells as distinct from cells from RHOA mutation negative patients. Computational analysis of single cell morphological parameters revealed RHOA mutated cells have reduced eccentricity (more circular) compared to RHOA non-mutated AITL cells.

Overall, this study expands our understanding of AITL and demonstrates that there are specific cell biologic and morphologic manifestations of RHOA mutations in cases of AITL.

KeyPoints:

1) RHOA mutated AITL show distinctly increased and more deleterious mutations than RHOA unmutated cases

2) RHOA mutated T-cells have distinct morphologic features from RHOA unmutated T-cells