De Novo CD5-positive diffuse large B-cell lymphoma: A genomic profiling study and prognostic analysis of 46 patients

We reported 46 cases of Diffuse Large B-cell lymphoma which abnormally expressed CD5 protein (De Novo CD5-positive DLBCL), which had attracted researcher's attention for a period of time for its poor prognosis. However, there were few studies on its molecular change. In the present article, we summarized the genetic alterations using a lymphopanel detection method by Next Generation Sequencing(NGS). The most frequently mutated genes were MYD88^L265P (20/46, 43.5%), followed by PIMI (19/46, 41.3%), IGLL5 (13/46, 28.3%)and CD79B (11/46, 23.9%). We further investigated the relationship between gene alterations and prognosis using OS(Overall survival) and PFS(Progression-free survival). MYD88, CREBBP, and ACTB mutation were significantly associated with inferior OS (P = 0.032, 0.000, 0.001), PIMI, CREBBP, ACTB and CXCR4 mutation were significantly associated with inferior PFS (P = 0.016, 0.001, 0.045, 0.024). Meanwhile, we found that De Novo CD5-positive DLBCL had BCL-6(9/46,19.6%), C-MYC (4/46, 8.7%) and IRF4 (2/19, 10.5%) rearrangement, but without BCL-2 rearrangement, there were no significantly associations with prognosis. In summary, our research explored the gene alterations of De Novo CD5-positive DLBCL in a relatively large scale for the first time, the most common gene mutation was MYD88^L265P which was also a potential prognostic factor, providing a potential therapeutic target for the patients of De Novo CD5-positive DLBCL.