Dissecting Clonal Hematopoiesis in Tissues of Classical Hodgkin Lymphoma Patients.

Clonal hematopoiesis predisposes to hematological malignancies. However, clonal hematopoiesis is understudied in classical Hodgkin lymphoma (cHL), a mature B-cell neoplasm exhibiting the most abundant microenvironment. We analyzed clonal hematopoiesis in 40 cHL cases by sequencing microdissected tumor cells and matched normal cells from blood and/or lymph nodes. Five patients had blood and/or tissue clonal hematopoiesis. In three of five patients (all failing first-line therapy), clonal hematopoiesis spread through the tissue microenvironment extensively, and featured mutant DNMT3A ^R882H , KRAS ^G60D and DNMT3A ^R882H + TET2 ^Q1274 * in 33%, 92% and 60% of non-neoplastic cells, respectively. In the latter case, DNMT3A/TET2- mutant clonal hematopoiesis seeded the neoplastic clone, which was infected by the Epstein-Barr virus and showed almost no other somatic mutations exome-wide. In the former case, DNMT3A -mutant clonal hematopoiesis did not originate the neoplastic clone despite dominating the blood and B-cell lineage (~94% leukocytes; ~96% mature blood B cells), yet led to NPM1 -mutated acute myeloid leukemia 6 years after therapy for cHL. Our results expand to cHL the spectrum of hematologic malignancies associated with clonal hematopoiesis.
Competing Interests: Conflict of interest: M.P. Martelli reports personal fees from AbbVie, Amgen, Pfizer, Jazz Pharmaceuticals, Novartis, and Janssen outside the submitted work. The authors declare no potential conflicts of interest.