The potential of 3rd-generation nanopore sequencing for B-cell clonotyping in lymphoproliferative disorders.

Lymphoid malignancies are characterized by clonal cell expansion, often identifiable by unique immunoglobulin rearrangements. Heavy (IGH) and light-chain gene usage offers diagnostic insights and enables sensitive residual disease detection via next-generation sequencing. With its adaptable throughput and variable read lengths, Oxford Nanopore thirdgeneration sequencing now holds promise for clonotyping. This study analyzed CD138+ plasma-cell DNA from eight multiple myeloma patients, comparing clonotyping performance between Nanopore sequencing, Illumina MiSeq, and Ion Torrent S5. We demonstrated clonotype consistency across platforms through Smith-Waterman local alignment of nanopore reads. The mean clonal percentage of IGH V and J gene usage in the CD138+ cells was 69% for Nanopore, 67% for S5, and 76% for MiSeq. When aligned with known clonotypes, clonal cells averaged a 91% similarity, exceeding 85%. In summary, Nanopore sequencing, with its capacity for generating millions of high-quality reads, proves effective for detecting clonal IGH rearrangements. This versatile platform offers the potential for measuring residual disease down to a sensitivity level of 10