Abstract Bovine leukemia virus (BLV), a retrovirus, infects into B cells of ruminants and causes aggressive leukemia or lymphoma in cattle, enzootic bovine leukosis (EBL). Clonal expansion of BLV-infected cells is a promising marker for early detection and diagnosis of EBL. Recently, we developed rapid amplification of the integration site without interference by genomic DNA contamination (RAISING) and CLOVA, a software to analyze clonality. RAISING-CLOVA could assess the risk of adult T-cell leukemia/lymphoma development in human T-cell leukemia virus-I-infected individuals through its clonality analysis. Thus, we herein examined the performance of RAISING-CLOVA for the clonality analysis of BLV-infected cells and conducted a comprehensive clonality analysis by RAISING-CLOVA in EBL and non-EBL cattle. RAISING-CLOVA successfully distinguished EBL from non-EBL cattle with high sensitivity and specificity. A longitudinal clonality analysis in BLV-infected sheep, an EBL model, also confirmed the effectiveness of BLV clonality analysis with RAISING-CLOVA for early detection of EBL development. Therefore, our study emphasizes the usefulness of RAISING-CLOVA as a routine clinical test for monitoring virus-related cancers.

Diagnosis and early prediction of lymphoma using high-throughput clonality analysis of bovine leukemia virus-infected cells