The frequency of B- and T-cell gene Rearrangements and Epstein-Barr virus in T-cell lymphomas - A comparison between angioimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma, unspecified with and without associated B-cell proliferations

We report on a series of 58 cases of angioinmiunoblastic T-cell lymphoma (AILT) and 59 cases of peripheral T-cell lymphoma, unspecified (PTCL-NOS). Subsets of cases from both diagnostic groups were complicated by associated B-cell proliferations, and we performed Band T-cell clonality studies and in situ hybridization for Epstein-Barr virus (EBV) to investigate the relationship between B-cell proliferation, B-cell clonality, and EBV. Using multiplex polymerase chain reaction assays based on the BIOMED-2 collaborative study, we detected TCR gamma T-cell clones in 78 and 81% of AILT and PrCL-NOS cases, respectively, and IGH B-cell clones in 34 and 35% of AILT and PTCL-NOS cases, respectively. The majority of cases contained EBV-positive cells, including 50% of AILT and 57% of PTCL-NOS cases, and cases with B-cell proliferations were more often EBV-positive. Although a relatively high rate of B-cell clonality has been shown for AILT, our findings for PTCL-NOS differ from previous reports in that B-cell clonality was relatively frequent Overall, a positive B-cell clone correlated, in part, with the presence of a B-cell proliferation but not with EBV. Our findings demonstrate that B-cell clonality is a common finding in AILT and PrCL-NOS, and its presence should not negate the diagnosis established by morphologic, immunophenotypic, and clinical findings.