Frequent detection of Epstein-Barr virus-infected B cells in peripheral T-cell lymphomas

Although Epstein-Barr virus (EBV) positivity has been described in peripheral T-cell lymphomas (PTCLs) in Chinese patients, the cellular lineage of EBV-harbouring cells is unknown, Forty-four cases of PTCL mere therefore studied by in situ hybridization OSH) for EBV-encoded small non-polyadenylated RNA 1 and 2 (EBER), and the lineage of the EBER+ cells was determined by double labelling, The findings were further correlated with the clonality of EBV and the genotype of these EBER+ rumours. The results for the detection of EBV by ISH show that 23 of the 44 cases mere EBER+, In 5/23 of the EBER+ cases, EBER mas found in around 50 per cent of atypical cells and in 18/23 cases, EBER was found in a subpopulation of atypical cells. Amongst the EBER+ cases, all 15 tested shelved clonal T-cell receptor gene rearrangement by Southern blot hybridization, Double labelling was successfully done in 11 EBER+ cases, and by comparison, EBER+/CD20 + B cells outnumbered the EBER+/CD3 + T cells in all these cases, EBV clonality analysis revealed that EBV was monoclonal in six EBER+ cases and biclonal in three cases, With the predominance of EBV+ B cells over EBV+ neoplastic T cells being observed in most of these cases, it is possible that the EBV-infected clonal population may be of B-cell lineage. This was supported in some cases where a faint clonal band was seen over a background smear in the gene rearrangement study of immunoglobulin heavy chain gene by polymerase chain reaction (PCR), indicating a minor B-cell clone. It is concluded that in EBV+ PTCL, EBV is preferentially localized in B cells rather than neoplastic T cells. The neoplastic T cells may support the clonal proliferation of a subpopulation of EBV+ B cells in PTCLs. (C) 1998 John Wiley & Sons, Ltd.