Detection of Epstein-Barr virus genome in Ki-1 (CD30)-positive, large-cell anaplastic lymphomas using the polymerase chain reaction

Abstract

Ki-1 (CD30)-positive, large-cell anaplastic lymphoma (LCAL) is a distinctive subset of non-Hodgkin's lymphoma; morphologically, the neoplastic cells of LCAL may closely resemble Reed-Sternberg cell variants of Hodgkin's disease. The neoplastic cells in Hodgkin's disease are often CD30-positive, as are some of the transformed lymphocytes in infectious mononucleosis. Recent evidence suggests an etiologic role for the Epstein-Barr virus (EBV) in Hodgkin's disease. Because of the phenotypic similarities between Hodgkin's disease and LCAL, we used the polymerase chain reaction (PCR) to analyze eight specimens of LCAL for EBV genome. Diagnoses were established by paraffin section morphology and immunohistochemistry. For comparison, we also analyzed nine non-Hodgkin's lymphomas other than the LCAL type, three Hodgkin's disease specimens, and nine non-neoplastic lymph nodes. PCR was performed using DNA extracted from frozen tissue; DNA was amplified using two sets of oligonucleotide primers corresponding to the BamH1 W-fragment of the EBV genome. Amplified EBV genome was obtained from all specimens except for one mantle zone lymphoma, one diffuse mixed-cell lymphoma, and six non-neoplastic lymph nodes. EBV terminus region probing and in situ hybridization techniques, each less sensitive than PCR, were performed in selected cases in an attempt to corroborate our PCR results. Only 2 of 13 specimens contained EBV detectable by these other techniques, and neither specimen was a LCAL. In view of the high incidence of latent EBV infections in humans, the biologic significance of our PCR results is uncertain. Despite the detection of EBV genome by PCR in a high percentage of lymphomas, we were unable to substantiate an etiologic role for EBV in LCAL. The PCR technique may be too sensitive to provide meaningful data on the possible role of EBV in lymphomagenesis.