Latent membrane protein antibody reacts with normal hematopoietic precursor cells and leukemic blasts in tissues lacking Epstein-Barr virus genome by polymerase chain reaction

Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP) has been detected in various reactive and neoplastic lymphoproliferations and in some epithelial malignancies. However, data are lacking on LMP immunoreactivity in normal and neoplastic hematopoietic cells. Therefore, the authors studied LMP staining in 29 paraffin-embedded tissues containing these cells and correlated the findings with polymerase chain reaction (PCR) analysis for a EBV-BAM III W genome sequence in 15 of these cases. Latent membrane protein immunostains showed strung uniform marking of normal early myeloid and erythroid precursors, whereas neutrophils, bands and late normoblasts were negative. Leukemic myeloblasts and lymphoblasts were also strongly positive for LMP. Polymerase chain reaction analysis showed no evidence of EBV-BAM HI W genome in 13 cases with amplifiable DNA. This study indicates normal hematopoietic precursor cells and leukemic blasts mark strongly with monoclonal LMP antibody. Furthermore, the absence of EBV genome in these tissues suggests a lack of specificity of monoclonal LMP for EBV-infected cells in the marrow.