Expression of the Epstein-Barr virus in lymphoproliferative diseases of the lung

There have been few studies regarding the etiology of lymphoproliferative disorders of the lung. To examine the possible involvement of the Epstein-Barr virus (EBV) in these diseases, EBV mRNAs, proteins and DNA, were detected. Two non-Hodgkin's lymphomas (NHL) originating in the lung, 5 mucosal-associated lymphoid tissue lymphomas (MALT lymphoma) of the lung, 1 lymphoid hyperplasia of the lung and 1 lymphoid interstitial pneumonia (LIP), were subjected to mRNA in situ hybridization, indirect immunofluorescence staining and PCR. mRNA in situ hybridization using BamHIW, BamHIY1Y2, the Epstein-Barr virus nuclear antigen (EBNA) and the EBV encoded small non-polyadenylated RNA (EBER1) probe revealed signals in all the examined samples, although some samples showed weak signals by using the EBER1 probe. Indirect immunofluorescence staining using the anti-leader protein, anti-EBNA2, the anti-latent member protein-1 and anti-BamHIZ coding leftward reading frame-1 antibodies showed definitive fluorescence. PCR also revealed EBV DNA in these specimens. EBV infected all the lymphoproliferative diseases of the lung irrespective of the histological or clinical stages. Furthermore, EBV infected not only the atypical lymphocytes but also the macrophages in the tissues of these diseases. These results suggest that the expression of EBV could be involved in the pathogenesis of many lymphoproliferative diseases of the lung.