Asian Pacific Journal of Cancer Prevention, Vol 14, 2013 3963 DOI:http://dx.doi.org/10.7314/APJCP.2013.14.6.3963 Epstein-Barr Virus Expression in Non-Hodgkin Lymphomas Asian Pacific J Cancer Prev, 14 (6), 3963-3967 Introduction Non Hodgkin lymphoma (NHL) is a diverse group of neoplasms both in their natural history and in their response to treatment. Available epidemiological data from various parts of Asia indicate marked geographical variation in the incidence, histopathologic and clinical behavior of NHL. Non Hodgkin lymphoma appears to be more common in developing countries, where a combination of environmental, infectious and genetic factors affect the development of these disorders. In the developed countries, the disease occurs more often in whites than in blacks, and it is about 50% more common among men than women (Mushtaq et al., 2008). In one Pakistani study, 73% of lymphomas were Non-Hodgkin lymphomas (NHL) and 27% were Hodgkin lymphomas (Mushtaq et al., 2008). Amongst the Non-Hodgkin lymphomas, B cell lymphomas were 86% and T cell Department of Pathology, Shaukat Khanum Cancer Hospital, Johar Town, Lahore, Pakistan *For correspondence: drusmanhassan256@gmail.com Abstract Background: The presence of Epstein-Barr virus (EBV) in Non-Hodgkin’s lymphoma can be identified by immunohistochemistry for detection of EBV latent membrane protein (LMP). The role of EBV as an etiologic agent in the development of non-Hodgkin lymphoma has been supported by detection of high levels of latent membrane protein 1 (LMP-1) expression in tumors. However, no study has been conducted in a Pakistani population up till now to determine the frequency of Epstein-Barr virus positivity. The objective of our study was to determine a value for non-Hodgkin lymphoma patients using EBV LMP-1 immunostaining in our institution. Materials and Methods: This study was carried out at the Department of Histopathology, Armed Forces Institute of Pathology (AFIP), Pakistan from December 2011 to December 2012. It was a cross sectional study. A total of 71 patients who were diagnosed with various subtypes of NHL after histological and EBV LMP-1 immunohistochemical evaluation were studied. Sampling technique was non-probability purposive. Statistical analysis was achieved using SPSS version 17.0. Mean and SD were calculated for quantitative variables like patient age. Frequencies and percentages were calculated for qualitative variables like subgroup of NHL, results outcome of IHC for EBV and gender distribution. Results: Mean age of the patients was 53.6±16 years (Mean±SD). A total of 50 (70.4%) were male and 21 (29.6%) were female. Some 9 (12.7%) out of 71 cases were positive for EBV–LMP-1 immunostaining, 2 (22.2%) follicular lymphoma cases, 1 (11.1%) case of T-cell lymphoblastic lymphoma, 4 (44.4%) cases of diffuse large B cell lymphomas, 1 (11.1%) mantle cell lymphoma and 1 (11.1%) angioimmunoblastic T cell lymphoma case. Conclusion: In our study, frequency of EBV in NHL is 12.7% and is mostly seen in diffuse large B cell lymphoma. This requires further evaluation to find out whether this positivity is due to co-infection or has a role in pathogenesis. Keywords: Epstein-Barr virus - NHL - immunohistochemistry - latent membrane protein-1 RESEARCH ARTICLE Determination of Frequency of Epstein-Barr Virus in Non- Hodgkin Lymphomas Using EBV Latent Membrane Protein 1 (EBV-LMP1) Immunohistochemical Staining Sheeba Ishtiaq, Usman Hassan*, Sajid Mushtaq, Noreen Akhtar lymphomas were 14%. The most common B cell NHL was Diffuse large B cell lymphoma (DLBCL), followed by follicular lymphoma (6%), Burkitt’s lymphoma and Lymphoblastic lymphoma (4% each) and others (10%) (Matsushita et al., 2012). Epstein-Barr virus (EBV) is a widespread tumorigenic human herpes virus that establishes lifelong asymptomatic infection of B cells in the majority of humans, generally without causing disease (Williams et al., 2006; Mao et al., 2013). Epstein-Barr virus is associated with number of lymphoproliferative disorders including Burkitt’s lymphoma (98%) (Nourse et al., 2012), post transplantation lymphoproliferative disease (PTLD), Angioimmunoblastic T-cell Lymphomas (AITL) (84.6%), natural killer (NK) cell lymphomas, lymphomatoid granulomatosis and Hodgkin’s lymphoma (40%) (Nourse et al., 2012). While the exact role of EBV in the pathogenesis of each type of lymphoma still needs to