Immunohistochemical Expression of Epstein - Barr virus Latent Membrane Protein-1 (LMP-1) in Hodgkin’s Lymphoma

The etiology of Hodgkin’s lymphoma remains unknown, but there is a considerable evidence to suggest that Epstein Barr virus plays an important role. Epstein Barr virus was the first human virus to be directly implicated in a carcinogenesis. It infects more than 90% of the world's population. Although most humans coexist with the virus without serious sequalae, a small proportion will develop tumors. Epstein-Barr virus encodes a series of products one of them is Latent Membrane Protein-1. The aim of the study was designed to assess expression of Epstein Barr virus protein (Latent Membrane Protein-1) in Hodgkin’s lymphoma using immunohistochemical technique and correlate its relationship with different pathological parameters (age, gender, histological types and location of the lymph-node involved). Patients and Methods:
Formalin-fixed, paraffin embedded tissue blocks of (32) cases Hodgkin’s Lymphoma, randomly selected from the files of the Department of Pathology Al-Kadhemyia Teaching Hospital , Hospital of Specialized Surgeries and Al Hilla Teaching Hospital between the years 2003-2006, they included (2) Nodular Lymphocyte Predominant Hodgkin’s Lymphoma, (4) Lymphocyte Rich Hodgkin’s Lymphoma, (11) Nodular Sclerosis Hodgkin’s Lymphoma, (11) Mixed Cellularity Hodgkin’s Lymphoma and (4) Lymphocyte Depletion Hodgkin’s Lymphoma. For each case four thin paraffin sections (4µm thickness) were prepared, two were stained with Heamatoxylin and Eosin and others were prepared on positively charged slides for the immunohistochemical staining of Latent Membrane Protein-1. Results: The mean age of 32 patients with Hodgkin’s lymphoma was (24.7 ± 18.6) years. The highest percentage of patients was in the age group (5-18) years comprising about (53.1%), while the lowest percentage (6.25%) was in the age group (59-70) years, with a male to female ratio (1:1). Immunohistochemically, Latent Membrane Protein-1 was positively expressed in (75%) of the total cases and the highest frequency of Latent Membrane Protein-1 positivity was in age group (5-18) years and in Mixed Cellularity type (81.8%) but statistically no significant correlation was seen. A significant correlation was found between Latent Membrane Protein-1 expression and male gender in Mixed Cellularity Hodgkin’s Lymphoma as well as a significant correlation with cervical lymph nodes involvement. Conclusions: Seventy five percent of cases of Hodgkin’s Lymphoma were Epstein - Barr virus protein (LMP-1) positive mainly in male gender in Mixed Cellularity type and cervical lymph nodes.