Association of Epstein-Barr Virus (EBV) Infection with Histomorphological and Immunohistochemical Features of Hodgkin Lymphoma
Background: Lymphomas are a heterogenous group of lymphoproliferative disorders arising from B-cells, T-cells or Natural Killer (NK) cells, which are classified into Hodgkin and Non-Hodgkin Lymphoma. Hodgkin Lymphoma is categorised into Classical Hodgkin Lymphoma (CHL) and Non Classical types according to clinical, histomorphological, phenotypic and genotypic features. In India, the incidence of lymphoma has increased in the last decade and the increased incidence is found in patients of fifth and sixth decade. The etiology of HL remains unclear, usually arises denovo or seen to arise from Epstein-Barr viral infection. Analyzing expression of abundant EBV small nuclear RNA transcripts (EBER) in RS cells by RNA In Situ Hybridisation (RISH) and immunehistochemical expression of latent membrane protein (LMP1)together are more conclusive for identifying EBV-related Hodgkin Lymphomas than either assay alone. Here we studied etiopathogenic role of EBV in HL.
Methods: This was a hospital based ethics approved study conducted at the Department of Pathology, Health Care Global Specialty Hospital, Bangalore from June 2017 to May 2019.
Results: We found among 57 cases of Hodgkin Lymphoma, 33 were EBER positive, 37 were LMP 1 positive, overall, 41 cases (71.9%) were EBV positive. There was statistically significant association between gender and LMP1 (p=0.037). There was a statistically significant association of EBER with morphological subtypes (p=0.034) and Ann Arbor Staging (p=0.013). EBER expression was more frequently found in mixed cellularity subtype and in advanced stages of Hodgkin Lymphoma.
Conclusion: EBER expression had significant association (p=0.034) with HL subtypes and EBV also had significant association (p=0.041). But, withLMP1 expression alone, there was no significant association (p=0.191) with the subtypes, suggesting analysing expression of both EBER and LMP1 for studying association of EBV in HL.