Molecular characterisation of Epstein-Barr Virus in lymphomas diagnosed at the University Teaching Hospital,Lusaka

Abstract

Epstein-Barr virus (EBV) is a ubiquitous virus that infects more than 90% of the world‘s population, and is implicated in the initiation and progression of lymphomas. In Zambia lymphomas are among the most commonly diagnosed malignancies in both men and women. However, the diagnosis of lymphomas is not linked to any aetiological agents since it is mainly based on clinical suspicion and morphological appearance of tissue on microscopy. This poses a risk of misdiagnosis, resulting in improper patient care as the probable cause of the disease is not targeted during diagnosis. Therefore, the objective of this study was to characterise Epstein-Barr virus detected in lymphomas diagnosed at the University Teaching Hospital in Lusaka. One hundred and fifty suspected archival formalin-fixed paraffin embedded lymphoma tissues stored over a 4 year period from January 2011 to December 2014 in the Histopathology Laboratory were analysed. It involved tissue processing, DNA extraction, molecular detection and subtyping of the EBV using Polymerase Chain Reaction and DNA sequencing. Most commonly diagnosed lymphomas were non-Hodgkin‘s lymphoma (NHL) (80%) followed by Hodgkin‘s lymphoma (HL) (20%). EBV was detected in 51.8% of the cases, 54.5% of which were associated with NHL cases and 40.9% with HL cases. Subtyping of the virus showed that NHL harboured 81.3% and 18.8% of EBV subtype 1 and type 2, respectively. HL cases harboured 55.6% EBV subtype 1 and 44.4% EBV subtype 2. One of the cases harboured both subtypes of the virus. EBV subtype 1 strains showed genetic diversity. These findings indicate that EBV is closely associated with lymphomas. Therefore, targeting of EBV for identifying new therapy targets in EBV-positive lymphomas should be of interest as this may lead to the improvement of current lymphoma diagnosis