Hiv-Related Lymphoproliferative Disorders

Lymphoproliferative disorders including non-Hodgkin lymphomas (NHL) are not uncommon neoplasms in patients infected with the human immunodeficiency virus (HIV). It has been established that HIV-infected individuals are more prone to develop certain lymphoproliferative disorders and lymphomas compared to non-infected individuals. The exact mechanisms underlying these associations is yet to be established [1]. Two of the more accepted proposed mechanisms include the prolonged B-cell activation due to impaired immune function and the loss of immunoregulation of Epstein-Barr virus (EBV) and/or human Herpes virus-8 (HHV8) in HIV infection [2,3]. Different molecular pathogenetic pathways have also been studied to explore this relationship [4]. These pathways involve various types of oncogenes as well as tumor suppressor genes, i.e. inactivating mutations or deletions of the p53 tumor suppressor gene in HIVassociated Burkitt lymphoma and rearrangements in BCL-1, BCL2, BCL-6, and MYC genes in aggressive large B-cell lymphomas. Lymphomas associated with HIV infection are often aggressive with an adverse clinical course. EBV and/or HHV8 co-infection is often seen in this group and these viruses are responsible for the pathologic disruption of cytokine networks [5]. The lymphomas associated with HIV are also heterogeneous and the incidence varies mostly depending on the anti-viral therapy status.