[Lymphomas and infections]

The incidence of non-Hodgkin lymphoma (NHL) has more than doubled in the last 20 years. The various mechanisms underlying malignant transformation of lymphoid cells all lead to an increased cellular proliferation and/or inhibition of apoptosis. Many infectious agents favor the development of NHL. Direct infection by lymphotropic viruses establishing a latent infection, such as the Epstein-Barr virus, interferes with cellular homeostasis and contribute to lymphoid transformation. Other infectious agents inducing chronic infections but unable to directly infect lymphocytes may also induce NHL. In this case, the sustained lymphoid proliferation induced by the persistent pathogen, increases the likelihood of malignant transformation, as exemplified by Helicobacter pylori-associated gastric MALT NHL. Identification of an associated infection in the setting of a NHL is important as eradication of the pathogen by antimicrobial therapy may lead to tumor regression.