We characterised the effects of HIV infection on the production of Interleukins in lymphoid organs by studying the expression of the genes for two TH1 type Interleukins, IL2 and Interferon gamma, of two TH2 type Interleukins, IL4 and IL10, and of two proinflammatory Interleukins, IL6 and IL1 beta. Our results show, in benign hyperplastic lymph nodes, a hyperexpression of Interferon gamma by cytotoxic T8 cells, without increased expression of TH2 type or of proinflammatory Interleukins. In contrast lymphomatous lymph nodes are characterised by a paracrine hyperproduction of IL6 and an autocrine hyperproduction of IL10.