Lymphocyte transformation and autoimmune disorders

The many features that link autoimmune disorders (AD) and lymphoma are reviewed herein. Firstly, the epidemiology indicates the increased risk of non-Hodgkin's lymphoma (NHL) development in many AD, and especially in Sjögren's syndrome, rheumatoid arthritis and systemic lupus erythematosus. In these AD, the relative risk of NHL occurrence varies between 2 and 4 up to 40 fold higher than in the general population, according to various surveys. Factors favouring or predicting NHL have been reported in detail. B-cell activation and proliferation are part of AD and are essential factors for the onset of malignant cell clones in a deregulated immunological environment. Targeting deregulated or malignant B-cells is the goal of some newly developed treatments. The prototype is anti-CD20 rituximab that has substantially modified the prognosis of B-cell NHL and is also an effective new treatment opportunity for some AD. Similarly, intensified treatments with autologous haematopoietic stem cell transplant (ASCT) that were developed for high-risk lymphoma are now under advanced investigation for use in some refractory AD. Thus, the successful use of rituximab and ASCT in both AD and NHL further emphasizes the close link between these two entities. This review provides details on the main epidemiological features regarding NHL incidence in AD, the pathogenetic factors that favour lymphoma onset and some recent advances in therapeutic approaches that are effective in both autoimmune and malignant lymphoproliferative disorders.