Mice transgenic for BAFF develop lymphocytic disorders along with autoimmune manifestations

The cause of many autoimmune and inflammatory diseases is unresolved, altho ugh dysregulated production of tumor necrosis factor (TNF) family members a ppears to be important in many cases. BAFF, a new member of the TNF family, binds to B cells and costimulates their growth in vitro. Mice transgenic f or BAFF have vastly increased numbers of mature B and effector T cells, and develop autoimmune-like manifestations such as the presence of high levels of rheumatoid factors, circulating immune complexes, anti-DNA autoantibodi es, and immunoglobulin deposition in the kidneys. This phenotype is reminis cent of certain human autoimmune disorders and suggests that dysregulation of BAFF expression may be a critical element in the chain of events leading to autoimmunity.