Autoimmune lymphoproliferative syndrome - A human disorder of abnormal lymphocyte survival

An important aspect of the immune system is the maintenance of a homeostatic balance between lymphocyte survival and death. This is regulated by apoptosis (programmed cell death). One pathway of this active process of cell suicide is mediated by the lymphocyte receptor Fas (CD95). Its importance in this homeostatic balance is underscored by the consequences of defective Pas-mediated apoptosis in patients with autoimmune lymphoproliferative syndrome (ALPS). Abnormal accumulation of lymphocytes results in lymphadenopathy, hepatosplenomegaly, and hypersplenism Failure of removal of potentially autoreactive lymphocytes is associated with the appearance of autoimmune manifestations. Finally, inappropriate survival of lymphocytes may lead to the development of malignancies.