Autoimmune lymphoproliferative syndrome

Abstract Apoptosis regulates immunologic homeostasis by participating in lymphocyte compartment contraction after an immune response. Apoptosis is also involved in tolerance as part of the selection process. Humans with genetic defects affecting different apoptotic and proliferation control pathways have common clinical features with expansion of lymphoid organs and autoimmunity being the most common clinical features. This set of disorders is also characterized by varying degrees of lymphocyte accumulation in tissues, and a higher risk of lymphoid malignancies. In this chapter we review these conditions, including clinical and laboratory findings, and their pathophysiology.