Autoimmune Lymphoproliferative Syndrome

This chapter discusses the background, prevention, diagnosis, treatment, and prognosis for autoimmune lymphoproliferative syndrome (ALPS). ALPS is a lymphoproliferative syndrome with autoimmunity, and results from genetic defects of programmed cell death, or apoptosis, which leads to abnormal lymphocyte homeostasis. Patients with ALPS have an enlarged spleen and lymph nodes, and various manifestations of autoimmunity. One of the cardinal features is the presence of a circulating population of “double negative T-cells”, T lymphocytes bearing alpha-beta T-cell receptors but neither CD4 nor CD8 surface antigens. Lymphocytes cultured in vitro from ALPS patients are more resistant to programmed cell death than cells from healthy controls. The incidence of lymphoma is increased in ALPS. The ALPS leads to anemia, thrombocytopenia, and sometimes neutropenia. Steroids or other immunosuppressants are used for only short periods as needed for prevention/management of complications.