Major diagnostic criteria:
(1) chronic splenomegaly due to nonmalignant (benign) lymphoproliferation
(2) chronic noninfectious lymphadenopathy due to nonmalignant (benign) lymphoproliferation
(3) increased numbers of T cells that are CD4 and CD8 negative, both in peripheral blood and lymphoid tissue
(4) impaired apoptosis of lymphocytes cultured in vitro
Additional findings:
(1) one or more autoimmune disorders:
(1a) autoimmune hemolytic anemia (AIHD)
(1b) autoimmune thrombocytopenia (ITP)
(1c) autoimmune neutropenia
(1d) positive direct antiglobulin (Coombs) test
(1e) other autoimmune disorders
(2) family history of autoimmune lymphoproliferative syndrome
(3) family history of B-cell non-Hodgkin's malignant lymphoma
(4) variable hepatomegaly
(5) poor or unsustained response to polysaccharide antigens
(6) presence of deleterious mutations
(6a) deleterious mutation of Fas (CD95 or APO-1, a cell surface receptor)
(6b) deleterious mutation of caspase 10 (a cysteine protease required for apoptosis)
