Diagnostic criteria for ALPS

 Required 

1. Chronic nonmalignant lymphoproliferation 
2. Defective in vitro Fas-mediated lymphocyte apoptosis 
3. At least 1% TCR {alpha}/{beta}+, CD3+, CD4-, CD8- cells (DNTs) in peripheral blood or lymphoid tissue 

 Supporting 

1. Autoimmune antibodies 
2. Mutations in Fas gene, Fas ligand gene, or caspase 8 or 10 genes 

Abbreviations: TCR, T-cell receptor; DNTs, double-negative T cells

References:

1. Teachey DT, Manno CS, Axsom KM, Andrews T, Choi JK, Greenbaum BH, McMann JM, Sullivan KE, Travis SF, Grupp SA. Unmasking Evans syndrome: T-cell phenotype and apoptotic response reveal autoimmune lymphoproliferative syndrome (ALPS). Blood. 2005 Mar 15;105(6):2443-8. [Medline]
2. Bleesing JJ, Straus SE, Fleisher TA. Autoimmune lymphoproliferative syndrome: a human disorder of abnormal lymphocyte survival. Pediatr Clin North Am. 2000;47: 1291-1310. [Medline]