title: Investigation of suspected deficient Fas-mediated apoptosis in a father and son.
abstract: BACKGROUND
  A 2-year-old boy presented with symptoms consistent with a diagnosis of autoimmune lymphoproliferative syndrome (ALPS). His father had been splenectomized at age 12 with similar symptoms. ALPS is a rare hereditary syndrome that may result from a functional defect in Fas-mediated apoptosis.
  
  
  METHODS
  Peripheral blood lymphocytes (PBL) and splenic lymphocytes from the patient and PBL from his father and a normal control were analyzed for surface Fas expression. They were then stimulated with an anti-Fas monoclonal antibody (DX2). Apoptosis was assayed by flow cytometry at 0, 20, 28, and 34 h.
  
  
  RESULTS
  There was no significant difference in expression of Fas (CD95) in the PBL of the patient, his father, or the normal control, or the splenic lymphocytes. Compared with the normal control, the PBL of the patient and his father failed to progress to apoptosis. They also contained a markedly elevated proportion of CD3+CD4-CD8- "double-negative" cells.
  
  
  CONCLUSIONS
  PBL from both the patient and his father expressed CD95, but failed to proceed to apoptosis after stimulation, suggesting a functional defect. These results and the clinical presentation are consistent with published descriptions of ALPS.
authors.affiliation: Department of Immunology and Infectious Diseases, The New Children's Hospital, Westmead, NSW, Australia. markh@chw.edu.au
authors.forename: M G
authors.initials: MG
authors.lastname: Hanlon
authors.forename: M L
authors.initials: ML
authors.lastname: Gacis
authors.forename: A M
authors.initials: AM
authors.lastname: Kakakios
authors.forename: H
authors.initials: H
authors.lastname: Kilham
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000097:blood; D017209:Apoptosis / Q000235:genetics / Q000502:physiology*; D001327:Autoimmune Diseases / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D002675:Child, Preschool; D005434:Flow Cytometry; D006801:Humans; D008214:Lymphocytes / Q000276:immunology / Q000473:pathology; D008232:Lymphoproliferative Disorders / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008297:Male; D012016:Reference Values; D013156:Splenectomy; D019014:fas Receptor / Q000097:blood*
chemical_list: D015703:Antigens, CD; D019014:fas Receptor