title: Perforin expression in cytotoxic lymphocytes from patients with hemophagocytic lymphohistiocytosis and their family members.
abstract: Mutations in the perforin gene have been described in some patients with hemophagocytic lymphohistiocytosis (HLH), but the role of perforin defects in the pathogenesis of HLH remains unclear. Four-color flow cytometric analysis was used to establish normal patterns of perforin expression for control subjects of all ages, and patterns of perforin staining in cytotoxic lymphocytes (natural killer [NK] cells, CD8(+) T cells, CD56(+) T cells) from patients with HLH and their family members were studied. Eleven unrelated HLH patients and 19 family members were analyzed prospectively. Four of the 7 patients with primary HLH showed lack of intracellular perforin in all cytotoxic cell types. All 4 patients showed mutations in the perforin gene. Their parents, obligate carriers of perforin mutations, had abnormal perforin-staining patterns. Analysis of cytotoxic cells from the other 3 patients with primary HLH and remaining family members had normal percentages of perforin-positive cytotoxic cells. On the other hand, the 4 patients with Epstein-Barr virus-associated HLH typically had depressed numbers of NK cells but markedly increased proportions of CD8(+) T cells with perforin expression. Four-color flow cytometry provides diagnostic information that, in conjunction with evidence of reduced NK function, may speed the identification of life-threatening HLH in some families and direct further genetic studies of the syndrome.
authors.affiliation: Division of Hematology/Oncology, Children's Hospital Medical Center, Cincinnati, OH 45229-3039, USA.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kogawa
authors.forename: Susan M
authors.initials: SM
authors.lastname: Lee
authors.forename: Joyce
authors.initials: J
authors.lastname: Villanueva
authors.forename: Daniel
authors.initials: D
authors.lastname: Marmer
authors.forename: Janos
authors.initials: J
authors.lastname: Sumegi
authors.forename: Alexandra H
authors.initials: AH
authors.lastname: Filipovich
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D020031:Epstein-Barr Virus Infections; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D015616:Histiocytosis, Non-Langerhans-Cell / Q000235:genetics* / Q000821:virology; D006801:Humans; D007223:Infant; D007694:Killer Cells, Natural / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D009154:Mutation; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D011446:Prospective Studies; D013602:T-Lymphocytes, Cytotoxic / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin