title: Absence of circulating natural killer (NK) cells in a child with erythrophagocytic lymphohistiocytosis lacking NK cell activity.
abstract: A 5-year-old girl who was diagnosed as having erythrophagocytic lymphohistiocytosis died at age 9 years. Peripheral lymphocytes from the patient persistently lacked natural killer (NK) cell activity during the 4-year observation period: the percent lysis values as measured by a 4-hr 51Cr release assay at a 40:1 effector:target ratio were below 1.0% against K562 and Molt-4 cells as compared with the normal lymphocyte value (mean +/- SD) of 46.2% +/- 5.8% and 43.9% +/- 6.7%, respectively. The patient's lymphocytes never developed NK cell activity by their incubation with target cells for longer time periods or by their stimulation with interferon-alpha, interleukin-2, or polyinosinic-polycytidilic acid. Single cell-in-agarose assay showed the absence of target-binding cells (TBCs): TBC numbers were below 0.3% as compared with the normal lymphocyte value of 8.1% +/- 1.3% (mean +/- SD). Flow cytometry showed a marked decrease in Leu-7+ cells (1.7%) and the absence of Leu-11+ cells (0.4%) in the peripheral blood. These results first demonstrate a case of erythrophagocytic lymphohistiocytosis in which there is the lack of NK cell activity due to the absence of circulating NK cells.
authors.affiliation: Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kawai
authors.forename: A
authors.initials: A
authors.lastname: Komiyama
authors.forename: K
authors.initials: K
authors.lastname: Aoyama
authors.forename: Y
authors.initials: Y
authors.lastname: Miyagawa
authors.forename: T
authors.initials: T
authors.lastname: Akabane
mesh_terms: D002675:Child, Preschool; D002860:Chromium Radioisotopes; D003584:Cytological Techniques; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic; D004912:Erythrocytes; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000473:pathology* / Q000502:physiology; D008206:Lymphatic Diseases / Q000097:blood* / Q000503:physiopathology; D008218:Lymphocytosis / Q000097:blood* / Q000503:physiopathology; D010587:Phagocytosis
chemical_list: D002860:Chromium Radioisotopes