title: Expansion of natural killer cells in peripheral blood in a Japanese elderly with human T-cell lymphotropic virus type 1-related skin lesions.
abstract: Natural killer (NK) cells were proposed to play an important role in the pathogenesis of human T-cell lymphotropic virus type 1- (HTLV-1-) associated neurologic disease. Our patient was a 77-year-old Japanese man, who had been treated for infective dermatitis associated with HTLV-1 for nearly 10 years. When referred to us, he had facial eczema/edema as well as extensive dermatitis at the neck/upper chest and nuchal area/upper back regions. Dermal lesions had CD3+CD4+ cells, but no NK cells. Flow cytometry of his peripheral blood showed a phenotype of CD2+ (97%), CD3+ (17%), CD4+ (12%), CD7+ (94%), CD8+ (6%), CD11c+ (70%), CD16+ (82%), CD19+ (0%), CD20+ (0%), CD56+ (67%), HLA-DR+ (68%), and NKp46+ (36%). Absolute numbers of CD56+NK cells in the peripheral blood were in a range of 986/μL-1,270/μL. The expanded NK cells in the peripheral blood are considered to be reactive, to maintain the confinement of the HTLV-1-positive CD4+ cells in the skin, and to prevent the progression of the disease.
authors.affiliation: Division of Hematology, Takasago Seibu Hospital, 1-10-41 Nakasuji, Takasago 676-0812, Japan.
authors.forename: Shinsaku
authors.identifier: 0000-0001-9795-0819
authors.initials: S
authors.lastname: Imashuku
authors.affiliation: Division of Hematology, Takasago Seibu Hospital, 1-10-41 Nakasuji, Takasago 676-0812, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Kudo
authors.affiliation: Division of Internal Medicine, Takasago Seibu Hospital, Takasago 676-0812, Japan.
authors.forename: Kagekatsu
authors.initials: K
authors.lastname: Kubo
authors.affiliation: Department of Pathology, School of Medicine, Kurume University, Kurume 830-0011, Japan.
authors.forename: Kouichi
authors.initials: K
authors.lastname: Ohshima