title: The occurrence subtype and significance of haemopoietic inhibitory T cells (HIT cells) in myelodysplasia: an in vitro study.
abstract: This study examines the occurrence, subtype and possible significance of haemopoietic inhibitory T cells (HIT cells) in patients with myelodysplasia (n = 21), acute myeloblastic leukaemia (n = 8) and in normal subjects (n = 13) using an autostimulary CFU-GM stem cell assay. HIT cells were detected when colony numbers increased by 30% or more following T-lymphocyte subpopulation ablation. HIT cells occurred in 28% of the MDS patients, were always CD8-positive and never occurred in the normal subjects. Sequential studies in MDS patients with HIT cells and treated with low dose Ara-C showed no correlation between occurrence of these cells and clinical outcome. HIT cells appear to be a clinically irrelevant manifestation of the cell dysfunction associated with MDS.
authors.affiliation: Department of Haematology, Royal United Hospital, Bath, U.K.
authors.forename: M A
authors.initials: MA
authors.lastname: Smith
authors.forename: J G
authors.initials: JG
authors.lastname: Smith
mesh_terms: D003561:Cytarabine / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006098:Granulocytes / Q000502:physiology; D006410:Hematopoiesis / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000502:physiology; D006801:Humans; D008264:Macrophages / Q000502:physiology; D009190:Myelodysplastic Syndromes / Q000097:blood* / Q000188:drug therapy; D016176:T-Lymphocyte Subsets / Q000502:physiology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000502:physiology
chemical_list: D003561:Cytarabine