title: Early detection of response to hydroxyurea therapy in patients with sickle cell anemia.
abstract: Red blood cells (RBC) and reticulocyte parameters were determined on peripheral blood from a subset of patients enrolled in the multicenter study of hydroxyuea (HU) in sickle cell anemia. Multiple blood samples were obtained every 2 weeks. Cellular indices were measured by flow cytometry. Generalized linear models were used to determine the relationship between the longitudinal trajectories of RBC and reticulocyte indices and HU usage. There was a significant relationship between HU usage and most of the RBC and reticulocyte indices. Hydroxyurea produced higher value trajectories than those generated by placebo usage for the hemoglobin (Hb) content of both the RBCs and reticulocytes and for the mean corpuscular volume (MCV) of reticulocytes. These changes were first detected 10 weeks after starting HU and before the increase in Hb F levels. The data suggest that subtle and early markers of response to HU reside in the hemogram.
authors.affiliation: Cardeza Foundation for Hematologic Research, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA. samir.ballas@jefferson.edu
authors.forename: Samir K
authors.initials: SK
authors.lastname: Ballas
authors.forename: William F
authors.initials: WF
authors.lastname: McCarthy
authors.forename: Nan
authors.initials: N
authors.lastname: Guo
authors.forename: Carlo
authors.initials: C
authors.lastname: Brugnara
authors.forename: Gail
authors.initials: G
authors.lastname: Kling
authors.forename: Robert L
authors.initials: RL
authors.lastname: Bauserman
authors.forename: Myron A
authors.initials: MA
authors.lastname: Waclawiw
mesh_terms: D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000188:drug therapy*; D000986:Antisickling Agents / Q000627:therapeutic use; D004909:Erythrocyte Indices / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005319:Fetal Hemoglobin / Q000032:analysis; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D017701:Reticulocyte Count; D012156:Reticulocytes / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000986:Antisickling Agents; D006454:Hemoglobins; D005319:Fetal Hemoglobin; D006918:Hydroxyurea