title: Reticulated platelets: a reliable measure to reduce prophylactic platelet transfusions after intensive chemotherapy.
abstract: BACKGROUND
  Reticulated platelets (RPs) are the youngest circulating platelets (PLTs). The aim of our study was to predict PLT recovery with RP percentage (RP%) and therefore to identify PLT transfusions that could be avoided after autologous peripheral blood progenitor cell (PBPC) transplantation.
  
  
  METHODS
  With a whole-blood dual-labeling flow cytometric method, RP% was prospectively assessed in 47 patients who received myeloablative chemotherapy followed by autologous PBPC transplantation. Retrospective analysis of RP evolution identified three time points: nadir of the RP% (NRP), imminent PLT recovery (IPR) corresponding to an RP% of greater than 7 percent, and PLT transfusion autonomy (PTA).
  
  
  RESULTS
  Median occurrences of NRP, IPR, and PTA were on Days +5, +8, and +12 after transplantation, respectively. The RP% value at NRP (4%) was significantly lower compared to the IPR (15%) and PTA (14%). Thirty patients (64%) achieved PTA within 4 days after IPR. On Day +8, if RP% was greater than 7 percent, positive and negative predictive values for PTA within 4 days, specificity, and sensitivity were 79, 63, 66, and 76 percent, respectively. Fever between IPR and PTA was the only factor found to negatively influence PLT recovery (p = 0.02). All patients required at least one PLT transfusion. Among patients with rapid PLT recovery (IPR-PTA interval < 4 days; n = 30), half of them received one PLT transfusion after RP increase, which could be avoided.
  
  
  CONCLUSIONS
  These encouraging results may allow us to reduce the prophylactic PLT transfusion according to patients RP% increase.
authors.affiliation: Department of Hematology and Medical Oncology, Biological Hematology Service, Hôtel-Dieu, AP-HP, Paris, France.
authors.forename: Driss
authors.initials: D
authors.lastname: Chaoui
authors.forename: Tahar
authors.initials: T
authors.lastname: Chakroun
authors.forename: Françoise
authors.initials: F
authors.lastname: Robert
authors.forename: Bernard
authors.initials: B
authors.lastname: Rio
authors.forename: Ramdane
authors.initials: R
authors.lastname: Belhocine
authors.forename: Ollivier
authors.initials: O
authors.lastname: Legrand
authors.forename: Celia
authors.initials: C
authors.lastname: Salanoubat
authors.forename: Chantal
authors.initials: C
authors.lastname: Lecrubier
authors.forename: Nicole
authors.initials: N
authors.lastname: Casadevall
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Marie
authors.forename: Ismail
authors.initials: I
authors.lastname: Elalamy
mesh_terms: D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001792:Blood Platelets / Q000166:cytology; D016922:Cellular Senescence; D003131:Combined Modality Therapy; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D019337:Hematologic Neoplasms / Q000188:drug therapy*; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count / Q000379:methods*; D017713:Platelet Transfusion; D011446:Prospective Studies; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D019172:Transplantation Conditioning
chemical_list: D000970:Antineoplastic Agents