TY  - CHAP
M1  - Book, Section
TI  - Preservation and Clinical Use of Platelets
A1  - Gernsheimer, Terry
A1  - Slichter, Sherrill
A2  - Kaushansky, Kenneth
A2  - Lichtman, Marshall A.
A2  - Prchal, Josef T.
A2  - Levi, Marcel M.
A2  - Press, Oliver W.
A2  - Burns, Linda J.
A2  - Caligiuri, Michael
PY  - 2015
T2  - Williams Hematology, 9e
AB  - SUMMARYThe  numbers  of  platelet  transfusions  administered  in  the  United  States  increased  dramatically  during  the  1980s,  and  has  continued  to  grow  as  increasingly  aggressive  medical  and  surgical  treatments  have  been  developed  and  become  more  widely  available.  In  particular,  the  growth  of  more  intensive  treatments  for  hematologic  and  other  malignancies  has  spurred  demands  for  platelet  transfusion  support  and  put  pressure  on  platelet  inventories  nationwide.The  response  to  a  platelet  transfusion  is  affected  by  platelet  recovery  and  platelet  survival  and  includes  the  random  loss  of  platelets  in  maintaining  endothelial  integrity.  In  a  normal  individual,  weighing  70  kg,  approximately  4.8  ×  1010  platelets  per  day  will  be  consumed  maintaining  the  endothelium,  less  than  the  number  of  platelets  in  a  single  concentrate.  However,  many  clinical  conditions  can  adversely  affect  platelet  recovery  and  platelet  survival  in  the  circulation.  Prophylactic  platelet  transfusion  is  an  important  part  of  supportive  care  of  patients  with  hypoproliferative  thrombocytopenia  because  of  hematologic  malignancy  and  the  effects  of  its  treatment  with  cytotoxic  drugs.  A  morning  blood  platelet  count  of  less  than  10  ×  109/L  appears  to  be  an  appropriate  threshold  for  prophylactic  transfusion.  Although  higher  thresholds  may  be  indicated  for  patients  at  high  risk  or  who  have  active  bleeding,  little  or  no  data  support  specific  platelet  count  goals  and  a  transfusion  plan  should  be  guided  by  the  clinical  setting.  Larger  doses  of  platelets  do  not  confer  additional  protection  against  bleeding  in  this  patient  population,  although  they  do  result  in  higher  increments  and  a  longer  interval  until  the  next  platelet  transfusion,  a  potential  benefit  in  the  outpatient  setting.  The  platelet  count  at  which  an  invasive  procedure  or  major  surgery  can  be  safely  performed  is  not  supported  by  randomized  control  studies  and  practice  has  been  governed  by  retrospective  data  and  case  reports.  Most  minor  invasive  procedures  and  even  major  surgery  can  be  safely  performed  at  platelet  counts  of  20  to  50  ×  109/L  whereas  high-risk  procedures  or  severe  bleeding  may  require  platelet  counts  above  100  ×  109/L.  Patients  may  become  refractory  to  platelet  transfusion  and  fail  to  respond  for  many  reasons.  Patients  alloimmunized  to  platelets  may  respond  to  platelet  transfusions  from  class  I  human  leukocyte  antigen  (HLA)-matched  donors.Platelets  can  be  collected  by  apheresis  or  obtained  from  whole  blood  and  pooled  for  transfusion.  Both  preparations  have  comparable  effectiveness  in  the  prevention  of  bleeding  in  patients  with  hematologic  malignancy.  Platelets  should  remain  at  room  temperature  and  so  are  approved  for  only  5  days  of  storage  because  of  risks  of  bacterial  contamination  and  may  lose  viability  within  days  after  that.  Leukocyte  reduction  of  platelet  components,  either  upon  apheresis  collection  or  by  filtration,  reduces  HLA  alloimmunization,  prevents  cytomegalovirus  transmission  by  transfusion,  and  reduces  febrile  transfusion  reactions.  Pathogen  reduction  of  platelets  prevents  replication  of  RNA  and  DNA  in  contaminating  organisms  and  leukocytes  and  may  prevent  alloimmunization  and  decrease  transfusion  reactions.  Prospective  clinical  trials  are  needed  to  better  define  indications  for  platelet  transfusion  and  improve  upon  the  effectiveness  of  transfusion  therapy.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/18
UR  - hemonc.mhmedical.com/content.aspx?aid=1121106079
ER  -