Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/ijtm/public_html/includes/connectdb.php on line 20

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/ijtm/public_html/includes/DbSql.inc.php on line 13

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/ijtm/public_html/includes/DbSql.inc.php on line 13
Indian Journal of Transfusion Medicine
  Indian Journal of Transfusion Medicine Indian Journal of Transfusion Medicine

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/ijtm/public_html/includes/DbSql.inc.php on line 13

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/ijtm/public_html/includes/DbSql.inc.php on line 13
image Image
Bottom Image
image Image
Journal Menu
Browse Journal
Current Articles
Last Articles
Archives
About the Journal
Bottom Image
Image SUBMIT YOUR ARTICLES Image
image Image
Important Links
Subscribe / Renew
Submit an Article
Submit Now!
Bottom Image
image Image
Newsletter Subscription

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/ijtm/public_html/includes/DbSql.inc.php on line 13

Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/ijtm/public_html/includes/DbSql.inc.php on line 13
NAME
EMAIL
Unsubscribe
  
Bottom Image
 
image Image
Advances in Platelet Transfusion Therapy: Indian Perspective
 

Dr. Rajesh B Sawant

MD, PDCR

 
 

There has been a major increase in the usage of platelets as a means of hematologic support in cancer treatment as well as in outbreaks like dengue, leptospirosis and malaria.

Platelet transfusions are used for the treatment and/or prevention of bleeding in patients with a decreased number or function of platelets. Prophylactic platelet transfusion is the standard of care for malignancy or chemotherapy/radiation-induced thrombocytopenia. Therapeutic platelet transfusions are commonly used in the postoperative period after bypass cardiac surgery for platelet dysfunction and in thrombocytopenia associated with consumption coagulopathy (i.e., disseminated intravascular coagulopathy (DIC)). Platelet transfusions are expensive and are associated with a number of side effects, including febrile reactions, transmission of viral (particularly cytomegalovirus) and rarely bacterial infections, fluid overload, graft vs host disease, hemolysis, and alloimmunization.

 
     
  Random Donor Platelets(RDP) or Apheresis/Single Donor Platelets (SDP), which component to use?  
  The Apheresis technology is widely available and popular in many parts of India currently. The use of single donor platelets obtained by apheresis has increased substantially in the past decade in part because of perceptions that single donor platelets are a better transfusion product. Both platelet concentrates derived from whole blood (RDP) or single donor platelets (SDP) obtained from a single donor by apheresis are indicated to treat acute hemorrhage secondary to thrombocytopenia or to provide prophylaxis from hemorrhage in patients with bone marrow aplasia.   There is debate about which platelet product should be used; many transfusion services favor the primary use of  RDP, whereas others favor SDP. The following five areas should be considered when considering the use of SDP or RDP: (1) The impact on infectious complications, (2) Transfusion reaction rate, (3) Leukodepletion, (4) Reduction of transfusion frequency in patients with bone marrow suppression and, (5) The treatment and prevention of alloimmunization.  
     
  Prophylactic Transfusion and Platelet Transfusion Trigger  
  Most platelet transfusions are given for the prevention of bleeding rather than for treatment of active hemorrhage. Indeed, the incidence of serious or fatal hemorrhage is extremely low in most leukemia or transplant trials and is even less common in patients with solid tumors. In most patients with serious bleeding episodes, other factors, including concurrent coagulopathies, sepsis, and anatomic bleeding sites as seen in patients with necrotic tumors, may actually be more important than the low platelet count itself. Platelet counts lower than 20,000/ul have traditionally been the "trigger" for prophylactic transfusion by clinicians for the past 20-30 years. Recently, randomized trials conducted in patients with acute leukemia have shown support for safely lowering the threshold for prophylactic transfusion upto 10,000/ul.  
     
  Single Donor vs Pooled Platelet Concentrates  
  Although the concept of ‘Pooled Platelets’ is not new and pooled platelets are licensed components in the Europe and USA, pooling of RDPs is not commonly practiced in India. Many patients however receive transfusion of RDPs of various ABO blood group depending upon their availability and the urgency of requirement. There is evidence to show that RDPs can be pooled prior to storage without altered effects on platelet quality both in vitro and in vivo, and SDPs are no different in quality than pooled platelets.  Apheresis platelets are more expensive than pooled random donor platelet concentrates (PC), and comparative studies have shown that post-transfusion platelet increment and the incidence of alloimmunization are similar using both the preparations. In an effort to meet platelet transfusion requirements, platelets pooled prior to storage may prove to be an acceptable alternative when apheresis product is not available. There are additional turnaround time issues with pooled platelets. With improved donor screening, it is unlikely that there would be any detectable difference between the two platelet products in terms of the incidence of infectious disease transmission. Thus, except in cases where histocompatible donors are needed for alloimmunized patients, there is no compelling reason to choose single donor over pooled platelets.  
     
  Platelet Dose  
  The number of units transfused should depend on the goal of the transfusion. For more routine prophylactic transfusions, 5-6 units of RDP’s is appropriate for average-sized adults and should increase post-transfusion counts greater than 30,000/uL above baseline. Patients who are bleeding or scheduled for surgical procedures often require larger numbers of transfusions, depending on their pre-transfusion platelet counts. It is important that clinicians be aware of the average number of platelets per unit in their respective blood centers, particularly for apheresis collections.  Calculating the corrected count increment (CCI) or percentage platelet recovery (PPR) is helpful for choosing the right dose of platelets for individual patients.  
     
  Effectiveness of Platelet Transfusion  
  The magnitude of increase in platelet count after platelet transfusion is variable and is influenced by the release of stored platelets from the spleen and peripheral platelet destruction. Transfusion of one platelet concentrate will increase the platelet count by approximately 5-10 x 109 /l in the average adult. The usual therapeutic dose is one platelet concentrate per 10 kg body weight.  
     
  Alloimmunization and Refractoriness to Platelet Transfusion  
  Clinicians should suspect immune-mediated refractoriness to platelet transfusions if post-transfusion increases are minimal (<5000) after more than 1 transfusion. This can be confirmed by screening for the presence of lymphocytotoxic (anti-HLA) antibodies. Histocompatible donors can be identified either by HLA matching or by using a variety of platelet cross-matching techniques. If donors cannot easily be found, patient management can be quite difficult. Randomized trials have shown that the rate of alloimmunization can be decreased in leukemic patients receiving multiple transfusions by the use of leukocyte-depleted (filtered) blood products. Very few centres in India currently practice laboratory leucodepletion.  
     
 

Thrombopoietin

It had been hoped that the availability of highly active thrombopoietin preparations might decrease the need for platelet transfusion in many patients in future. For now and the foreseeable future, it appears that there is no better substitute for platelet transfusions.

Future Perspectives

There have been significant advances in platelet transfusion  therapy over the last several years. Ongoing  ollaborative efforts, including safe and rational component therapy workshops involving clinicians, blood ank directors, and members of hospital transfusion committees, can do much to alter existing practices. nitoring the patterns of platelet   use on a continuing basis in the form of audits will provide a means for evaluating the impact of existing strategies and a basis for suggesting additional or alternative pproaches. Some of the uncertainty surrounding platelet transfusion practices is related to the lack of  ethods for predicting which  patients are at risk to bleed and the effectiveness of various platelet   reparations. Research initiatives to provide better guidelines for transfusion practice are necessary.  Ntroduction and utility of pooled platelets in clinical practice needs to be  evaluated in our country. More  asic research to elucidate the  role of platelets in hemostasis is needed. Efforts to overcome the problems associated with alloimmunization to platelets  are imperative. Elimination of bacterial growth in platelet concentrates stored at room temperatures warrants special  attention. Finally, our thrombocytopenic  atients deserve  nothing lesser than the best and safest possible platelet  transfusion.

 Recommended further Reading:

  1. Ness P et al. Single-donor platelets reduce the risk of septic platelet transfusion reactions. Transfusion 2001;41:857-61.
  2. Kleinman S et al. Risks associated with transfusion of cellular blood components in Canada. TransfusMed Rev 2003;17:120-62.
  3. Gaydos LA, Freireich EJ, Mantel N, et al. The quantitative relation between platelet counts and hemorrhage in patients with acute leukemia. N Engl J Med. 1962;266:905-909.
  4. Heckman KD, Weiner GJ, Davis CS, et al.Randomized study of prophylactic platelet transfusion threshold during induction therapy for adult acute leukemia: 10,000/mcL versus 20,000/mcL. J Clin Oncol.1997;15:1143-9.
  5. Snyder EL, Stack G, Napychank P, Roberts S. Storage of pooled platelet concentrates. In vitro and in vivo  analysis. Transfusion. 1989 Jun; 29(5):390-5.
  6. Moroff G, Holme S, Dabay MH, Sawyer S, Heaton WA, Law P, Alsop P. Storage of pools of six and eight platelet concentrates. Transfusion. 1993 May; 33(5):374-8.
  7. O’Connell B, Lee EJ, Schiffer CA. The value of 10- minute posttransfusion platelet counts. Transfusion.1988;28:66-67.
  8. The TRAP Study Group. Leukocyte reduction and UVB irradiation of platelets to prevent   immunization and refractoriness to platelet transfusion. N Engl J Med. 1997;337:1861-1869.
 
     
     

 

Bottom Image
image Image
Dr. RAJESH B SAWANT
MD,PDCR
View Full CV
Bottom Image
Image FOLLOW US RSS Feed Twitter Facebook in Image
Developed By LBM Infotech