Discussion Forums > Thalassemia Major
Slow rate transfusion and warm antibody
Zaini:
Give lots of hugs and kisses to Maani from his aunt Zaini :bighug :bighug :bighug
I hope everything will be alright with this handsome young man :)
ZAINI.
Sharmin:
Thank you Zaini :hugfriend
I love you Manal and Zaini - what would I do without you??
We are still waiting for the blood bank to find blood. I'm sure they will find it either later today or tomorrow morning.
I'll let you know when they do:)
:bighug :bighug
Sharmin
Andy Battaglia:
Sharmin,
The slower transfusion rate with less blood should make some difference.
http://www.clinlabnavigator.com/transfusion/WarmAutoimmuneHemolyticAnemia.html
--- Quote --- A critical aspect of transfusing patients with AIHA is to avoid over- transfusion. The kinetics of red cell destruction always describe an exponential decay curve, indicating that the number of cells removed during a unit of time is a percentage of the number of cells present at the start of this time interval. Raising the hemoglobin level abruptly is likely to increase the amount of hemolysis that is occurring and may precipitate DIC. Indeed, the most common cause of post transfusion hemoglobinemia and hemoglobinuria in AIHA may not be alloantibody induced hemolysis but rather the quantitative effect of increasing the red cell mass subjected to ongoing autoantibody hemolysis. Accordingly, transfusion of comparatively small volumes of blood is the optimal means of minimizing the danger of transfusion-induced intravascular hemolysis. The patient's hemoglobin level should be maintained just above a tolerable level until more specific therapy becomes effective.[/size]
--- End quote ---
I've been reading about blood matching which has been done using phenotyping. In recent years, it has been shown that genotype matching of blood can give a more accurate match.
http://www3.interscience.wiley.com/journal/98518982/abstract?CRETRY=1&SRETRY=0
--- Quote ---Genotyping was very important in determining the true blood groups of many polytransfused patients with -thalassemia, and it assisted in the identification of suspected alloantibodies and the selection of antigen-negative RBCs for transfusion.
--- End quote ---
By using this along with phenotyping, a better match is found. After many transfusions, it becomes difficult to determine the true blood type because so many foreign antibodies have been introduced via transfusions. Genotyping matches for the true blood type.
http://cat.inist.fr/?aModele=afficheN&cpsidt=1466407
--- Quote ---After multiple transfusions, the serologic typing of autologous blood group phenotypes is difficult, because of mixed RBC populations. The genotyping of ABO, Rh, Kell, Kidd, and Duffy systems could be used to determine autologous blood group antigen status...Genotyping from peripheral blood produced results identical to the autologous blood group phenotypes, regardless of the amount of blood transfused or of the length of the sampling period after transfusion. CONCLUSION: A fast and reliable PCR.sequence-specific primer DNA genotyping assay for simultaneous determination of autologous ABO, Rh, Kell, Kidd, and Duffy blood groups can be performed on peripheral blood samples, even though the patients have recently received multiple transfusions.
--- End quote ---
http://cat.inist.fr/?aModele=afficheN&cpsidt=18300371
--- Quote ---The development of red blood cell (RBC) isoimmunization with alloantibodies and autoantibodies complicate transfusion therapy in multiply transfused thalassemia patients...In conclusion, the transfusion of matched blood is essential for chronically multiply transfused patients in order to avoid alloimmunization. Considering the high frequency of anti E at our hospital, it is advisable to genotype patients and match the red cells for E antigens in multiply transfused thalassemia patients.
--- End quote ---
I do not know where the current state of genotyping is or if it is even being done on a routine basis. There is a movement in Europe to replace the old method of phenotype with DNA genotype. There is a group called Bloodgen that is working to make genotyping the standard for blood matching.
http://science.uwe.ac.uk/projectshowcase/neil_avent.asp
--- Quote ---Bloodgen is an international consortium led by Professor Neil Avent and colleagues in FAS. The consortium aims to use genotyping to improve patient safety and blood transfusion compatibility.
In most developed countries safe blood transfusion is taken for granted. But, not all blood groups are compatible, and blood grouping is complex, with two cross-matching tests required prior to transfusion.
What's more, these tests are based on technology that has not changed since the early days of blood transfusions. Bloodgen aims to change all that with the development of a 'Bloodchip' - a CE-marked commercial product that will be sold to Blood Services worldwide.
There are 29 different blood group systems but currently only ABO and Rh (Rhesus) are routinely tested for. Professor Avent, Director of UWE's Centre for Research in Biomedicine and leader of the project said:
"Inevitably there is going to be some incompatability with blood transfusions, especially in those that receive multiple transfusions, because if it is incompatible the patients' immune system will create an antibody. Blood grouping at the moment uses antibodies that interact with proteins on the surface of cells.Our research looks at blood group specific genes which vary from one individual to another. This is certainly a safer means of testing blood because of its comprehensiveness. The Bloodchip will embrace all blood groups that are clinically significant and we'll be able to have those tested on a routine basis."
"The ultimate goal is that a new technology will come in and replace techniques that have been around for 100 years or so. Genotyping is incredibly accurate and could be used for a wide range of routine testing of patients in the near future."
The Bloodgen consortium, which is supported by a large EC Framework V grant, pulls together expertise from around the globe. The partners are: Biotest AG Dreieich, Germany; Bloodbank, Rotterdam; Blood Group Reference Centre, Barcelona; Institute of Haematology and Blood Transfusion, Prague; the North Bristol NHS Trust, Southmead, Bristol; Progenika SA, Spain; Sanquin Research Foundation, Amsterdam; University Hospital, Lund; University of Ulm, and the University of the West of England, Bristol (lead partner).
--- End quote ---
Genotyping will eventually replace phenotype matching of blood. One article I read from 1999 talked about the white population having been genotyped but others, such as Asian still needed to be done. I don't know how much progress has been made in the past nine years but I think this is an important subject to bring up when you speak with Dr Vichinsky.
I read until I couldn't keep my eyes open the past two nights, trying to find information for you and Rozitka about antibody reactions. It is somewhat frustrating because it is a very difficult problem that affects a percentage of those receiving blood transfusions and there are no easy answers. I hope each little bit of knowledge can come together to help in some way.
Sharmin:
Andy,
I can't thank you enough! This is so much useful information - and I can see the pattern - when our doctor began transfusing him more aggressively - the antibody only became more active. I will take all of this information to him so that we can find the optimal method of treating him. Thank you from the bottom of my heart :hugfriend
I'll keep you posted,
Sharmin
Andy Battaglia:
Sharmin,
I have worked so hard at trying to find answers and it makes it all worth it to know that anything I found can be of even the smallest help. I am also really happy that your doctor is willing to look at these things and use what he thinks may help. I never am trying to show doctors up and really hope that my contributions can be seen as what they are, and that is sincere attempts to give some information that can help. I realize that with the amount of work many doctors are confronted with, that they may not have the time available to do the hunting that I can do. (And believe me, no one wants their doctor to be as bleary eyed as me after a couple nights reading medical study summaries). I hope any doctor can find some answers in the information I compile. Your doctor has been so open to the information I dig up. I hope all doctors can understand that we're all trying to do the same thing and that is help patients. We hear a lot of negative comments directed towards doctors and much of this is the result of doctors just not having prior experience with thalassemia. I don't think any doctor should be criticized for this, but the criticism may begin when a doctor is confronted with thal and makes no attempt to further his/her understanding. I feel this is a minority of doctors who are like this and I think if patients encourage their doctors to find correct information, that we will see far fewer complaints, as most doctors do take their work seriously and will try to learn what they can if they know the information they possess is not complete. Sharmin, your doctor is doing a great job and has shown so much willingness to look at information that may help make life better for your son. I hope a solution to this autoantibody problem is forthcoming.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version