D positive apheresis platelets to D negative recipient.

[Malcolm Needs ☆]

Thanks Liz.

I can't argue with that!

[conwaysbb]

Xxxxx

Edited September 7, 2010 by conwaysbb
quoted the wrong reply

[JEMarti]

This subject drives me batty.

When one considers how apheresis platelets are leukoreduced one realizes that those products contain nearly zero red cell contamination if collected properly. Trima and to a lesser degree Amicus platelets should be essentially free of RBC's (Haemonetics platelets can have more, but with the US plt customers of Haemonetics so few you can count them on your fingers this doesn't matter much).

Far more likely, is RBC contamination in plasma. With the drive to produce larger volumes of plasma, both from male donors for FFP and female for recovered plasma labs are cutting it very close on the collections. I have seen far more bloody plasma units than platelets in the last 5 years. In fact I cannot remember the last bloody platelet I saw. But we did have a 21 YO female who received 6 units Rh POS plasma last year. She was O NEG and developed anti-D and anti C. She received 4 units of O NEG RBC in addition to the plasma and nothing else.

Unfortunately, our lab pushes RhIg on Rh NEG recipients of Rh POS plts but does nothing about Rh POS plasma recipients. If the risk is significant enough to give RhIg for the plt population it is certainly high enough for the plasma. The practice of giving it for plt recipients is borne of how platelets were manufactured a generation ago. We need to reassess our practices, but unfortunately are slow to do so.

[conwaysbb]

Thank you Malcolm that is a relief!

Liz

I would defer you to the manufacturer's information on the particular platelet collection system that is used to collect the platelets that you receive, as there are several different platelet apheresis systems out there, for information on how much residual red cells may be contained in a apheresis platelet product. This is the information that they have supplied to the FDA and has come from hundreds of products that were collected. As the volume of apheresis platelet products vary greatly, the very term "Visibly Tinged" is highly subjective and may indicate a vast difference in red cell contamination of the product transfused. I am sure if you contacted the platelet collection system manufacturer's technical support line you could get this information and then use it to make your decision. I am equally sure your blood center will be able to provide the phone number of same.

My understanding is that you will never get visibly tinged apheresis platelets, as these platelets would be non-leuko-reduced and not be able to have bacterial blood cultures performed. but I may be wrong :-)

[heathervaught]

Hi Liz,

Based on your post #25 above, I think that all of the statements are in agreement.

Per Standards, A platelet containing 2 mL of RBC or more requires a crossmatch (note that even a D+ unit would be compatible if the patient has not made anti-D).

According to my experience, a clear, yellow component contains less than approximately 0.2 mL of RBCs.

The Technical Manual states that, a platelet may contain enough RBCs to stimulate an immune response in some patients.

If you chose NOT to issue Rh immune globulin and the patient develops anti-D, what do you do? For any subesquent RBC transfusions, they would only get D-negative AHG-crossmatch compatible units. If you transfuse a platelet that contains 0.2 mL of D+ RBCs to a patient who has anti-D, will they develop any adverse symptoms? I really don't know.

[Malcolm Needs ☆]

Hi Liz,

If you transfuse a platelet that contains 0.2 mL of D+ RBCs to a patient who has anti-D, will they develop any adverse symptoms? I really don't know.

I doubt very much that they would develop any adverse symptoms, as the amount of free Hb that would be released would be minimal, but, according to the early experiments carried out by Professor Patrick Mollison, that is certainly a volume large enough for a secondary immunisation; in other words, the existing anti-D would become more avid and the titre would rise, because of the memory cells.

[Colin Barber]

From the 2003 BCSH Platelet guidelines:

2. RhD incompatibility

• RhD-negative platelet concentrates should be given, where possible, to RhD-negative patients, particularly to women who have not reached the menopause (grade B recommendation, level III evidence).

• If RhD-positive platelets are transfused to a RhD-negative woman of childbearing potential, it is recommended that anti-D should be given (grade B recommendation, level III evidence). A dose of 250 i.u. anti-D should be sufficient to cover five adult therapeutic doses of RhD-positive platelets within a 6-week period, and it should be given subcuta- neously in thrombocytopenic patients.

• It is not necessary to administer anti-D to RhD-negative men or women without childbearing potential who have haematological disorders and receive platelet concen- trates from donors who are RhD positive.

[Liz]

That was helpful Colin from the the 2003 BCSH Platelet guidelines.

Thank you all for your very helpful posts!

Where is the thank you button?

What are the new star and the green button next to the avatar about being a distinguished road??

[Liz]

Oh, the star is like a thank you, I think...

[rravkin@aol.com]

Hey Liz,

You may be interested in knowing that some blood component suppliers are titering Anti A, B in "O" type platelet pheresis do to an article from Transfusion Magazine where the researchers showed a connection between "O" type platelet phoresis donors and hemolyitic transfusion reactions do to elevated concentration of Anti A,B in this small population of donors. I saw a titer sticker on an type O phoresis platelet the other day. It was somewhat releiving given that ABO compatibility is not practiced strictly when transfusing platelets. However, my facility practices strict Rh compatibilty do to reasons given in previous posts.

[Liz]

Interesting!

Thanks.

I have implemented strict Rh compatibility policy, to the surprise of the doctors. On the day that I did start we had a very ill D- peds pt and only D+ plts. The doctor did not want to give RhIG due to all the possible side effects.

Liz

[jeanne.wall]

Here are a couple of references - conflicting of course

Immunohematology

Journal of Blood Group Serology and Education

Volume 14, Number 4, 1998

Immunoprophylaxis using intravenous Rh immune globulin should be standard practice when selected D-negative patients are transfused with D-positive random donor platelets

C.A. EWING,D.H. RUMSEY,A.F. LANGBERG,AND S.G. SANDLER

Immunohematology

Journal of Blood Group Serology and Education

Volume 25, Number 1, 2009

D+ platelet transfusions in D– patients: cause for concern?

A.N. Bartley, J.B. Carpenter, and M.P. Berg

[rravkin@aol.com]

Are there any known cases where D neg platelets caused allo-D antibody formation? Given the info in the previous post by jeanne.wall, in 1998 they seemed sure of the practice and in 2009 they seem to question it. I wonder why the change in opinion after nine years?

[Malcolm Needs ☆]

There is some interesting stuff in Mollison's Blood Transfusion in Clinical Medicine, 11th Edition, Harvey G Klein and David J Anstee, 2005, Blackwell Publishing.

On page 187, they discuss the minimum dose of D-positive red cells for primary immunization, and conclude that this can be as little as 0.03mL.

On page 189, they discuss RhD immunization by red cells present as a contaminant in platelets, and it would seem that D-Negative patients with impaired immunological reactivity (mostly due to acute leukaemia) and all of whom were on immunosuppressive drugs could still make anti-D. This is worrying, to say the least, and they recommend that, if a D-Negative female of child bearing potential is given D-Positive platelets, then she should always be offerred anti-D immunoglobulin prophylaxis.

:omg::omg: