Dear colleagues

Any one knows number of platelets units or plasma units’ D+ve can be affected after one Rhogam injection for female D-ve patient who had been transfused by those D-ve platelets or plasma units.

I don't understand the question... Punctuation may help :tongue:

In other words, In some caes female patient Rh D-ve need urgent platelet or plasma tansfusion, but sometime we have no D-ve units and we have to life saving by give units D+ve, so we don't want to make her strile so give her anti D (Rhogam) injection, my question is how many units can be affected by using single Rhogam injection; thats for correct calculation.

In our trust we do not restrict D- patients to D- platelets. There is very little evidence that there are enough red cells contaminating platelets to illicit and immune response. Platelets contain no Rh antigens so cannot illicit an immune response by themselves.

This is a paper her covering one hospital's study. http://www.ncbi.nlm.nih.gov/pubmed/19856725

If you have any concerns and wish to be on the 'safe side', 500iu of will cover up to 4mls of blood - it is highly unlikely that the platelets are going to be contaminated with any more than this.

And don't worry, giving D+ platelets wouldn't make the woman sterile...

Edit - the sample applies to cryo and FFP.

Edited October 27, 201113 yr by Auntie-D

Rh is not on platelets. But in the Netherlands it is advised to gife anti D profilaxis in case of an transfusion of RhD pos platelets tot an RhD neg woman (<45 years) because of the smal amount of red cells in de product. I donot know any reports of destruction of platelets because of that.

Peter

thanks for all, I know there is no Rh antigen on platelets but still my question how many units of plateles or plasma affected by one Rhogam injection?

anyone knows

A full dose of RhIg (in the USA) should deal with 15mL of red cells. If you have plts with that many you will know by the color.

In Canada, one vial of 300ug (1500IU) can cover 15mL of Rh pos. RBCs which is equivalent to the RBCs in 30 units of random platelets (containing 40-70mL of plasma with >=55x10^9 platelets and < 8.3x10^5 leukocytes per unit) or in 7 units of apheresis platelets (containing ~250mL of plasma with >=300x10^9 platelets and <5x10^5 leukocyts per unit).

I agree with David and Clarest and have recommended one vial of RhIG in such cases.

JB

In Canada, one vial of 300ug (1500IU) can cover 15mL of Rh pos. RBCs which is equivalent to the RBCs in 30 units of random platelets (containing 40-70mL of plasma with >=55x10^9 platelets and < 8.3x10^5 leukocytes per unit) or in 7 units of apheresis platelets (containing ~250mL of plasma with >=300x10^9 platelets and <5x10^5 leukocyts per unit).

Thanks clarest what about number of plasma units can be affected by Rhogam?

Thanks clarest what about number of plasma units can be affected by Rhogam?

The answer to that is 'none'. It is the RBC contamination that is affected by it. It's a bit like asking 'how long is a piece of string?'

Our Transfusion Medical Director has told us that 7 pheresis plts (Rh+) will be coverd by 1 dose of rhogam. This one dose of rhogam can last 2-4 weeks. This we only use for women of child bearing age (which can vary within itself) and if it comes to a pediatic we try to avoid at all cost (unless medical emergency). We had a patient we had to do this twice (give rhogam to a child bearing age female), 3rd time was Winrho. (this patient also had HLA ab's to make it even more fun)! Hope this helps a bit!

I agree with auntie-D. As I understand the reason why Rhig is needed for transfusing Rh pos. Plt. to Rh neg. patient is that there is a trace of RBCs in Plt. unit due to the way how to prepare (e.g., retrieving from buffy coat)

For example, one pooled plt. unit which we currently use (- containes 280mL plasma and equals to about 4 units of random plt. as I mentioned in previous post) has about 0.5mL RBCs.

As I understand, plasma units (e.g., FFP/FP) do not contain RBCs, which is why we do not consider Rhig givingto patients. To be frankly, we even do not put Rh type in to our system when we receive FPs to our inventory.

Please correct me if I am wrong.

Your platelet supplier should be able to tell you what level of RBC contamination you could expect in your plts. Then you can calculate based on your country's usual RhIG dose. In the US I agree that around 6 pheresis units would be covered by one dose of RhIG over a few week's time. Although FFP can have RBC stroma and has very rarely been implicated in stimuating antibody production, in the US, we do not consider that a risk and do not worry about giving Rh+ FFP to an Rh- female--at least any place that I know of. Likewise for Cryo although I have no idea if the stroma end up in the cryoprecipitate or not. I think this issue is covered in the AABB Technical Manual, at least for platelets.

Please remember that non-apheresis platelets have more RBC's within the unit. It has been shown that as little as 0.1ml of RBC's can cause alloimmunization in an Rh-negative patient.