I would appreciate your opinions on transfusing D positive Apheresis platelets to D negative patients. Any references?

Thank you

Liz

If you are fortunate enough to be able to provide Rh identical I am glad for you. I have a difficult time obtaining ABO identical products. I would give a dose of RhIg to the patient.

We only infuse platelets based on patient blood type, Rh does not matter. For example, O patient can receive any type platelet products. A patients receive A or we volume reduce other types and so on. The only type of platelets we transfuse are plateletpheresis.

We only transfuse apheresis platelets, and we almost never have type specific available. Our only "exception" is that when we give a child or woman in "child bearing years" Rh positive platelets, we give it with a dose of RhIg.

We are estatic to obtain any platelets when we have a need.

We suggest RhIg if patient is Rh neg and donor is Rh pos. But in reality, only the younger females get it.

Thank you for your replies.

RhIg is expensive or so tell me the attending physicians.

Is there a reference about giving RhIg if administering D+ apheresis platelets to D- pts?

Thank you.

Liz

cmelloh, you are the only one who says D does not matter, that was my policy until now. Where did you obtain your reference? and are there such studies?

Thanks

Liz

NB: for patients over 40kgs we do not worry about ABO unless the pt is to receive frequent apheresis plts over a short period (eg: 2x day for a few days).

For peds <40kgs we give ABO compatible plts.

Under 2 years old, pregnancy and bone marrow patients always have their RH negative status matched. Sometimes the pathologist has requested matching RH over type.

What is the volume of rbcs in one concentrate of apheresis plts? Enough to justify RhIg? The doctors would want me to justify the cost of RhIg.

Thank you.

Liz

We are lucky to even get close to ABO group compatible half of the time with plateletpheresis units. We used to try and give RhIG when we were giving out of (Rh) type random platelets - they had a lot morer RBCs in them. Since we have been on 100% plateletpheresis now for several years, we have not seen any Anti-Ds that we can attribute to giving Rh pos platelets to an Rh neg pt (and we give a lot of them) and we have not dosed with RhIG in a long time.

Edited August 30, 201014 yr by carolyn swickard
wording

We are lucky to even get close to ABO group compatible half of the time with plateletpheresis units. We used to try and give RhIG when we were giving out of (Rh) type random platelets - they had a lot morer RBCs in them. Since we have been on 100% plateletpheresis now for several years, we have not seen any Anti-Ds that we can attribute to giving Rh pos platelets to an Rh neg pt (and we give a lot of them) and we have not dosed with RhIG in a long time.

This is what I think and practice.

What are others' thoughts?

Are there any references either way?

I understand with random platelets but with apheresis?

Thanks

Liz

We only worry about Rh Negative platelets for Rh Negative women less than 50 years of age, just to be safe. We also use 100% pheresis platelets. I know when I was working in apheresis for the military we would still label platelets that had been created under suspicion/confirmed red cell spillover but they a) had to be checked out and cleared by the QA team would only be used in our facility and that the blood bank was aware of the circumstances. I realize now that I'm unaware of what the Red Cross' policies for that sort of thing are and I wonder.

Liz most RhIg costs between $78-roughly $90 in most hospitals. Alot cheaper than treating a woman who becomes sensitized.

In your pheresis platelets, the RBC concentration is basically 0. A pheresis platelet containing 0.2 mL of RBCs is visibly red-tinged (I spiked a unit of platelets and added RBCs at varying concentrations to determine this). I will comfortably say that a clear, yellow apheresis platelet product contains less than 0.2 mL of RBCs.

We avoid giving Rh Pos pheresis platelets to Rh neg women of child bearing age and would also avoid it for children. We would offer RhoGAM to these patients. We do not offer RhoGAM to other Rh neg patients who receive Rh pos platelets.

We've used pheresis platelets exclusively for the last 5-6 years (low volume, maybe 150 units per year) and have seen one patient develop anti-D from a pheresis platelet - an oncology patient, no less, and the last person I would have expected to do it to us! The unit she received was not red tinged, so the RBC count would have been very low. Naughty patient!!!

I find this to be a difficult situation to put into black and white terms. It really is dependent of your particular patient population, frequency of transfusion, and blood supplier. I believe in a perfect world, the best product would be an exact match for ABO/Rh. Group O patients receiving out of group product often don't get a good rise. Group A or B getting group O may be have risk of hemolysis. Rh negatve patients can and do build D's from Rh Positive platelets, although not frequently. Whether or not to give RhIg may need to be handled on a case by case basis. Just my opinion.

On page 586 of the 16th edition of the AABB Tehnical Manual, it talks about giving RhIg to prevent D alloimmuniztion when giving Rh Positive platelets to Rh Negative patients. Even platelet apheresis products can contain an immunogeneic does of red cells. From past experience, the manufacturer indicates that there may be up to 2 mL of RBCs in a unit of apheresis platelets. Therefore, attempts should be made to provide Rh negative recipients with platelets from Rh Negative donors (although the platelets do not have the Rh antigen). ALthough the clinical magnitude of this issue is less than one might expect, the production of anti-D in the female patient of child bearing potential, most facilities would be inclide to recommend RHIG to these patientsif Rh Positive platelets were transfused. This would support AABB Standard 5.20.

In past AABB Technical Manuals there was a formual for how much RhIg to reccomd. as follows "A full dose of RhIG, which is considered immuno-prophylactic for up to 15 mL of Rh Positive RBCs, should protect the red cells in a minimum of 30 units of Rh Positive Platelets or 7 units of platelets apheresis" Pg 457, 14th Editiion, AABB Technical Manual..

As for ABO matching, it is preferable to give ABO matched platelets first, ABO compatible and as a last resot, ABO incompatible. The rise in platelets is higher in ABO matched platelets. In Pediatric patients is is more critical as ABO incompatible plasma may have more serious effects do to the reduce blood volume of the recipient. If ABO matched or compatible plateles are not available, we would volume reduce after notifying the patient's physician. We also titer the ABO anitbody and only transfuse if the titer is less than 1:100.

Of course in the end, we would rather take care of the underlying condition and save the life of the patient and worry about what happens later than not give incompatible platelets ,if they were the only ones available.

On page 586 of the 16th edition of the AABB Tehnical Manual, it talks about giving RhIg to prevent D alloimmuniztion when giving Rh Positive platelets to Rh Negative patients. Even platelet apheresis products can contain an immunogeneic dose of red cells. From past experience, the manufacturer of the apheresis sets and collection system indicates that there may be up to 2 mL of RBCs in a unit of apheresis platelets. Therefore, attempts should be made to provide Rh negative recipients with platelets from Rh Negative donors (although the platelets do not have the Rh antigen). ALthough the clinical magnitude of this issue is less than one might expect, the production of anti-D in the female patient of child bearing potential is of concern, so most facilities would recommend RHIG to these patients if Rh Positive platelets were transfused. This would support AABB Standard 5.20.

In past AABB Technical Manuals there was a formula for how much RhIg to reccomend. as follows "A full dose of RhIG, which is considered immuno-prophylactic for up to 15 mL of Rh Positive RBCs, should protect the red cells in a minimum of 30 units of Rh Positive Platelets or 7 units of platelets apheresis" Pg 457, 14th Editiion, AABB Technical Manual..

As for ABO matching, it is preferable to give ABO matched platelets first, then ABO compatible and as a last resort, ABO incompatible. The rise in platelets is higher in ABO matched platelets. In Pediatric patients is is more critical as ABO incompatible plasma may have more serious effects due to the reduce blood volume of the recipient. If ABO matched or compatible plateles are not available, we would give volume reduced incompatible after the patient's physician is notified and they agree to transfuse. We also titer the ABO anitbody and only transfuse if the titer is less than 1:100.

Of course in the end, we would rather take care of the underlying condition and save the life of the patient and worry about what happens later than not give incompatible platelets ,if they were the only ones available.

Incidentially, we have had two serious hemolytic transfusion events when we have transfused ABO incompatible platelets. Both cases the titer of the offending ABO antibody was greter than 1:1250. Both cases the supplying blood center was notified and they removed the donor from their apheresis platelet program.

Ours is a hospital based blood bank. We always give ABO matched platelets to our patients. In case of apheresis platelets they are Rh matched. We normally have directed plateletpheresis donors so this takes taken care of. Problem occurs only in case of emergency cases where it may not be possible to get a ABO/Rh matched plt donor for pheresis . Random small units of ABO plts are being given in these cases with advice Rh Ig in case pt is Rh neg.

Thank you all so much. I do agree and will implement a policy that the platelets should match the D status of all recipients but especially for females below 50 years and if not available we will administer RhIg to the female recipients.

On the same note would this apply to FFP and Cryo?

Thank you

Liz

Hi Liz,

My first thought would be that it would not apply nearly so much.

Firstly, of course, the centrifugal force used to produce both products would make it far less likely that there would be many red cells left in the plasma that is going to be made into the FFP or cryo (although it does depend on the heavy-handedness, or otherwise, of the person then seperating the plasma).

Secondly, the very act of freezing the plasma would disrupt the membrane of any red cell left in the plasma (well, the thawing, as much, if not more so, than the freezing) and, as the D antigen relys upon not only the sequence of the amino acid residues to be expressed properly and an immunogen, but also on the juxtaposition of these amino acid residues, sensitisation against the D antigen is far less likely.

Indeed, in the NHSBT now, the D typing is not necessarily shown on the component label of frozen components, as the risk is considered so small.

:):)

Edited September 1, 201014 yr by Malcolm Needs
Terrible punctuation.

Thank you Malcolm that is a relief!

Liz

5.14.5

The red cells in Apheresis Granulocytes and Platelets shall be ABO-compatible with the recipient’s plasma and be crossmatched as in Standard 5.15 unless the component is prepared by a method known to result in a component containing <2 mL of red cells. The donor blood cells for the crossmatch may be obtained from a sample collected at the time of donation.

AABB Standards.

So if there are: < 0.2mL of RBCs as heathervaught posted:

"In your pheresis platelets, the RBC concentration is basically 0. A pheresis platelet containing 0.2 mL of RBCs is visibly red-tinged (I spiked a unit of platelets and added RBCs at varying concentrations to determine this). I will comfortably say that a clear, yellow apheresis platelet product

contains less than 0.2 mL of RBCs

. "

Then this standards does not support:

Rh Matching

A small but immunogenic dose of red cells can be contained in a platelet transfusion. This is more likely in whole-blood-derived platelet units than in apheresis platelet units but is at least theoretically possible with any platelet unit. Therefore, attempts are usually made to provide Rh-negative recipients with platelets from Rh-negative donors even though platelets themselves do not express or carry Rh antigens. When an Rh-negative patient must receive platelets from an Rh- positive donor, a dose of Rh Immune Globulin (RhIG) may be administered to prevent D alloimmunization. The clinical magnitude of this issue is far less than one might expect. Most patients receiving platelets are severely immunosuppressed, and a primary response to the D or other red cell antigens is very uncommon. Additionally, for most patients, the formation of anti-D would have minimal effect on their subsequent hemotherapy support. However, if the patient is a female of child-bearing potential, the formation of anti-D could have a significant effect on future pregnancies. Rather than provide RhIG to all Rh-negative recipients of platelets from an Rh-positive donor, many centers supply RhIG only to premenopausal females. Given the 3- week half-life of IgG and the minimal red cell content of most platelet units, a single dose of RhIG would be expected to provide prophylaxis for multiple transfusions over a 2- to 4- week period (certainly for the period during which anti-D was detectable serologically).

Because the recipient was (and probably still is) thrombocytopenic, an intravenous form of RhIG may be administered to avoid a hematoma (particularly if the platelet count re- mains below 50,000/μL).

Ref: AABB technical Manual 16th edition, 2008

Any thoughts?

Thanks

Liz

I realise that the Standard speaks about ABO and the Technical Manual about Rh, however I am consdering the volume of RBCs.

Liz

Hi Liz,

My first thought would be that it would not apply nearly so much.

Firstly, of course, the centrifugal force used to produce both products would make it far less likely that there would be many red cells left in the plasma that is going to be made into the FFP or cryo (although it does depend on the heavy-handedness, or otherwise, of the person then seperating the plasma).

Secondly, the very act of freezing the plasma would disrupt the membrane of any red cell left in the plasma (well, the thawing, as much, if not more so, than the freezing) and, as the D antigen relys upon not only the sequence of the amino acid residues to be expressed properly and an immunogen, but also on the juxtaposition of these amino acid residues, sensitisation against the D antigen is far less likely.

Indeed, in the NHSBT now, the D typing is not necessarily shown on the component label of frozen components, as the risk is considered so small.

:):)

Hi Malcolm,

I was reviewing my policies, AABB and the CAP checklist, look what I found:

TRM.47000

Routine Typing

Phase II

The routine procedure includes tests with anti-A and anti-B, A1 and B cells, anti-D, and if negative for anti-D, a test for weak D.

NOTE: Routine procedures must include at a minimum, forward and reverse A and B grouping, and a test for the D antigen. Negative-appearing D tests must be confirmed by a test for weak D.

Evidence of Compliance:

✓ Records of donor blood typing for each unit

REFERENCES

1)

Domen RE. Policies and procedures related to weak D phenotype testing and Rh immune globulin administration. Results from supplementary questions to the comprehensive transfusion medicine survey of the College of American Pathologists. Arch Pathol Lab Med. 2000;124:1118-1121

This is a passage from the reference, indeed as you said it is not non-existent but very rare:

During

a 2

½-year study period, this author observed 4 cases of

anti-D alloantibody formation following the transfusion of

Rh(D)-positive blood components in patients determined

to have the weak D phenotype by a standard serologic

technique.

9 This was an incidence of approximately 0.8%

to 2.1% of all patients positive for the weak D phenotype

who were seen by one transfusion service. One of these 4

cases occurred in a young woman, 2 cases were women

aged 52 and 60 years, and 1 case was a 59-year-old man

whose only Rh(D)-positive red blood cell exposure was 8

U of Rh(D)-positive fresh frozen plasma.9