Exchange Transfusion for Sickle Cell Patients

[Malcolm Needs ☆]

We have a sickle cell patient with an Anti-U that gets exchanged every 6 - 8 weeks. For her we ignore our Sickle Cell Protocol which is to give antigen matched for the Rh's and K. We have about 10 patients that do get RBC exchange transfusions on a regular basis. In fact we keep a log to track them.

As a matter of interest, what is her Rh and K type, and which antigens are you ignoring?

An exchange every 6 to 8 weeks with anti-U! Lucky U! I bet that's fun finding blood for her that often.

:)

[clmergen]

Her phenotype is C-E-, K-, M+N+S-s-, Le(a-b+), Jk(a+b-), Fy(a-b-). We assume c+e+. She has only formed the Anti-U. For a typical SCD patient with this phenotype we would give blood that is C-E-K- and sickle negative.

She had her 6th exchange for the year last month. She usually has a 6 unit exchange, most of which come through the Rare Donor Program. Luckily we tend to get 2-3 weeks notice of the procedure.

[Malcolm Needs ☆]

Her phenotype is C-E-, K-, M+N+S-s-, Le(a-b+), Jk(a+b-), Fy(a-b-). We assume c+e+. She has only formed the Anti-U. For a typical SCD patient with this phenotype we would give blood that is C-E-K- and sickle negative.

She had her 6th exchange for the year last month. She usually has a 6 unit exchange, most of which come through the Rare Donor Program. Luckily we tend to get 2-3 weeks notice of the procedure.

Thanks for that.

You would be a bit unlucky if your donors were C+, E+ or K+, given that they would also have to come from the Black population (not impossible, I know, but much less likely), but there is still a good chance of encountering a Jk(a+b+) donor.

:)

[kate murphy]

Actually, we've found that simple transfusion of 1 or 2 units every 4-6 weeks is enough to keep the crit up and the %HgbS down. That's why we only exchange for crisis or pre-op. We convinced our Hematologists that chelation therapy for iron overload is less risky for the patient than multiple donor exposures - both possilbe disease transmission and rbc Ab stimulation.

Also, not all sicklers are at risk of stroke.

Malcolm, I'm amazed at the 24 antibodies. The danger is trying to recognize when there's a new one!

[Gumby]

We are currenly located next to a childrens hospital and as their patients age they are coming over to our facility for treatment. We perform single or double exchanges on a weekly basis, but currently have three patient who need exchanges on a frequent basis. These sickle cell patient have had strokes in the past and have been placed on this protocol for the rest of their lives. Our goal is to provide the best quality of care for our patients. I guess since we are a large facility that we see more of these patients with the added benefit of having a childrens hospital right next to us.

The problem that we see with the iron chelation therapy is that the medication tastes horrible and most sickle patients do not take it on a regular basis.

[Malcolm Needs ☆]

Malcolm, I'm amazed at the 24 antibodies. The danger is trying to recognize when there's a new one!

As I understand it (if I understand it!), the NHSBT is providing blood negative for the major blood group antigens against which the patient has made atypical antibodies (things like S, K, Fya, etc - although, off the top of my head, I'm not sure if these actual specificities are involved) and then cross-match compatible blood is given as far as the others are concerned.

I think they have given up searching for new antibodies are produced, on the grounds that a) they would have to show up in the cross-match and there are only a certain number of antigens recognised by the ISBT!!!!!!!!!!!!!!!!

[dstoever]

This is a great forum, I hope it does not get outdated and hard to find in some archive.

[John C. Staley]

There is some good news out there. I just read where bone marrow transplants are working for adults with sickle cell disease now. They had to tweak the radiation dosage prior to the transplant. Apparently adults do better and childer at a lower dose of radiation. With any kind of luck this will take care of 90% of the transfusion issues concerning these folks.

[jcdayaz]

There is some good news out there. I just read where bone marrow transplants are working for adults with sickle cell disease now. They had to tweak the radiation dosage prior to the transplant. Apparently adults do better and childer at a lower dose of radiation. With any kind of luck this will take care of 90% of the transfusion issues concerning these folks.

YES! I attended an AABB Teleconference last week that dealt specifically with Bone Marrow/Stem Cell transplants. There was a part on its application to sickle cell disease and the recent success rates!!!

[Townsend]

We are a children's hospital and have the same sickle protocol as aakupaku, Kate, and clmergen: RBC matched for Rh antigens and K, until the patient makes an antibody, at which point we begin also matching for Duffy, Kidd, and S/s. The blood is fresh (7 days or less) and sickle negative.

Currently we have about 35 sickle patients that are exchanged 2-8 units every 3-5 weeks, depending on the patient's size, Hgb S level, Hct. So they total approximately 150 red cell units per month (half are some combo of C/c/E/K neg and the other half have antibodies requiring about 5-8 antigens negative per unit). We now have almost 300 sickle and thalassemia patient phenotypes that we keep in a spreadsheet!

The key is to collaborate with the physicians, sickle and apheresis nurses, transfusion service, and blood supplier. Our local ARC has done a lot of recruiting for our sickle patients. They're "looking" for those black donors who are Rh pos, but C/E negative (Ro) so that we can try to salvage our Onegative blood supply. After years of tweeking, the process currently in place is moving pretty smoothly, and we just keep getting busier (and more complex antibody workups).

Stephanie Townsend, MT(ASCP)SBB:rolleyes:

[Malcolm Needs ☆]

We are a children's hospital and have the same sickle protocol as aakupaku, Kate, and clmergen: RBC matched for Rh antigens and K, until the patient makes an antibody, at which point we begin also matching for Duffy, Kidd, and S/s. The blood is fresh (7 days or less) and sickle negative.

Currently we have about 35 sickle patients that are exchanged 2-8 units every 3-5 weeks, depending on the patient's size, Hgb S level, Hct. So they total approximately 150 red cell units per month (half are some combo of C/c/E/K neg and the other half have antibodies requiring about 5-8 antigens negative per unit). We now have almost 300 sickle and thalassemia patient phenotypes that we keep in a spreadsheet!

The key is to collaborate with the physicians, sickle and apheresis nurses, transfusion service, and blood supplier. Our local ARC has done a lot of recruiting for our sickle patients. They're "looking" for those black donors who are Rh pos, but C/E negative (Ro) so that we can try to salvage our Onegative blood supply. After years of tweeking, the process currently in place is moving pretty smoothly, and we just keep getting busier (and more complex antibody workups).

Stephanie Townsend, MT(ASCP)SBB:rolleyes:

It may just help (I don't know) if you get your patients genotyped for the FY genes too. IN that case you may well find that a awful lot of your phenotypically Fy(a-b-) sicklers are genotypically either FYB/FYB or FYB /FY, in which case they can safely be given Fy(a-b+) blood, rather than completely Duffy matched (because of the up-stream GATA-1 mutation), once they have made other antibodies than Rh and K.

It may be easier to match (albeit, genotyping is not cheap).

:confused::confused:

[Townsend]

Thanks for the suggestion Malcom! I'm sure you understand the frustration of trying to provide units for "needy" Transfusion Services like us.:tongue:

We actually only give Fya negative (not Fyb neg) to those who type Fy(a-b-). We have been sending our patients who type Fy(a+b-) for the GATA box mutation - most of them have come back positive so we can drop the Fyb neg requirement. Glad to hear that others recommend this policy.

Stephanie Townsend, MT(ASCP)SBB

[jcdayaz]

WOW!!! I'm so far out of my league here it's scary!!!!!

[Eagle Eye]

Do you screen units in house or order them from red cross. I believe red cross would not give you antigen negative unit for sickle cell patient when patient hasn't made those antibodies. Particularly negative for 4-6 antigen......

[Malcolm Needs ☆]

WOW!!! I'm so far out of my league here it's scary!!!!!

Most Black individuals who are Fy(a-b-) by red cell typing are, in fact, genetically either FYB/FYB or FYB/FY.

Upstream of the Duffy genes is a GATA-1 box that "allows" the Duffy antigens to be expressed on red cells, but many within the Black population have a mutation that prevents the antigens being expressed on red cells, and so they appear as Fy(a-b-).

BUT, they express the Fy( antigen on other tissues, such as brain, colon, endothelium, lung, spleen thyroid, thymus and kidney, and so their immune system does not recognise the Fy( antigen as foreign, and hence they do not make anti-Fyb (or anti-Fy3 come to that).

You can find the explanation under References (at the top of the page, Document Library on the drop-down list, educational material and then find the Powerpoint lecture and accompanying Word document.

Best wishes,

Malcolm

:D:D:D:D

[jcdayaz]

Most Black individuals who are Fy(a-b-) by red cell typing are, in fact, genetically either FYB/FYB or FYB/FY.

Upstream of the Duffy genes is a GATA-1 box that "allows" the Duffy antigens to be expressed on red cells, but many within the Black population have a mutation that prevents the antigens being expressed on red cells, and so they appear as Fy(a-b-).

BUT, they express the Fy( antigen on other tissues, such as brain, colon, endothelium, lung, spleen thyroid, thymus and kidney, and so their immune system does not recognise the Fy( antigen as foreign, and hence they do not make anti-Fyb (or anti-Fy3 come to that.

Best wishes,

Malcolm

:D:D:D:D

I will confess to not knowing this information prior to your post. I will go to references right now and learn it!!! THANK YOU

[Malcolm Needs ☆]

According to Geoff Daniels (and I am NOT about to argue with him!), a similar sort of thing happens amongst the popoulation of Papua New Guinea, but there the "unexpressed" Duffy antigen is Fy(a).

:)

[Townsend]

Do you screen units in house or order them from red cross. I believe red cross would not give you antigen negative unit for sickle cell patient when patient hasn't made those antibodies. Particularly negative for 4-6 antigen......

We actually do both... the units that we need that are "complete" phenotypically similar (Rh, K, Duffy, Kidd, S/s) come from the ARC Reference Lab (we do not have the supply to search for those kinds of units). Most of the Rh and K neg only units are screened in-house. I must admit that it has become very time consuming to provide blood for these patients, but at least none of us are worried about job security!!!

And jcdayaz - you should never feel bad about some of these subjects being "out of your league". We all have our strengths and different experiences; some are Reference Lab specialists, while others come from children's hospitals or community blood banks. It's great to see the wealth of knowledge that the combination can bring to the forum!

Stephanie Townsend, MT(ASCP)SBB

[L106]

I will confess to not knowing this information prior to your post. I will go to references right now and learn it!!! THANK YOU

Thanks, jcdayaz, for making me feel not so lonely! (I didn't even know that I didn't know this!) I've got to get cracking on those Powerpoint lectures in the Reference section!

Donna

[Malcolm Needs ☆]

And jcdayaz - you should never feel bad about some of these subjects being "out of your league". We all have our strengths and different experiences; some are Reference Lab specialists, while others come from children's hospitals or community blood banks. It's great to see the wealth of knowledge that the combination can bring to the forum!

Stephanie Townsend, MT(ASCP)SBB

Hear! Hear!

I'm always learning things on this site.

It's a fantastic fount of knowledge.

:D:D:D:D

[PAWHITTECAR]

We do a red cell exchange to prevent sickle crisis in out known patients. They first evaluate the pateints to determine which are at increased risk for stroke (I do not know how) and then set them up on a schedule of usually monthly exchanges. They do this with an apheresis unit so it is basically like when you donate a unit of platelets and they give you your cells back but in the case of the sickle cell exchange they spin the blood, replace the red cells, and give the plasma portion back with new sickle negative cells.

It really works well in that we are seeing far fewer patients present in the ER with sickle crisis. They can do this on the really young patients (we have a couple of 3 year olds) all the way up to adults.