frozen red cells and irradiation

[kate murphy]

I have 2 questions that I have not been able to find any references for:

1. are there enough viable lymphocytes in deglyc'd units to warrant irradiating the unit?

2. damage to red cell membranes from irradiation is well known - can these units then be frozen and deglyc'd?

We are moving to a total irradiated red cell inventory. My medical director and I are unsure what to do with our large-ish frozen inventory.

[Mary**]

Wow! Totally irradiated.

[Malcolm Needs ☆]

I have 2 questions that I have not been able to find any references for:

1. are there enough viable lymphocytes in deglyc'd units to warrant irradiating the unit?

2. damage to red cell membranes from irradiation is well known - can these units then be frozen and deglyc'd?

We are moving to a total irradiated red cell inventory. My medical director and I are unsure what to do with our large-ish frozen inventory.

I'll be honest with you, I don't know the answer (but I am going to find out from the National Frozen Blood Bank early next week).

That having been said, I would not have thought that there were sufficient viable T lymphocytes to cause GvHD in frozen red cells. As I understand it, the red cells are thoroughly washed before addition of the freezing mixture, and then thoroughly washed again whe they are thawed and reconstituted.

Therefore, I would have thought that irradiation after cryopreservation was a step too far (whether I am right or not we will find out next week, and, even if I am, whether the FDA would agree is another matter).

This is a very different process to the cryopreservation of stem cells when, of course, the white cells are deliberately kept viable.

We have a couple of cancer hospitals in our area, Anna, that will only accept irradiated blood and cellular blood components, just in case there are viable T lymphocytes present and these are transfused to immunocompromised patients; and this is despite universal leukodepletion this side of the pond. It's a pain, to be frank!

[kate murphy]

We're joking that our inventory will be "totally rad"!

Thanks Malcolm - that's what our thoughts were as well.

Oddly enough, the FDA is rather vague about irradiation, there's no definitive standards.

What do you think about freezing red cells that had been already irradiated? I agree that the washing steps would remove excess potassium, but I can find no literature about "damaged" red cell membranes going through the glycerolization, freezing, and deglyc'g steps. Is there more damage to the red cells, and do we end up with a therapeutic product?

[Malcolm Needs ☆]

We're joking that our inventory will be "totally rad"!

Thanks Malcolm - that's what our thoughts were as well.

Oddly enough, the FDA is rather vague about irradiation, there's no definitive standards.

What do you think about freezing red cells that had been already irradiated? I agree that the washing steps would remove excess potassium, but I can find no literature about "damaged" red cell membranes going through the glycerolization, freezing, and deglyc'g steps. Is there more damage to the red cells, and do we end up with a therapeutic product?

Once again, I'm not sure and will find out, but, certainly, red cells from sickle cell disease patients do not freeze, thaw and reconsitute very well (however, rare their blood group may be)!

[Malcolm Needs ☆]

Right then Kate, I've finished doing my ferreting around, and here is the answer.

From the BCSH draft irradiation guidelines 2009:

"TA-GVHD has not been described following transfusion of frozen deglycerolized cells, which are in any case thoroughly washed free of leucocytes after thawing."

Recommendation. For at-risk patients, all red cell, platelet and granulocyte transfusions should be irradiated, except cryopreserved red cells after deglycerolization. It is not necessary to irradiate fresh frozen plasma, cryoprecipitate or fractionated plasma products."

So it would appear that, more by luck than judgement, I was correct!

:):)

[kate murphy]

Thanks Malcolm! Nice to have our thoughts validated.

[SMW]

1. Yes

2. Yes

See Suda BA, Leitman SF, Davey, RJ. Characteristics of red cells irradiated and subsequently frozen for long-term storage. Transfusion 1993 Vol.33, Issue 5, 389-392.

[eric1980]

1. Yes

2. Yes

See Suda BA, Leitman SF, Davey, RJ. Characteristics of red cells irradiated and subsequently frozen for long-term storage. Transfusion 1993 Vol.33, Issue 5, 389-392.

I've copied and pasted the abstract of this article over here...

Characteristics of red cells irradiated and subsequently frozen for long-term storage

BA Suda; SF Leitman; RJ DaveyDepartment of Transfusion Medicine, National Institutes of Health, Bethesda, Maryland.

Copyright

ABSTRACT

Irradiation of blood components eliminates the risk of transfusion- associated graft-versus-host disease. Freezing directed or rare red cell units that are irradiated but not transfused would facilitate inventory management and would increase the transfusion options for the involved patients. However, no studies have been performed to evaluate whether prestorage irradiation damages subsequently frozen red cells. Ten normal volunteers donated a unit of whole blood on two separate occasions. One unit was irradiated with 15 Gy (1500 rad), stored at 4 degrees C for 6 days, and then frozen and stored at -75 degrees C for 56 days. The other unit (control) was similarly stored but was not irradiated. Aliquots of the units were tested on Day 0 and Day 6 and, after deglycerolization, on Day 62. Comparison of means and changes in means showed no significant differences in red cell ATP, 2,3 DPG, or supernatant hemoglobin and glucose in control and irradiated units. The difference in the change in supernatant potassium from Day 0 to Day 6 in control and irradiated units was significant (1.5 to 28.6 mmol/L vs. 1.5 to 48.5 mmol/L: p < 0.0001). Irradiation did not cause significant differences in postdeglycerolization red cell recovery (control, 84.5% vs. irradiated, 81.2%) or in 24-hour posttransfusion autologous red cell survival (control, 91.1% vs. irradiated, 90.9%). Red cells can be irradiated, stored at 4 degrees C for 6 days, and subsequently frozen with no increase in detectable damage as compared to controls that were not irradiated.

So it means that there are no significant differences between deglycerolised irridiated and non-irridiated RBCs?