Transfusion Post Allogeneic Stem Cell Transplant

Robert C. Skeate, MD MS

Overview

• Discuss stem cell sources for transplant-Advantages and disadvantages-Double cord blood transplants and why they are done

• That ABO type is not often a consideration• Consequences of ABO mismatch• Natural history of ABO type post transplant• Choosing blood products post transplant• Investigation of increasing O neg blood use at

the medical center where I previously worked

Options for Stem Cell Transplant

• Obtain stem cells directly from bone marrow• Obtained via invasive procedure in the

operating room• Are able to collect all the cells you need

Options for Stem Cell Transplant

• Peripheral blood stem cells• Very often can obtain needed cell dose

Options for Stem Cell Transplant

• Cord Blood• Limiting factor is small cell dose

Choosing a Stem Cell Product

• Most important parameter: HLA match-Prefer a matched sibling donor (30%)-Want a “6 out of 6” match-HLA-A, HLA-B, and HLA-DR genes-Typically use PBSC, but can do marrow if unable to get enough cells via apheresis

• No matched sibling?-Unrelated HLA matched donor (30%)-Not enough donors (HLA type and race)-Many month delay before transplant

Majhail, N, Brunstein, C, & Wagner, J. Double umbilical cord blood transplantation. Current Opinion in Immunology 2006; 18:571–575

Choosing a Stem Cell Product

• HLA-matched unrelated cord blood• Cell dose needed = (TNC) 2.5 X 107/ Kg• Only 25% of adults are small enough given

typical cell doses in cord blood units• Can increase the dose by using two cord

blood units (double cord blood transplant)• Sustained hematopoiesis after DUCBT is

usually from one donor• Increasingly common at U of MN

Majhail, N, Brunstein, C, & Wagner, J. Double umbilical cord blood transplantation. Current Opinion in Immunology 2006; 18:571–575

Advantages of Cord Blood

• Ease of procurement• Absence of risk for donors• Decrease likelihood of infections (CMV)• Store HLA-typed units frozen for rapid use

Cord compared to unrelated matched PBSC• Decreased graft-vs-host disease• Similar long term survival• Less well HLA-matched have similar outcome

Gluckman, E. History of cord blood transplantation. Bone Marrow Transplantation 2009; 44:621–626

Bensinger, W, and Storb, R. Allogeneic peripheral blood stem cell transplant. Rev Clin Exp Hematol 2001; 5(2):67-86

Haspel, R & Ballen, K. Double cord blood transplants: filling a niche? Stem Cell Rev 2006; 2(2):81-6

Brunstein, C & Laughlin, MJ. Extending cord blood transplant to adults: dealing with problems and results overall. Semin Hematol 2010; 47(1):86-96

What Parameter Not Considered?

• Donor and recipient ABO type• Recipients become donor ABO type over time

so one would think this would have an impact• 25% or so are mismatched for ABO

• ABO mismatch does not impact:-Overall graft failure-Graft vs. host disease-Survival

Yazer, M. & Triulzi, D Immune hemolysis following ABO mismatched stem cell or solid organ transplantation. Current Opinion in Hematology 2007, 14:664–670

Consequences to ABO Mismatch

• There is a downside to ABO mismatch• Antibodies stay around for many weeks post-

transplant• Destroy red cells and precursors

1. Delayed red cell engraftment

2. Increased RBC transfusion requirements

3.Pure red cell aplasia

• Post-transplant hemolysis

Consequences to ABO Mismatch

• Delayed RBC engraftment:41 days for mismatched20 days for matched

• Pure red cell aplasia (Not graft failure?)• Recipients engrafts with white cells and

platelets but has no red cell production• ABO antibodies destroy red cell precursors• Frequency 8 - 38% of mismatched

Yazer, M. & Triulzi, D Immune hemolysis following ABO mismatched stem cell or solid organ transplantation. Current Opinion in Hematology 2007, 14:664–670

Post-Transplant Hemolysis

Example: Recipient A Donor B• Acute hemolysis of the B red cells in the stem

cell product by the recipient’s anti-B• Subacute hemolysis of recipient’s A red cells

due to anti-A from infused donor lymphocytes (passenger lymphocyte syndrome)

• Delayed hemolysis of recipient-type A red cells as the donor immune system engrafts

• Do not want to potentiate this by transfusing mismatched red cells

Post-Transplant Hemolysis

Petz, L. Immune hemolysis associated with transplantation. Seminars in Hematology 2005; 42:145-155

ABO Type Post-Transplant

Over weeks to months, recipient develops

donor hematopoiesis and immune function• Recipient red cell type at first

– Slowly transitions to donor type– Will have mixed field in the transition

• Recipient back type at first (anti-A and/or B)– Is often weak due to chemotherapy– Slow transition to donor back type– Often is weak, incomplete, or not present

• Transfused products can obscure transition

Isoagglutinins and RBC Engraftment

• Comparison of RBC engraftment to determine if preparative regimen matters

• Myeloablative (SCT) PBSC transplant• Non-myeloablative (NST) PBSC transplant• January 1997 - May 2000 at NIH• Groups were concurrent, consecutive

patients with HLA matched family members• Major ABO mismatch patients• 16 NST and 12 SCT (90 day survivors)

Bolan, C. et al. Delayed donor red cell chimerism and pure red cell aplasia following major ABO-incompatible nonmyeloablative hematopoietic stem cell transplantation. Blood. 2001; 98:1687-1694

Time to Donor RBC “Chimerism”

Chimerism = Detect donorRBCs on two consecutiveperipheral blood samples(2 - 5 % donor cells)

Time to absence of Isohemagglutinin

RBC Chimerism and Isohemagglutinin

NST Patients

Red Cell Transfusion Strategy

Yazer, M., Triulzi, D. Immune hemolysis following ABO-mismatched stem cell or solid organ transplantation. Curr Opin Hematol 2007; 14:664–670

Matched

Mismatched

BeforeRemovePlasma

AfterRemovePlasma

Benjamin, R, & Antin, J.Transfusion 1999; 39: 1273-4

292 BMTs

120 BMTs

n = 153

n = 139

1993-1997

Protocol to Switch to Donor-type Blood

Criteria to switch to donor-type blood:

1. Only donor-type red cells present

2. Back-type does not have to match donor to give donor cells*

3. No transfusions for 120 days

4. 100% donor type by molecular studies

*Cells must be compatible with back-type

Monthly Percent O- Use UMMC

(1/03 – 4/07)

Who Was Using O- RBCs?

• We performed a retrospective review of all O- transfusions over a 2 month period

• Noted in particular instances where O- cells given to non-O- patients

O- Units O- Patient Non-O- Patient

105 48 57

O- for Non-O- Patients

Which Transplants Used O-Neg?

• Retrospective review of all allogeneic stem cell transplants over a 5 month period

• Noted transplant type, and whether recipient switched to requiring O or O negative cells post transplant given our policy

• 52 allogeneic transplants• 29 one donor (PBSC, CBT, or BMT)• 23 double cord blood transplants (DCBT)

Which Transplants Used O-Neg?

Transplant N Switched to O Switched to O-

Single Donor

29 6 (21%) 5 (17%)

Double Cord

23 12 (52%) 8 (35%)

Amount of Blood Products Used

McCullough J. Collection and use of stem cells; role of transfusion centers in bone marrow transplantation Vox Sang 1994; 67 (Suppl 3):35-42

Do DCBT Patients Use Blood?

• Looked at red cell use in 41 DCBT patients• Participants in the platelet dosing study• Counted RBCs used by switched to O- group

Used O- Switched RBCs Range Mean Median

23(56%) 15(37%) 407 5-141 27 18

Conclusions

• Half the O- cells used in non-O- patients went to stem cell transplant patients

• Many non-O- DCBT recipients required O- blood post transplant, and they used a substantial number of O- units

• Should alert blood supplier of increased O- blood if implementing a DCBT program

• Current DCBT programs should alert blood supplier when DCBT procedures increase

Follow-up Study

• Wanted to confirm our findings with a higher number of transplants

• Contacted cell therapy lab to see what data were available

• Cell therapy lab has database of all transplants and ABO types (donor / recipient)

• Pulled data from 1st quarter 2005 to 1st quarter 2008 (n = 566 transplants)

• Parameters: transplant type (BMT, PBSC, UCBT, DUCBT), ABO of recipient / donor

Total Transplants Per Quarter

ABO Types / Recipients and Donors

SDT

DUCBT

Mismatches

Red Cells Post-Transplant

Plasma / Platelets Post-Transplant

Results Summary

• The majority (76%) of SDTs require O RBCs• Nearly all DUCBTs (91%) require O RBCs• About a third of DUCBTs require O- RBCs

(34%), which is approximately double the percent for SDTs (18%)

• Approximately 4 times as many DUCBTs (44%) require AB plasma than do SDTs (12%)

• In the majority of cases, choosing matched donors would prevent AB and O- use

Discussion

• Why is using more O RBCs problematic?– Universal donor, but many can only receive O– O units needed for reference lab cases

• Why is using O- RBCs problematic?– Needed for trauma cases / emergency release– Needed for O- females of child bearing age– Needed for neonatal transfusions

• What about AB platelets / plasma?– Surgeons want available for emergency trauma– Plasma exchanges on AB patients– Increased work for the blood bank staff

Implications

• DUCBT becoming the predominant transplant• TRALI mitigation

– Current effort underway to reduce TRALI– Common strategy is to limit female donation– We need female donors to meet CURRENT AB

plasma / platelet demand

• Platelet additive solutions– Currently the Europeans use platelet additive

solutions to remove much of the plasma– DUCBT programs could push this in the US

Implications

• Increased pressure on blood suppliers to not only supply lots of blood, rather to supply the KIND of blood needed for the medical care in the community

• Pressure to make more effort to ABO match stem cell products when available?

• There ARE clinical consequences to ABO mismatch

• There are consequences to the blood supply

Conclusions

• Due to very real clinical concerns (hemolysis, delayed red cell engraftment, pure red cell aplasia), blood that is compatible with recipients & donors is necessary

• DUCBT becoming more common procedure• Multiple blood types involved in DUCBT

procedures results in a requirement for an increased number of rare blood products– 34% require O- RBCs– 44% require AB platelets / plasma

Conclusions

• The majority of the time the need for rare blood is due to choosing an ABO incompatible stem cell product

• DUCBTs put pressure on blood centers to innovate (platelet additive solutions, apheresis, targeted donor programs, engineering of blood products) to meet increasing need for specific blood products

• Pressure on transplant physicians and cell therapy labs to carefully choose products

Blood Types in the US

http://www.givebloodtoday.org/images/blood%20type%20compat%20chart.jpg