Modify Heart Policy for Intended Incompatible Blood Type (ABOi) Offers to Pediatric Candidates
At a glance
Currently, pediatric heart candidates who are registered on the waiting list as Status 1a or 1b before they turn two years old have the option to accept hearts from donors whose blood type is incompatible with their own. If they are less than one year old at the time of the match run, they are classified as a primary blood type match per OPTN policy. If they are at least one year old at the time of the match run, they can be a secondary blood type match if they meet certain isohemagglutinin titer values and haven’t received treatments that could lower their titer values. Pediatric lung candidates also have similar requirements.
- Allow all pediatric heart, heart-lung, and/or lung candidates registered before turning age 18 the option to accept an ABO-incompatible heart, heart-lung, and/or lung
- Will now include pediatric heart Status 2 candidates and pediatric priority 2 lung candidates
- Will change eligibility from candidates registered before turning two to candidates registered before turning 18
- What it's expected to do
- Allow more flexibility for transplant programs when caring for pediatric heart, heart-lung, and/or lung candidates
- Increase access to heart and lung offers for pediatric candidates who are able to accept an ABO-incompatible organ
- Improve waitlist mortality among pediatric heart candidates
- What it won't do
- Require pediatric heart or lung patients to accept an ABO-incompatible organ
- Change the existing heart ABO-incompatible policy requirements regarding isohemagglutinin titers or treatments that could reduce titers
- Change policy for ABO-compatible heart, lung, or heart-lung transplants
Terms to know
- ABO-incompatible: When people who have one blood type receive blood from someone with a different blood type, this may cause their immune system to react.
- Isohemagglutinin: The naturally occurring antibodies in the ABO blood group system. These antibodies are what can cause a blood type to be rejected by the body.
- Match Run: A computerized ranking of transplant candidates based upon donor and candidate medical compatibility and criteria defined in OPTN policies.
Region 6 | 03/15/2023
1 strongly support, 7 support, 5 neutral/abstain, 0 oppose, 0 strongly oppose
Region 11 | 03/15/2023
6 strongly support, 8 support, 10 neutral/abstain, 0 oppose, 0 strongly oppose
Joseph Hillenburg | 03/14/2023
As the parent of an ABO-incompatible heart recipient, I am in full support of this proposal, including the added comments provided by Transplant Families.
I was struck by the opposition vote by a Region 7 member (my own region), and am curious what reasons one might have for not supporting the policy.
Transplant Families | 03/14/2023
Transplant Families, an OPTN member, is an advocacy and outreach organization which advocates and represents pediatric recipients and their caregivers. Transplant Families supports the proposal, with the following comments:
* The policy should not rank ABOi and ABOc children differently in terms of primary allocation order. If titers permit, a heart should go to the first available child.
* We are disappointed that adults who may have received an ABOi heart as a child are not eligible for ABOi retransplantation. While this case is currently very rare (due to ages of the recipients), it will become increasingly common over the next several years. We are aware that this was part of the initial policy proposal, and strongly disagree with its removal, We ask that the Heart committee consider its inclusion in adult policy, no later than the implementation of Continuous Distribution.
* Consider allowing for newer and more advanced assays.
* Are there additional data points that could be collected to allow research groups like PHTS and ISHLT to continue research in this area?
* We otherwise also agree with the comments delivered by Drs. Daly, Feingold, Spinner, and Zuckerman.
Ultimately, we would like to see the pediatric heart allocation system in the United States keep closer pace with peer systems in other countries. Thank you to the Heart Committee for moving this forward, and especially to the Pediatric Committee for initiating the discussion. We know that many heart kids will benefit as as result.
Association of Organ Procurement Organizations | 03/14/2023
Thank you for the opportunity to submit comments on the Organ Procurement and Transportation Network’s (OPTN’s) policy development process on behalf of the Association of Organ Procurement Organizations (AOPO). AOPO collectively represents 48 federally designated, non-profit Organ Procurement Organizations (OPOs) in the United States, which together serve millions of Americans. As an organization, AOPO is dedicated to providing education, information sharing, research, technical assistance, and collaboration with OPOs, other stakeholders, and federal agencies to continue this nation’s world-leading transplantation rates while consistently improving towards the singular goal of saving as many lives as possible. We offer the following comments for your consideration:
AOPO is pleased to offer our support for the proposal “Modify Heart Policy for Intended Incompatible Blood Type (ABOi) Offers to Pediatric Candidates.”
The goal of this proposal, to expand access for all pediatric heart and lung candidates is consistent with our member’s mission of saving more lives through organ donation and transplantation. Expanding the age limit for candidates to accept an ABO-incompatible heart, heart-lung, and/or lung from 2 years to up to 18 years, will increase pediatric candidates’ access to heart and lung transplant and impact the pediatric mortality rate.
The policy will have no direct implications on the operational practices of OPOs. AOPO members will continue to adhere to the allocation guidelines established by the OPTN.
Donor Network of Arizona | 03/14/2023
Donor Network of Arizona supports this proposal.
NATCO | 03/14/2023
NATCO appreciates the efforts of the Heart committee in preparing this proposal. NATCO strongly supports this proposal to increase the cutoff age for ABOi listing from < 2 years of age to < 18 years of age and to allow status 2 patients to be eligible for ABOi listing as well. NATCO feels this will expand access to our pediatric heart candidates and decrease wait list times and mortality. NATCO members support removing the 30-day repeat titer requirements and feel the maintenance of 1:16 as a titer cutoff for eligibility should be left to the discretion of individual transplant programs. NATCO members feel that during the evaluation and listing phases of transplant eligibility would be a great time to make candidates, their families and their caregivers aware of the opportunities to accept ABOi donor hearts and lungs.
Joe DiMaggio Children's Hospital | 03/14/2023
Expanding access to all pediatric candidates who are <18 yrs irrespective of status (1A, 1B and 2), and maintaining qualifying titers as high as 1:16, will potentially be of positive impact if we choose to exercise this option on behalf of our patients. The main impact will be on the blood bank who will need to provide adequate “naïve” plasma and RBCs for much larger patients to accommodate the necessary exchange transfusion antibody wash-out at the time of transplant. Alternative forms of targeted blood group antibody removal (immunoadsorption column apheresis) are not yet routinely available in the US.
Region 7 | 03/14/2023
4 strongly support, 7 support, 2 neutral/abstain, 1 oppose, 0 strongly oppose
A member commented that this is fair and sensible and if it will decrease infant mortality, it should move forward with close monitoring.
Gift of Life Michigan | 03/14/2023
We support the goal to expand access to all pediatric heart and lung candidates is consistent with our members’ mission of saving more lives through organ donation and transplantation. By expanding the age limit of the option to accept an ABO-incompatible heart, heart-lung, and/or lung from 2 years to up to 18 years, this policy holds promise to address the high mortality rate of children in need of a transplant and increase access to heart and lung transplantation for pediatric candidates.
The policy will have no direct implications on the operational practices of OPOs. Our members will continue to adhere to the allocation guidelines established by the OPTN.
Region 1 | 03/14/2023
1 strongly support, 5 support, 4 neutral/abstain, 0 oppose, 0 strongly oppose
Region 1 supported this proposal with no comments.
American Society of Transplant Surgeons | 03/14/2023
What factors or considerations are preventing transplant programs and/or candidates and candidate support teams from indicating a willingness to accept an intended incompatible blood type donor heart or heart-lungs? A survey of pediatric transplant cardiologists/pulmonologists and surgeons would be encouraged to answer this question. The ASTS suspects a lack of outcome data would be the reason. What steps can be taken to improve the use of this policy, even if no changes are made? The ASTS encourages OPTN/UNOS to gather outcome data and disseminate it, along with disseminating any policy changes. We encourage outcome data for ABOi transplants to be made available in the proposal. Are candidates who are registered on the heart waiting list put at unnecessary risk by the proposed changes to the eligibility criteria for receiving a heart from an intended blood group incompatible deceased donor? The ASTS does not think this will be a concern if there are steps involving an intentional acceptance of the incompatible donor. To what extent might adult heart candidates be impacted by increasing pediatric candidates’ access to intended incompatible blood type donor hearts and heart-lungs? The ASTS does not think adult heart candidates would be substantially impacted by this change. Are pediatric candidates who are registered on the lung waiting list put at unnecessary risk by the proposed changes to the eligibility criteria for receiving a heart-lung from an intended blood group incompatible deceased donor? The ASTS does not think this will be a concern if there are steps involving an intentional acceptance of the incompatible donor. To our knowledge the data for ABO incompatible heart-lung, lung transplant is extremely limited. The proposal will expand eligibility to receive a heart from an intended blood group incompatible deceased donor to pediatric heart status 2 candidates. Is that appropriate? Should only the pediatric heart status 1A and status 2A candidates continue to be eligible? Why or why not? Should a pediatric candidate be hospitalized at the time of listing to qualify for eligibility? The availability and use of such organs is quite limited. It would be reasonable to remove restrictions based on status and then audit use of organs to determine its impact. The impact would likely be small. Policy 6.6.B: Eligibility for Intended Blood Group Incompatible Offers for Deceased Donor Hearts currently states that a “candidate must not have received treatments that may have reduced isohemagglutinin titers to 1:16 or less within 30 days of when this blood sample was collected.” The proposal maintains the timeframe of 30 days from when the blood sample was collected for candidates with titers of 1:16 or less. Is 30 days the appropriate timeframe? Why or why not? If not, what is the appropriate timeframe? The ASTS recommends consulting with experts in this particular area to answer this question. Are there opportunities to make pediatric candidates, their families, and their caregivers aware of the opportunity to accept ABOi donor hearts and lungs? Knowledge of these proposals should be disseminated amongst recipients and transplant centers to the extent possible. Opportunity might lie in pediatric patient support groups.
American Society of Transplantation | 03/14/2023
The American Society of Transplantation (AST) supports the proposal, “Modify Heart Policy for Intended Incompatible Blood Type (ABOi) Offers to Pediatric Candidates.” Increasing the age limit for ABOi eligibility from younger than 2 years to younger than 18 years at the time of listing is expected to expand access to heart transplantation in the older pediatric age group; however, there is an opportunity to consider how the proposal will interact with primary and secondary blood group allocation. In particular, consider a patient who is blood type A who is listed as ABOi heart transplant prior to 1 year of age. Per the current allocation policy, an ABOi eligible candidate younger than 1 year old is a primary candidate for A and O hearts. Upon the candidate’s first birthday, they are then classified as a primary candidate for A blood group donors and secondary for O blood group donors. While this is intended to balance the inequities for O blood group recipients, this change on the pediatric candidate’s first birthday decreases the likelihood these one year and older pediatric heart candidates will receive an appropriate, timely donor heart offer. To address this issue, the AST recommends modifying this proposal to increase the upper age limit of primary blood type classification for intended ABOi candidates to at least 2 years old given the waiting list mortality and morbidity in the younger than 2 years old cohort.
American Society for Histocompatibility and Immunogenetics (ASHI) | 03/14/2023
This proposal is not pertinent to ASHI or its members.
OPTN Lung Transplantation Committee | 03/14/2023
The OPTN Lung Transplantation Committee thanks the OPTN Heart Transplantation Committee for their proposal and the opportunity to provide feedback. The Committee supports this proposal. Members commented that they do not expect the rate of blood type incompatible (ABOi) lung transplants to increase, but they are in support of leaving this up to clinical discretion. They also agree this will increase transplants for pediatric heart candidates and the data supports this proposal.
Region 8 | 03/14/2023
3 strongly support, 9 support, 8 neutral/abstain, 0 oppose, 0 strongly oppose
Region 8 supports this proposal and an attendee recommend the committee add tracking non-utilization of lungs to the post-implementation monitoring. Another attendee commented that this proposal makes perfect sense.
OPTN Transplant Coordinators Committee | 03/14/2023
The Transplant Coordinators Committee thanks the Heart Transplantation Committee for their work on this proposal.
A member commented that this proposal is prioritizing a vulnerable population with the goal to decrease waitlist mortality and providing access to transplants. Another member, who is a pediatric heart coordinator, noted that this proposal is great and supports the science around transplanting patients using intended incompatible blood type offers for pediatric candidates.
Another member from a pediatric transplant center added that this proposal will be great for her patients.
Kevin Daly | 03/13/2023
I strongly support the proposal entitled “Modify Heart Policy for Intended Incompatible Blood Type (ABOi) Offers to Pediatric Candidates.” This is a timely change to heart allocation policy that allows for better alignment of OPTN policy with the science of ABOi heart transplantation. For those who may benefit, this policy cannot come soon enough. The chance of dying remains too high for those children in need of a heart transplant and I am most appreciative that UNOS and the OPTN Executive Committee will consider expedited approval of key portions of this policy proposal. This is truly a patient centric approach to organ allocation policy.
One area of the policy that could be improved is the change in allocation of ABOi donors from primary offers to secondary offers when candidates reach 1 year of age. There is not a clear biological reason for why 1 year of age would be tied to a change in the allocation order. In our practice we have seen patients receive a decrease in offer frequency after turning 1 year of age. This results in a disadvantage to O blood type recipients in particular. This occurs even when there has been no change in isohemagglutinin titer, the best available biomarker to determine the safety of ABOi heart transplant. Since it would be better to link this change in allocation order to a relevant biomarker AND it is not clear what isohemagglutinin titer cutoff should lead to a change from primary to secondary allocation order, I would recommend that all highest urgency (Status 1A) candidates remain eligible for primary allocation of ABOi offers regardless of age. One could consider changing from primary to secondary allocation order at 1 year of age for less urgent (Status 1B and Status 2) candidates. I would be equally accepting of a policy that allowed all patients who remain eligible for ABOi heart transplant under policy to be eligible for primary allocation of ABOi offers regardless of age and status.
This prior point does raise the question of how to try to balance the opportunity for a given heart transplant candidate such that each candidate has equal access to a donor heart. While the availability of ABOi for our youngest candidates helps balance that opportunity, the biological constraint of ABO compatibility does eventually become relevant for older children and adults. I think that it is of vital importance to simulate whether the current ABOc primary/secondary allocation order remains the optimal way to offer organs. We recently demonstrated that children who are blood type O continue to wait the longest prior to transplantation compared to children from other blood groups. (Williams, R. J., et al. (2022). "Pediatric heart transplant waiting times in the United States since the 2016 allocation policy change." Am J Transplant 22(3): 833-842.) As continuous distribution of donor organs is implemented for heart transplant recipients, an attempt should be made to rebalance the opportunity for candidates to receive donor offers with regard to both blood group compatibility AND HLA compatibility. By this I mean that allocation policy should attempt, as much as possible, to ensure that the opportunity for heart transplantation is not tied to blood type or anti-HLA sensitization.
In response to the other questions posed in the policy proposal, I do not feel that candidates are put at unnecessary risk by the proposed changes. I think that there will be minimal impact on adult heart candidates, largely because the number of older re-transplant candidates will remain small. Any potential inequity in organ offers could be mitigated under a continuous distribution framework if blood type is also considered as part of that allocation policy. I do believe that Status 2 candidates should have the ability to receive an ABOi heart transplant. ABOi heart transplant has been demonstrated to have equal outcomes for ABOc heart transplant. Offering ABOi transplant to Status 2 candidates is not expected to worsen post-transplant outcomes.
Rebecca Ameduri | 03/13/2023
I strongly support this proposal to increase the cutoff age for ABOi listing from < 2 years of age to < 18 years of age and to allow status 2 patients to be eligible for ABOi listing. Thank you to everyone who put significant effort into preparing this proposal. I strongly believe our patients and families will benefit greatly from these proposed changes.
International Society for Heart and Lung Transplantation | 03/10/2023
ISHLT Supports this proposal with the following comments:
- Expanding access to ABO incompatible (ABOi) transplant for heart transplant young children beyond titers of 1:16 and 2 years of age is overdue. Current literature provides evidence for equal outcomes in children beyond current (arbitrary) limits with evidence of partially better outcomes (lower rate of rejection and infection) in young children after ABOi than ABO compatible (ABOc) transplantation. ISHLT supports liberalizing the approach to allow centers to include lower urgency listed patients, generally higher titers (standard approach in Canada up to 1:32 with no mandated limits) and selected patients of higher age and/or titers.
- In heart transplant, limiting the applicability of ABOi to higher risk patients and the ABOc allocation policy pursued until 2016 in the US disadvantages patients given the shorter wait times (with associated risk of pre-transplant deterioration and complications) especially for blood group O recipients clearly evidenced in recent publications in the US and other jurisdictions.
- The evidence in pediatric lung and heart lung transplantation is much more limited with very little clinical data published or shared. Liberalizing the policy to include these patients will allow centers to proceed after individual consideration and thereby fortify the evidence basis for this approach to be safe. While there is no immunological reason to assume ABOi lung or heart lung transplant would be less safe than heart alone in young children, at present the available clinical data does not allow a clear conclusion on safety or long-term outcomes for these patients.
- We recommend the addition of lung non-utilization rates as well as post-transplant survival for ABOi vs ABOc lung and heart-lung recipients to the post-implementation monitoring.
MUSC | 03/10/2023
Enough evidence to extend the age restriction
Christina Brodie | 03/09/2023
As a mother of a pediatric heart transplant recipient, specifically an ABOi recipient, we (as a family) strongly support this proposal. The gift of receiving an ABOi heart transplant allowed our child years of life, love and adventure. Without the allowance our child would have never survived the long wait to transplant, even with the aid of a VAD. This proposal would allow children like my own the option of receiving their gift before it is too late; right now the wait is long and dangerous for these children. Providing additional options for providers, patients and parents shows hope and light in a time of panic and despair. Our child is a silly, wonderful, an amazing kid all because of the ability to receive an ABOi heart, this should be the hope for all children on the transplant waiting list.
Region 9 | 03/09/2023
2 strongly support, 8 support, 6 neutral/abstain, 0 oppose, 0 strongly oppose
Region 9 supported this proposal with no comments.
Alfred Asante-Korang | 03/08/2023
While I favor expanding the age range for ABO-I candidates to <18 yrs at time of listing, I recommend following the same stepwise approach as in UK and Canada by initially expanding to 5 years of age, and based on good comparative outcomes, expand to 18 yrs of age over a period of 2 years. Individual centers would decide with the parents’ consent and the child’s assent what cut-off titers they are comfortable with.
Allow status 2 candidates to enjoy the same access to ABO-I transplant as Status 1 patients.
In addition, as readily available in Europe and Canada, centers should be encouraged to obtain immunoadsorption columns to facilitate urgent and safe antibody removal
Change the existing heart ABO-I policy requirements regarding isohemagglutinin titers or treatments that could reduce titers, since these treatments may be beneficial to the candidate.
Swati Sehgal | 03/08/2023
The data available in the area of ABOi heart transplant is encouraging and therefore I support the proposed modifications.
Region 5 | 03/03/2023
9 strongly support, 13 support, 7 neutral/abstain, 0 oppose, 0 strongly oppose
Region 5 supports the proposal. A member commented that this proposal will better align pediatric heart allocation policy with current evidence and allow centers to choose more appropriate offers for pediatric candidates waiting for a heart transplant. The member further noted that the proposal has the potential to decrease pediatric waitlist mortality. A member suggested there should be follow up monitoring to see if the proposal causes an increase in ABOi pediatric transplants and transplant outcomes.
Carol Wittlieb-Weber | 02/28/2023
I would like to recognize the hard work of the committees involved with this very important proposal. Wait times remain long for our infants and toddlers awaiting heart transplant, which puts these patients at risk for waitlist mortality. Further, MCS support strategies for infants and toddlers are challenging particularly with complex anatomy. Therefore, it is crucial that we adjust allocation policies to safely allow our smallest patients more expanded access to donors. I strongly support the proposal to increase the cut-off age for ABOi listing from < 2 yrs to < 18 yrs, and to allow status 2 patients to be eligible for ABOi listing as well. I would also support increasing the cut-off age from < 1 yr to < 2 yrs for primary allocation of an ABOi heart given the relatively high waitlist mortality in this age group. Finally, I think we now know that the titer cutoff of < 1:16 is arbitrary and would consider removing this to allow for individual centers to determine eligibility for ABOi based on their own titer cut-off and experience. Thank you for the hard work put into this proposal.
Region 10 | 02/28/2023
5 strongly support, 9 support, 8 neutral/abstain, 0 oppose, 0 strongly oppose
Region 3 | 02/24/2023
6 strongly support, 8 support, 3 neutral/abstain, 0 oppose, 0 strongly oppose
Brian Feingold | 02/24/2023
I strongly support the initiative to expand access to ABO incompatible heart transplantation. I believe this policy proposal would be enhanced by removal of the requirement for repeated isohemagglutinin titers while listed and the requirement to not have received antibody depleting therapies in the prior 30 days of the posted titer. Reporting titers at listing and at transplant and tracking outcomes of patients who receive ABOi transplant (including titers at/near outcomes) will be important to understanding this proposed practice change.
Joseph Spinner | 02/23/2023
I strongly support this proposal to increase the cutoff age for ABOi listing from < 2 years of age to < 18 years of age and to allow status 2 patients to be eligible for ABOi listing. Thank you to everyone who put significant effort into preparing this proposal. I strongly believe our patients and families will benefit greatly from these proposed changes. My comments are: 1) I would support increasing the cutoff age from < 1 year to < 2 years for primary allocation of an ABOi heart. There is still high waitlist mortality for children with congenital heart disease between 1 – 2 years of age who may not have ideal mechanical circulatory support options, and they should not be at a disadvantage. 2) I agree with frequent monitoring of isohemagglutinin titers while awaiting transplant. However, I believe that reporting values every 30 days is an unnecessary administrative and logistical burden. The 30-day timeframe is probably somewhat arbitrary, and this proposal may significantly increase (hopefully) the number of possible recipients to receive an ABOi transplant. Most status 2 patients are outpatients. Requiring labs on each of these patients every 30 days to maintain ABOi listing could create an unnecessary burden for these patients and their families as well as logistical issues for transplant centers. We can still require updated isohemagglutinin titers within a certain timeframe before transplant without requiring they be checked as frequently as every 30 days.
OPTN Pediatric Transplantation Committee | 02/23/2023
The OPTN Pediatric Transplantation Committee thanks the Heart Committee for presenting this topic and for working to bring this proposal into policy. The Committee is strongly supportive of the proposal and believes that it will have positive impact on expanding heart transplant access for children and decreasing wait time, as well as providing centers with more flexibility in determining what is appropriate for their patients. The Committee felt it was important to note that although they are highly supportive of the proposal, eligibility for ABOi transplantation does not always lead to changes in practice. Changes to ABOi transplant rates stratified by age and other metrics should be closely monitored in the post-implementation reports.
The Committee notes that centers with high transplant volume may be quicker to adopt this policy than lower-volume centers that may have barriers to ABOi listing. The Committee also suggests that UNOS or a collaborative consider the development of practical clinical information and educational materials -about ABOi transplants in Canada and the UK to help guide decision making for both families and providers. We suggest that the Heart Committee consider whether to centers should be encouraged or even required to disclose the option for an ABOi transplant to families as part of the evaluation or listing process. The Committee is somewhat hesitant regarding the 30-day repeat titer requirement in the proposal and notes that the testing can be relatively imprecise and variable. Additionally, strict and frequent titer requirements could present a barrier to centers and may pose a safety risk to very young children with lower blood volumes. In summary, the Committee is supportive of the proposal and suggests that the Heart Committee consider these key issues moving forward.
Children's Cardiomyopathy Foundation | 02/23/2023
The Children's Cardiomyopathy Foundation (CCF) supports the proposed policy changes to allow for ABO-i transplants among patients being listed prior to age 18 including status 2 patients. Offering increased flexibility and access to transplantation, while allowing for center discretion and interaction with families to address their child’s individual medical needs, will help to address waitlist mortality and lack of available organs among the pediatric population. Through the policy's proposed expanded ABO-i transplant criteria, it is our hope that mortality rates and outcomes for pediatric heart transplant candidates/recipients will ultimately improve.
Anonymous | 02/23/2023
I fully support this proposal. Access to donor organs is already incredibly difficult for pediatric transplant candidates. Increasing the cutoff from age 2 to age 18, as well as including those considered status 2, will make a great difference.
Region 2 | 02/21/2023
6 strongly support, 13 support, 6 neutral/abstain, 0 oppose, 0 strongly oppose
This was not discussed during the meeting, but OPTN representatives were able to submit comments with their sentiment. One member noted that the proposal is a valuable opportunity to expand the availability of donor organs. Additionally, it will allow research to better understand the pre- and post-transplant ABO antibody profiles, giving further support to the ABO incompatible transplants in older patients.
Region 4 | 02/21/2023
4 strongly support, 14 support, 5 neutral/abstain, 0 oppose, 0 strongly oppose
Rakesh Singh | 02/15/2023
I strongly agree with the proposal to increase the cutoff age for ABOi listing from < 2 yrs to < 18 yrs, and to allow status 2 patients to be eligible for ABOi listing. I would also support increasing cutoff age from < 1 yr to < 2 yrs for primary allocation of an ABOi heart given their relatively high waitlist mortality. Finally, I think the titer cutoff of < 1:16 is arbitrary and would consider removing that to allow for individual centers to determine eligibility for ABOi based on their own titer cutoff. Thanks for all you hard work on this proposal.
Rakesh Singh, MD, MS
Hassenfeld Children's Hospital at NYU
Warren Zuckerman | 02/12/2023
I am in support of the proposed policy changes to intended ABOi offers to pediatric candidates. While I do feel that allowing for center discretion, similar to the treatment of anti-HLA pre-sensitization, is ultimately the way to go, I think that starting with the removal of 2 years of age as an arbitrary cutoff for such offers is a solid start. It will be most crucial to follow the proposed metrics that will be evaluated at scheduled time points following this policy change. Maintenance of 1:16 as a titer cutoff for eligibility is somewhat arbitrary as well, but this proposal will allow for the accumulation of ABOi transplant data not previously available, and the proposal also demonstrates a willingness of the thoracic transplant community to re-evaluate and provide for the best possible overall outcomes in pediatric patients. Finally, I know that this proposal required years of dedication and collaboration between the Pediatric Committee and the Heart Transplantation Committee, and this collaborative effort should be applauded.
Yuk Law | 02/10/2023
I favor treating ABO-I candidates in the pediatric age range (at time of transplant, not listing), the same as candidates sensitized to HLA antigens. Let individual centers decide with the families consent. That means allow status 2 to have same access to ABO-I transplant. Allow desensitization, meaning not have to enter titers or timing to exposure to plasma removal/desensitization protocols. Over time, we will have a better idea of what is too high a titer under various clinical scenarios. Thank you.
Steven Weitzen | 01/29/2023
If this will increase likelihood of better outcomes for the pediatric community, I believe it should move forward.
Melanie Everitt | 01/25/2023
Supportive of increasing the age eligible for ABOi to <18 yrs. I also support increasing the age for primary allocation from <1 yr for primary offers to <2 yrs for intended ABOi hearts given the waitlist mortality in the <2 yr old cohort.
Deipanjan Nandi | 01/23/2023
Anything that increases the ability to transplant these smaller children should be considered, including this expansion of ABO(i) potential transplants, and I am strongly in favor. While I recognize that the historical data would imply that 1:16 would not be widely sought in the older children transplants, why not leave that a question for individual programs? Some sites choose to accept transplant across known HLA types, and the intricacies of brief rises in PRA and isoheme titers just after a surgical palliation or VAD are best known by individual sites.