Pre-transplant education · Blood type matching
ABO Blood Group Compatibility in Liver Transplantation
Understanding identical, compatible, and incompatible donor–recipient matches.
A different blood type does not always mean an incompatible liver. Standard compatibility, allocation rules, and specialist exceptions must be considered separately. [2] [3] [4]
Image source: Wikimedia Commons
ABO Blood Groups: The Basics
The four ABO groups are A, B, AB, and O. They reflect the presence or absence of A and B antigens on red blood cells. Rh positive or negative is a separate blood-group characteristic. [1]
ABO incompatibility can trigger antibody-mediated rejection (AMR) of a transplanted liver. Matching therefore involves more than knowing whether two people have different blood-type labels. [4]
| Term | Meaning | Example: donor → recipient |
|---|---|---|
| ABO-identical | Same ABO group | A → A |
| Compatible, nonidentical | Different groups, but compatible under usual ABO rules | O → A |
| ABO-incompatible | Outside usual ABO compatibility | A → O |
Nonidentical does not automatically mean incompatible. Always specify which blood type belongs to the donor and which belongs to the recipient. [2]
Who Can Receive Which Liver?
| Recipient | ABO-identical donor | Other ordinarily compatible donors |
|---|---|---|
| O | O | None under the usual ABO rules |
| A | A | O |
| B | B | O |
| AB | AB | A, B, or O |
This chart describes biological compatibility, not allocation priority or a guarantee of safety. Subtype exceptions, including selected non-A1 (A2) donors, and specialist ABO-incompatible protocols require separate assessment. A type O recipient is not categorically excluded from every non-O liver. [2] [4]
Blood-component transfusions have their own compatibility requirements; plasma rules differ from red-cell rules. This organ chart should not be used to choose transfusion products. [1]
Blood Type and the Waiting List
In the United States, liver allocation considers blood type, medical urgency, donor and recipient size, distance, age, and other factors. Blood type alone cannot predict your waiting time or position for every organ offer. [3]
Being biologically compatible with an organ does not mean you have priority to receive it. Actual offers follow OPTN policies and the circumstances of the donor and candidate. Consult the official current policy document, especially Policy 9, rather than treating a simplified chart as an allocation rule. [3] [7]
ABO-Incompatible Transplantation: Benefits and Risks
Selected patients can undergo ABO-incompatible liver transplantation, particularly through experienced living-donor programs using planned desensitization. It may widen donor options, but results from specialist programs should not be assumed to apply to every patient or center. [4] [5]
In a single-center series of 235 adults, three-year patient survival after ABO-incompatible living-donor transplantation was 92.3%, with graft survival of 89.2%. Survival was comparable to the study’s compatible group. However, 17 patients (7.2%) developed antibody-mediated rejection with diffuse intrahepatic biliary strictures; some required retransplantation or died. [5]
Similar survival does not mean identical complication risk. The decision must weigh additional treatment and graft risks against the risks of continuing to wait. [5]
Desensitization and Monitoring
Desensitization aims to reduce the immune response to the donor’s ABO antigens. Protocols may include rituximab to deplete B cells, plasma exchange to remove antibodies, and transplant immunosuppression. Treatment is individualized; there is no single regimen suitable for every recipient. [4] [5]
The team may follow anti-A or anti-B antibody titers and monitor for rejection, infection, and bile-duct complications. Ask which tests and additional treatments your center uses, how long preparation takes, and how complications would be managed. [4] [6]
Infants and Children
Infants and young children can have lower anti-A and anti-B antibody levels than older recipients. This may make ABO-incompatible transplantation more feasible, but age alone does not determine safety or remove the need for careful evaluation. [6]
A 2023 single-center study compared 18 ABO-incompatible transplants in 17 children with compatible transplants in children aged 24 months or younger. Overall patient and graft survival were not statistically different. The study was small and retrospective, so it cannot guarantee equivalent outcomes for every child. [6]
Antibody levels, illness severity, donor options, and center experience help guide treatment. Some children need more intensive antibody-directed therapy than others. Parents should ask for outcomes in children with a similar age and diagnosis. [6]
Questions for Your Transplant Team
- What is my confirmed blood type, and which donor types can you consider?
- Is the proposed match identical, compatible but nonidentical, or incompatible?
- How do current allocation rules affect my options?
- If an incompatible transplant is proposed, why is it preferable to waiting?
- What preparation, extra treatment, and monitoring would I need?
- What are this center’s rejection, bile-duct complication, graft-survival, and patient-survival results for comparable cases?
- For a child, how do age and antibody levels affect the plan?
Use these questions to discuss the matching, allocation, and treatment issues described above. [3] [5] [6]
Verified References
Highlighted citation numbers and reference titles open the source or its bibliographic record in a new tab. Sources checked October 19, 2026.
- American Red Cross. Facts About Blood and Blood Types. Patient education.
- United Network for Organ Sharing (UNOS). Organ Transplant: Donor and Recipient ABO Blood Type Compatibility Chart. Biological compatibility reference; PDF.
- HRSA / OPTN. Questions and Answers About Liver Allocation. Official patient resource.
- Egawa H, Ohdan H, Saito K. Current Status of ABO-incompatible Liver Transplantation. Transplantation. 2023;107(2):313–325. doi:10.1097/TP.0000000000004250.
- Song GW, et al. ABO-Incompatible Adult Living Donor Liver Transplantation Under the Desensitization Protocol With Rituximab. American Journal of Transplantation. 2016;16(1):157–170. doi:10.1111/ajt.13444.
- Lemoine CP, Brandt KA, Keswani M, Superina R. Outcomes after ABO incompatible pediatric liver transplantation are comparable to ABO identical/compatible transplant. Frontiers in Pediatrics. 2023;11:1092412. doi:10.3389/fped.2023.1092412.
- HRSA / OPTN. OPTN Policies. Official policy index. See Policy 9 for liver allocation; consult the current document.