ABO-Incompatible Kidney Transplant

Introduction

If you have end-stage kidney disease and a willing living donor in your family, you may have been told that your donor’s blood group does not match yours. For many years, this was a dead end. A donor with the “wrong” blood group could not safely give you a kidney, even if they were healthy and willing, because your immune system would attack the new organ within hours.

That has changed. An ABO-incompatible kidney transplant (sometimes shortened to ABOi transplant) is now an established option in major transplant centres. It uses a careful pre-surgery treatment to lower the antibodies in your blood that would otherwise reject a mismatched kidney. Once those antibodies are low enough, the transplant itself is performed in much the same way as any other living-donor kidney transplant.

This article is written for people who already know they need a kidney transplant and are now exploring the ABO-incompatible pathway — either because a family member is a blood-group mismatch, or because a paired exchange has not been possible. It explains what the treatment involves, who can have it, how the desensitization process works, what surgery and recovery look like, the risks, and what life is like in the months and years afterwards.

What Is an ABO-Incompatible Kidney Transplant?

An ABO-incompatible kidney transplant is a living-donor kidney transplant performed across a blood-group barrier. The donor and the recipient have different ABO blood groups that would, under normal rules, make transplantation unsafe.

The usual rules of blood-group matching for transplantation are:

• Group O can donate to anyone but can only receive from group O
• Group A can donate to A or AB, and receive from A or O
• Group B can donate to B or AB, and receive from B or O
• Group AB can receive from any group but can only donate to AB

These rules exist because your body makes natural antibodies against the blood-group antigens you do not have. If you are blood group O, for example, you carry anti-A and anti-B antibodies. If a group A kidney were placed inside you without preparation, those antibodies would bind to the new kidney almost immediately and destroy it. This is called hyperacute rejection.

An ABO-incompatible transplant gets around this in two ways. First, the level of these antibodies in your blood is brought down before the surgery using a process called desensitization. Second, the immune system is suppressed with medication so that, when the new kidney is in place, the antibodies cannot rebuild quickly enough to harm it. Over time, the transplanted kidney becomes “accommodated,” meaning it can tolerate low levels of these antibodies without injury.

Why It Is Performed

The main reason an ABO-incompatible transplant is offered is that a healthy, willing living donor is available, but their blood group does not match yours. In many families, this is the only available donor. Without ABO-incompatible transplantation, that person would face one of two paths: years on the waiting list for a deceased-donor kidney, or remaining on dialysis indefinitely.

Major transplant societies, including the Kidney Disease: Improving Global Outcomes (KDIGO) group and the European Association of Urology, describe living-donor transplantation — including ABO-incompatible pathways where appropriate — as generally offering better long-term outcomes than long-term dialysis for suitable candidates.

Why an ABO-Incompatible Transplant May Be Considered

You may end up exploring this option for one of several reasons.

A family member is willing but mismatched. A spouse, parent, sibling, or adult child wants to donate, but their blood group rules them out by the standard compatibility chart.

Paired kidney exchange is not available or has not produced a match. In a paired exchange (also called swap transplantation), two incompatible donor-recipient pairs trade donors so that each recipient gets a compatible kidney. This is a good option when it is available, but suitable matching pairs cannot always be found.

The waiting list for a deceased-donor kidney is long. In many countries, including India, the wait for a deceased-donor kidney can stretch over many years. For some patients, waiting on dialysis carries its own risks to the heart and overall health.

You wish to avoid or minimise time on dialysis. Pre-emptive transplantation — transplant before dialysis is started — is associated with better long-term outcomes in many studies. If a living donor is available, even one who is blood-group mismatched, the ABO-incompatible route may make pre-emptive transplant possible.

Who Is a Candidate?

Not every patient with end-stage kidney disease and a mismatched donor is a candidate for ABO-incompatible transplantation. The decision is made by a transplant team after a detailed evaluation.

Factors that generally support candidacy include:

• A confirmed diagnosis of end-stage kidney disease or advanced chronic kidney disease where transplant is the next step
• A healthy, willing living donor who has passed donor evaluation
• Antibody titres (the measured strength of your anti-A or anti-B antibodies) within a range the transplant team considers manageable with desensitization
• Good overall health to tolerate the desensitization process and major surgery
• No active infection or untreated cancer
• Heart and lung function adequate for the procedure

Factors that may make the ABO-incompatible route harder or unsuitable include very high starting antibody titres, recent severe infections, certain heart conditions, or other medical issues that would make heavy immunosuppression dangerous.

In India, living kidney donation is governed by the Transplantation of Human Organs and Tissues Act (THOTA). Donations from near relatives — parents, children, siblings, spouses, and grandparents — follow one pathway; donations from non-relatives require additional review by a hospital authorisation committee to confirm that the donation is voluntary and not for payment. Your transplant team will explain which pathway applies to your donor and what documentation is needed.

Alternatives to Consider

Before committing to an ABO-incompatible transplant, transplant teams generally discuss the alternatives. Each has different trade-offs.

Paired Kidney Exchange (Swap Transplant)

If another donor-recipient pair exists with the opposite mismatch, the two pairs can swap donors. Each recipient then receives a blood-group compatible kidney. This avoids the need for desensitization entirely. Many centres consider paired exchange a preferred option when a suitable match can be found, and registries exist in some countries to facilitate matching. Availability depends on the size of the local exchange programme.

Deceased-Donor Transplant

You can remain on the waiting list for a kidney from a deceased donor of a compatible blood group. The wait varies widely by country and region. In India, the wait can be several years. For some patients, especially those who are stable on dialysis, this remains a reasonable path.

Continuing Dialysis

Dialysis — either haemodialysis through a machine or peritoneal dialysis using the lining of the abdomen — is a life-sustaining treatment for kidney failure. It is not a cure, and it requires significant time and lifestyle adjustment. Long-term studies show better survival and quality of life for transplant recipients than for those on long-term dialysis, but dialysis remains the appropriate choice for patients who are not transplant candidates or who choose not to undergo transplant.

Desensitization for a Highly Sensitised Recipient

Some patients have high levels of antibodies for reasons other than ABO mismatch — for example, after previous transplants, blood transfusions, or pregnancies. Specialised desensitization protocols exist for these patients too. The principles are similar to ABO-incompatible desensitization but the antibodies targeted are different.

The choice among these options is a clinical decision made with your transplant team based on your antibody profile, donor availability, urgency, and overall health.

How an ABO-Incompatible Transplant Works: The Two Phases

An ABO-incompatible transplant unfolds in two clear phases: a preparation phase in the weeks before surgery, and the transplant operation itself. Understanding both helps explain why this pathway takes more time and planning than a standard living-donor transplant.

Phase 1: Desensitization

The main components of desensitization usually include:

• Rituximab. This is a medication, given as an infusion, that reduces the immune cells (B cells) responsible for producing the troublesome antibodies. It is often given once, several weeks before the planned transplant date.
• Plasmapheresis or immunoadsorption. These are blood-cleaning procedures, similar in setup to dialysis. Your blood is passed through a machine that removes antibodies and then returned to you. Plasmapheresis removes a wider range of plasma proteins; immunoadsorption is more selective and targets the specific blood-group antibodies. Several sessions are usually needed, with antibody levels measured between sessions.
• Standard immunosuppressive medications. These are started before surgery and continued lifelong. They typically include tacrolimus, mycophenolate, and corticosteroids.
• Intravenous immunoglobulin (IVIG). Some protocols include IVIG to further modulate the immune response.

Your antibody titres are checked repeatedly during desensitization. The transplant goes ahead once the antibody level reaches the threshold your centre considers safe — typically a titre of 1:8 or lower, though the exact cut-off varies by protocol.

Phase 2: The Transplant Operation

The donor operation. The donor’s kidney is removed, almost always through a minimally invasive approach — either laparoscopic donor nephrectomy or robotic-assisted donor nephrectomy. These approaches use small incisions, leading to less pain and faster recovery for the donor than older open surgery.

Preserving the kidney. Once removed, the kidney is flushed with a cold preservation solution and kept cool while it is prepared for transplant. The time between removal from the donor and placement in the recipient is kept short — usually well under an hour for a same-hospital living donor transplant.

The recipient operation. An incision is made in the lower abdomen, usually on one side. The new kidney is placed in the pelvis, lower than your own kidneys. Your own kidneys are usually left in place unless there is a specific reason to remove them. The surgeon connects the donor kidney’s artery and vein to your blood vessels, then attaches the donor ureter (the tube that carries urine) to your bladder. When the blood vessels are unclamped, blood flows into the new kidney and, in many cases, urine production begins almost straight away. The recipient operation typically takes 3 to 4 hours.

Preparing for an ABO-Incompatible Transplant

Preparation for an ABO-incompatible transplant is more involved than for a standard living-donor transplant because of the desensitization phase. The full process — from initial evaluation to surgery — typically spans 2 to 3 months.

Evaluation of the Recipient

You will undergo a complete pre-transplant assessment, including:

• Confirmation of blood group and measurement of anti-A and anti-B antibody titres
• HLA (tissue) typing and a crossmatch test against your donor
• Detailed kidney function testing and dialysis assessment if you are already on dialysis
• Heart evaluation — ECG, echocardiogram, and sometimes stress testing or coronary angiography depending on your risk profile
• Lung function tests
• Screening for infections including hepatitis B, hepatitis C, HIV, tuberculosis, and cytomegalovirus
• Cancer screening appropriate for your age
• Dental evaluation to identify any sources of infection
• Psychological assessment

Evaluation of the Donor

Your donor undergoes an independent and thorough evaluation, including:

• Confirmation of blood group
• Detailed kidney function testing and imaging (usually CT angiography) to map the kidney’s blood vessels and confirm both kidneys are healthy
• Screening for infections, diabetes, high blood pressure, and other conditions that could affect long-term kidney health
• Cardiac and general health assessment
• Psychological evaluation to confirm the decision to donate is voluntary and well-considered

Donor safety is the central concern at this stage. A donor whose remaining kidney might not safely sustain them in the long term will not be approved, regardless of the recipient’s need.

Practical Preparation

In the weeks before surgery, you will typically:

• Continue or adjust your dialysis schedule as advised
• Begin scheduled desensitization treatments
• Receive any vaccinations recommended before immunosuppression begins (some vaccines cannot be given safely after transplant)
• Have dental work completed if needed
• Receive counselling on lifelong medication adherence
• Arrange for a support person to help during the early recovery

What Happens During the Surgery

On the day of surgery, you will be admitted to hospital. Final antibody titres are checked. If they remain within the safe range, the operation proceeds.

General anaesthesia is used. A urinary catheter is placed once you are asleep. The transplant team monitors blood pressure, fluid balance, and other vital signs throughout.

The donor operation usually starts first. As the donor kidney is being removed, your surgical team prepares the site in your lower abdomen and exposes the iliac artery and vein — the large blood vessels that will supply the new kidney. The kidney is then brought across, placed in the prepared site, and the blood vessels are connected. The ureter is connected to the bladder, usually over a temporary internal stent that will be removed weeks later. Drains are placed, the incision is closed, and you are moved to a recovery area and then to a transplant ICU or high-dependency unit.

Many patients begin producing urine on the operating table, which is a reassuring early sign that the new kidney is functioning. Some patients have delayed graft function — the kidney takes days or weeks to start working — and may need a few sessions of dialysis after surgery. Delayed graft function is more common after deceased-donor transplants than after living-donor transplants, but it can occur in any transplant and is usually temporary.

Recovery and Healing

In Hospital

You will have:

• A urinary catheter for several days to monitor urine output and protect the new connection to the bladder
• One or more drains near the surgical site for a few days
• An intravenous line for fluids and medications
• Regular blood tests, often daily at first

Immunosuppressive medication is continued and dose-adjusted based on blood levels. In some cases, plasmapheresis is repeated in the early days after surgery if antibody levels rise.

Walking is encouraged as soon as it is safe — usually within the first day or two — to reduce the risk of blood clots and pneumonia.

The First Weeks at Home

After discharge, you will return for follow-up visits very frequently at first — often two or three times a week for the first month, then gradually less often as the kidney stabilises. Blood tests at each visit check kidney function, drug levels, infection markers, and antibody levels.

During the first 4 to 6 weeks at home:

• Light walking is encouraged; heavy lifting and strenuous exercise are avoided
• You should drink fluids as advised by your team to keep the new kidney well perfused
• You take immunosuppressive medications on a strict schedule
• You watch for warning signs of rejection or infection (described later) and report them promptly
• You avoid crowds and people who are unwell, because immunosuppression makes infections more likely

Most patients can return to light office work or working from home around 6 to 8 weeks after surgery, with full physical activity resumed by around 3 months. Patients whose work involves heavy physical labour usually need longer.

Longer-Term Recovery

By 3 to 6 months, most transplant recipients feel substantially better than before transplant. Energy returns, appetite improves, and most can resume normal daily life. Immunosuppressive medication doses are usually reduced from the high early-period levels to lower maintenance doses by this stage, though they are not stopped.

Risks and Complications

An ABO-incompatible transplant carries the same general risks as any kidney transplant, plus some specific to the desensitization process and the blood-group mismatch.

General Transplant Risks

• Bleeding during or after surgery
• Blood clots in the leg veins or lungs
• Wound infection or wound healing problems
• Urine leak or ureteric stricture at the connection between the new kidney’s ureter and the bladder
• Lymphocele — a collection of lymph fluid near the new kidney that sometimes needs draining
• Delayed graft function — the new kidney is slow to start working

Rejection

Rejection is the immune system’s attempt to attack the transplanted kidney. Several types exist:

• Hyperacute rejection — very rare with modern desensitization, but the reason desensitization exists. It happens within hours if antibodies are not adequately controlled.
• Acute rejection — can happen in the days, weeks, or months after transplant. It is treatable, especially when caught early, with adjusted medications and sometimes additional plasmapheresis. ABO-incompatible recipients have a somewhat higher risk of antibody-mediated rejection than ABO-compatible recipients, especially in the first few weeks.
• Chronic rejection — slow, gradual immune injury to the transplant over years. This is the main long-term cause of transplant kidney loss.

Most rejection episodes do not cause symptoms you can feel — they are picked up on blood tests showing a rising creatinine. This is why frequent follow-up testing is essential, especially in the early months.

Infection

Immunosuppression increases the risk of infection. The risk is highest in the first 6 months when drug doses are highest. Particular concerns include:

• Urinary tract infections
• Respiratory infections, including pneumonia
• Viral infections such as cytomegalovirus (CMV), BK virus, and shingles
• Fungal infections in some cases

Preventive antiviral and antibiotic medications are usually given for the first several months to reduce these risks.

Risks Specific to Desensitization

• Reactions to plasmapheresis (low blood pressure, bleeding, low calcium)
• Infusion reactions to rituximab
• A temporary increase in infection risk during the most intensive period of antibody removal
• Antibody “rebound” in the early days after surgery, which may require additional plasmapheresis sessions

Long-Term Medication Side Effects

Lifelong immunosuppression carries risks that develop over years:

• Increased risk of certain cancers, particularly skin cancers and post-transplant lymphoproliferative disorder (PTLD)
• Diabetes (sometimes new-onset after transplant)
• High blood pressure
• Raised cholesterol
• Bone thinning
• Increased infection susceptibility

Regular monitoring is designed to catch these issues early and address them.

Outcomes

Published transplant series report that, with current desensitization protocols, ABO-incompatible kidney transplants now achieve graft and patient survival rates comparable to ABO-compatible living donor transplants in experienced centres. The early post-transplant period — particularly the first 1 to 3 months — carries a somewhat higher risk of antibody-mediated rejection, but once a transplant survives this early phase, long-term outcomes are similar. Personalised outcome estimates should be discussed with your transplant team based on your antibody titre, donor characteristics, and overall health.

Life After an ABO-Incompatible Transplant

Lifelong Immunosuppression

Your transplant requires immunosuppressive medication for as long as the kidney functions. The standard combination usually includes tacrolimus, mycophenolate, and a corticosteroid (such as prednisolone), with doses adjusted by your transplant team based on blood levels and clinical response. Missing doses, even occasionally, is one of the leading causes of late rejection, and the importance of strict adherence is emphasised by every transplant team.

Follow-Up Schedule

Follow-up is intensive at first and lifelong overall. A typical schedule:

• First month: 2–3 visits per week
• Months 2–3: weekly visits
• Months 4–6: every 2 weeks
• Months 6–12: every 4–6 weeks
• After 1 year: every 2–3 months, then eventually every 3–6 months long-term

Each visit usually includes blood tests for kidney function, drug levels, blood counts, and (especially in the first year) antibody titres.

Lifestyle Adjustments

Most transplant recipients return to a full life. Specific habits that transplant teams typically advise:

• Hydration. Drinking plenty of fluids unless told otherwise
• Diet. A balanced diet, often with attention to salt and sometimes sugar; some foods (such as grapefruit) interact with immunosuppressive medications and are avoided
• Food safety. Avoiding raw or undercooked foods that carry infection risk — for example, raw eggs, undercooked meat, and unpasteurised dairy
• Sun protection. Daily sunscreen and protective clothing, because skin cancer risk is higher on long-term immunosuppression
• Exercise. Regular moderate activity once recovery is complete
• Avoiding tobacco. Smoking accelerates kidney damage and worsens cardiovascular risk
• Limiting alcohol as advised by your team
• Vaccinations. Inactivated vaccines, including annual influenza vaccination, are usually recommended; live vaccines are generally avoided after transplant

Return to Work and Travel

Most patients return to work between 6 weeks and 3 months after surgery, depending on the nature of their work. Travel is usually possible after the first few months, with planning for medications and access to medical care at the destination.

Pregnancy After Transplant

Pregnancy is possible after a kidney transplant, including after ABO-incompatible transplant. It is generally advised to wait at least 1 to 2 years after transplant, when kidney function is stable and medication doses are at maintenance level. Some immunosuppressive medications are not safe in pregnancy and need to be switched before trying to conceive. Pregnancy after transplant is managed jointly by the transplant team and a high-risk obstetrics team.

Warning Signs to Report Promptly

After your transplant, you will be given clear instructions on when to contact your transplant team urgently. Common warning signs include:

• Fever, chills, or feeling generally unwell
• A sudden drop in urine output
• Pain or tenderness over the transplant site
• Sudden weight gain or new swelling in the legs or face
• Burning, frequency, or blood when passing urine
• Persistent vomiting that prevents you from keeping medications down
• Severe diarrhoea
• A rising creatinine on routine blood tests, even if you feel well

Many problems, including early rejection, are treatable when caught quickly. Delayed reporting is one of the main reasons treatable problems become serious ones.

ABO-Incompatible Transplant in Children

ABO-incompatible kidney transplantation is performed in children in some specialised paediatric transplant centres, particularly in young children below about 2 years of age, whose immune systems produce lower levels of blood-group antibodies and who tend to tolerate the mismatch more easily. Older children typically require desensitization protocols similar to those used in adults, modified for size and age.

The principles of evaluation, desensitization, and lifelong follow-up are the same. Differences in paediatric transplant include attention to growth, development, schooling, and the transition to adult transplant care during the teenage years. Paediatric transplant teams also work closely with families on medication adherence, which can be especially challenging during adolescence.

If you are a parent considering this option for your child, decisions are made by a paediatric transplant team with experience in ABO-incompatible transplantation.

Frequently Asked Questions

Is an ABO-incompatible transplant as good as a blood-group matched transplant?

In experienced centres using current desensitization protocols, published series show graft and patient survival rates comparable to ABO-compatible living-donor transplants over the long term. The first few months after transplant carry a somewhat higher risk of antibody-mediated rejection. Your transplant team can discuss what these patterns mean for your specific situation.

How long does the whole process take, from evaluation to surgery?

From the first transplant clinic visit to the day of surgery, the timeline is typically 2 to 3 months. Donor evaluation, recipient evaluation, and desensitization all need to be completed and coordinated.

Can my donor change their mind?

Yes. Donation is voluntary at every stage. A donor can withdraw at any point before surgery without having to give a reason. Transplant teams confirm voluntariness repeatedly throughout the evaluation process.

Will my body eventually accept the new kidney without antibody attacks?

Yes — this is called accommodation. Over weeks and months after surgery, the transplanted kidney adapts to the recipient’s low residual antibody levels and stops being injured by them. This is one of the reasons modern ABO-incompatible transplants succeed.

Will I need dialysis after the transplant?

If the new kidney begins working immediately, no. If there is delayed graft function, a few sessions of dialysis may be needed in the early days while the new kidney recovers. Most transplant recipients are off dialysis permanently within days of surgery.

Will I need lifelong medication?

Yes. Immunosuppressive medication is required for the life of the transplant. Stopping or skipping doses is one of the most common causes of late rejection.

Can family members other than first-degree relatives donate?

Yes, including spouses and other relatives. In India, donation from a near relative follows one regulatory pathway under the Transplantation of Human Organs and Tissues Act, while donation from a non-near relative requires authorisation committee review to confirm the donation is voluntary and not for payment. Your transplant team will explain the documentation needed for your donor’s relationship.

Are there situations where ABO-incompatible transplant is not advised even if a donor is available?

Yes. Very high starting antibody titres, recent severe infections, certain heart conditions, active cancer, or other medical issues may make the desensitization process or the heavy immunosuppression unsafe. The transplant team makes this judgment after the full evaluation.

Conclusion

An ABO-incompatible kidney transplant has changed what is possible for many patients with end-stage kidney disease. A family member whose blood group would once have made donation impossible can now, in the right circumstances, donate a kidney safely. The process takes more preparation than a standard transplant — weeks of desensitization with rituximab, plasmapheresis, and immunosuppressive medication — and the early months require close monitoring. In experienced centres, the long-term results are comparable to those of blood-group matched living-donor transplants.

If you are exploring this option, the next step is a detailed conversation with a transplant team about your antibody profile, your donor’s suitability, the alternatives available to you, and the long-term commitment to immunosuppression and follow-up. The decision is individual, and there is time to ask every question that matters to you and your family.