Patient Resources 9 min read·Updated 22 July 2026 Clinician-reviewed

Kidney Transplant Rejection — Signs & Treatment

A UK Consultant Nephrologist's guide to recognising, diagnosing and treating kidney transplant rejection — and what you can do every day to reduce the risk.

  • Clinically Reviewed
  • NHS & NICE Aligned
  • UK Evidence-Based
  • Last Reviewed 22 July 2026

Professor Mohammed Mahdi Althaf

Consultant Nephrologist & Acute Physician

View Credentials

Professor Mohammed Mahdi Althaf

MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN

Consultant Nephrologist & Acute Physician · GMC 7216325

View profile →

Direct answer

Rejection is usually silent and detected on routine bloods. Take your immunosuppressants exactly as prescribed, attend every clinic, learn the warning signs, and call the transplant unit immediately if your urine output drops, transplant becomes tender, or you feel flu-like.

Key recommendation: Most rejection is silent — bloods catch it early.

Quick answer

✓ Best choices

  • Thoroughly cooked meats, fish and eggs
  • Washed, peeled fruit and vegetables
  • Vegetables, whole grains, beans and olive oil
  • Adequate hydration and dietary calcium for bone health

✓ Foods to limit

  • Grapefruit and Seville orange — they interact with tacrolimus and ciclosporin
  • Unpasteurised dairy, soft-ripened cheeses, raw eggs and undercooked meat
  • Excess salt and ultra-processed foods (BP and weight gain)

Key takeaway

Rejection is usually silent and detected on routine bloods. Take your immunosuppressants exactly as prescribed, attend every clinic, learn the warning signs, and call the transplant unit immediately if your urine output drops, transplant becomes tender, or you feel flu-like.

Who should be cautious

People on dialysis, post-transplant, pregnant or breastfeeding, or taking prescription medication — confirm with your renal team before changes.

Kidney Transplant Rejection — Signs & Treatment

Why rejection happens

Your immune system recognises the transplanted kidney as 'foreign'. Immunosuppressants suppress this response — but rejection can still occur:

  • If immunosuppressant levels drop (missed doses, drug interaction, vomiting).
  • If donor-specific antibodies develop.
  • Spontaneously, even years later.

Rejection rates: ~10% in year 1, ~1-2%/year thereafter. Most are caught early and successfully treated.

Types of rejection

HYPERACUTE (minutes-hours):

  • Caused by preformed antibodies.
  • Prevented by pre-transplant crossmatching.
  • Now extremely rare.

ACUTE CELLULAR REJECTION (days-months, sometimes years):

  • T-cell attack on the kidney.
  • Most common type.
  • Usually fully reversible with treatment.

Acute Antibody-mediated Rejection (Amr)

  • B-cells produce antibodies.
  • Harder to treat than cellular.
  • Worse long-term outcomes.

Chronic Allograft Injury

  • Months to years.
  • Slow rise in creatinine, increasing proteinuria.
  • Combination of immune and non-immune injury.
  • Hard to reverse — focus on slowing.

Warning signs — when to call urgently

Call the transplant team SAME DAY for:

  • Reduced urine output (less than usual)
  • Tenderness, swelling or pain over the transplant kidney
  • Sudden weight gain (>1 kg/day) or ankle swelling
  • Fever > 38°C
  • Flu-like aches
  • Unusual fatigue
  • Blood in urine
  • Drop in BP or unwell feeling

Most units have a 24-hour transplant emergency line. Use it — never wait.

Always confirm any new supplement with your transplant team. Kidney Vitality is a daily multivitamin developed using renal nutrition principles, with no added potassium, magnesium, phosphorus or iron. See the formulation.

How rejection is diagnosed

  1. RISING CREATININE on routine bloods (often the only sign).
  2. Same-day USS to exclude obstruction or vascular issue.
  3. Transplant kidney BIOPSY — gold-standard. Done under local anaesthetic, results in 24-48 hours.
  4. DONOR-SPECIFIC ANTIBODY (DSA) test in blood.
  5. Banff classification grades the rejection severity.

Treatment

Acute Cellular Rejection

  • High-dose IV methylprednisolone (500-1000mg daily x 3 days).
  • If severe or steroid-resistant: anti-thymocyte globulin (ATG).
  • Optimise immunosuppression (raise tacrolimus target).

Antibody-mediated Rejection

  • Plasma exchange (removes antibodies).
  • IV immunoglobulin.
  • Rituximab (anti-CD20 to deplete B-cells).
  • Bortezomib in resistant cases.

Chronic Injury

  • Tight BP control (target < 130/80).
  • ACE inhibitor/ARB for proteinuria.
  • Reduce nephrotoxic drugs.
  • Monitor frequently.

Outlook and prevention

Treated acute rejection: most transplants recover full function, no impact on long-term survival.

Key prevention steps:

  • NEVER miss immunosuppressant doses.
  • Take tacrolimus exactly 12 hours apart.
  • Avoid grapefruit, NSAIDs, St John's Wort.
  • Attend every clinic and blood test.
  • Report ANY new symptoms early.
  • Don't 'self-adjust' your dose if you feel unwell.

Missed doses are the #1 preventable cause of late transplant failure in UK data.

Kidney Transplant — What to Expect
Related reading: Kidney Transplant — What to Expect.

Key practical tips

Designed for quick scanning — what to order, what to avoid, sensible portions, common mistakes.

  • Keep fridge ≤ 5 °C and reheat leftovers to piping hot
  • Track weight monthly — steroid-driven weight gain is common but manageable
  • Bring your full medication list to every dietetic review

Clinical guidance

TL;DR summary

Rejection is usually silent and detected on routine bloods. Take your immunosuppressants exactly as prescribed, attend every clinic, learn the warning signs, and call the transplant unit immediately if your urine output drops, transplant becomes tender, or you feel flu-like.

Key takeaways
  • Most rejection is silent — bloods catch it early.
  • Tenderness, low urine, fluid gain = call urgently.
  • Three types: hyperacute, acute, chronic.
  • Acute rejection usually treatable with steroids.
  • Missing immunosuppressants is the biggest risk.
Kidney Diet & Nutrition Considerations After Transplant

After a kidney transplant the diet broadens — but food safety, weight, blood pressure and bone health become the priorities. Immunosuppressants raise infection risk and can affect blood sugar and lipids, so a balanced Mediterranean-style plate plus careful food hygiene works well.

Foods to prioritise

  • Thoroughly cooked meats, fish and eggs
  • Washed, peeled fruit and vegetables
  • Vegetables, whole grains, beans and olive oil
  • Adequate hydration and dietary calcium for bone health

Foods to limit

  • Grapefruit and Seville orange — they interact with tacrolimus and ciclosporin
  • Unpasteurised dairy, soft-ripened cheeses, raw eggs and undercooked meat
  • Excess salt and ultra-processed foods (BP and weight gain)

Potassium, phosphate and protein needs vary between individuals — please confirm personal targets with your renal team or dietitian. Browse the Kidney Diet Hub for more guides in this cluster.

Frequently asked questions

What are the early signs of transplant rejection?

Most early rejection is silent — picked up only on routine blood tests (rising creatinine). When symptoms occur they include: tenderness or swelling over the transplant, reduced urine output, fluid retention, fever, flu-like symptoms, and unexplained weight gain. Always call the transplant team if in doubt.

What types of rejection are there?

Three types: HYPERACUTE (within minutes — preventable by crossmatching, very rare). ACUTE (days to months — usually treatable with steroids/antibody therapy). CHRONIC (months to years — slow function decline, harder to reverse).

How is rejection diagnosed?

Rising creatinine on bloods triggers investigation. Confirmed by transplant kidney biopsy showing the type and severity of rejection (Banff classification). Donor-specific antibody (DSA) tests detect antibody-mediated rejection.

Can rejection be treated?

Yes — most acute cellular rejection responds well to high-dose IV steroids. Antibody-mediated rejection needs plasma exchange + IV immunoglobulin + rituximab. Chronic rejection is harder — focus shifts to slowing decline and planning future treatment.

What foods should I avoid after a kidney transplant?

Avoid grapefruit and Seville orange (they raise tacrolimus and ciclosporin levels), unpasteurised dairy, soft-ripened cheeses, pâté, raw or undercooked meat, raw shellfish and any food past its use-by date. These reduce the risk of serious infection while you are on immunosuppressants.

Nutritional challenges in kidney disease

Many people living with kidney disease have to limit foods because of potassium, phosphate, diabetes, dialysis, appetite changes or simply the time it takes to cook from scratch every day. That can make it harder to keep daily nutrition balanced — particularly for vitamins and minerals that food alone may not fully cover.

Kidney Vitality is a UK-formulated daily nutritional support product designed by Consultant Nephrologist Professor Mohammed Mahdi Althaf with renal nutrition in mind from the start. It keeps doses moderate, leaves out added potassium, phosphate and magnesium, and avoids megadose vitamin A — sitting alongside a kidney-friendly diet, not replacing it.

Why Kidney Vitality fits this need

Built around UK renal guidance

Aligned with British Transplantation Society guidelines, Banff 2022 classification and NICE TA481.

Designed by a UK Consultant Nephrologist

Formulated and reviewed by Professor Mohammed Mahdi Althaf (GMC 7216325).

Evidence-based by design

Practical UK transplant pathways with 24-hour emergency advice.

Designed by a UK Consultant Nephrologist

Ready to support your kidney health?

If you have been researching kidney health, supplements, CKD nutrition or kidney-friendly living, Kidney Vitality was developed specifically around those principles by Professor Mohammed Mahdi Althaf (GMC 7216325). Nephrologist Developed Daily Multivitamin.

  • Active-Form B-Complex
  • No Added Potassium
  • No Added Phosphorus
  • Developed by a Consultant Nephrologist
  • One capsule daily
  • UK GMP — BRCGS, NSF GMP, Halal
Subscribe & Save — £20.39/monthCheck your current multivitamin

✓ Free UK tracked delivery  ·  ✓ Delivered every 30 days  ·  ✓ Pause or cancel anytime  ·  ✓ Never run out

ComparisonKidney VitalityTypical high-street multivitamin
Added potassiumNoneOften included
Added phosphateNoneOften included (E338–E452)
Vitamin A (retinol)No megadoseOften high-dose retinol
Kidney-focused formulationYesNo — general population
Consultant Nephrologist involvementYes (GMC 7216325)No
UK GMP manufacturedYes (BRCGS, NSF GMP)Varies

Food supplement. Not a medicine and not a treatment for kidney disease. Speak with your GP, pharmacist or renal team before starting any new supplement, especially in advanced CKD, on dialysis, post-transplant, pregnant or breastfeeding.

Clinical reviewer

Professor Mohammed Mahdi Althaf

Consultant Nephrologist

Acute Physician

GMC 7216325

View Full Biography

Professor Mohammed Mahdi Althaf is a UK Consultant Nephrologist and Acute Physician with a special interest in chronic kidney disease, AKI prevention and renal nutrition. He combines hospital practice with patient education and clinical guidance review.

View professional profile →
View Credentials
  • MD
  • MSc
  • PgDip (Clin Ed)
  • FRCP
  • FHEA
  • FASN

About this article

Written for UK patients and based on:

  • NICE guidance
  • NHS resources
  • British Dietetic Association guidance
  • Kidney Care UK resources
View methodology

Each article is researched against current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO and KDOQI international guidelines, and the British Dietetic Association Renal Nutrition Group. Drafts are written by the Kidney Vitality editorial team and reviewed by a UK Consultant Nephrologist before publication. Content is reviewed on a rolling basis and updated when guidance changes.

Editorial standards

  • Clinically reviewed
  • NHS-aligned
  • NICE-aligned
  • Evidence-based
  • Reviewed before publication
View full editorial process

Every article is researched and written by the Kidney Vitality editorial team using current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO/KDOQI international guidelines, and British Dietetic Association renal nutrition guidance. Drafts are reviewed for clinical accuracy by Professor Mohammed Mahdi Althaf, MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN (Consultant Nephrologist & Acute Physician, GMC 7216325) before publication. Content is updated when UK guidance changes.

References (4)View Sources
  1. NICE NG203: Chronic kidney disease — assessment and management
  2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD
  3. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update
  4. British Dietetic Association — Renal Nutrition Group

Medical disclaimer

This content is educational only and does not replace personalised medical advice.

Read full disclaimer

This page is general information, not personal medical advice. If you have chronic kidney disease, are on dialysis, have had a kidney transplant, are pregnant or breastfeeding, or take prescription medication, please confirm any supplement with your GP, pharmacist or renal team before starting.

← Back to all guides