Related Subjects:
| Oncological Emergencies
| Acute Myeloid Leukaemia (AML)
| Acute Lymphoblastic Leukaemia (ALL)
| Chronic Lymphocytic Leukaemia (CLL)
| Chronic Myeloid Leukaemia (CML)
| Immune Thrombocytopenic Purpura (ITP)
| Multiple Myeloma
| Graft-versus-Host Disease (GVHD)
| Cytomegalovirus (CMV) Infections
|Flow Cytometry
|Haematology Laboratory Values
|Indications for Irradiated Blood Products
🩸 Irradiated blood products are used to prevent transfusion-associated graft-versus-host disease (TA-GVHD) — a rare but usually fatal complication in which viable donor T-lymphocytes engraft and attack the recipient’s tissues.
☢️ Irradiation inactivates donor lymphocytes while preserving red cell function, making transfusion safer in high-risk patients.
🧬 What is TA-GVHD? (Why irradiation matters)
- 👥 Donor T-cells survive in the transfused blood.
- ⚔️ They recognise the recipient as “foreign”.
- 🔥 They attack skin, liver, gut, and bone marrow.
- 📉 This leads to pancytopenia, sepsis, and multiorgan failure.
- ⚠️ Mortality >90% → prevention is essential.
📌 Indications for Irradiated Blood Products
- 🎗️ Hodgkin’s Lymphoma (Lifelong indication)
- Causes long-lasting T-cell dysfunction.
- Risk persists even after remission.
- ➡️ All blood must be irradiated for life.
- 🧪 Stem Cell / Bone Marrow Transplant Recipients
- Includes autologous and allogeneic transplants.
- Conditioning destroys immune surveillance.
- Donor lymphocytes can engraft easily.
- ➡️ Irradiated blood needed until immune recovery.
- 🧬 Donor Lymphocyte Infusions (DLI)
- Highly immunogenic donor T-cells.
- Extreme GVHD risk.
- 🦠 Granulocyte Transfusions
- Contain large numbers of active lymphocytes.
- High TA-GVHD risk.
- ➡️ Must always be irradiated.
- 🧒 Congenital Immunodeficiency Disorders
- Examples: SCID, DiGeorge syndrome.
- Impaired T-cell function → cannot reject donor cells.
- ➡️ Absolute indication.
- 🤰 Intrauterine Transfusions (IUT)
- Fetal immune system is immature.
- Cannot mount rejection response.
- ➡️ Blood must be irradiated.
- 👶 Neonatal Exchange Transfusions
- Large donor lymphocyte exposure.
- High vulnerability.
- ➡️ Irradiation mandatory.
- 💊 Purine Analogue Therapy
- Examples: fludarabine, cladribine, pentostatin.
- Profound, prolonged T-cell depletion.
- Risk may persist for years.
- 👨👩👧👦 First-Degree Relative Donations
- Partial HLA matching.
- Donor cells evade immune detection.
- ➡️ High TA-GVHD risk.
- 🩺 Post-Splenectomy (Selected Patients)
- Mainly if underlying haematological disease.
- Reduced immune clearance.
⏳ Duration of Irradiation Requirement
- 🧬 Allogeneic HSCT
- From start of conditioning.
- Continue ≥ 6–12 months.
- Longer if GVHD/immunosuppression persists.
- 🔁 Autologous HSCT
- During conditioning.
- Continue ≥ 3 months post-transplant.
- 💊 Purine Analogue Therapy
- Minimum 6 months.
- Often lifelong (local policy dependent).
- 👶 Neonates after IUT
- Continue until 6 months of age.
- 🎗️ Hodgkin’s Lymphoma
⚠️ Important Practical Points
- 📉 Irradiation does NOT prevent CMV transmission.
- 🧂 Does NOT remove potassium (use washed cells if hyperkalaemia risk).
- 📆 Shortens red cell shelf-life (28 days post-irradiation).
- 🪪 Patients should carry an irradiated blood alert card.
📝 Exam & Clinical Pearls
- ⭐ Hodgkin’s lymphoma = irradiated blood for life.
- ⭐ Relatives donating blood = always irradiate.
- ⭐ Fludarabine = think irradiation.
- ⭐ TA-GVHD = pancytopenia + rash + diarrhoea + liver failure.
- ⭐ Prevention is the only effective treatment.
📚 References (UK-Based)
