What are the potential side effects of platelet transfusion in patients with a history of allergies or previous transfusion reactions?

Side Effects of Platelet Transfusion

Platelet transfusions carry significant risks including life-threatening complications (TRALI, TACO, bacterial sepsis), common reactions (febrile and allergic responses), and immune-mediated complications (alloimmunization and refractoriness), with patients having prior allergies or transfusion reactions requiring heightened monitoring and specific preventive strategies. 1

Life-Threatening Complications

Transfusion-Related Acute Lung Injury (TRALI)

• TRALI is a leading cause of transfusion-related mortality, presenting within 6 hours of transfusion with acute hypoxemia, respiratory distress, dyspnea, bilateral pulmonary infiltrates, and fever 1, 2
• Fresh frozen plasma and platelet concentrates are the blood products most frequently implicated 1
• The mechanism involves donor leukocyte antibodies (HLA class I, class II, or granulocyte-specific) interacting with recipient neutrophils and causing granulocyte aggregation in lung capillaries 1, 2
• Stop the transfusion immediately when TRALI is suspected and provide critical care respiratory support—do NOT give diuretics as they are ineffective and may worsen the condition 1, 2, 3
• Blood banks now screen donors for leukocyte antibodies and preferentially use male-only plasma donors to reduce TRALI risk 1, 3

Transfusion-Associated Circulatory Overload (TACO)

• TACO is now the most common cause of transfusion-related mortality and major morbidity, occurring during or up to 12 hours after transfusion 4, 1
• Presents with acute respiratory compromise, pulmonary edema, cardiovascular changes (hypertension and tachycardia—not hypotension), and evidence of fluid overload 4, 1, 3
• Patients at highest risk include those over 70 years old, non-bleeding patients, and those with heart failure, renal failure, hypoalbuminemia, or low body weight 4, 1
• Treatment requires immediate cessation of transfusion and diuretic therapy (in direct contrast to TRALI management) 1, 3
• Prevention strategies include assessing transfusion need carefully, body weight-based dosing of blood products, slow transfusion rates, and prophylactic diuretic prescribing in high-risk patients 4, 1

Bacterial Contamination and Sepsis

• Bacterial contamination should be suspected if patients experience severe febrile reactions during or shortly after platelet transfusions 1
• Storage at 20°C to 24°C creates conditions that permit bacterial growth, making platelets the blood product with highest contamination risk 1
• Storage time is limited to 5 days (or 7 days with bacterial detection testing or pathogen reduction technologies) to minimize this risk 1
• Stop the transfusion immediately, obtain blood cultures from both patient and blood product, and strongly consider empiric antibiotics, particularly in neutropenic recipients 1

Common Adverse Reactions

Febrile and Allergic Reactions

• Febrile or allergic transfusion reactions are among the most common side effects of platelet transfusion, with increasing incidence in recent years 4, 1
• Red blood cell units are usually associated with febrile-type reactions, whereas plasma and platelets more commonly cause allergic reactions 4
• Current recommendations advise against indiscriminate use of steroids and/or antihistamines—instead use a personalized approach tailored to symptoms 4
• For febrile reactions, only intravenous paracetamol may be required 4
• For allergic reactions, only an antihistamine should be administered 4
• If severe reaction and/or anaphylaxis is suspected, follow local anaphylaxis protocols 4
• Repeated doses of steroids may further suppress immunity in immunocompromised patients 4

Alloimmunization and Platelet Refractoriness

• Repeated platelet transfusions induce alloantibodies in recipients, potentially resulting in platelet transfusion refractoriness (PTR) 1
• The incidence of alloantibody-mediated refractoriness can be decreased when both platelet and RBC products are leukoreduced before transfusion 1
• Prestorage leukoreduction is recommended from the time of diagnosis to ameliorate this problem 1
• Patients who received non-leukoreduced blood products had higher rates of alloimmune refractoriness (14%) compared to those receiving universal prestorage leukoreduced products (4%) 4
• Leukoreduction also substantially reduces transfusion reactions and transmission of cytomegalovirus (CMV) infection 1

Additional Serious Complications

Transfusion-Associated Graft-Versus-Host Disease (TA-GVHD)

• TA-GVHD is a rare but usually fatal complication resulting from transfusion of viable lymphocytes capable of immune attack against the recipient 1
• Prevention requires pretransfusion gamma irradiation of blood products for high-risk patients including stem-cell transplant recipients, those receiving blood from partially matched family members, and patients with severe immunosuppression (e.g., Hodgkin's lymphoma) 4, 1
• Leukocyte depletion alone does not eliminate this risk 1
• Some cancer centers with large numbers of providers have chosen to irradiate blood products routinely for all patients to guarantee vulnerable recipients receive proper products 4

Hemolytic Reactions

• Rare hemolytic reactions can occur due to incompatible plasma, particularly when O donor platelets are transfused to A or B recipients 1
• ABO-compatible products should be provided whenever possible, though clinically significant hemolysis is unusual in adult recipients 1

RhD Alloimmunization

• Because of the low rate of RhD alloimmunization in patients with cancer (1.44%), prevention approaches need not be applied universally 4
• Prevention of RhD alloimmunization may be used for female children and female adults of child-bearing potential being treated with curative intent 4
• This can be achieved either through exclusive use of platelet products from RhD-negative donors or via anti-D immunoprophylaxis 4

Special Considerations for Patients with Prior Allergies or Transfusion Reactions

Monitoring Requirements

• Respiratory rate should be monitored throughout transfusion as dyspnea and tachypnea are typical early symptoms of serious transfusion reactions 4
• Observations including pulse, blood pressure, and temperature should be completed and documented before transfusion (within 60 min), 15 minutes after the start of each unit, and within 60 minutes of the end of transfusion 4
• Monitor vital signs every 5-15 minutes during suspected reactions including heart rate, blood pressure, temperature, respiratory rate, and oxygen saturation 3

Risk Mitigation Strategies

• Use leukoreduced blood products universally to minimize adverse effects 1
• Provide ABO-compatible platelets when possible 1
• Irradiate products for immunocompromised patients 1
• Transfuse single units in non-hemorrhaging patients and reassess before additional units 1
• Report all suspected transfusion reactions immediately to the blood bank 1
• Consider pathogen-reduced platelet products when available 1
• Contact the transfusion laboratory immediately to report any reaction and initiate investigation, and double-check all documentation for administration errors 3

Common Pitfalls to Avoid

• Never confuse TRALI and TACO management—TRALI requires NO diuretics while TACO requires diuretics 1, 2, 3
• Do not routinely give platelet transfusions to patients with immune thrombocytopenia or thrombotic thrombocytopenic purpura, as this is relatively contraindicated 4
• Avoid indiscriminate prophylactic use of antihistamines and steroids before transfusion 4
• Do not assume leukoreduction alone prevents TA-GVHD—irradiation is required for high-risk patients 1
• Never continue a transfusion when any reaction is suspected—stopping immediately is the single most critical intervention 3