Transfusion Reactions

Introduction Blood transfusion is safe, effective way to correct hematology defects and crucial part of supportive care of some patients Sometimes unwanted results may occur during or after transfusion One of these is transfusion reactions 2

Transfusion Reactions They are adverse reactions associated with the transfusion of blood and its components 3% of individuals receiving blood transfusions have a transfusion reaction

Transfusion reactions Non-threatening to fatal (Fatal ~ 1/50000) Immunological or Non-immunological May or may not cause RBC destruction Immediate to delayed Immediate – rapid onset (<24 hours) Delayed – >24 Hours,Occur days, weeks, May involve infectious agents

Transfusion Reactions Most common causes of transfusion related DEATHS: Improper specimen identification Improper patient identification Antibody identification error Crossmatch procedure error Most transfusion reactions (not all) are the result of human error.

Immediate

Immediate Hemolytic Reactions Most common cause is ABO incompatibility (clerical error) Red cell destruction due to complement activation by IgM RBCs hemolysed due to reaction between Abs in recipient (A & B) & Ags on donor’s RBCs As little as 10-15 mL can trigger a reaction

Symptoms Fever Pain at infusion site Back/chest pain Physical signs Hypotension Bleeding Renal failure Hemoglobinuria

Steps taken if hemolytic reaction is suspected Stop transfusion Keep IV line open with physiologic saline Perform bedside clerical checks Contacts patient’s physician & blood bank Return unit, set & attached solutions to Lab Collect suitable blood samples for evaluation Microbiological on unit, culture of patient’s blood, Check for DIC, Renal function

Treatment Treat hypotension by fluid replacement Maintenance of renal blood flow Replacement of depleted coagulation factors Dialysis in case of renal failure

Transfusion of RBCs Allo-Abs Rarely, patient’s red cells can be hemolyzed by Abs in transfused whole blood or plasma Caused by anti-A or Anti-B in certain plasma products Cryoprecipitate Factor VIII or IX Positive DAT, Anti-A or Anti-B can be eluted from red cells

Transfusion Induced Alloimmunization Ags are administered during transfusion In 1st transfusion Induce alloantibodies This will cause problems in subsequent transfusions Prior transfusion beneficial in some cases E.g. renal transplantation is more successful in patients with prior multiple transfusions

Pseudo-Hemolytic Reactions Some transfusions may appear to be immediate HTR, but they are not due to immune RBC destruction These are called pseudo-hemolytic TR

Manifestation Possible Mechanism Hemolysis 1- Excessive Infusion pressure 2- Infusion through small pre needles 3- Overheating of donor red cells 4- Infusion of congenitally abnormal red cells 5- Freezing of red cells prior to infusion 6- Infusion of RBCs damaged by microorganisms Hypotension or Shock 1- Infusion of infected blood products 2- Anaphylactic reactions Fever 1- Febrile reaction 2- Infusion of infected blood Hyperbilirubinemia 1- Infusion of large quantities of blood stored for 4-5 weeks 2- Infusion of hemolysed blood

Delayed Hemolytic Transfusion Reactions DHTRs occur at least 24 hrs after transfusion Mediated by IgG antibodies Patient previously exposed to RBC antigen and has low antibody titer until exposed again Cannot be detected in crossmatch Rh, Kidd, Duffy, and Kell

Delayed Hemolytic Transfusion Reactions Patients have no symptoms The only indication is a fall in hemoglobin Diagnosis made by re-crossmatch DAT is usually positive Elutions are performed to identify Ab

White Cell Reactions Febrile Reactions Most common, 2% of all transfusions Caused from HLAs on the WBCs of the donor that react with the recipient antibody Any component that contains WBCs could cause FNHTRs Cytokines IL-1, 6,8 and Tnf-alpha generated in stored blood/products. Determining factor is age of blood products Leukocytes reduced units may be given TNF alpha: is a cytokine involved in systemic inflammation and is a member of a group of cytokines that stimulate the acute phase reaction.

Pulmonary Infiltrates Transfusion Related Acute Lung Injury Can be due to: Hypervolemia Donor antibodies that react with the recipient’s granulocytes or vice versa which cause embolism to blood vessels in lung tissue Then fluids and proteins leak into alveolar space/ interstitium The lungs fill with a high-protein fluid Patient displays acute respiratory insufficiency with x-ray showing pulmonary edema without cardiac failure

Graft-versus-Host Disease Rare but fatal condition that has a 90% mortality rate May be caused by donor lymphocytes transfused into an immunocompromised recipient acute graft-versus-host-disease is characterized by selective damage to the liver, skin and mucosa, and the gastrointestinal tract Any components that contain T-lymphocytes should be irradiated to prevent GVHD

Platelet Reactions Post Transfusion Purpura (PTP) PTP characterized by severe consumptive thrombocytopenia Typically in women with a history of pregnancy, immunized with Human platelet Specific Alloantigen (HPA) Thrombocytopenia is self-limiting and lasts for 2-6 weeks Occur in patients who are negative for HPA-1a

Plasma Protein Reactions Anaphylaxis Cause Infusion of IgA proteins into Pt with IgA antibodies IgA deficiency about 1 in 700 Hypotension and bronchospasm Transfusion should be stopped immediately IgA deficient patients should be transfused with blood products lacking IgA

Urticaria Second most comon type of TR Characterized by a pruritic rash during or following transfusion Allergic reactions are IgE mediated.  These reactions are usually attributed to hypersensitivity to soluble allergens found in the transfused blood component. Associated with anti-IgA in recipients who are IgA deficient. حساسية الجلد

Urticaria If not accompanied by other signs or symptoms, transfusion can be continued Anti-histamines are given