Blood Bank Ch. 11

Adverse Reactions of Transfusions

What is the hemovigilance model in blood banking?

a system that tracks and analyzes adverse transfusion reactions by collecting data from participating hospitals to the CDC

• goal: to improve transfusion outcomes

What are some general symptoms of an adverse transfusion reaction?

fever, hypotension or hypertension, skin rash, edema, jaundice, nausea, chills, respiratory distress, pain at infusion site, DIC, etc.

Transfusion reactions are classified into two categories, what are they?

• immune-mediated reactions

  • reactions involving antigen-antibody complexes, cytokine release, or complement activation

• non-immune mediated reactions

  • reactions that can be due to the product transfused, the patient’s underlying condition, or method of infusion

What are acute hemolytic transfusion reactions (AHTRs)?

• serious, acute, immune-mediated transfusion reactions

• rapid destruction of RBCs within 24 hours

• signs can range from fever to death

  • fever, chills, pain, hypotension, epistaxis, hemoglobinuria, DIC, renal failure, and shock

• usually due to ABO incompatibility

  • as little as 10 mL of incompatible blood can trigger symptoms

What is the immune mechanism of action of acute hemolytic transfusion reactions?

• transfused antibody binds to RBC antigens

• complement is activated and acts in 3 different ways:

  • RBCs are opsonized and cleared from circulation (intravascular hemolysis)

  • complement system releases anaphylatoxin into plasma, resulting in vasodilation, which causes increased vascular permeability and hypotension

  • the MAC lyses red cells, freeing Hgb into the blood, causing cytotoxic effects

What is the result of the coagulation and fibrinolytic systems becoming activated in AHTRs?

• antigen-antibody complexes are deposited in tissues, leading to thrombus formation

• DIC can occur

What causes shock in AHTRs?

• release of anaphylatoxins

  • as a result, hypotension can occur, causing reduced blood supply to tissues, causing renal failure

What are some common causes of acute hemolytic transfusion reactions?

• patient misidentification

• incorrect sample collection

• incorrect or skipped entry of test results

• failure to follow standard operating procedures

delayed hemolytic transfusion reactions (DHTRs)

• less severe than acute reactions

• results in extravascular hemolysis

• usually due to IgG antibodies formed from prior exposure to an antigen

  • these antibodies may go undetected in pretransfusion testing

• antibodies associated with DHTRs:

  • anti-C, anti-E, Kidd, Duffy, Kell, and MNS

What are the signs, symptoms, and prevention of DHTRs?

• signs and symptoms

  • fever (with or without chills), low Hgb or HCT, jaundice, hemoglobinuria

• prevention

  • check patients records for any previously identified antibodies

What is a delayed serologic transfusion reaction (DSTR)?

• occurs when antibodies that were not detected prior to transfusion react with transfused red blood cells

• confirmed by the detection of the antibody after transfusion

• must be considered if: an antibody develops between 24 hours to 28 days post-transfusion, despite normal Hgb levels

3 major causes of febrile nonhemolytic transfusion reactions

• major causes:

  • non-leukocyte reduced RBCs are transfused

  • transfused cytokines or cytokines produced by the recipient causes a reaction

  • or patient may have an HLA antibody to donor WBCs

symptoms and prevention of febrile nonhemolytic transfusion reactions?

• symptoms

  • fever, chills, headache, nausea, vomiting — all nonthreatening

  • hemolysis must be ruled out

• prevention

  • use of leukocyte-reduced RBCs and other blood products

What are allergic transfusion reactions?

• acute, local, or systemic type 1 hypersensitivity reaction to allergens in the donor plasma

• symptoms: hives, itching, and angioedema

• treatment:

  • antihistamine

  • transfusion can continue after symptoms are resolved

  • if someone has a history of these reactions, they can be given antihistamines beforehand

What are anaphylactic allergic transfusion reactions?

• serious reaction

• can occur in IgA deficient patients that have an anti-IgA antibody that reacts with transfused plasma

• symptoms occur within seconds to minutes

  • severe hypotension, shock, loss of consciousness, respiratory distress, potential cardiovascular symptoms

• can be fatal

What is transfusion-related acute lung injury (TRALI)?

• acute, pulmonary edema that can be a life-threatening or fatal result of transfusion

• symptoms: respiratory distress, hypoxemia, chills, hypotension, and cyanosis

• currently thought to be a result of the patient’s underlying condition or the transfusion itself

risk factors/causes of TRALI

• donor plasma contains antibodies to class I and II HLAs and human neutrophil antigens that react with the recipient

  • women with several children who form HLA or HNA antibodies after repeated exposure to antigens during pregnancy

TRALI prevention

• only collect plasma from male donors or women who have not been pregnant

• or collect plasma from women who test negative for HLA antibodies

transfusion-associated graft vs. host disease (TA-GVHD)

• rare, but highly lethal reaction

• immunocompetent donor lymphocytes trigger an immune response against the recipient's tissues upon transfusion

• prevention

  • irradiate blood before transfusion

    • eliminates the ability of WBCs to replicate, causing the reaction

  • transfuse psoralen treated platelets (psoralen binds to the DNA in WBCs and inhibits their replication)

posttransfusion purpura (PTP)

• patient produces platelet-specific alloantibodies (like P1A1) after previous exposure to platelet antigens via pregnancy or transfusion

• these antibodies destroy transfused platelets AND autologous platelets

• marked by purpura, bleeding, and low PLT count

• treated with plasmapheresis, exchange transfusions, or IVIG

What is transfusion-associated circulatory overload (TACO) and who is most at risk?

• A condition that occurs when blood transfusions are administered too rapidly, leading to fluid overload

  • leading cause of transfusion-related mortality

• Those at greatest risk include elderly patients, infants, individuals with preexisting heart failure, and patients with renal impairment

What are the symptoms, treatment for, and ways to prevent TACO?

• symptoms

  • similar to congestive heart failure: dyspnea, severe headache, peripheral edema, and increased BNP

• treatment

  • oxygen therapy and diuretics

• prevention

  • avoid transfusing large volumes at once and transfuse slowly

causes of nonimmune hemolytic anemia (6)

• exposure of red cells to extreme temperatures

  • use of malfunctioning blood warmers, accidental warming during refrigeration, RBCs that are frozen without preservatives

• improper deglycerolizing

• mechanical destruction

  • using small IV needles, mechanical heart valves in the patient, excessive pressure on the blood bag

• utilizing incompatible solutions in the blood product

  • only physiologic saline should be used

• bacterial contamination of blood unit

• intrinsic defects in the patient

  • sickle cell, G6PD deficiency, or PNH

nonimmune hemolytic anemia caused by bacterial contamination

• can lead to serious or potentially fatal complications

• causes of bacterial contamination:

  • donor has a latent infection

  • improper cleaning of venipuncture site

  • pinhole in the unit

  • error in testing platelet products

    • apheresis PLTs and PLT products must be tested for bacteria

symptoms and prevention of nonimmune hemolytic anemia caused by bacterial contamination

• symptoms

  • fever, chills, headache, hypotension, shock, muscular pain, vomiting, diarrhea

  • how to differentiate from AHTRs: ABO incompatibility must be ruled out (so antibiotics can be started)

• prevention

  • inspect units for discoloration, cloudiness, or hemolysis

  • clean venipuncture sites adequately

  • perform a donor health check

  • give instructions to donors post-transfusion to report any health issues afterward

If it is discovered that a patient had a transfusion reaction due to bacterially contaminated units, what should be done afterward?

• the donor bag should be gram stained

• blood cultures from the patient should also be obtained

What are two methods used to detect and inactivate bacteria in platelet products (to prevent transfusion reactions)?

• bacterial testing of the unit

• treating the platelets with psoralen (binds to bacterial nucleic acids and inhibits their replication)

cause of hemosiderosis (transfusion related)

long-term transfusions in patient with sickle cell and thalassemia

What causes citrate toxicity?

• when large amounts of citrated blood are transfused

• can have adverse effects in:

  • those receiving large amounts of blood, patients with impaired liver function, and preterm infants

• prevention:

  • remove plasma that may contain citrate

  • give the patient CaCl₂ or calcium gluconate to counteract the citrate

After an adverse transfusion reaction, what items are sent to the lab for postreaction workups?

• a post-transfusion blood sample

• the blood bag

• IV solutions used during transfusion

• labels and forms

• first voided urine (if possible)

What must blood bankers do with the post-transfusion specimen after an adverse transfusion reaction?

• inspect the specimen for any signs of hemolysis or being icteric

• perform a DAT

Any transfusion-related diseases or bacterial contamination cases are reported to:

the blood donation center

A patient has experienced two febrile nonhemolytic reactions after RBC transfusion. What is the preferred blood component if future transfusions are necessary?

leukocyte-reduced RBCs

Which of the following patient histories might suggest future transfusions with saline-washed RBCs?

A) history of multiple red cell alloantibodies

B) history of congestive heart failure

C) recipient with absolute IgA deficiency and anti-IgA

D) history of transfusion-associated sepsis

C. recipient with absolute IgA deficiency and anti-IgA

What lab test aids in detecting a clerical error of sample identification in an acute or immediate transfusion reaction investigation?

ABO typing

In a delayed serologic or hemolytic transfusion reaction, what is the typical result of the DAT?

weakly positive, with a mixed field