Immunology Quiz 5

• TACO

  Transfusion Associated Circulatory Overload
• TRALI

  Transfusion Related Acute Lung Injury
• TRALI

  • It is a form of ARDS (Acute Respiratory Distress Syndrome)
  • Symptoms appear in 6 hours and typically resolve within 96 hours
  • Supportive care is needed to keep patient alive due to the fluid filling their lungs
• Hypotension


  Found in TRALI, not TACO
• TRALI types


  • TRALI I: For patients that do not have risk factors. Quick onset, hypoxemia, bilateral pulmonary edema
  • TRALI II: Pre-existing mild respiratory condition or acute but has been stable in the past 12 hours. The transfusion then brings them back to an acute process.
• TACO

  Transfusion Associated Circulatory Overload, differentiated from TRALI by cardiac edema (heart distress)
• Transfusion Reaction Workup


  1. Stop the transfusion

  2. Check the documentation: Clerical errors are the most common causes of complications

  3. Consult the clinical team to coordinate a care plan

  4. Identify what do we need to do to work it up

  5. Transfusion service is contacted: Is there an issue with the donor we should know about

  6. Return unit but keep the tubing maybe

  7. Notify the blood bank to determine if the component is at fault or if we may want to identify units that have been spread elsewhere like other hospitals

  8. Notify FDA of fatal reactions because technically blood is a drug
• Lab Investigation


  1. Check the paperwork

  2. Repeat ABO testing: Draw another tube from patient and hopefully it matches the first

  3. Visual checks: Was the bag hemolyzed? Check the urine for hemoglobinuria not hematuria

  4. Post transfusion DAT, report findings to the blood bank supervisor/medical director
• Investigation for Hemolytic Transfusion Reaction (HTR)

  1. Repeat ABO and Rh on pre and post transfusion specimens and donor segments

  2. Antibody ID on pre and post transfusion specimens

  3. Repeat the crossmatch

  4. Outside the blood bank: Check the patient's Haptoglobin, LDH (marker of tissue breakdown especially red cells, indicates hemolysis), unconjugated bilirubin

  5. Look at the bag to rule out traumatic or mechanical hemolysis

  6. Micro: Was donor septic, was donor draw site not cleaned properly
• Products treated to deactivate viruses like Plasma protein factor do not present a risk for Hepatitis
• Hepatitis A Virus (HAV)


  Small RNA virus, no envelope
• HAV is not typically transmitted through blood products. Fecal-Oral route.
• HAV is often found in daycare centers (improper handwashing), prisons, IV drug users
• There is no carrier state for HAV, only spread during active infection
• Hepatitis B Virus (HBV)


  • dsDNA virus, Surface and core antigens, DNA polymerase enzyme, only 4 genes
• HBV Disease Progression


  1. Incubation is 2 weeks – 6 months

  2. Can be subclinical, to acute and self-limited, to fatal fulminant

  3. 5-10% become chronic carriers

  4. 1-3% get fulminant disease (liver failure) and die

  5. Immune system damages liver as it tries to clear infection
• HBV Serological Markers


  • Surface antigen first
  • E antigen denotes active infection
  • Antibody to core antigen next, found in the beginning
  • Anti-E antibody means infection is going down
  • Last marker is anti-surface antigen
  • Window period is time when IgM antibody to core antigen is detectable
• HBV Vaccine

  Made by inserting a plasmid with the gene for the surface antigen into S. cerevisiae then lysing the yeast cells. The surface antigen is administered through the vaccine and triggers an immune response.
• The HBV vaccine is a 3 vaccine series that is 90% effective with no known side effects and is safe for newborns
• Transmission of HBV

  -       More likely to get it from IV drug user with HBV

  -       Blood and body fluids

  -       Parenterally (ingestion), sexually, or perinatally
• Symptoms of HAV

  • Incubates in the liver and begins multiplying.
  • Leaves with the bile and exits through stool
  • Brief period of viremia.
  • Mild symptoms: nausea, vomiting, loss of appetite, malaise, and diarrhea
  • Jaundice is often present
• Prevention of HAV

  -       Vaccination

  -       So many people have it so we don’t usually test for it.

  -       Patient questionnaire is used to screen it out.