Transfusion Reactions - Non Immune

• FNHTR: febrile nonhemolytic transfusion reaction
• FNHTR is the most common of all adverse effects of transfusion, occurs in about 1% of transfusions
• FNHTR is the least likely to be life threatening
• FNHTR is defined as a rise in patient temperature of 1 degree C or more during or after a transfusion, unrelated to the patient's underlying condition
• FNHTR recognition requires diagnosis by exclusion
• FNHTR symptoms may also be present in several other types of transfusion reactions, if the patient is already spiking fevers during admission, it may be hard to rule out FNHTR
• FNHTR is mostly likely due to antileukocyte antibodies present in the recipient's plasma
• antileukocyte antibodies are usually directed against antigens present on monocytes, granulocytes, and lymphocytes in the donor blood
• alloimmunization causing FNHTR usually stems from prior transfusion, transplant, or pregnancy
• usually HLA antigens trigger FNHTR response, it is though that complement from the antigen/antibody reaction may trigger the release of pyrogens from WBCs
• a second mechanism which causes FNHTR is platelet storage changes
• during storage, white cells in the unit start to release cytokines; can have a reaction against these accumulated cytokines which causes the symptoms
• symptoms of FNHTR caused by platelet storage changes include chills, headache, and vomiting

  treat by closely monitoring and antipyretics
• febrile reactions of FNHTR usually happen to people who have had multiple transfusions or pregnancies
• about 15% of patients with a history of febrile reactions will have one again
• prevention of FNHTR can be achieved by performing pre-storage leukocyte reduction, can use leukocyte filters to reduce the WBCs

  • studies show that 0.25 x 10^9 WBCs can cause in increase in temperature
• treatment of FNHTR

  • stop transfusion
  • antipyretic administered
• bacterial reactions

  • a rise in temperature of more than 1 degree C can be due to bacterial infection of the blood product
  • it is potentially fatal
  • contamination usually results from skin flora during blood collection
• bacterial reactions

  • alternatively, the donor may be bacteremic, asymptomatically
  • mild cases can be confused with FNHTRs
• bacterial reactions

  • platelets, which are stored at RT, are particularly susceptible to bacterial proliferation
  • get typical symptoms that are characteristic of sepsis, fever and hypotension
  • may also see shock, abdominal pain, nausea
• severe cases of bacterial reactions may progress to DIC or renal failure
• Gram-positives tend to cause fevers after transfusion; these are most commonly found in platelets
• Gram-negatives cause more severe symptoms, such as DIC, renal failure, and shock
• most organisms die at cold temperatures, but endotoxins or pyrogens may be released OR bacteria may survive in the cold
• common causes of infection include Babesia, S aureus, E coli, S marcescens, S epidermidis, S lugdunensis
• to demonstrate infection from components, we need to culture the same organisms from the patient and the rest of the blood components
• therapy for infections include intravenous steroids, antibiotics, fluids, electrolytes, and vasopressor drugs for shock
• ATR: allergic transfusion reactions
• allergic reactions are relatively common transfusion reactions -- it happens in about 1-3% of transfusions of platelets and plasma components and about 10x less with RBCs
• most ATRs are mild, but can range from urticaria (hives) to anaphylaxis
• symptoms of ATR usually occur within seconds to minutes of transfusion, while others may take hours
• allergic urticarial tranfusion reactions - possible mechanisms

  • donor has a plasma protein which is an allergen, and the patient's IgG or IgE responds
  • histamine is released when an allergen/antibody complex attaches to the surface of tissue mast cells
  • mechanisms not totally understood
• results of allergic transfusion rxns include mast cells and basophils, which causes release of histamine and vasoactive amines; this results in vascular permeability (vascular fluid escapes into tissue) which leads to hives (urticaria) and severe itching
• treatment for allergic urticarial transfusion rxn include administering antihistamines, then resume transfusion after treatment
• allergic reactions are usually mild and not life threatening, includes: erythema, pruritis, urticaria, angioedema, fever; however, there is no reliable test to determine the allergen
• erythema is redness
• pruritis is itching
• urticaria is hives (raised, red welts)
• angioedema is painless swelling under th skin
• treatment for allergic reaction due to blood transfusion

  • monitor patient
  • treat with antihistamine like benadryl
  • in patients with history of allergic reactions, wash blood and pre-medicate with history
  • if reactions are more severe, can use epinephrine or corticosteroids