Critical Care Medicine-Infections and Immunologic Disease>>>>>Immune Suppression: Congenital, Acquired, Drugs
Question 3#

A 53-year-old man with celiac disease is admitted to hospital from primary physician’s office for a workup of weakness and anemia. His hemoglobin is 6.0 g/dL and is suspected to be a result of a slow GI bleed. His vitals are notable for:

Two units of cross-matched packed red blood cells are ordered. Ten minutes into the blood transfusion, patient becomes febrile (38.6°C), but other vitals remain unchanged. Transfusion is continued. Fifteen minutes later the patient develops worsening hypotension to 75/40 mm Hg, urticarial rash, and wheezing. 

Which of the following is the MOST likely etiology of the patient’s decompensation?

A. Bacterial contamination of blood product
B. Hemolytic transfusion reaction related to ABO incompatibility
C. IgA deficiency with exposure to Immunoglobulin A (IgA) in the blood product
D. Worsening GI bleed

Correct Answer is C


Correct Answer: C

This patient developed anaphylactic reaction to blood product. Anaphylactic reactions to blood products occur in about 1 out of 1.3 million transfusions. These reactions occur most commonly either during or within 4 hours of a transfusion. Anaphylactic reactions should be treated by immediately stopping the blood transfusion, administration of intramuscular epinephrine, intravenous H1 blocker antihistamines (eg, diphenhydramine), H2 blocker antihistamines (eg, ranitidine), intravenous methylprednisolone, and beta-agonists (eg, albuterol) as needed. Adequate respiratory support including supplemental oxygen and/or mechanical ventilatory support should be provided based on the clinical status of the patient. 

Isolated IgA deficiency is the most common immunoglobulin deficiency with the prevalence estimated to be between 1 in 200 and 1 in 500. AntiIgA–mediated anaphylactic reactions occur when patients with IgA deficiency have developed anti-IgA antibodies that can react with IgA in red blood cell products. Sensitization to IgA may occur during prior blood transfusions, pregnancy, or intravenous immunoglobulin infusions. However, some patients do not have a history that suggests prior sensitization. In these cases, it is postulated the anti-IgA antibodies may either occur spontaneously or as a consequence of sensitization either in utero or via breast milk. IgA deficiency is common in patients with celiac disease, such as the patient in this vignette.

Hemolytic blood transfusion reactions occur when there is ABO incompatibility. This is exceptionally rare in the setting of rigorous crossmatching protocols. Symptoms of a hemolytic transfusion reaction include temperature increase >1 or <1°C with associated fevers, chills, hypotension, nausea or vomiting, and evidence of hemolysis. Acute airway compromise and wheezing are not classic signs of hemolytic transfusion reactions.

A diagnosis of septic transfusion is made when bacteria are isolated from both the blood product and the patient. A presumptive diagnosis can be made when bacteria are isolated solely from the blood product in a patient with a clinical syndrome of sepsis. Urticarial rash and respiratory distress would not be consistent with bacterial contamination. Guidelines recommend starting empiric antibiotics (β-lactam or aminoglycoside) with pseudomonas coverage. While a sudden GI bleed could present with worsening hypotension, an urticarial rash and respiratory distress would be atypical. 


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