A 57-year-old woman comes to the emergency department with 12 hours of fever, chills, and severe generalized weakness. She also has discomfort in her right upper quadrant and has had 2 episodes of vomiting. The patient underwent a liver transplant for primary biliary cirrhosis 2 weeks ago and currently takes prednisone, tacrolimus, and mycophenolate. Temperature is 39.1 C (102.5 F), blood pressure is 85/55 mm Hg, and pulse is 130/min. Physical examination reveals tenderness in her right upper quadrant with mild guarding. Laboratory results are as follows:
| Complete blood count | |
| Hemoglobin | 10.8 g/dL |
| Platelets | 450,000/mm3 |
| Leukocytes | 28,800/mm3 |
| Serum chemistry | |
| Sodium | 139 mEq/L |
| Potassium | 4.1 mEq/L |
| Chloride | 101 mEq/L |
| Bicarbonate | 25 mEq/L |
| Blood urea nitrogen | 31 mg/dL |
| Creatinine | 1.3 mg/dL |
| Calcium | 9.2 mg/dL |
| Glucose | 105 mg/dL |
| Liver function studies | |
| Total bilirubin | 1.3 mg/dL |
| Alkaline phosphatase | 203 U/L |
| Aspartate aminotransferase | 105 U/L |
| Alanine aminotransferase | 63 U/L |
| Coagulation studies | |
| INR | 1.3 |
Which of the following is the most likely cause of this patient's condition?
This patient underwent liver transplantation 2 weeks ago and now has right upper quadrant pain, high fever, hypotension, tachycardia, and significant leukocytosis, suggesting sepsis due to an ongoing bacterial infection.
Infections continue to be the major cause of morbidity and mortality in patients who have undergone liver transplantation. Length of time since transplant helps categorize the likely infectious organism as follows:
<1 month: Bacterial causes from operative complications (eg, hepatic abscess, biliary leak, wound infection) or hospitalization (eg, intravascular catheter, external drain)
Months 1-6: Opportunistic pathogens (eg, Cytomegalovirus, Aspergillus, Mycobacterium tuberculosis) in the setting of high-dose immunosuppressive medication
>6 months: Immunosuppressants usually at maintenance levels. Patients primarily at risk for typical community-acquired pathogens (at a higher rate than the general population)
(Choice A) Acute cellular rejection occurs <90 days after transplantation and can cause fever, right upper quadrant pain, and elevations in liver function tests. However, this patient also has rapid-onset hemodynamic instability, making a bacterial infection more likely. In addition, although prednisone use can cause leukocytosis, significant leukocytosis and high fever are more likely to indicate bacterial infection.
(Choices B, D, and E) Opportunistic infections such as Cytomegalovirus, Aspergillus, and Epstein-Barr virus are most common 1-6 months post transplantation in the setting of high-dose immunosuppressive regiments. This patient had rapid-onset hemodynamic decompensation with significant leukocytosis 2 weeks post transplantation, making a bacterial cause more likely.
(Choice F) Hyperacute rejection is a relatively rare form of rejection due to an antibody/complement-mediated response (eg, ABO mismatch). This outcome manifests <1 week after transplantation.
(Choice G) Post-transplant lymphoproliferative disease is usually due to Epstein-Barr virus in the setting of chronic high-dose immunosuppression. Fever, weight loss, and fatigue are common presenting symptoms. This patient with significant leukocytosis and rapid-onset symptoms 2 weeks post transplantation likely has a bacterial infection.
Educational objective:
Infections are common in patients who undergo liver transplantation. Likely etiology can be discerned based on the length of time since transplantation. Most infections within the first month are due to bacterial causes; infections during months 1-6 are usually caused by opportunistic pathogens (in the setting of high-dose immunosuppression).