S2441 Acute Liver Failure Due to Toxoplasmosis After Orthotopic Liver Transplantation

Abstract

INTRODUCTION: Solid organ transplant recipients are at risk for a wide range of opportunistic infections, the most common being Cytomegalovirus (CMV). These infections may occur as re-activation of latent disease, donor-derived or de novo. Though less common, infection with Toxoplasma gondii may also present in patients following solid organ transplantation. We present a case of acute liver failure secondary to toxoplasmosis following orthotopic liver transplantation. CASE DESCRIPTION/METHODS: A 61-year-old female presented five weeks after orthotopic liver transplantation with altered mental status and fatigue. Her immunosuppression regimen included tacrolimus, mycophenolic acid, and prednisone. In addition, she was on prophylactic acyclovir for CMV. However, trimethoprim-sulfamethoxazole prophylaxis was held 4 weeks prior due to renal dysfunction. Upon presentation, laboratory data revealed acute kidney injury and elevated liver tests (total bilirubin 1.2 mg/dL, alanine aminotransferase 69 U/L, aspartate aminotransferase 101 U/L, alkaline phosphatase 286 U/L). She was found to have elevated CMV PCR in the blood (679,198 IU/mL) and cerebrospinal fluid (>2,000,000 IU/mL), as well as biopsy proven CMV hepatitis. CMV infection resolved with intravenous ganciclovir. However, she subsequently developed acute liver failure due to toxoplasmosis, which is hypothesized to be donor derived, and expired. Postmortem histological studies performed during the acute illness showed hepatic necrosis and intrahepatic protozoa, consistent with Toxoplasma bradyzoites. Immunohistochemical stain for Toxoplasma performed by the Centers for Disease Control and Prevention confirmed Toxoplasma infection. DISCUSSION: Infection with Toxoplasma may be asymptomatic in the immunocompetent host. However, in immunocompromised hosts, such as solid organ transplant recipients, this infection can be life threatening. Though prophylaxis with trimethoprim-sulfamethoxazole may prevent infection with Toxoplasma, it is often held for renal dysfunction, hyperkalemia, or other side effect, placing patients at risk. With 13 cases now reported, routine screening of donor and recipient for Toxoplasma exposure may be warranted. Although disseminated toxoplasmosis is rare in the post orthotopic liver transplant patient, 61% of reported cases have resulted in death of the patient.Figure 1.: CMV viral inclusion (Hematoxylin and Eosin stain at 600x original magnification).Figure 2.: Intrahepatic protozoa (∼1–2 um in diameter), consistent with Toxoplasma cyst with bradyzoites (Hematoxylin and Eosin stain at 600x original magnification).Figure 3.: Immunohistochemical stain for Toxoplasma gondii confirms the diagnosis. It shows multiple intrahepatocytic protozoa that are arranged individually, consistent with Toxoplasma tachyzoites infection. (IHC at 200X). Inset box at 630x original magnification).