Identification of occult active infection using PET-CT in a combined liver-kidney transplant candidate

Area of Science:

• Nephrology
• Hepatology
• Nuclear Medicine

Background:

• Caroli's disease is a rare congenital disorder characterized by cystic dilatation of the intrahepatic bile ducts.
• Patients with Caroli's disease may require liver transplantation, and some may have concurrent or prior renal issues, necessitating combined organ transplantation.
• A failed renal transplant can present diagnostic challenges, particularly when associated with unexplained fever.

Observation:

• Standard imaging modalities, including ultrasonography and computed tomography, failed to identify the source of chronic sepsis in a patient with Caroli's disease and a history of renal transplant.
• The patient presented with persistent fever of unknown origin, raising suspicion for an occult infectious or inflammatory process.

Findings:

• Positron Emission Tomography-Computed Tomography (PET-CT) revealed increased metabolic activity in the retained, non-functioning renal transplant, indicating a chronic septic focus.
• The non-functioning transplant was identified as the source of the unexplained fever.

Implications:

• This case underscores the utility of PET-CT in diagnosing difficult cases of fever of unknown origin, especially in patients with complex medical histories and prior organ transplants.
• Retained non-functioning transplants should be considered in the differential diagnosis of fever of unknown origin in transplant recipients.
• Advanced imaging techniques like PET-CT can be crucial for identifying occult sources of infection in immunocompromised or post-transplant patients.