Febrile Immunocompromised Renal Transplant Recipient with Allograft Dysfunction: Detection of an Undiagnosed Prostate Abscess by [ 18 F]FDG-PET/CT along with Treatment Response Monitoring

TL;DR

A renal transplant patient with fever and graft dysfunction was diagnosed with a prostate abscess using PET/CT, and treatment response was monitored with follow-up scans.

Contribution

Demonstrates the utility of [18F]FDG-PET/CT in diagnosing and monitoring treatment response for a rare post-transplant complication.

Findings

PET/CT identified a prostate abscess and pyelonephritis in a renal transplant patient.

Follow-up PET/CT showed reduced metabolic activity, indicating treatment response.

Despite successful infection treatment, graft function declined, leading to dialysis dependence.

Abstract

The purpose of this report is to provide a comprehensive description of a post-transplant febrile patient's clinical course, complications, surgical procedure, and long-term management including evaluation by
18
F-fluorodeoxyglucose [(
18
F)FDG] positron-emission tomography combined with computed tomography (PET/CT). A 35-year-old male, a postrenal transplant patient, developed chronic allograft dysfunction and presented with fever with chills, with suspicion of acute-on-chronic graft dysfunction, but no infective focus localization on chest X-ray, ultrasonography (USG) whole abdomen, or blood culture. Urine microscopy showed 8 to 10 pus cells/high-power field (hpf) and culture showed
Klebsiella pneumoniae
and
Pseudomonas aeruginosa
with low colony count. Culture-sensitive antibiotics were prescribed for 2 weeks, and after 3 weeks febrile episodes relapsed, symptoms progressed, and required emergency hospitalization due to acute painful urinary retention. Proteinuria and no growth were noted in urine analysis, serum creatinine was 5.36 mg/dL, and C-reactive protein was 15.7mg/dL, and remaining parameters were unremarkable. [
18
F]FDG-PET/CT was considered in order to resolve diagnosis, which revealed abnormal heterogeneous tracer uptake in the enlarged prostate with hypodense areas within, suggesting prostatitis with abscess formation and pyelonephritis in the upper pole of the transplant kidney. USG kidney urinary bladder (KUB) correlation confirmed prostatic abscess and transurethral drainage done, and pus culture revealed
Burkholderia pseudomallei
. Culture-sensitive intravenous meropenem treatment was given for 3 weeks. At 5 weeks, follow-up [
18
F]FDG-PET/CT showed low metabolic residual prostate uptake, suggesting a good response with residual infection. Thus, intravenous antibiotics was changed to oral antibiotics for another 6 weeks. His symptoms completely resolved at the end of treatment; however, his graft function worsened, with serum creatinine reaching 6 to 7 mg/dL, and eventually, after 8 months he became dialysis dependent.

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