A Pilot Trial to Examine the Changes in Carotid Arterial Inflammation in Renal Transplant Recipients as Assessed by 18F-Fluorodeoxyglucose (18F-FDG) Positron Emission Tomography Computed Tomography (PET/CT).

BACKGROUND Inflammatory activity of the artery can be assessed by measuring 18F-fluorodeoxyglucose (18F-FDG) uptake with positron emission tomography computed tomography (PET/CT). Improvement in vascular function after renal transplantation has been reported, but no studies have used 18F-FDG PET/CT to examine the changes in vascular inflammation. This study investigated the changes in the inflammatory activity in the carotid artery after renal transplantation in patients with chronic kidney disease (CKD). MATERIAL AND METHODS 18F-FDG PET/CT was performed before and at 4 months after transplantation. We quantified 18F-FDG uptake as the target-to-background ratio (TBR) in the carotid artery in 10 CKD patients. TBR was evaluated in the whole carotid artery (WH) and most-diseased segment (MDS), and the mean and maximum values were analyzed. The concentrations of inflammatory cytokines, including tumor necrosis factor-alpha, interleukin-6, plasminogen activator inhibitor-1, and endothelin-1, were measured. RESULTS Eight patients showed a decrease in mean or maximum TBR. The average mean or maximum TBRs in the WH and MDS of the right and left arteries were all reduced after transplantation. The average mean TBR for the right WH decreased significantly (% reduction [95% CI]) by -5.74% [-15.37, -0.02] (p=0.047). TBRs did not correlate significantly with cytokine concentrations. The changes in cytokine concentrations after transplantation varied. CONCLUSIONS 18F-FDG uptake by the WH and MDS tended to reduce after renal transplantation. Therefore, renal transplantation may confer an anti-inflammatory effect on carotid atherosclerosis in patients with CKD; however, this effect is not large enough to be demonstrated in this study with small sample size.