Cyst infection in hospital-admitted autosomal dominant polycystic kidney disease patients is predominantly multifocal and associated with kidney and liver volume

Positron-emission tomography/computed tomography (PET/CT) has improved cyst infection(CI) management in autosomal dominant polycystic kidney disease (ADPKD). Thedeterminants of kidney and/or liver involvement, however, remain uncertain. In thisstudy, we evaluated clinical and imaging factors associated with CI in kidney (KCI)and liver (LCI) in ADPKD. A retrospective cohort study was performed inhospital-admitted ADPKD patients with suspected CI. Clinical, imaging and surgicaldata were analyzed. Features of infected cysts were evaluated by PET/CT. Total kidney(TKV) and liver (TLV) volumes were measured by CT-derived multiplanar reconstruction.CI was detected in 18 patients who experienced 24 episodes during an interval of 30months (LCI in 12, KCI in 10 and concomitant infection in 2). Sensitivities of CT,magnetic resonance imaging and PET/CT were 25.0, 71.4, and 95.0%. Dysuria(P<0.05), positive urine culture (P<0.01), and previous hematuria (P<0.05)were associated with KCI. Weight loss (P<0.01) and increased C-reactive proteinlevels (P<0.05) were associated with LCI. PET/CT revealed that three or moreinfected cysts were present in 70% of the episodes. TKV was higher in kidney-affectedthan in LCI patients (AUC=0.91, P<0.05), with a cut-off of 2502 mL (72.7%sensitivity, 100.0% specificity). TLV was higher in liver-affected than in KCIpatients (AUC=0.89, P<0.01) with a cut-off of 2815 mL (80.0% sensitivity, 87.5%specificity). A greater need for invasive procedures was observed in LCI (P<0.01),and the overall mortality was 20.8%. This study supports PET/CT as the most sensitiveimaging method for diagnosis of cyst infection, confirms the multifocal nature ofmost hospital-admitted episodes, and reveals an association of kidney and livervolumes with this complication.