#2898 Treatment outcomes of liver cyst infection in patients with autosomal dominant polycystic kidney disease

Abstract Background and Aims Liver cyst infection (LCI) is a rare and severe complication of autosomal dominant polycystic kidney disease (ADPKD), and evidence-based data for optimal management is lacking. Method We conducted a multicentric retrospective study (from 2012 to 2024) to investigate the treatment and outcomes of LCI. LCI was either defined by (i) C-reactive protein levels ≥50 mg/L and suspicion at computed tomography scan, 18Fluorodeoxyglucose (18FDG) positron-emission tomography computed tomography (PET/CT), magnetic resonance imaging, or (ii) proven by cyst puncture. We studied the determinants of treatment failure (persistent infection with requirement for antibiotic therapy (ATBT) change, cyst drainage, hepatectomy), relapse (<2 months) and recurrence (>2 months) of LCI after ATBT discontinuation, using multivariate analysis. Results Sixty-two patients and 112 episodes were included. At least one microorganism was identified in 70/112 (63%) episodes, mainly Escherichia coli in 36/70 (51%) of cases. E. coli was resistant to 3rd generation cephalosporin, fluoroquinolone or cotrimoxazole in 13%, 16% and 34%, respectively. Treatment failure and relapse occurred in 30/112 (27%) episodes, including 5 episodes requiring cyst drainage and 1 episode requiring partial hepatectomy. Risk factors for treatment failure/relapses included an ATBT duration <14 days (OR = 39, IC 95% [3.56;427], P = 0.002) and a WBC count >15.000/mm3 (OR =13, IC 95% [2.27; 74.50], P = 0.003). When treatment failure and relapses were analyzed separately, WBC >15.000/mm3 was a risk factor for treatment failure (OR = 9.2, IC 95% [1.68; 50.42], P = 0.009) and ATBT duration <14 days was a risk factor for relapses (OR = 25, IC 95% [3.38; 192.33], P = 0.001). Recurrence occurred in 24/62 (38%) patients, within 1 year for 15 (24%) after the 1st episode. ATBT duration <28 days (OR = 9.22, IC 95% [2.19; 50.08], P = 0.04) and history of renal cyst infection (OR = 5.90, IC 95% [1.11; 37.74], P = 0.04) increased the risk of recurrence <1 year. Follow-up 18FDG-PET/CT was performed in 19 episodes within 64 [54–95] days post LCI diagnosis. Among them, 17 were followed at least 1 year after follow-up 18FDG-PET/CT: 6/8 (75%) and 3/9 (33%) patients with and without persistent liver cyst uptake, respectively, had relapse or recurrent LCI <1 year (P = 0.15). Neither fluoroquinolone nor dual ATBT reduced the risk of treatment failure/relapse or recurrence. No death was attributed to LCI. Conclusion Treatment failure/relapse or recurrence of LCI both occurred in one-third of cases, and are associated with a shorter ATBT duration <28 days.