Clinical features of cyst infection and hemorrhage in ADPKD: new diagnostic criteria

Cyst infection and cyst hemorrhage are frequent and serious complications of autosomal dominant polycystic kidney disease (ADPKD), often being difficult to diagnose and treat. The first objective of this study is to clarify the clinical features of ADPKD patients with cyst hemorrhage or infection. The second objective is to establish diagnostic criteria for ADPKD patients with cyst infection or cyst hemorrhage. Patients with definite cyst infection or hemorrhage were enrolled from among the ADPKD patients referred to us between January 2004 and October 2011. We investigated their symptoms, laboratory data, and the computed tomography (CT)/magnetic resonance imaging (MRI) features of infected cysts (before and after onset), normal cysts, and cysts with hemorrhage. There were 24 patients with cyst infection (36 infected cysts) and 12 patients with acute cyst hemorrhage (13 bleeding cysts). White blood cell (WBC) count > 10,000/mu l, serum C-reactive protein (CRP) > 15.0 mg/dl, and body temperature > 38 A degrees C strongly suggested cyst infection. All of the cysts with hemorrhage contained a high-density mass-like area or showed overall high density on CT, and all patients with cyst hemorrhage had abdominal pain or gross hematuria. On the other hand, infected cysts showed an increase of intensity on MRI [diffusion-weighted imaging (DWI)], while a fluid-fluid level, wall thickening, and gas were also evidence of infection. Abdominal pain and/or sequential changes on MRI after onset of symptoms were useful for localizing infected cysts. Acute cyst hemorrhage and infection can be identified from symptoms, laboratory data, and CT/MRI findings.