Clinical experience with white blood cell-PET/CT in autosomal dominant polycystic kidney disease patients with suspected cyst infection: A prospective case series.

AIMS: Cyst infection (CI) is a common problem in patients with autosomal dominant polycystic kidney disease (ADPKD). Localization is of great importance in CI. We describe the clinical experience with [18F] FDG-labelled white-blood cell (WBC) PET/CT in detecting CI in ADPKD. METHODS: Nineteen ADPKD patients (M:F = 7:12) suspected of having CI were enrolled in this prospective study. All underwent WBC-PET/CT and MRI or CT. The degree of their WBC accumulation was evaluated from the maximal standardized uptake value of cystic wall. RESULTS: Cyst infection was diagnosed in 14 cases [definite (n = 6), probable (n = 1), or possible (n = 7); kidney (n = 11), or liver (n = 3)]. There was no difference in fever or laboratory findings (White blood cell count, C-reactive protein, culture results, and eGFR). The blood culture was positive only in a subset of CI patients (n = 4). Cyst fluid culture yielded bacterial growth in 80% of aspirates. WBC-PET/CT detected 64% of CI cases, whereas conventional imaging, 50%. WBC-PET/CT showed false-positive results in two of five cases with no CI. The reasons for false negatives with WBC-PET/CT were poor host immune reaction, low virulence, or prior antibiotic therapy. Haemorrhagic cysts were the most common cause of false positivity in WBC-PET/CT. However, WBC-PET/CT detected CI in three cases, in which the conventional imaging failed to find CI. CONCLUSIONS: Clinical information may play little role in the diagnosis of CI. WBC-PET/CT can be used to detect CI with better sensitivity in ADPKD patients, circumventing the exposure to contrast media.

Helicobacter cinaedi kidney cyst infection and bacteremia in a patient with autosomal dominant polycystic kidney disease.

A 48-year-old man with autosomal dominant polycystic kidney disease (ADPKD) was admitted to our hospital with a 5-day history of lower right back pain, high-grade fever, and arthralgia. He was diagnosed with right kidney cyst infection and bacteremia due to Helicobacter cinaedi (H. cinaedi) based on these symptoms, highly elevated CRP (32.25 mg/dL), abdominal magnetic resonance imaging findings, and the identification of H. cinaedi from blood cultures using PCR and sequence analysis of the 16S ribosomal DNA gene. Intravenous cefotaxime 0.5 g twice daily followed by meropenem 0.5 g twice daily and ciprofloxacin 200 mg twice daily were partially effective; oral doxycycline added at 200 mg/day finally eradicated the infection. Total duration of antimicrobial therapy was 9 weeks. H. cinaedi infections typically present as bacteremia with or without cellulitis in immunocompromised patients such as those with AIDS or malignant disease. To our knowledge, this is the first report describing an ADPKD patient with H. cinaedi cyst infection. Although H. cinaedi infections are increasingly recognized, even in immunocompetent subjects, numerous cases may still be overlooked given that this bacterium is slow-growing, and is difficult to culture, be Gram-stained, and identify on phenotypic tests. Consideration of this bacterium as a possible pathogen and sufficient duration of incubation with molecular testing are necessary in treating ADPKD patients with cyst infection.

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). The determinants of kidney and/or liver involvement, however, remain uncertain. In this study, we evaluated clinical and imaging factors associated with CI in kidney (KCI) and liver (LCI) in ADPKD. A retrospective cohort study was performed in hospital-admitted ADPKD patients with suspected CI. Clinical, imaging and surgical data 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 30 months (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 protein levels (P<0.05) were associated with LCI. PET/CT revealed that three or more infected cysts were present in 70% of the episodes. TKV was higher in kidney-affected than 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 KCI patients (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 sensitive imaging method for diagnosis of cyst infection, confirms the multifocal nature of most hospital-admitted episodes, and reveals an association of kidney and liver volumes with this complication.

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). The determinants of kidney and/or liver involvement, however, remain uncertain. In this study, we evaluated clinical and imaging factors associated with CI in kidney (KCI) and liver (LCI) in ADPKD. A retrospective cohort study was performed in hospital-admitted ADPKD patients with suspected CI. Clinical, imaging and surgical data 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 30 months (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 protein levels (P<0.05) were associated with LCI. PET/CT revealed that three or more infected cysts were present in 70% of the episodes. TKV was higher in kidney-affected than 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 KCI patients (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 sensitive imaging method for diagnosis of cyst infection, confirms the multifocal nature of most hospital-admitted episodes, and reveals an association of kidney and liver volumes with this complication.

Emphysematous polycystic infection in a patient on peritoneal dialysis.

Emphysematous infection of the cysts in patients with polycystic kidney disease is very rare and seldom reported. We herein report a case of emphysematous polycystic infection in a 61-year-old male patient who was on peritoneal dialysis for end-stage renal disease caused by adult polycystic kidney disease.

Multiple liver cyst infection caused by Salmonella ajiobo in autosomal dominant polycystic kidney disease.

Most Salmonella infections are usually self-limited; however, some cases of enteritis result in bacteremia, and there have been reports of extra-intestinal manifestations. Cyst infections are rare, and few cases have been reported. We report a 77-year-old woman with autosomal dominant polycystic kidney disease (ADPKD) complicated with a multiple liver cyst infection caused by Salmonella ajiobo. The patient was hospitalized for fever, abdominal pain, and diarrhea. The blood culture identified Salmonella sp., but the source of infection was not detected by computed tomography or echography. The patient was initially treated with meropenem followed by fluoroquinolones for 3 weeks; however, her C-reactive protein level was high (10-20 mg/dL) even after the antimicrobial therapy. The patient had a fever again on day 51, and Salmonella sp. was detected again from 2 sets of blood cultures. Despite the antimicrobial treatment, her general condition gradually deteriorated, and she died on day 66. The autopsy revealed that most of the liver had been replaced by cysts. Several cysts filled with pus were detected and Salmonella ajiobo was identified in the pus of the infected cysts.

Hemoperfusion treatment in a septic shock patient with autosomal dominant polycystic kidney disease and increased HMGB1 protein levels.

This case report describes polymyxin B-immobilized fiber (PMX-F) treatment of septic shock caused by pyelonephritis in a 68-year-old woman with autosomal dominant polycystic kidney disease. She was admitted for severe lower left abdominal pain, high fever (40°C) and gross hematuria. Her endotoxin and high-mobility group box-1 protein (HMGB1) levels were extremely elevated. Her blood pressure was 68/36 mm Hg. Urinalysis revealed innumerable white blood cells (WBCs). Blood and urine cultures were positive for Klebsiella pneumoniae and Pseudomonas aeruginosa. Plain abdominal radiography showed large kidney shadows and calcium deposition. Septic shock with endotoxemia was diagnosed. Her symptoms of septic shock persisted for 3 days with antibiotics, γ-globulin and dopamine. Direct hemoperfusion was performed twice with a PMX-F column. The patient's body temperature, WBC count and C-reactive protein level decreased. Her blood endotoxin level and blood HMGB1 level also decreased to an almost normal level. She was discharged on day 23 after admission.

Mycobacterium tuberculosis infection of a native polycystic kidney following renal transplantation.

Tuberculosis is a recognized complication following renal transplantation. Patients with autosomal-dominant polycystic kidney disease are increasingly being offered renal transplantation as an alternative to chronic hemodialysis. These patients are uniquely susceptible to serious upper urinary tract infections that are associated with significant morbidity and mortality. While involvement with gram-negative organisms is well described, mycobacterial infection of native polycystic kidneys after transplantation has not been addressed. We report a case of a renal transplant recipient who suffered an isolated Mycobacterium tuberculosis infection of a native polycystic kidney. With a 4-drug anti-tuberculosis therapy (ATT) regimen, the patient responded and became afebrile 8 weeks after initiation of drug therapy. ATT was continued for a total of 1 year. Two years after completion of ATT, the patient enjoys a normal life and has stable graft function. M. tuberculosis, though not common, must be recognized as a potential source of infection of native polycystic kidneys in immunocompromised transplant recipients. Similar to the pattern observed with more common pathogens, these infections may be difficult to eradicate with standard antimicrobial drug regimens.

MRI isolation of infected renal cyst in autosomal dominant polycystic kidney disease.

The use of gadolinium-enhanced magnetic resonance (MR) to isolate an infected renal cyst in the setting of autosomal dominant polycystic kidney disease (ADPKD) has not been previously described. A case in which T1- and T2-weighted and gadolinium-enhanced MR images were used to identify a single purulent cyst in a patient with ADPKD is herein presented. We suggest that gadolinium-enhanced MR be considered useful in the evaluation of ADPKD patients with suspected infected cyst.