Diagnostic Algorithm in the Management of Acute Febrile Abdomen in Patients with Autosomal Dominant Polycystic Kidney Disease

Performance of [18F]FDG PET/CT in Diagnosing Cyst Infections in Patients with Autosomal Dominant Polycystic Kidney Disease: A Systematic Review and a Bivariate Meta-Analysis

BACKGROUND

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) has been suggested as a useful imaging method for diagnosing cyst infections in patients with autosomal dominant polycystic kidney disease (ADPKD). The aim of this article is to provide evidence-based data in this setting.

METHODS

A systematic literature review (exploring several bibliographic databases) and a bivariate meta-analysis were carried out to calculate the pooled diagnostic performance of [18F]FDG PET/CT in diagnosing probable cyst infection in ADPKD.

RESULTS

Ten studies (282 PET/CT scans and 249 patients) were included in the analysis. The pooled sensitivity and specificity of [18F]FDG PET/CT in this setting were 84.6% (95% confidence interval: 75.4-90.7) and 94.9% (95% confidence interval: 72.6-99.2), respectively, without statistical heterogeneity or significant publication bias. [18F]FDG PET/CT significantly changed patient management in more than half of ADPKD patients with suspected cyst infection.

CONCLUSIONS

[18F]FDG PET/CT has high performance in diagnosing probable cyst infections in ADPKD patients with an impact on management in the majority of patients. Although more studies are warranted, the provided evidence-based data are an important step towards the integration of [18F]FDG PET/CT in clinical and diagnostic guidelines on probable cyst infection in ADPKD patients.

Standardized 4-point scoring scale of [18F]-FDG PET/CT imaging helps in the diagnosis of renal and hepatic cyst infections in patients with autosomal dominant polycystic kidney disease: a validation cohort

Background

Autosomal dominant polycystic kidney disease (ADPKD) is prone to multiple complications, including cyst infection (CyI). 2-Deoxy-2-[18F]fluoro-d-glucose positron emission tomography/computed tomography ([18F]-FDG PET/CT) imaging has proved useful in the diagnosis of renal and hepatic CyI. A 4-point scale comparing the uptake of [18F]-FDG in the suspected infected cyst versus the hepatic physiological background has been recently proposed. We performed an independent validation of this semi-quantitative scoring system.

Methods

All ADPKD patients hospitalized between January 2009 and November 2019 who underwent an [18F]-FDG PET/CT for suspected CyI were retrospectively identified using computer-based databases. Medical files were reviewed. CyI was conventionally defined by the combination of fever (≥38°C), abdominal pain, increased plasma C-reactive protein levels (≥70 mg/L), absence of any other cause of inflammation and favourable outcome after ≥21 days of antibiotics. [18F]-FDG uptake of the suspected CyI was evaluated using a 4-point scale comparing the uptake of [18F]-FDG around the infected cysts with the uptake in the hepatic parenchyma. Statistics were performed using SAS version 9.4.

Results

Fifty-one [18F]-FDG PET/CT scans in 51 patients were included, of which 11 were cases of CyI. The agreement between the 4-point scale and the gold-standard criteria of CyI was significant [odds ratio of 6.03 for CyI in case of a score ≥3 (P = .014)]. The corresponding sensitivity, specificity, and positive and negative predictive values of [18F]-FDG PET/CT using the 4-point scale were 64% [Clopper-Pearson 95% confidence interval (CI) 30%-89%], 78% (95% CI 62%-89%), 44% (95% CI 20%-70%) and 89% (95% CI 73%-97%), respectively.

Conclusions

Our independent validation cohort confirms the use of a semi-quantitative 4-point scoring system of [18F]-FDG PET/CT imaging in the diagnosis of CyI in patients with ADPKD. Considering its performance metrics with high specificity and negative predictive value, the scoring system is particularly useful to distinguish other causes of clinical inflammation than CyI and as such avoid unnecessarily long antibiotic treatment.

A Systematic Review of Reported Outcomes in ADPKD Studies

Introduction

Methods

Results

Conclusion

Incidence, risk factors and outcomes of kidney and liver cyst infection in kidney transplant recipient with autosomal dominant polycystic kidney disease

Introduction

Methods

Results

Conclusion

[What is evidence-based in the treatment of autosomal dominant polycystic kidney disease?]

The cystic transformation of the kidneys and liver are the most common symptoms of autosomal dominant polycystic kidney disease (prevalence 1:400-1:1000). A set of other manifestations can be observed less frequently, such as intracranial aneurysms. End-stage renal disease affects 50% of patients by the age of 70 years. To date, a targeted treatment is only available for patients at risk of rapidly progressive kidney failure. In 2015, the vasopressin receptor antagonist tolvaptan was approved in Germany for slowing down the decline of renal function in autosomal dominant polycystic kidney disease. Selecting the patients that benefit from tolvaptan treatment remains a major challenge. In recent years numerous clinical trials were carried out showing unspecific approaches to slow down the decline in renal function: strictly controlling blood pressure is one of the most important factors. Furthermore, unspecific approaches comprise suppression of vasopressin by sufficient fluid intake and restricted intake of salt. Weight reduction is recommended for obese patients. Lacking more causal approaches, these unspecific measures should be exploited in all patients. Currently, preclinical and clinical trials are testing numerous agents for the establishment of targeted treatment against the cystic degeneration of the kidneys and liver. This also includes dietary approaches. So far, in contrast to other genetic diseases, there are currently no gene therapy approaches for autosomal dominant polycystic kidney disease.

A practical guide for the management of acute abdominal pain with fever in patients with autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the development of numerous renal cysts leading to kidney enlargement and chronic kidney disease. Extra-renal manifestations, including polycystic liver disease and connective tissue defects, are frequently observed in ADPKD. Acute cyst complications, i.e. hemorrhage and infection, represent rare but severe conditions of ADPKD. The distinction between cystic versus non-cystic abdominal complications is often problematic. Here, we propose a practical guide for the diagnostic and therapeutic management of an "acute abdominal pain with fever" in patients with ADPKD.

FDG PET/CT for Detection of Infectious Complications Following Solid Organ Transplantation

Infectious complications after solid organ transplantation (SOT) are often more severe and remain a diagnostic challenge due to vague and atypical clinical presentations. Diagnostic performance of conventional diagnostic tools is frequently inadequate which may lead to delayed diagnosis with the risk of poorer outcomes. This literature review aimed to investigate the current evidence on the use of ¹⁸F-fluoro-deoxy-glucose (FDG) Positron Emission Tomography (PET)/computer tomography (CT) in infectious complications after SOT. Based on search in PubMed, Medline, and Cochrane databases, 13 articles and 46 case reports were included. For inclusion, articles were to include data on patients with infectious complications after SOT, and where FDG PET/CT was part of the work-up. Final searches were conducted on 02 September 2020. Overall, in the absence of initial diagnostic clues, FDG PET/CT should be considered as the imaging technique of choice as it may guide further investigations and eventually reveal the diagnosis in most of the patients. However, the available literature of the role of FDG PET/CT in SOT recipients with infectious complications is scarce and well-designed prospective studies including control groups are warranted to establish the role of FDG PET/C/ in SOT recipients. The main drawback of FDG PET/CT is the lack of ability to differentiate between cancer and infectious diseases which are both highly prevalent in this patient group. Accordingly, the main reasons for "false" results of FDG PET/CT is the misdiagnosis of cancer in benign inflammatory or infectious processes, information which nonetheless can be useful.

In-hospital management of acute complicated urinary tract infections

Upper tract urinary tract infections that require hospitalization have been the focus of national recommendations in 2018 by the French society of infectious diseases (Spilf). We here propose to discuss several complex-challenging situations: severe infection with sepsis, pyelonephritis in the pregnant woman, management of infections involving multiresistant bacteria and infection in polycystic kidney disease.

International consensus statement on the diagnosis and management of autosomal dominant polycystic kidney disease in children and young people

These recommendations were systematically developed on behalf of the Network for Early Onset Cystic Kidney Disease (NEOCYST) by an international group of experts in autosomal dominant polycystic kidney disease (ADPKD) from paediatric and adult nephrology, human genetics, paediatric radiology and ethics specialties together with patient representatives. They have been endorsed by the International Pediatric Nephrology Association (IPNA) and the European Society of Paediatric Nephrology (ESPN). For asymptomatic minors at risk of ADPKD, ongoing surveillance (repeated screening for treatable disease manifestations without diagnostic testing) or immediate diagnostic screening are equally valid clinical approaches. Ultrasonography is the current radiological method of choice for screening. Sonographic detection of one or more cysts in an at-risk child is highly suggestive of ADPKD, but a negative scan cannot rule out ADPKD in childhood. Genetic testing is recommended for infants with very-early-onset symptomatic disease and for children with a negative family history and progressive disease. Children with a positive family history and either confirmed or unknown disease status should be monitored for hypertension (preferably by ambulatory blood pressure monitoring) and albuminuria. Currently, vasopressin antagonists should not be offered routinely but off-label use can be considered in selected children. No consensus was reached on the use of statins, but mTOR inhibitors and somatostatin analogues are not recommended. Children with ADPKD should be strongly encouraged to achieve the low dietary salt intake that is recommended for all children.

A Case Report of Autosomal Dominant Polycystic Kidney Disease Under Peritoneal Dialysis With Cyst Infection and Culture-Positive Peritoneal Fluid

Background:

Cyst infection is a complication sometimes seen in patients with autosomal dominant polycystic kidney disease (ADPKD) and often shows through a positive blood culture. However, there have been no reports of ADPKD patients whose cyst infection propagate to peritoneal fluid leading to positive peritoneal fluid culture.

Case presentation:

A 74-year-old Japanese man with ADPKD under peritoneal dialysis (PD) was presented with left flank pain, fever, and chills at our hospital. He did not show any symptoms or signs suggestive of peritonitis. There were no elevated cell counts or polymorphonuclear leucocytes in his PD fluid. There were some complicated cysts found in computed tomography and magnetic resonance imaging examinations. We clinically diagnosed him as having a renal cyst infection rather than PD-related peritonitis. We initiated treatment by administering ceftriaxone with an immediate favorable response. As the possibility of accompanying prostatitis still remained, we switched to intravenous levofloxacin on the second day. On the 10th day, Helicobacter cinaedi was detected in 2 sets of blood culture as well as in PD fluid. We switched back to ceftriaxone and this treatment was entirely successful.

Conclusions:

This is the first report of H cinaedi cyst infection which propagates to peritoneal fluid in a patient with ADPKD.

[18F-FDG positron emission tomography in non-oncological renal pathology: Current indications and perspectives]

Positron emission tomography combined with computed tomography (PET/CT) is a nuclear imaging technique which provides anatomical and functional information. PET/CT is increasingly used in non-oncological nephrology since conventional radiological approaches after injection of contrast agents are relatively contra-indicated in patients with chronic kidney disease (CKD). PET/CT after i.v. injection of ¹⁸F-fluoro-deoxy-glucose (FDG) is not toxic and is characterized by a high sensitivity. The level of irradiation (∼5mSv) is acceptable. CKD does not significantly influence tissue uptake of ¹⁸F-FDG. The purpose of the present review aims at detailing the non-oncological indications of ¹⁸F-FDG PET/CT in general nephrology and after kidney transplantation. Particularly, ¹⁸F-FDG PET/CT appears useful in the diagnosis of cyst infection in patients with autosomal dominant polycystic kidney disease, as well as in the characterization of retroperitoneal fibrosis. In kidney transplant recipients, ¹⁸F-FDG PET/CT may help in the diagnostic work-up of suspected acute rejection, thereby eventually avoiding unnecessary kidney transplant biopsy. Perspectives in ¹⁸F-FDG PET/CT imaging are discussed, including innovative approaches of image analysis.

Polycystic kidney disease

Cystic kidneys are common causes of end-stage renal disease, both in children and in adults. Autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD) are cilia-related disorders and the two main forms of monogenic cystic kidney diseases. ADPKD is a common disease that mostly presents in adults, whereas ARPKD is a rarer and often more severe form of polycystic kidney disease (PKD) that usually presents perinatally or in early childhood. Cell biological and clinical research approaches have expanded our knowledge of the pathogenesis of ADPKD and ARPKD and revealed some mechanistic overlap between them. A reduced 'dosage' of PKD proteins is thought to disturb cell homeostasis and converging signalling pathways, such as Ca²⁺, cAMP, mechanistic target of rapamycin, WNT, vascular endothelial growth factor and Hippo signalling, and could explain the more severe clinical course in some patients with PKD. Genetic diagnosis might benefit families and improve the clinical management of patients, which might be enhanced even further with emerging therapeutic options. However, many important questions about the pathogenesis of PKD remain. In this Primer, we provide an overview of the current knowledge of PKD and its treatment.

Infected cyst in patients with autosomal dominant polycystic kidney disease: Analysis of computed tomographic and ultrasonographic imaging features

Purpose

To investigate the imaging features of cyst infection in autosomal dominant polycystic kidney disease (ADPKD) patients using computed tomography (CT) and ultrasonography (US).

Materials & methods

The institutional review board approved this retrospective study. Fifty-one episodes with proven cyst infection in forty-three ADPKD patients were included. Two experienced abdominal radiologists reviewed CT and US images and evaluated the following imaging features in consensus: cyst size, location, cyst shape, intracystic attenuation, intracystic echogenicity, intracystic heterogeneity, wall thickness, the presence of fluid-fluid level, septation, intracystic gas, pericystic fat infiltration, and pericystic hyperemia. Intracystic attenuation was measured for all infected cysts and two presumed normal cysts and compared using the Wilcoxon rank-sum test.

Results

On CT scans, the median size of infected cysts was 5.5 cm (range: 2.3–18.8 cm) and 46 of 51 (90.2%) infected cysts were located in the subcapsular region. Most (48 of 51, 94.1%) infected cysts showed lobulated, focal bulging or irregular shape. Discernible wall thickening (84.1%) was the most frequently found imaging feature of infected cysts followed by relatively higher intracystic attenuation compared to normal cysts (79.1%) and pericystic fat infiltration (52.9%). Fluid/fluid level was found in 3 of 51 (5.9%) infected cysts and intracystic gas was found in 3 of 51 (5.9%) infected cysts, respectively. For hepatic cysts, 11 of 14 (78.6%) infected cysts showed pericystic hyperemia. Intracystic attenuation was significantly higher in infected cysts (median; 19.0 HU) than in presumed normal cysts (median; 8.5 HU) (P<0.001), and exceeded 25 HU in 18 (35.3%) of 51 infected cysts. Among the 41 infected cysts for which US images were available, 35 (85.1%) showed heterogeneous echogenicity.

Conclusion

Minute imaging features such as minimal wall thickening or relatively high attenuation compared to normal cysts would be helpful to detect infected cysts in ADPKD patients.

The Risk of Adverse Events in Patients With Polycystic Kidney Disease With Advanced Chronic Kidney Disease

Background:

Polycystic kidney disease (PKD) leads to progressive chronic kidney disease (CKD) with a subsequent risk of adverse events such as cardiac disease, infections, end-stage kidney disease (ESKD), and mortality.

Objectives:

To determine the risks of CKD-related adverse outcomes in patients with PKD compared with patients without PKD.

Setting:

Canadian study of prediction of death, dialysis and interim cardiovascular events (CanPREDDICT) was a prospective pan-Canadian cohort study from 2008-2013 involving 28 facilities with adjudicated outcomes.

Patients:

Adult CKD patients (estimated glomerular filtration rate [eGFR] = 15-45 mL/min/1.73 m²) under the care of a nephrologist.

Measurements:

Polycystic kidney disease as identified by the treating physician.

Methods:

Patients with PKD (PKD) and non-PKD were propensity score (PS) matched (1:4) using demographics, comorbidities, and laboratory values. We used conditional Cox proportional hazards models to examine the risk of cardiac disease (defined as coronary artery disease or congestive heart failure), infection, ESKD, or all-cause mortality in patients with PKD compared with no PKD.

Results:

Among a total of 2370 patients, 105 with PKD were matched with 416 without PKD with a baseline mean age and eGFR of 62.6 years and 27.8 mL/min, respectively. During 1680 person-years of follow time (median follow-up: 3.8 years), there were a total of 43 cardiac, 83 ESKD, 117 infectious, and 39 all-cause mortality events. PKD was associated with a higher risk of cardiac events (9.5% vs 7.9%, hazard ratio [HR] = 1.46, 95% confidence interval [CI] = 1.04-2.04) and ESKD (25.7% vs 13.5%, HR = 2.00, 95% CI = 1.33-3.01), and with similar risks for infection (21.9% vs 22.6%, HR = 1.16, 95% CI = 0.75-1.82) or all-cause mortality (6.7% vs 7.7%, HR = 0.87, 95% CI = 0.40-1.91) compared with non-PKD. There were no differences in the types of infections (urinary, respiratory, hematologic, or other) between the 2 groups (P = .585).

Conclusions:

Patients with PKD with advanced CKD are at a potentially higher risk of ESKD and cardiac events compared with patients without PKD. These findings, if confirmed in larger cohorts, suggest that monitoring and treatment for adverse outcomes in patients with PKD, especially related to cardiac disease, may be beneficial.

18F-FDG PET/CT in Autosomal Dominant Polycystic Kidney Disease Patients with Suspected Cyst Infection

The objective of this study was to determine the value of ¹⁸F-FDG PET/CT for diagnosing renal or hepatic cyst infection in patients with autosomal dominant polycystic kidney disease (ADPKD). Methods: This retrospective, single-center study included all patients who had ADPKD and underwent ¹⁸F-FDG PET/CT because of suspected cyst infection between 2010 and 2017. Results: Thirty ¹⁸F-FDG PET/CT scans of 30 individual patients were included; 19 of them had positive results for cyst infection. According to a previously established clinical and biochemical reference standard, ¹⁸F-FDG PET/CT achieved a sensitivity of 88.9%, a specificity of 75.0%, a positive predictive value of 84.2%, and a negative predictive value of 81.8% for the diagnosis of cyst infection. In 5 cases, ¹⁸F-FDG PET/CT suggested that the symptoms could be explained by a different pathologic process, including pneumonia (n = 1), generalized peritonitis (n = 1), pancreatitis (n = 1), colitis (n = 1), and cholangitis (n = 1). The total duration of the hospital stay and the duration between the ¹⁸F-FDG PET/CT scan and hospital discharge for patients with ¹⁸F-FDG PET/CT scan results that were positive for cyst infection were significantly longer than those for patients with negative scan results (P = 0.005 and P = 0.009, respectively). Creatinine levels were significantly higher in patients with ¹⁸F-FDG PET/CT scan results that were positive for cyst infection than in patients with negative scan results (P = 0.015). Other comparisons of clinical parameters (age, sex, presence of fever [>38.5°C] for more than 3 d, abdominal pain, history of solid-organ transplantation and nephrectomy, and immune status), laboratory values (C-reactive protein level, leukocyte count, and estimated glomerular filtration rate), and microbiologic test results (blood and urine cultures) were not significantly different (P = 0.13-1.00) in patients with positive and negative ¹⁸F-FDG PET/CT scan results. Conclusion: ¹⁸F-FDG PET/CT is a useful imaging modality for the evaluation of patients with ADPKD and suspected cyst infection.

Hepatointestinal complications in polycystic kidney disease

Background

The objective of this study was to determine the incidence of major hepatointestinal complications in patients with polycystic kidney disease (PKD).

Methods

We analyzed the Taiwan National Health Insurance claims data (2000-2010) of 6031 patients with PKD and 23,976 non-PKD hospitalized controls. The control cohort was propensity score matched with the PKD cohort at a 1:4 ratio. All patients were followed up from the index date to the first inpatient diagnosis of hepatointestinal complications, death, or 31 December, 2011. Cox proportional hazard regression models were used to identify the risk of outcome after adjustment for potential confounders.

Results

The incidence rates of acute pancreatitis, cholangitis, peptic ulcer bleeding, and cirrhosis were 5.72, 4.01, 19.9, and 5.46 per 1000 person-years, respectively, in the PKD cohort. Compared with the non-PKD controls, patients with PKD exhibited an increased risk of hospitalization for acute pancreatitis, cholangitis, peptic ulcer bleeding, and cirrhosis (adjusted subhazard ratio [aSHR]: 2.36, 95% confidence interval [95% CI], 1.95-2.84]; 2.36, [95% CI, 1.95-2.84]; 2.41, [95% CI, 1.93-3.01]; 2.41, [95% CI, 2.17-2.67]; and 1.39, [95% CI, 1.16-1.66], respectively; all p < 0.001). PKD, chronic kidney disease, and alcoholism were independent predictors of all these hepatointestinal complications. Kaplan-Meier analysis revealed an increased overall mortality in patients with PKD who developed acute pancreatitis and peptic ulcer bleeding (log-rank p < 0.05).

Conclusion

PKD is associated with clinically significant extrarenal complications including acute pancreatitis, cholangitis, peptic ulcer bleeding, and cirrhosis.

Infected renal cyst presented with pleural effusion in a woman with autosomal dominant polycystic kidney disease

We present a 64-year-old woman with autosomal dominant polycystic kidney disease and hepatic cysts admitted to our hospital for high fever, intense coughing and right abdominal pain. The chest X-ray showed right pleural effusion suggestive of pneumonia. An abdominal ultrasound and computed tomography (CT) were done but did not show evidence of cyst infection or other abdominal complications. A gallium-67-citrate single-photon emission CT/CT, a relatively cheaper technique than positron emission tomography/CT was performed. This revealed an infected kidney cyst that was the cause of the right pleural effusion and fever.

The Role of PET Scanning in the Evaluation of Patients With Kidney Disease

Patients with underlying kidney disease are often required to undergo imaging for a variety of purposes including diagnosis and prognosis. A test that is being increasingly used with for this group of patients is the positron emission test (PET) scan. In addition, combining the nuclear medicine technique (PET) with computed tomography scan allows additional imaging advantages over either alone. These imaging modalities are commonly used for a number of extrarenal indications (ie, cancer, coronary artery disease, central nervous system disease, infectious diseases, and others). They have also been used for diagnosis of acute tubulointerstitial nephritis, evaluation and management of retroperitoneal fibrosis, identifying infection within kidney and liver cysts, and distinguishing complex kidney cysts from kidney cancer in patients with underlying CKD. We will review PET scan utility in patients with kidney disease.