Polycystic liver disease: a clinical review

Imaging features and management of focal liver lesions

Notably, the number of incidentally detected focal liver lesions (FLLs) has increased dramatically in recent years due to the increased use of radiological imaging. The diagnosis of FLLs can be made through a well-documented medical history, physical examination, laboratory tests, and appropriate imaging methods. Although benign FLLs are more common than malignant ones in adults, even in patients with primary malignancy, accurate diagnosis of incidental FLLs is of utmost clinical significance. In clinical practice, FLLs are frequently evaluated non-invasively using ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). Although US is a cost-effective and widely used imaging method, its diagnostic specificity and sensitivity for FLL characterization are limited. FLLs are primarily characterized by obtaining enhancement patterns through dynamic contrast-enhanced CT and MRI. MRI is a problem-solving method with high specificity and sensitivity, commonly used for the evaluation of FLLs that cannot be characterized by US or CT. Recent technical advancements in MRI, along with the use of hepatobiliary-specific MRI contrast agents, have significantly improved the success of FLL characterization and reduced unnecessary biopsies. The American College of Radiology (ACR) appropriateness criteria are evidence-based recommendations intended to assist clinicians in selecting the optimal imaging or treatment option for their patients. ACR Appropriateness Criteria Liver Lesion-Initial Characterization guideline provides recommendations for the imaging methods that should be used for the characterization of incidentally detected FLLs in various clinical scenarios. The American College of Gastroenterology (ACG) Clinical Guideline offers evidence-based recommendations for both the diagnosis and management of FLL. American Association for the Study of Liver Diseases (AASLD) Practice Guidance provides an approach to the diagnosis and management of patients with hepatocellular carcinoma. In this article, FLLs are reviewed with a comprehensive analysis of ACR Appropriateness Criteria, ACG Clinical Guideline, AASLD Practice Guidance, and current medical literature from peer-reviewed journals. The article includes a discussion of imaging methods used for the assessment of FLL, current recommended imaging techniques, innovations in liver imaging, contrast agents, imaging features of common nonmetastatic benign and malignant FLL, as well as current management recommendations.

Liver transplant recipients with polycystic liver disease have longer waiting times but better long-term clinical outcomes than those with liver disease due to other causes: A retrospective cross-sectional study

INTRODUCTION

Liver transplantation is the only curative option for patients with polycystic liver disease (PLD). In the United Kingdom, these patients are listed on the variant syndrome list due to their preserved liver function reflected in the United Kingdom End-stage Liver Disease (UKELD) score. The transplantation and survival rates for this patient group in the UK have not been previously reported.

METHODS

A retrospective cross-sectional analysis of patients receiving liver transplantation between 2010 and 2017 was performed using the NHS blood and transplantation database. This database contains the demographic, clinical parameters, indication for transplantation and follow-up of all patients in UK-based transplant centres. Basic statistics was performed using SPSS version 27.

RESULTS

5412 recipients received elective liver allografts in the study period. 1.6% (100) of recipients had PLD as their primary indication for transplantation with 60 receiving liver only allografts and 40 receiving combined liver-kidney allografts. PLD patients had a >3-fold longer mean waiting time for transplantation compared to non-PLD patients, 508 days v 154 days respectively. PLD patients receiving combined liver-kidney allografts had a longer waiting time than those receiving a liver only allograft, 610 days v 438 days respectively. There were comparable patient survival rates for people with PLD and non-PLD primary indications at 30 days (94.0% vs 97.6%) and 1 year (92.0% vs 93.2%) but improved survival rates at 5 years (81.3% vs 76.5%). There were also comparable allograft survival rates for people with PLD and non-PLD primary indications at 30 days (93.9% vs 95.3%) and 1 year (91.9% vs 91.2%) but improved survival rates at 5 years (82.5% vs 77.3%). Transplant centre-level analysis identified variation in the proportion of liver transplantations for people with PLD as their primary listed indication.

CONCLUSIONS

Patients with PLD wait significantly longer for liver transplantation compared to other indications. However, transplanted PLD patients demonstrate better longer-term patient and liver allograft survival rates compared to transplanted non-PLD patients. The unexpected variation between individual UK centres transplanting for PLD deserves further study.

Isolated polycystic liver disease in a child

INTRODUCTION

Polycystic liver disease (PCLD) is a genetic disorder characterized by the growth of >10 cysts in the liver. PCLD is associated with polycystic kidney disease (PKD) in 80-90%of cases (Kothadia et al., 2023 [1]). PCLD can occur in isolation though rarely in children. We present a case report of a child with symptomatic isolated PCLD.

CASE PRESENTATION

A 23-month old female child presented with a 17-month history of gradual increase in abdominal mass. She had acute onset of postprandial vomiting and shortness of breath while lying flat. On examination, she was irritable with massive abdominal distension. Liver function test done showed markedly elevated liver enzymes with preservation of liver synthesis function. Computed tomography (CT) scan showed a large intra-abdominal cyst and normal kidneys bilaterally. During laparotomy, we found multiple exophytic cysts arising from segment IVa of the liver. Hepatic resection was done successfully and patient recovered uneventfully. Histology showed Von Meyenburg complexes characteristic of PCLD.

CLINICAL DISCUSSION

The goal of management should be to counter symptomatology by intervening on developed cysts. The therapeutic options are individualized to address the symptoms and improve the patients' quality of life. Follow up of the patients is based on the presentation and intervention performed, during which period recurrence of cysts is assessed. Complete resection of the liver cysts is recommended to avoid the risk of cholangiocarcinoma.

CONCLUSION

Close follow up by physical examination, laboratory tests and imaging modalities is necessary to detect any recurring masses and malignancy transformation of the cysts to enable timely intervention.

Factors Associated With the Development and Severity of Polycystic Liver in Patients With Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Factors related to the development and severity of polycystic liver disease (PLD) have not been well established. We aimed to evaluate the genetic and epidemiologic risk factors of PLD in patients with autosomal dominant polycystic kidney disease (ADPKD).

METHODS

Adult patients with inherited cystic kidney disease were enrolled from May 2019 to May 2021. Demographic, clinical, and laboratory data were collected at the initial study visit. The severity of PLD was graded based on the height-adjusted total liver volume: < 1,000 mL/m (Gr1), 1,000-1,800 mL/m (Gr2), and > 1,800 mL/m (Gr3). Targeted exome sequencing was done by a gene panel including 89 ciliopathy-related genes. We searched out the relative factors to the presence and the severity of PLD using logistic regression analysis.

RESULTS

Of 602 patients with typical ADPKD, 461 (76.6%) patients had PLD. The patients with PLD showed female predominance and a higher frequency of other ADPKD-related complications. The genetic variants with truncating mutation of PKD1 (PKD1-protein-truncating [PT]) or PKD2 commonly affected the development and severity of PLD. An older age, female sex, and higher kidney volume with Mayo classification 1C-1E was significantly associated with the development of PLD, but not with the severity of PLD. On the other hand, higher body mass index, lower hemoglobin, and higher alkaline phosphatase (ALP) were the significant risk factors of severe PLD (≥ Gr2).

CONCLUSION

Hepatic involvement in ADPKD could be related to kidney manifestations and genetic variants including PKD1-PT or PKD2. Monitoring hemoglobin and ALP and evaluating the genetic variants might help predict severe PLD.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0005580.

Usefulness of intraoperative transesophageal echocardiography for hemodynamic management of liver transplantation in a patient with massive polycystic liver disease: a case report

BACKGROUND

Hemodynamic management during anesthesia in liver transplantation for patients with polycystic liver disease (PLD) can be more challenging because of the bleeding and hemodynamic alterations due to the markedly enlarged liver. We hereby report a case of PLD wherein transesophageal echocardiography (TEE) was employed for optimal hemodynamic monitoring during liver transplantation.

CASE PRESENTATION

A 61-year-old man was scheduled to undergo liver transplantation for massive PLD. Hemodynamic instability was associated with mechanical displacement of the giant cystic liver. TEE results revealed the collapse of the inferior vena cava due to liver displacement. TEE also detected intrathoracic hemorrhage triggered by detachment from the markedly enlarged liver.

CONCLUSION

TEE is a valuable monitoring tool for sharing information with surgeons and diagnostic modality for finding the source of bleeding in liver transplantation for PLD and may contribute majorly to the quality of perioperative management.

Novel α-1,3-Glucosyltransferase Variants and Their Broad Clinical Polycystic Liver Disease Spectrum

Protein-truncating variants in α-1,3-glucosyltransferase (ALG8) are a risk factor for a mild cystic kidney disease phenotype. The association between these variants and liver cysts is limited. We aim to identify pathogenic ALG8 variants in our cohort of autosomal dominant polycystic liver disease (ADPLD) individuals. In order to fine-map the phenotypical spectrum of pathogenic ALG8 variant carriers, we performed targeted ALG8 screening in 478 ADPLD singletons, and exome sequencing in 48 singletons and 4 patients from two large ADPLD families. Eight novel and one previously reported pathogenic variant in ALG8 were discovered in sixteen patients. The ALG8 clinical phenotype ranges from mild to severe polycystic liver disease, and from innumerable small to multiple large hepatic cysts. The presence of <5 renal cysts that do not affect renal function is common in this population. Three-dimensional homology modeling demonstrated that six variants cause a truncated ALG8 protein with abnormal functioning, and one variant is predicted to destabilize ALG8. For the seventh variant, immunostaining of the liver tissue showed a complete loss of ALG8 in the cystic cells. ALG8-associated ADPLD has a broad clinical spectrum, including the possibility of developing a small number of renal cysts. This broadens the ADPLD genotype-phenotype spectrum and narrows the gap between liver-specific ADPLD and kidney-specific ADPKD.

Combined liver-kidney transplant in polycystic diseases: a case report

Polycystic liver disease, a hereditary pathology, usually manifests as autosomal dominant polycystic kidney disease. The many cysts in the liver cause massive hepatomegaly, majorly affecting the patient's quality of life. In cases of refractory symptoms, liver transplantation is the only treatment choice. A 43-year-old woman was followed up as a hepatology outpatient in August 2020, with a progressive increase in abdominal volume, lower limb edema, and cachexia. The patient was diagnosed with polycystic renal and liver disease with massive hepatomegaly in March 2021, a combined kidney-liver transplant. Liver size represented 13% of the patient's corporal composition, weighing 8.6kg. The patient was discharged on the 7th postoperative day with no complications. Only 10-20% of patients with polycystic liver disease have clinical manifestations, most of which result from hepatomegaly. An increase in liver volume deteriorates liver function until the condition becomes end-stage liver disease, as kidney function is already compromised; liver-kidney transplantation remains the only treatment choice. The case described drew significant attention to the massive hepatomegaly presented in the patient, with the liver representing over 10% of the patient's body weight, approximately five to six times larger than a normal-sized liver.

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e Interventistica (SIRM), Società Italiana di Chirurgia (SIC), Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB), Associazione Italiana di Chirurgia Epatobilio-Pancreatica (AICEP), Società Italiana Trapianti d'Organo (SITO), Società Italiana di Anatomia Patologica e Citologia Diagnostica (SIAPEC-IAP) - Part I - Cystic lesions

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicated document. This document was drawn up according to the present Italian rules and methodologies necessary to produce clinical, diagnostic, and therapeutic guidelines based on evidence. Here we present the first part of the guideline, concerning the characterization of focal hepatic lesions detected by ultrasound, and the diagnosis and clinical management of simple and parasitic hepatic cysts, and of polycystic liver disease.

Polycystic Liver Disease: Pathophysiology, Diagnosis and Treatment

Polycystic liver disease (PLD) is a clinical condition characterized by the presence of more than 10 cysts in the liver. It is a rare disease Of genetic etiology that presents as an isolated disease or assoc\iated with polycystic kidney disease. Ductal plate malformation, ciliary dysfunction, and changes in cell signaling are the main factors involved in its pathogenesis. Most patients with PLD are asymptomatic, but in 2–5% of cases the disease has disabling symptoms and a significant reduction in quality of life. The diagnosis is based on family history of hepatic and/or renal polycystic disease, clinical manifestations, patient age, and polycystic liver phenotype shown on imaging examinations. PLD treatment has evolved considerably in the last decades. Somatostatin analogues hold promise in controlling disease progression, but liver transplantation remains a unique curative treatment modality.

Genetics, pathobiology and therapeutic opportunities of polycystic liver disease

Polycystic liver diseases (PLDs) are inherited genetic disorders characterized by progressive development of intrahepatic, fluid-filled biliary cysts (more than ten), which constitute the main cause of morbidity and markedly affect the quality of life. Liver cysts arise in patients with autosomal dominant PLD (ADPLD) or in co-occurrence with renal cysts in patients with autosomal dominant or autosomal recessive polycystic kidney disease (ADPKD and ARPKD, respectively). Hepatic cystogenesis is a heterogeneous process, with several risk factors increasing the odds of developing larger cysts. Depending on the causative gene, PLDs can arise exclusively in the liver or in parallel with renal cysts. Current therapeutic strategies, mainly based on surgical procedures and/or chronic administration of somatostatin analogues, show modest benefits, with liver transplantation as the only potentially curative option. Increasing research has shed light on the genetic landscape of PLDs and consequent cholangiocyte abnormalities, which can pave the way for discovering new targets for therapy and the design of novel potential treatments for patients. Herein, we provide a critical and comprehensive overview of the latest advances in the field of PLDs, mainly focusing on genetics, pathobiology, risk factors and next-generation therapeutic strategies, highlighting future directions in basic, translational and clinical research.

Molecular Mechanisms of Isolated Polycystic Liver Diseases

Polycystic liver disease (PLD) is a rare autosomal dominant disorder including two genetically and clinically distinct forms: autosomal dominant polycystic kidney disease (ADPKD) and isolated polycystic liver disease (PCLD). The main manifestation of ADPKD is kidney cysts, while PCLD has predominantly liver presentations with mild or absent kidney cysts. Over the past decade, PRKCSH, SEC63, ALG8, and LRP5 have been candidate genes of PCLD. Recently, more candidate genes such as GANAB, SEC61B, and ALR9 were also reported in PCLD patients. This review focused on all candidate genes of PCLD, including the newly established novel candidate genes. In addition, we also discussed some other genes which might also contribute to the disease.

Volume Progression and Imaging Classification of Polycystic Liver in Early Autosomal Dominant Polycystic Kidney Disease

BACKGROUND AND OBJECTIVES

The progression of polycystic liver disease is not well understood. The purpose of the study is to evaluate the associations of polycystic liver progression with other disease progression variables and classify liver progression on the basis of patient's age, height-adjusted liver cystic volume, and height-adjusted liver volume.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Prospective longitudinal magnetic resonance images from 670 patients with early autosomal dominant polycystic kidney disease for up to 14 years of follow-up were evaluated to measure height-adjusted liver cystic volume and height-adjusted liver volume. Among them, 245 patients with liver cyst volume >50 ml at baseline were included in the longitudinal analysis. Linear mixed models on log-transformed height-adjusted liver cystic volume and height-adjusted liver volume were fitted to approximate mean annual rate of change for each outcome. The association of sex, body mass index, genotype, baseline height-adjusted total kidney volume, and Mayo imaging class was assessed. We calculated height-adjusted liver cystic volume ranges for each specific age and divided them into five classes on the basis of annual percentage increase in height-adjusted liver cystic volume.

RESULTS

The mean annual growth rate of height-adjusted liver cystic volume was 12% (95% confidence interval, 11.1% to 13.1%; P<0.001), whereas that for height-adjusted liver volume was 2% (95% confidence interval, 1.9% to 2.6%; P<0.001). Women had higher baseline height-adjusted liver cystic volume than men, but men had higher height-adjusted liver cystic volume growth rate than women by 2% (95% confidence interval, 0.4% to 4.5%; P=0.02). Whereas the height-adjusted liver cystic volume growth rate decreased in women after menopause, no decrease was observed in men at any age. Body mass index, genotype, and baseline height-adjusted total kidney volume were not associated with the growth rate of height-adjusted liver cystic volume or height-adjusted liver volume. According to the height-adjusted liver cystic volume growth rate, patients were classified into five classes (number of women, men in each class): A (24, six); B (44, 13); C (43, 48); D (28, 17); and E (13, nine).

CONCLUSIONS

Compared with height-adjusted liver volume, the use of height-adjusted liver cystic volume showed greater separations in volumetric progression of polycystic liver disease. Similar to the Mayo imaging classification for the kidney, the progression of polycystic liver disease may be categorized on the basis of patient's age and height-adjusted liver cystic volume.

A Rare Case of Pelvic Organ Prolapse in a Nulliparous Female With Autosomal Dominant Polycystic Kidney Disease (ADPKD) and Polycystic Liver Disease (PLD)

Polycystic liver disease (PLD) is a condition that most often occurs in patients with autosomal dominant polycystic kidney disease (ADPKD) and less commonly as isolated liver disease. The presence of both conditions has proven to be a therapeutic challenge. Patients with ADPKD can suffer from significant renal and extra-renal complications and symptoms as a result of space-occupying cysts from polycystic kidney and liver enlargement. We present a case of ADPKD in a 56-year-old Caucasian female who developed pelvic organ prolapse, a rare complication, while also dealing with multiple other complications of ADPKD. Despite the high prevalence of ADPKD, complications such as pelvic organ prolapse have seldom been reported and discussed in the literature. The care team should do a prompt gynecological examination when they realize the burden of cysts becomes so large.

Preserving the organ donor pool and suprahepatic vena cava: Case series of transverse hepatectomy for polycystic liver disease

Management of symptomatic polycystic liver disease (PLD) has remained primarily unchanged since the early 20th century when multiple case reports described management of non-parasitic liver cysts. In 1968, Lin et al. described the fenestration procedure, "aspiration of the cysts, incision, partial excision with or without external drainage, or marsupilization and anastomosis to the gastrointestinal tract". Further surgical options have included cyst sclerotherapy, laparoscopic cyst aspiration, partial hepatectomy, and orthotopic liver transplant (OLT). Recently there has been discussion of medical management with somatostatin analogs to reduce hepatomegaly in PLD with varying success. There is no current consensus on treatment or standard of care for symptomatic PLD, it is largely up to surgeon preference and ability; however, there has been a movement toward early OLT with Model for End-Stage Liver Disease (MELD) score exception points. This case series reviews two female patients with normal renal and hepatic function with symptomatic PLD treated with transverse hepatectomy. We propose that patients suffering from symptomatic PLD, with retained renal and hepatic function, can be treated with transverse hepatectomy conserving limited donor livers for decompensated patients; moreover, transverse hepatectomy does not disrupt the major suprahepatic vena cava preserving potential surgical access for future OLT.

Liver organoid as a 3D in vitro model for drug validation and toxicity assessment

The past decade has seen many advancements in the development of three-dimensional (3D) in vitro models in pharmaceutical sciences and industry. Specifically, organoids present a self-organising, self-renewing and more physiologically relevant model than conventional two-dimensional (2D) cell cultures. Liver organoids have been developed from a variety of cell sources, including stem cells, cell lines and primary cells. They have potential for modelling patient-specific disease and establishing personalised therapeutic approaches. Additionally, liver organoids have been used to test drug efficacy and toxicity. Herein we summarise cell sources for generating liver organoids, the advantages and limitations of each cell type, as well as the application of the organoids in modelling liver diseases. We focus on the use of liver organoids as tools for drug validation and toxicity assessment.

Liver transplantation in adult polycystic liver disease: the Ontario experience

BACKGROUND

Liver transplantation (LT) remains the curative treatment for symptomatic Polycystic Liver Disease (PCLD) patients and is associated with excellent survival rates. The aim of the study is to review the Ontario experience in LT for PCLD.

METHODS

A retrospective study was performed from pre-existing LT databases from the LT Units at Toronto General Hospital and London Health Sciences Center, which are the two LT programs in Ontario, Canada. This database contains demographic, clinical parameters and follow-up of all patients transplanted for PCLD. Data was extracted for patients who underwent LT between January 2000-April 2017 and included follow up until December 31st, 2018.

RESULTS

A total of 3560 patients underwent LT, of whom 51 (1.4%) had PCLD and met inclusion criteria. 43 (84%) of these patients were female. The median physiologic Model for End Stage Liver Disease (MELD-Na) score at time of referral was 13 (IQR = 7-22), however all patients required MELD-Na exception points to receive LT. The median age of transplant was 62 years (IQR = 59-64) for male vs. 52 (IQR = 45-56) for female patients. 33 (65%) of our cohort had PCLD while 9 (17.5%) had ADPKD and 9 (17.5%) had both diseases. 39 (76%) had LT due to symptoms of mass effect, while 8 (16%) had portal hypertensive complications. After a median follow-up of 6.3 (IQR = 2.9-12.5) years, the probability of survival was 96% (95% CI: 90%, 100%). Log-rank test, comparing survival analysis between males and females did not show a statistically significant difference (p = 0.26).

CONCLUSION

Most patients underwent LT for PCLD due to symptoms of mass effect with women being more likely than men to undergo LT. LT for PCLD had excellent long-term survival.

Liver and kidney transplantation in polycystic liver and kidney disease

OBJECTIVE

To evaluate the results of isolated liver and combined liver and kidney transplantation in a retrospective series of 32 patients with hepatorenal liver and kidney disease.

MATERIALS AND METHODS

A retrospective observational study that enrolled patients with polycystic liver disease (PLD) and polycystic liver and kidney disease (PLKD) who were evaluated for transplantation between January 1999 and December 2019 at Hospital Clínic de Barcelona [Clinical Hospital of Barcelona].

RESULTS

We included a total of 53 patients enrolled, 32 (60.3%) had indication for transplantation, of which 12 received a single liver transplant and 20 received a double liver and kidney transplant. The mean age was 52 years and 83.9% of the recipients were women. The main indication for liver transplantation was disabling symptomatic hepatomegaly (93.5%). Among the postoperative complications, in the combined liver and kidney transplant group, hepatic artery thrombosis in one case and renal artery thrombosis in other were detected. In both groups there was one case of inferior vena cava lesion. Three patients presented acute cellular rejection responding to corticosteroids and one presented humoral rejection which was treated with plasmapheresis. During the follow-up period of 80 (27-121) months, the liver transplant survival rate was 100% and the kidney transplant survival rate was 90%. Two patients in the combined liver and kidney transplant group died (one due to cardiovascular causes and the other due to intestinal adenocarcinoma).

CONCLUSIONS

Isolated liver transplantation or combined liver and kidney transplantation in selected patients with polycystic disease yields excellent results, with few complications, very good transplant survival and excellent patient survival (93.8%).

CystAnalyser: A new software tool for the automatic detection and quantification of cysts in Polycystic Kidney and Liver Disease, and other cystic disorders

The Polycystic Kidney Disease (PKD) is characterized by progressive renal cyst development and other extrarenal manifestation including Polycystic Liver Disease (PLD). Phenotypical characterization of animal models mimicking human diseases are commonly used, in order to, study new molecular mechanisms and identify new therapeutic approaches. The main biomarker of disease progression is total volume of kidney and liver in both human and mouse, which correlates with organ function. For this reason, the estimation of the number and area of the tissue occupied by cysts, is critical for the understanding of physiological mechanisms underlying the disease. In this regard, cystic index is a robust parameter commonly used to quantify the severity of the disease. To date, the vast majority of biomedical researchers use ImageJ as a software tool to estimate the cystic index by quantifying the cystic areas of histological images after thresholding. This tool has imitations of being inaccurate, largely due to incorrectly identifying non-cystic regions. We have developed a new software, named CystAnalyser (register by Universidade de Santiago de Compostela–USC, and Fundación Investigación Sanitaria de Santiago—FIDIS), that combines automatic image processing with a graphical user friendly interface that allows investigators to oversee and easily correct the image processing before quantification. CystAnalyser was able to generate a cystic profile including cystic index, number of cysts and cyst size. In order to test the CystAnalyser software, 795 cystic kidney, and liver histological images were analyzed. Using CystAnalyser there were no differences calculating cystic index automatically versus user input, except in specific circumstances where it was necessary for the user to distinguish between mildly cystic from non-cystic regions. The sensitivity and specificity of the number of cysts detected by the automatic quantification depends on the type of organ and cystic severity, with values 76.84–78.59% and 76.96–89.66% for the kidney and 87.29–93.80% and 63.42–86.07% for the liver. CystAnalyser, in addition, provides a new tool for estimating the number of cysts and a more specific measure of the cystic index than ImageJ. This study proposes CystAnalyser is a new robust and freely downloadable software tool for analyzing the severity of disease by quantifying histological images of cystic organs for routine biomedical research. CystAnalyser can be downloaded from https://citius.usc.es/transferencia/software/cystanalyser (for Windows and Linux) for research purposes.

This work suggests CystAnalyser is the most reliable software tool currently available for the assessment of cystic pathologies including Polycystic Kidney Disease (PKD) and Polycystic Liver Disease (PLD). CystAnalyser combines automatic cyst recognition with a friendly graphical user interface, allowing user input prior to histological image quantification. CystAnalyser responds to the need to obtain reliable measurements of the universal biomarker for PKD and PLD disease progression, the Cystic index (area of cysts within the total area of tissue). This software tool is also able to calculate the number and size of cysts from the histological images. In summary, our results show that CystAnalyser overcomes the precision issues detected using the most commonly used software to date (ImageJ) for Cystic index quantification, offering users a reliable tool to easily characterize the phenotype and the pathophysiology of PKD and PLD in pre-clinical studies using animal models.

Polycystic liver disease: Classification, diagnosis, treatment process, and clinical management

Polycystic liver disease (PLD) is a rare hereditary disease that independently exists in isolated PLD, or as an accompanying symptom of autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease with complicated mechanisms. PLD currently lacks a unified diagnostic standard. The diagnosis of PLD is usually made when the number of hepatic cysts is more than 20. Gigot classification and Schnelldorfer classification are now commonly used to define severity in PLD. Most PLD patients have no clinical symptoms, and minority with severe complications need treatments. Somatostatin analogues, mammalian target of rapamycin inhibitor, ursodeoxycholic acid and vasopressin-2 receptor antagonist are the potentially effective medical therapies, while cyst aspiration and sclerosis, transcatheter arterial embolization, fenestration, hepatic resection and liver transplantation are the options of invasion therapies. However, the effectiveness of these therapies except liver transplantation are still uncertain. Furthermore, there is no unified strategy to treat PLD between medical centers at present. In order to better understand recent study progresses on PLD for clinical practice and obtain potential directions for future researches, this review mainly focuses on the recent progress in PLD classification, clinical manifestation, diagnosis and treatment. For information, we also provided medical treatment processes of PLD in our medical center.

Severe polycystic liver diseases: hepatectomy or waiting for liver transplantation?: Two case reports

INTRODUCTION

Choice of treatment in patients with symptomatic polycystic liver diseases (PLD) remains controversial. Various surgical procedures aiming at eliminating symptomatic cysts are widely used in mild and advanced PLD patients, but liver transplantation is currently recommended as the only curative treatment especially in severe cases.

PATIENT CONCERNS

Case 1: A 51-year-old male was admitted for severe eating disorder and dyspnea for 2 months. He had been diagnosed as PLD, PKD, and hypertension for 9 years, with only antihypertensive drug therapy. No significant family history could be traced.Case 2: A 54-year-old female was admitted to our hospital for ventosity during nearly 5 years. She had been diagnosed as PLD and hypertension for 22 years, for which only aspiration-sclerotherapy therapy was performed for multiple times. Both her mother and sister were diagnosed with PLD previously.

DIAGNOSIS

They were diagnosed as PLD by medical history, family history, and computed tomography scan (multiple cysts dispersively presenting in the liver).

INTERVENTIONS

The 2 patients underwent hepatectomy with fenestration, and were well recovered with no mortality.

OUTCOMES

While case 1 only experienced relief of symptoms, case 2 experienced massive growth of hepatic parenchyma, which indicated positive prognosis and showed the possibility to avoid or at least postpone liver transplantation for a long time, considering the lack of liver parenchyma is one of the main reason for urgency of liver transplantation.

CONCLUSION

Here we described subradical polycystic hepatectomy, a special form of hepatectomy with fenestration modified by us, as a safe and effective treatment to potentially achieve long-term effects in PLD patients.

Targeted Therapies for Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is the most common life-threatening genetic disease in humans, affecting approximately 1 in 500 people. ADPKD is characterized by cyst growth in the kidney leading to progressive parenchymal damage and is the underlying pathology in approximately 10% of patients requiring hemodialysis or transplantation for end-stage kidney disease. The two proteins that are mutated in ADPKD, polycystin-1 and polycystin-2, form a complex located on the primary cilium and the plasma membrane to facilitate calcium ion release in the cell. There is currently no Food and Drug Administration (FDA)-approved therapy to cure or slow the progression of the disease. Rodent ADPKD models do not completely mimic the human disease, and therefore preclinical results have not always successfully translated to the clinic. Moreover, the toxicity of many of these potential therapies has led to patient withdrawals from clinical trials.

RESULTS

Here, we review compounds in clinical trial for treating ADPKD, and we examine the feasibility of using a kidney-targeted approach, with potential for broadening the therapeutic window, decreasing treatment-associated toxicity and increasing the efficacy of agents that have demonstrated activity in animal models. We make recommendations for integrating kidney- targeted therapies with current treatment regimes, to achieve a combined approach to treating ADPKD.

CONCLUSION

Many compounds are currently in clinical trial for ADPKD yet, to date, none are FDA-approved for treating this disease. Patients could benefit from efficacious pharmacotherapy, especially if it can be kidney-targeted, and intensive efforts continue to be focused on this goal.

Isolated Polycystic Liver Disease: An Unusual Cause of Recurrent Variceal Bleed

Isolated polycystic liver disease is a rare disorder. Majority of the patients with isolated polycystic liver disease are asymptomatic with incidental detection of liver cysts on imaging studies done for other purposes. Minority of patients develop symptoms which are mostly secondary to enlarging cysts size and hepatomegaly. Rarely, these patients develop portal hypertension and can present with its clinical manifestations and consequences in the form acute variceal bleeding or recurrent ascites. We present a rare case of 67-year-old female patient with significant history of polycystic liver disease who presented to the hospital with recurrent hematemesis and melena. She underwent esophagogastroduodenoscopy which showed multiple large esophageal varices requiring banding.

Liver Failure in Advanced Adult-onset Polycystic Kidney Disease

Polycystic liver disease is the most common extrarenal manifestation of autosomal dominant polycystic kidney disease (ADPKD). Hepatic cysts are typically incidental findings, with occasional complications including cyst haemorrhage, infection and rupture. In contrast to the typically benign course of polycystic liver disease, we present a rare case of fatal decompensated liver failure in a patient with ADPKD. This is a case of a 58-year-old man with end-stage renal disease on haemodialysis presenting with new-onset ascites and decompensated liver failure following bilateral nephrectomy. Cirrhosis in ADPKD is a late manifestation of the disease, but it should be considered in the perioperative risk of patients with ADPKD.

The mitochondrial uncoupling protein 2 gene is causal for the spontaneous polycystic liver diseases in mice

Polycystic liver diseases (PCLDs) are autosomal dominant disorders. To date, 3 genes are known to be associated with the disease, SEC63 and PRKCSH and LRP5. Here, we report that mice deficient in the mitochondrial uncoupling protein 2 gene (Ucp2^-/-) spontaneously developed PCLDs when they were over 12months old. Macroscopical observation, blood chemistry as well as histopathological analysis demonstrated the PCLDs found in Ucp2^-/- mice were very similar to the findings in human PCLDs. This is the first report describing the gene encoding mitochondrial protein is causative for PCLDs. UCP2 may be a biomarker of the PCLDs in humans.

Primary benign liver lesions

Benign focal liver lesions can origin from all kind of liver cells: hepatocytes, mesenchymal and cholangiocellular line. Their features at imaging may sometimes pose difficulties in differential diagnosis with malignant primary and secondary lesions. In particular, the use of MDCT and MRI with extracellular and hepatobiliary Contrast Agents may non invasively help in correct interpretation and definition of hepatocellular or mesenchymal and inflammatory nature, allowing to choose the best treatment option. The peculiarities of main benign liver lesions at US, CT and MRI are described, with special attention to differential diagnosis and diagnostic clues.

Genetic, hematological, and immunological disorders transmissible with liver transplantation

It is well recognized that solid organ transplantation can transmit bacterial infection and chronic viral hepatitis as well as certain cancers. As indications for liver transplantation (LT) have expanded, it has been used to treat and even cure certain genetic cholestatic disorders, urea cycle defects, and coagulation abnormalities; many of these conditions are potentially transmissible with LT as well. It is important for clinicians and transplant patients to be aware of these potentially transmissible conditions as unexplained post-LT complications can sometimes be related to donor transmission of disease and thus should prompt a thorough exploration of the donor allograft history. Herein, we will review the reported genetic, metabolic, hematologic, and immunological disorders that are transmissible with LT and describe clinical scenarios in which these cases have occurred, such as in inadvertent or recognized transplantation of a diseased organ, domino transplantation, and with living related liver donation. Liver Transplantation 23 663-678 2017 AASLD.

Prediction of hepatic cyst recurrence after minocycline hydrochloride aspiration sclerotherapy using cyst computed tomography values

AIM

Polycystic liver disease (PLD) occasionally leads to abdominal pain, distention, and discomfort due to massively enlarged cysts. Patients with a small number of large liver cysts, which correspond to Gigot's classification type 1 PLD, are reported to be good candidates for treatment by aspiration sclerotherapy. However, there is a 21% reported recurrence rate of an enlarged cyst. A rule to predict outcome of aspiration sclerotherapy is explored in this study.

METHODS

The medical records of patients with autosomal dominant polycystic kidney disease or isolated polycystic liver disease, who underwent minocycline hydrochloride cyst aspiration sclerotherapy for their symptomatic PLD, were retrospectively analyzed. Changes in the volume of cysts from before to 1 year after treatment were calculated using computed tomography (CT) images. Mean CT values of the largest planes of cysts were also calculated. Specific gravity and other laboratory parameters of aspirated cyst fluid were also retrospectively investigated.

RESULTS

In total, 12 patients were selected and 21 cysts were analyzed that received aspiration sclerotherapy. Mean CT values more than 13.34 HU were predictive for 1-year non-sustainability of a cyst volume of less than 30% compared with the volume prior to the therapy. Specific gravity had good positive correlation with mean CT value and other laboratory parameters indicating exudative properties were also high in recurred cysts.

CONCLUSIONS

The CT values of cysts may become an aid in appropriate selection of therapy in patients with symptomatic polycystic disease by distinguishing cysts that are resistant to aspiration sclerotherapy.

Comparison of volume-reductive therapies for massive polycystic liver disease in autosomal dominant polycystic kidney disease

AIM

Polycystic liver disease (PLD) in autosomal dominant polycystic kidney disease (ADPKD) patients can induce massive hepatomegaly-related symptoms. Volume-reductive therapies for symptomatic PLD include transcatheter arterial embolization (TAE), liver resection and liver transplantation; however, consensus has not been reached regarding treatment selection. We compared three volume-reductive therapies for a better understanding of PLD treatment strategies.

METHODS

We retrospectively analyzed 28 ADPKD patients who underwent TAE, liver resection or liver transplantation for PLD at a single center, and compared their outcomes.

RESULTS

Of 18 TAE patients, five required repeat TAE, and five required rescue liver transplantation or liver resection because of refractory symptoms or hepatic failure. The treatment failure rate for TAE was high (69.6%). Nine underwent liver resection, and the degree of volume reduction in the liver resection group was greater than that in the TAE group (52.4% vs 7.6%, P < 0.001). One liver resection patient required rescue liver transplantation because of hepatic failure. Seven patients underwent liver transplantations. All liver transplant patients had successfully controlled symptoms or hepatic failure, and had good graft function. Three patients in the TAE group died of infections or hepatic failure, whereas no mortality occurred after surgical therapy.

CONCLUSION

Liver resection is a good first-line therapy in patients that have severe symptoms, cyst involvement in several segments with some spared segments and preserved liver function. Liver transplantation is a preferred first-line therapy in patients with poor liver function or whole-liver involvement. Liver transplantation is also a good rescue therapy following TAE or liver resection.

Cholangiocytes derived from human induced pluripotent stem cells for disease modeling and drug validation

The study of biliary disease has been constrained by a lack of primary human cholangiocytes. Here we present an efficient, serum-free protocol for directed differentiation of human induced pluripotent stem cells into cholangiocyte-like cells (CLCs). CLCs show functional characteristics of cholangiocytes, including bile acids transfer, alkaline phosphatase activity, γ-glutamyl-transpeptidase activity and physiological responses to secretin, somatostatin and vascular endothelial growth factor. We use CLCs to model in vitro key features of Alagille syndrome, polycystic liver disease and cystic fibrosis (CF)-associated cholangiopathy. Furthermore, we use CLCs generated from healthy individuals and patients with polycystic liver disease to reproduce the effects of the drugs verapamil and octreotide, and we show that the experimental CF drug VX809 rescues the disease phenotype of CF cholangiopathy in vitro. Our differentiation protocol will facilitate the study of biological mechanisms controlling biliary development, as well as disease modeling and drug screening.

[Pathophysiology, epidemiology, clinical presentation, diagnosis and treatment options for autosomal dominant polycystic kidney disease]

Autosomal dominant polycystic kidney disease (ADPKD) is the leading genetic cause of end-stage renal disease (ESRD) worldwide. Its prevalence is evaluated according to studies and population between 1/1000 and 1/4000 live births and it accounts for 6 to 8% of incident ESRD patients in developed countries. ADPKD is characterized by numerous cysts in both kidneys and various extrarenal manifestations that are detailed in this review. Clinico-radiological and genetic diagnosis are also discussed. Mutations in the PKD1 and PKD2 codifying for polycystin-1 (PC-1) and polycystin-2 (PC-2) are responsible for the 85 and 15% of ADPKD cases, respectively. In primary cilia of normal kidney epithelial cells, PC-1 and PC-2 interact forming a complex involved in flow- and cilia-dependant signalling pathways where intracellular calcium and cAMP play a central role. Alteration of these multiple signal transduction pathways leads to cystogenesis accompanied by dysregulated planar cell polarity, excessive cell proliferation and fluid secretion, and pathogenic interactions of epithelial cells with an abnormal extracellular matrix. The mass effect of expanding cyst is responsible for the decline in glomerular filtration rate that occurs late in the course of the disease. For many decades, the treatment for ADPKD aims to lessen the condition's symptoms, limit kidney damage, and prevent complications. Recently, the development of promising specific treatment raises the hope to slow the growth of cysts and delay the disease. Treatment strategies targeting cAMP signalling such as vasopressin receptor antagonists or somatostatin analogs have been tested successfully in clinical trials with relative safety. Newer treatments supported by preclinical trials will become available in the next future. Recognizing early markers of renal progression (clinical, imaging, and genetic markers) to identify high-risk patients and multidrug approaches with synergistic effects may provide new opportunities for the treatment of ADPKD.

Polycystic liver diseases: advanced insights into the molecular mechanisms

Polycystic liver diseases are genetic disorders characterized by progressive bile duct dilatation and/or cyst development. The large volume of hepatic cysts causes different symptoms and complications such as abdominal distension, local pressure with back pain, hypertension, gastro-oesophageal reflux and dyspnea as well as bleeding, infection and rupture of the cysts. Current therapeutic strategies are based on surgical procedures and pharmacological management, which partially prevent or ameliorate the disease. However, as these treatments only show short-term and/or modest beneficial effects, liver transplantation is the only definitive therapy. Therefore, interest in understanding the molecular mechanisms involved in disease pathogenesis is increasing so that new targets for therapy can be identified. In this Review, the genetic mechanisms underlying polycystic liver diseases and the most relevant molecular pathways of hepatic cystogenesis are discussed. Moreover, the main clinical and preclinical studies are highlighted and future directions in basic as well as clinical research are indicated.

Current treatment status of polycystic liver disease in Japan

AIM

Polycystic liver disease (PLD) is a genetic disorder characterized by the progressive development of multiple liver cysts. No standardized criteria for the selection of treatment exist because PLD is a rare condition and most patients are asymptomatic. We here aimed to clarify the status of treatment and to present a therapeutic strategy for PLD in Japan.

METHODS

From 1 June 2011 to 20 December 2011, we administered a questionnaire to 202 PLD patients from 86 medical institutions nationwide.

RESULTS

The patients included 45 men and 155 women, and the median age was 63 years. Two hundred and eighty-one treatments were performed for these patients, as follows: cyst aspiration sclerotherapy (AS) in 152 cases, cyst fenestration (FN) in 53, liver resection (LR) in 44, liver transplantation (LT) in 13 and other treatments in 19. For cases of type I PLD (mild form) according to Gigot's classification, the therapeutic effects of AS, FN and LR were similar. For type II (moderate form), LT demonstrated the best therapeutic effects, followed by LR and FN. For type III (severe form), the effects of LT were the best. The incidences of complications were 23.0% in AS, 28.4% in FN, 31.8% in LR and 61.5% in LT.

CONCLUSION

Considering the therapeutic effects and complications, AS, LR and LT showed good results for type I, type II and type III PLD, respectively. However, LT for PLD was performed in a small number of patients. In Japan, the transplantation therapy is expected to be common in the future.

ACG clinical guideline: the diagnosis and management of focal liver lesions

Focal liver lesions (FLL) have been a common reason for consultation faced by gastroenterologists and hepatologists. The increasing and widespread use of imaging studies has led to an increase in detection of incidental FLL. It is important to consider not only malignant liver lesions, but also benign solid and cystic liver lesions such as hemangioma, focal nodular hyperplasia, hepatocellular adenoma, and hepatic cysts, in the differential diagnosis. In this ACG practice guideline, the authors provide an evidence-based approach to the diagnosis and management of FLL.

MicroRNAs in Cholangiopathies

Cholangiocytes, the cells lining bile ducts, comprise a small fraction of the total cellular component of the liver, yet perform the essential role of bile modification and transport of biliary and blood constituents. Cholangiopathies are a diverse group of biliary disorders with the cholangiocyte as the target cell; the etiopathogenesis of most cholangiopathies remains obscure. MicroRNAs are small non-coding RNAs that post-transcriptionally regulate gene expression. These small RNAs may not only be involved in the etiopathogenesis of disease, but are showing promise as diagnostic and prognostic tools. In this brief review, we summarize recent work regarding the role of microRNAs in the etiopathogenesis of several cholangiopathies, and discuss their utility as prognostic and diagnostic tools.

Combined liver and kidney transplant in a patient with budd-Chiari syndrome secondary to autosomal dominant polycystic kidney disease associated with polycystic liver disease: report of a case with a 9-year follow-up

Polycystic liver disease (PLD) is a hereditary disease inherited by autosomal dominant trait that occurs as a frequent extrarenal manifestation of autosomal dominant polycystic kidney disease (ADPKD). We report a case of a 59-year-old woman diagnosed with ADPKD associated with PLD. End-stage chronic renal failure with a secondary Budd-Chiari syndrome developed during the patient's clinical course. She underwent combined liver and kidney transplantation, with a successful response over a 9-year follow-up period.

Modes of flagellar assembly in Chlamydomonas reinhardtii and Trypanosoma brucei

Defects in flagella growth are related to a number of human diseases. Central to flagellar growth is the organization of microtubules that polymerize from basal bodies to form the axoneme, which consists of hundreds of proteins. Flagella exist in all eukaryotic phyla, but neither the mechanism by which flagella grow nor the conservation of this process in evolution are known. Here, we study how protein complexes assemble onto the growing axoneme tip using (cryo) electron tomography. In Chlamydomonas reinhardtii microtubules and associated proteins are added simultaneously. However, in Trypanosoma brucei, disorganized arrays of microtubules are arranged into the axoneme structure by the later addition of preformed protein complexes. Post assembly, the T. brucei transition zone alters structure and its association with the central pair loosens. We conclude that there are multiple ways to form a flagellum and that species-specific structural knowledge is critical before evaluating flagellar defects.

DOI:http://dx.doi.org/10.7554/eLife.01479.001

Some cells have a whip-like appendage called a flagellum. This is most often used to propel the cell, notably in sperm cells, but it can also be involved in sensing cues in the surrounding environment. Flagella are found in all three domains of life—the eukaryotes (which include the animals), bacteria and ancient, single-celled organisms called Archaea—and they perform similar functions in each domain. However, they also differ significantly in their protein composition, overall structure, and mechanism of propulsion.

The core of the flagellum in eukaryotes is made up of 20 hollow filaments called ‘microtubules’ arranged so that nine pairs of microtubules form a ring around two central microtubules. The core also contains many other proteins, but it is not clear how all these components come together to make a working flagellum. Moreover, it is not known if the flagella of different groups of eukaryotes are all assembled in the same way.

Now, Höög et al. have discovered that although the core structure of the eukaryote flagellum is highly conserved, it can be assembled in markedly different ways. Some species of eukaryote—such as Chlamydomonas reinhardtii, a single-celled green alga, and Trypanosoma brucei, the protist parasite that causes African sleeping sickness—must grow new flagella when their cells divide, so that each new cell can swim. Using a form of electron microscopy called electron tomography, Höög et al. could see the detailed structure of the growing flagella in three dimensions. At first the cores of the flagella in these two distantly related species grow in the same way. However as the flagella get longer their cores grow in completely different ways. The microtubule filaments in longer flagella grow in a synchronized manner in the alga, but in a disorganized way in the protist.

The results of Höög et al. illustrate that it is not advisable to draw generalised conclusions based on studies of a few model species. However, since defects in flagella are known to cause several diseases in humans, this knowledge might inform future studies aimed at developing treatments for infertility, respiratory problems, and certain kinds of cancer.

DOI:http://dx.doi.org/10.7554/eLife.01479.002

Extra-renal manifestations of autosomal dominant polycystic kidney disease (ADPKD): considerations for routine screening and management

Autosomal-dominant polycystic kidney disease (ADPKD) is a systemic disease, marked by progressive increase of bilateral renal cysts, resulting in chronic kidney disease (CKD) and often leading to end-stage renal disease (ESRD). Apart from renal cysts, patients often have extra-renal disease, involving the liver, heart and vasculature. Other less common but equally important extra-renal manifestations of ADPKD include diverticular disease, hernias, male infertility and pain. Extra-renal disease burden is often asymptomatic, but may result in increased morbidity and mortality. If the disease burden is significant, screening may prove beneficial. We review the rationale for current screening recommendations and propose some guidelines for screening and management of ADPKD patients.

Young women with polycystic liver disease respond best to somatostatin analogues: a pooled analysis of individual patient data

BACKGROUND & AIMS

Clinical trials have shown that in patients with polycystic liver disease (PLD), short-term treatment with somatostatin analogues (SAs) reduces liver volumes by 4.5%-5.9%, compared with placebo. However, the effects of SA therapy vary among individuals. We collected data from individual patients with PLD to identify subgroups that benefit most from SA therapy.

METHODS

We analyzed data from 107 patients with PLD from 3 randomized placebo-controlled trials (67 received SAs, 52 received placebo). We used multiple linear regression analysis to determine the effects of SAs based on patients' age, sex, baseline liver volume, and diagnosis (autosomal dominant polycystic liver or kidney disease). The primary outcome was change in liver volume after 6-12 months of treatment.

RESULTS

The effects of SA therapy did not differ significantly among patients with different diagnoses or baseline liver volumes; the overall difference in liver volume between groups receiving SAs therapy vs placebo was 5.3% (P < .001). Among subjects given placebo, young women (48 years old or younger) had the greatest increase in polycystic liver volume (4.8%; 95% confidence interval: 2.2%-7.4%), and mean liver volumes did not increase in older women and men. Women 48 years old or younger had a greater response to therapy (a reduction in liver volume of 8.0% compared with placebo; P < .001) than older women (a reduction in liver volume of 4.1% compared with placebo; P = .022).

CONCLUSIONS

Based on a pooled analysis of data from individual patients with PLD, treatment with somatostatin analogues is equally effective for patients with autosomal dominant polycystic kidney disease or polycystic liver disease; efficacy does not depend on size of the polycystic liver. Young female patients appear to have the greatest benefit from 6-12 months of SA therapy, which might avert the progressive course of the disease in this specific group.