Tolvaptan for the Treatment of Enlarged Polycystic Liver Disease

Extrarenal Manifestations: Polycystic Liver Disease and Its Complications

The liver is the commonest site of involvement outside of the kidney in autosomal dominant polycystic kidney disease. Most individuals with polycystic liver disease are asymptomatic and require no therapeutic interventions, but a small number of affected individuals who experience symptomatic polycystic liver disease develop medical complications as a result of massive enlargement of cyst number and size and hepatic parenchyma and its subsequent associated complications. This can lead to deterioration in overall health and quality of life, increasing morbidity and mortality. In this review, we will touch upon disease pathogenesis, prevalence, and complications and discuss recent advances in surgical and medical management.

Liver transplantation for polycystic liver disease: a case report

A 57-year-old man complained about abdominal distension and pain, constant feeling of early satiety. He was diagnosed with polycystic kidneys at the age of 24 and liver cysts discovered at the age of 38. The CT scan revealed 33 x 21 x 27 cm polycystic liver with cysts up to 7 cm in diameter. In 2009-2019 the patient was repeatedly punctured for liver cysts. Considering the continued enlargement of the liver and the worsening of complaints, the patient was put on the waiting list for a liver transplant in the spring of 2019. The patient went through liver transplantation on 11th of July 2022, the liver measures were 53 x 37 x 39 x 16 cm and weight 14,75 kg. The postoperative course was uneventful. Liver transplantation can be very effective treatment method that significantly improves the quality of life in PLD patients.

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.

Polycystic Kidney/Liver Disease

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder that leads to chronic kidney disease and end-stage kidney disease (ESKD). Polycystic liver disease (PCLD) is the most common extrarenal manifestation of ADPKD. Though isolated PCLD and PCLD due to ADPKD are genetically distinct, they follow a similar clinical course of hepatomegaly from multiple cysts with preserved liver function. Tolvaptan use in ADPKD can slow down the deterioration of renal function and growth of cysts. Somatostatin analogs can slow the growth of polycystic livers but the effect is short-lived. The only curative therapy for PCLD is liver transplantation. Renal transplantation can significantly improve survival in patients with ESKD due to ADPKD.

Potential effect of tolvaptan on polycystic liver disease for patients with ADPKD meeting the Japanese criteria of tolvaptan use

Polycystic liver disease (PLD) is a common extrarenal complication of autosomal dominant polycystic kidney disease (ADPKD), which causes compression-related syndrome and ultimately leads to liver dysfunction. Tolvaptan, a V2 receptor antagonist, is widely used to protect kidney function in ADPKD but its effect on PLD remains unknown. An observational cohort study was conducted to evaluate tolvaptan’s effect on patients with PLD due to ADPKD. After screening 902 patients, we found the 107 ADPKD patients with PLD who met the criteria of tolvaptan use in Japan. Among them, tolvaptan was prescribed for 62 patients (tolvaptan group), while the other was defined as the non-tolvaptan group. Compared with the non-tolvaptan group, the tolvaptan group had larger height-adjusted total kidney volume (median 994(range 450–4152) mL/m, 513 (405–1928) mL/m, p = 0.01), lower albumin level (mean 3.9±SD 0.4 g/dL, 4.3±0.4g/dL, p<0.01), and higher serum creatinine level (1.2±0.4 mg/dL, 0.9±0.2 mg/dL, p<0.01). Although the median change in annual growth rate of total liver volume (TLV) was not statistically different between the tolvaptan group (-0.8 (-15.9, 16.7) %/year) and the non-tolvaptan group (1.7 (-15.6–18.7) %/year)(p = 0.52), 20 (43.5%) patients in the tolvaptan group experienced a decrease in the growth rate of TLV (responders). A multivariable logistic regression model adjusting for related variables showed that older age (odds ratio 1.15 [95% CI 1.01–1.32]) and a higher growth rate of TLV in the non-tolvaptan period (odds 1.45 95% CI 1.10–1.90) were significantly associated with responders. In conclusion, the change in annual growth rate of TLV in ADPKD patients taking tolvaptan was not statistically different compared with that in ADPKD patients without taking tolvaptan. However, tolvaptan may have the potential to suppress the growth rate of TLV in some PLD patients due to ADPKD, especially in older patients or those that are rapid progressors of PLD. Several limitations were included in this study, therefore well-designed prospective studies were required to confirm the effect of tolvaptan on PLD.

IFT-A deficiency in juvenile mice impairs biliary development and exacerbates ADPKD liver disease

Polycystic liver disease (PLD) is characterized by the growth of numerous biliary cysts and presents in patients with autosomal dominant polycystic kidney disease (ADPKD), causing significant morbidity. Interestingly, deletion of intraflagellar transport-B (IFT-B) complex genes in adult mouse models of ADPKD attenuates the severity of PKD and PLD. Here we examine the role of deletion of an IFT-A gene, Thm1, in PLD of juvenile and adult Pkd2 conditional knockout mice. Perinatal deletion of Thm1 resulted in disorganized and expanded biliary regions, biliary fibrosis, increased serum bile acids, and a shortened primary cilium on cytokeratin 19+ (CK19+) epithelial cells. In contrast, perinatal deletion of Pkd2 caused PLD, with multiple CK19+ epithelial cell-lined cysts, fibrosis, lengthened primary cilia, and increased Notch and ERK signaling. Perinatal deletion of Thm1 in Pkd2 conditional knockout mice increased hepatomegaly, liver necrosis, as well as serum bilirubin and bile acid levels, indicating enhanced liver disease severity. In contrast to effects in the developing liver, deletion of Thm1 alone in adult mice did not cause a biliary phenotype. Combined deletion of Pkd2 and Thm1 caused variable hepatic cystogenesis at 4 months of age, but differences in hepatic cystogenesis between Pkd2- and Pkd2;Thm1 knockout mice were not observed by 6 months of age. Similar to juvenile PLD, Notch and ERK signaling were increased in adult Pkd2 conditional knockout cyst-lining epithelial cells. Taken together, Thm1 is required for biliary tract development, and proper biliary development restricts PLD severity. Unlike IFT-B genes, Thm1 does not markedly attenuate hepatic cystogenesis, suggesting differences in regulation of signaling and cystogenic processes in the liver by IFT-B and -A. Notably, increased Notch signaling in cyst-lining epithelial cells may indicate that aberrant activation of this pathway promotes hepatic cystogenesis, presenting as a novel potential therapeutic target. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

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.

Management of portal hypertension and ascites in polycystic liver disease

Patients suffering from polycystic liver disease may develop Hepatic Venous Outflow Obstruction, Portal Vein Obstruction and/or Inferior Caval Vein Syndrome because of cystic mass effect. This can cause portal hypertension, leading to ascites, variceal haemorrhage or splenomegaly. For this review, we evaluate the evidence to provide clinical guidance for physicians faced with this complication. Diagnosis is made with imaging such as ultrasound, computed tomography or magnetic resonance imaging. Therapy includes conventional therapy with diuretics and paracentesis, and medical therapy using somatostatin analogues. Based on disease phenotype various (non-)surgical liver-volume reducing therapies, hepatic or portal venous stenting, transjugular intrahepatic portosystemic shunts and liver transplantation may be considered. Because of complicated anatomy, use of high-risk interventions and lack of empirical evidence, patients should be treated in expert centres.