Severe Polycystic Liver Disease Research Articles

Genetic Analysis of Severe Polycystic Liver Disease in Japan.

Polycystic liver disease (PLD) is present in most patients with autosomal dominant polycystic kidney disease (ADPKD). PLD can alternatively be found with few, if any, kidney cysts as a diagnosis of isolated polycystic liver disease (ADPLD). Several genes are identified as causative for this spectrum of phenotypes, however, the relative incidence of genetic etiologies amongst patients with severe PLD is unknown. Patients with ADPKD or ADPLD having severe PLD defined as height-adjusted total liver volume (hTLV) over 1,800mL/m were recruited. Subsequent clinical care was followed. Genetic analysis was performed using whole exome sequencing. We enrolled and sequenced 49 patients (38 females, 11 males). Pathogenic or suspected pathogenic variants in polycystic disease genes were found in 44 out of 49 patients (90%). The disease gene was PKD1 in 20/44 (45%), PKD2 in 15/44 (34%), PRKCSH in 5/44 (11%), GANAB in 2/44 (5%), SEC63 in 1/44 (2%), and ALG8 in 1/44 (2%). The median hTLV was no different between genetically-defined ADPKD and ADPLD groups (4431 (range 1817-9148) versus 3437 (range 1860-8211) mL, p=0.77), whereas height-adjusted kidney volume (hTKV) was larger as expected in ADPKD than ADPLD (607 (range 190-2842) versus 179 (range 138-234) mL/m, p<0.01). Of the clinically-defined ADPKD cases, 20/38 (53%) were PKD1, 15/38 (39%) were PKD2, and 3 (8%) remain genetically unsolved. Among patients with a pathogenic PKD1 or PKD2 variant, we found three cases with a liver-dominant ADPKD (severe PLD with hTKV <250mL/m). ADPLD-related genes represent 20% of severe PLD patients in our cohort. Of those enrolled with ADPKD, we observed a higher frequency of PKD2 carriers than in any previously reported ADPKD cohorts. While there was no significant difference in the hTLV between PKD1 versus PKD2 patients in this cohort, our data suggests that enrollment on the basis of severe PLD may enrich for PKD2 patients.

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.

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

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). 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. 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). 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. Clinical Research Information Service Identifier: KCT0005580.

Severe polycystic liver disease: An unsual cause of chronic Budd-Chiari Syndrome

Autosomal dominant polycystic kidney disease is a hereditary disease, characterized by the development of cysts in the renal parenchyma with extra-renal manifestations. Liver damage is rarely a source of complications. A Budd-Chiari syndrome could occur following the compression of the supra-hepatic veins by the cysts. It is an exceptional mechanical complication. We present a case of a 54 year old woman, with a diagnostic of an asymptomatic autosomal dominat polycystic kidney disease since childhood was admitted to our hospital due to significantly increased abdominal girth. The physical examination showed grade III ascites. A paracentesis for relief at admission disclosed an exudative fluid. A abdominal computed tomographic scan showed multiples cystic lesions in the kidneys and liver, with a large hepatic cyst responsible for compression of the suprahepatic veins and the inferior vena cava resulting in chronic Budd-Chiari syndrome. The treatment was radiological drainage followed by percutaneous sclerosis of cysts to alleviation of the compression. Unfortunately, the patient died a few days after an intraperitoneal cystic rupture.

Protocol for a randomized controlled multicenter trial assessing the efficacy of leuprorelin for severe polycystic liver disease: the AGAINST-PLD study

BackgroundIn patients with severe polycystic liver disease (PLD), there is a need for new treatments. Estrogens and possibly other female sex hormones stimulate growth in PLD. In some patients, liver volume decreases after menopause. Female sex hormones could therefore be a target for therapy. The AGAINST-PLD study will examine the efficacy of the GnRH agonist leuprorelin, which blocks the production of estrogen and other sex hormones, to reduce liver growth in PLD.MethodsThe AGAINST-PLD study is an investigator-driven, multicenter, randomized controlled trial. Institutional review board (IRB) approval was received at the University Medical Center of Groningen and will be collected in other sites before opening these sites. Thirty-six female, pre-menopausal patients, with a very large liver volume for age (upper 10% of the PLD population) and ongoing liver growth despite current treatment options will be randomized to direct start of leuprorelin or to 18 months standard of care and delayed start of leuprorelin. Leuprorelin is given as 3.75 mg subcutaneously (s.c.) monthly for the first 3 months followed by 3-monthly depots of 11.25 mg s.c. The trial duration is 36 months. MRI scans to measure liver volume will be performed at screening, 6 months, 18 months, 24 months and 36 months. In addition, blood will be drawn, DEXA-scans will be performed and questionnaires will be collected. This design enables comparison between patients on study treatment and standard of care (first 18 months) and within patients before and during treatment (whole trial). Main outcome is annualized liver growth rate compared between standard of care and study treatment. Secondary outcomes are PLD disease severity, change in liver growth within individuals and (serious) adverse events. The study is designed as a prospective open-label study with blinded endpoint assessment (PROBE).DiscussionIn this trial, we combined the expertise of hepatologist, nephrologists and gynecologists to study the effect of leuprorelin on liver growth in PLD. In this way, we hope to stop liver growth, reduce symptoms and reduce the need for liver transplantation in severe PLD.Trial registration Eudra CT number 2020-005949-16, registered at 15 Dec 2020. https://www.clinicaltrialsregister.eu/ctr-search/search?query=2020-005949-16.

Right Extended Hepatectomy and Cyst Fenestration in a Rare Severe Polycystic Liver Disease: How I Do it Safely

Introduction: Polycystic liver disease (PLD) is characterised by the presence of multiple fluid-filled liver cysts, >10 cysts. According to Gigot, type 3 (severe) is multiple cysts occupying >75% of TLV. Treatment options are limited, including surgical like aspiration-sclerotherapy, fenestration, hepatectomy, liver transplantation, and medical options such as somatostatin analogs. However, the efficacy of these treatments remains uncertain except liver transplantation which is curative especially in severe variety. Case: 32 year old female with a BMI of 26 presented with history of abdominal pain and swelling since 5 years with post prandial fullness. Preoperative evaluation with CT scan showed Gigot Type 3 PLD. She opted for all treatments except transplant. Right-extended hepatectomy and fenestration of cyst in seg 2,3(remnant volume 21%) was done in this patient. Intra-operatively the liver was so large that mobilisation was difficult leading to compression of the heart leading to hypotension every time liver was pushed. Routine outflow control was not feasible. 10 mins Intermittent dissection and 10 mins intermittent stoppage gave time to anesthesist for proper resuscitation. Careful parenchymal transection along the cantles line using the Belghiti technique prevented blood loss since the portal tracts are completely distorted. Some cyst were decompressed along with wall cauterisation to prevent post-operative ascites and in some tetracycline was injected as a sclerosant to prevent recurrence. Conclusion: Severe PLD is very rare. Extended hepatectomy and fenestrations are good palliative options for relieving patients symptoms. Few technical improvisations during hepatectomy along with energy devices can help HPB surgeons achieve these feats.

S2397 The Case for Octreotide: A Case Report on the Use of a Somatostatin Analogue to Decrease Ascites in Severe Polycystic Liver Disease

S2397 The Case for Octreotide: A Case Report on the Use of a Somatostatin Analogue to Decrease Ascites in Severe Polycystic Liver Disease

Severe polycystic liver disease as a rare indication for liver transplant.

Severe polycystic liver disease as a rare indication for liver transplant.

2365 A Rare Case of Severe Primary Polycystic Liver Disease

INTRODUCTION: Polycystic Liver Disease (PLD) is found mainly in association with autosomal dominant polycystic kidney disease (ADPKD). Isolated PLD is rare with a prevalence of less than 0.01%. Massive hepatomegaly causing symptoms associated with PLD is even rarer. We present a patient with severe PLD requiring surgical intervention. CASE DESCRIPTION/METHODS: A 55-year-old man had an incidental finding of multiple liver cysts on an ultrasound done for investigation of a superficial abdominal wall mass. He reported left upper quadrant pressure. Two siblings had hepatic cysts but no family history of kidney cysts. He had been in South Korea and central America in the past. Physical exam showed hepatomegaly, splenomegaly and a bulge in the right upper quadrant (Figure 1). Hepatic synthetic, excretory function and aminotransferases were normal. CT abdomen revealed too numerous to count hepatic cysts, some measuring up to 11cm in diameter, renal cysts and a 1.4 cm splenic cyst. MRI showed numerous intrahepatic cysts, measuring up to 14 cm, a small number of bilateral renal cysts and splenic cyst (Figure 2). AFP, Echinococcus IgG and chronic hepatitis panel were negative. He did not met criteria for ADPKD as the renal his cysts were simple and age-related according to nephrology. He reported worsening symptoms abdominal pressure and postprandial pain. He underwent laparoscopic fenestration of liver cysts and specimens were consistent with simple hepatic cysts. DISCUSSION: PLD is a rare condition that is often asymptomatic. At least one-third of PLD may also have a few kidney cysts that do not meet criteria for ADPKD. Gigot’s classification is based on imaging findings and can used to help determine management choice based on total liver involvement, cyst size and number (Table 1). Asymptomatic PLD patients do not require treatment. Symptomatic patients may be treated medically with somatostatin analogues or surgically including fenestration +/- hepatic resection or liver transplantation. Severe PLD causing bulging on the abdomen is rare. Our patient benefited from fenestration.

Effect of tolvaptan in a patient with autosomal dominant polycystic kidney disease after living donor liver transplantation.

Recently, a large randomized placebo-controlled trial indicated a beneficial effect of tolvaptan on the progression of autosomal dominant polycystic kidney disease (ADPKD) with near-normal kidney function. Meanwhile, the evidence of tolvaptan's efficacy in ADPKD with severe renal insufficiency was limited and higher frequency of liver enzyme elevations were observed in patients taking tolvaptan. Liver transplantation (LT) is the only curative treatment for patients with severe polycystic liver disease associated with ADPKD, but considering that liver injuries should be avoided particularly in patients who underwent LT, we must be careful to start tolvaptan in post-LT ADPKD patients. We describe the case of a patient who had developed severe renal insufficiency after living donor LT, for whom tolvaptan therapy showed marked reduction of total kidney volume and maintenance of renal function without any serious adverse events. This is the first report to show the beneficial effect and safety of tolvaptan, in a post-LT ADPKD patient with severe renal insufficiency, and hopefully will help broaden the spectrum of patients who will benefit from tolvaptan.

Effect of genotype on the severity and volume progression of polycystic liver disease in autosomal dominant polycystic kidney disease.

The autosomal dominant polycystic kidney disease (APDKD) genotype influences renal phenotype severity but its effect on polycystic liver disease (PLD) is unknown. Here we analyzed the influence of genotype on liver phenotype severity. Clinical data were retrieved from electronic records of patients who were mutation screened with the available liver imaging (n = 434). Liver volumes were measured by stereology (axial or coronal images) and adjusted to height (HtLV). Among the patients included, 221 (50.9%) had truncating PKD1 (PKD1-T), 141 (32.5%) nontruncating PKD1 (PKD1-NT) and 72 (16.6%) PKD2 mutations. Compared with PKD1-NT and PKD2, patients with PKD1-T had greater height-adjusted total kidney volumes (799 versus 610 and 549 mL/m; P < 0.001). HtLV was not different (1042, 1095 and 1058 mL/m; P = 0.64) between the three groups, but females had greater HtLVs compared with males (1114 versus 1015 mL/m; P < 0.001). Annualized median liver growth rates were 1.68, 1.5 and 1.24% for PKD1-T, PKD1-NT and PKD2 mutations, respectively (P = 0.49), and remained unaffected by the ADPKD genotype when adjusted for age, gender and baseline HtLV. Females <48 years of age had higher annualized growth rates compared with those who were older (2.65 versus 0.09%; P < 0.001). After age 48 years, 58% of females with severe PLD had regression of HtLV, while HtLV continued to increase in males. In contrast to the renal phenotype, the ADPKD genotype was not associated with the severity or growth rate of PLD in ADKPD patients. This finding, along with gender influence, indicates that modifiers beyond the disease gene significantly influence the liver phenotype.

Clinical Correlates of Mass Effect in Autosomal Dominant Polycystic Kidney Disease.

Mass effect from polycystic kidney and liver enlargement can result in significant clinical complications and symptoms in autosomal dominant polycystic kidney disease (ADPKD). In this single-center study, we examined the correlation of height-adjusted total liver volume (htTLV) and total kidney volume (htTKV) by CT imaging with hepatic complications (n = 461) and abdominal symptoms (n = 253) in patients with ADPKD. “Mass-effect” complications were assessed by review of medical records and abdominal symptoms, by a standardized research questionnaire. Overall, 91.8% of patients had 4 or more liver cysts on CT scans. Polycystic liver disease (PLD) was classified as none or mild (htTLV < 1,600 mL/m); moderate (1,600 ≤ htTLV <3,200 mL/m); and severe (htTLV ≥ 3,200 mL/m). The prevalence of moderate and severe PLD in our patient cohort was 11.7% (n = 54/461) and 4.8% (n = 22/461), respectively, with a female predominance in both the moderate (61.1%) and severe (95.5%) PLD groups. Pressure-related complications such as leg edema (20.4%), ascites (16.6%), and hernia (3.6%) were common, and patients with moderate to severe PLD exhibited a 6-fold increased risk (compared to no or mild PLD) for these complications in multivariate analysis. Similarly, abdominal symptoms including back pain (58.8%), flank pain (53.1%), abdominal fullness (46.5%), and dyspnea/chest-discomfort (44.3%) were very common, and patients with moderate to severe PLD exhibited a 5-fold increased risk for these symptoms. Moderate to severe PLD is a common and clinically important problem in ~16% of patients with ADPKD who may benefit from referral to specialized centers for further management.

Severe Polycystic Liver Disease Is Not Caused by Large Deletions of the PRKCSH Gene.

Isolated polycystic liver disease (ADPLD) is an autosomal dominant Mendelian disorder. Heterozygous PRKCSH (where PRKCSH is protein kinase C substrate 80K-H (80 kDa protein, heavy chain; MIM*177060) mutations are the most frequent cause. Routine molecular testing using Sanger sequencing identifies pathogenic variants in the PRKCSH (15%) and SEC63 (where SEC63 is Saccharomyces cerevisiae homolog 63 (MIM*608648); 6%) genes, but about approximately 80% of patients meeting the clinical ADPLD criteria carry no PRKCSH or SEC63 mutation. Cyst tissue often shows somatic deletions with loss of heterozygosity that was recently recognized as a general mechanism in ADPLD. We hypothesized that germline deletions in the PRKCSH gene may be responsible for hepatic cystogenesis in a significant number of mutation-negative ADPLD patients. In this study, we designed a multiplex ligation-dependent probe amplification (MLPA) assay to screen for deletions of PRKCSH exons. Genomic DNA from 60 patients with an ADPLD phenotype was included. MLPA analysis detected no exon deletions in mutation-negative ADPLD patients. Large copy number variations on germline level are not present in patients with a clinical diagnosis of ADPLD. MLPA analysis of the PRKCSH gene should not be considered as a diagnostic method to explain hepatic cystogenesis.

Efficacy of 4 Years of Octreotide Long-Acting Release Therapy in Patients With Severe Polycystic Liver Disease

ObjectiveTo observe the effect on total liver volume (TLV) on and off therapy in selected symptomatic patients with autosomal dominant polycystic kidney disease (ADPKD) or autosomal dominant polycystic liver disease (PLD) who received octreotide long-acting release (OctLAR) for up to 4 years. Patients and MethodsTwenty-eight of 42 participants in a prospective 2-year clinical trial of OctLAR (40 mg monthly) consisting of double-blind, randomized (year 1) and open-label treatment (year 2) phases reenrolled in a 2-year open-label extension (OLE) study after being off OctLAR a mean of 8.3 months (original study: July 1, 2007, through June 30, 2013). Participants underwent magnetic resonance imaging at baseline, years 1 and 2, reenrollment, and study completion. Primary end point: change in TLV; secondary end points: changes in total kidney volume, glomerular filtration rate, quality of life (QoL), safety, vital signs, and laboratory parameters. ResultsTwenty-five participants (59.5%) completed the OLE. Off therapy, TLVs increased a mean ± SD of 3.4%±8.2% per year; after resuming therapy, TLVs decreased a mean ± SD of −4.7%±6.1% per year. Despite regrowth off treatment, overall reductions were observed, with a median (interquartile range) TLV of 4047 mL (3107-7402 mL) at baseline and 3477 (2653-7131 mL) at study completion (−13.2%; P<.001) and with improved health-related QoL. Total kidney volumes increased, and glomerular filtration rates declined from 58.2 mL/min to 54.5 mL/min (n=16) in patients with ADPKD on therapy from baseline to study completion. ConclusionTherapy with OctLAR over 4 years in selected patients with symptomatic PLD arrested PLD progression, alleviating symptoms and improving health-related QoL. Discontinuation led to organ regrowth. Trial Registrationclinicaltrials.gov Identifier: NCT00426153.

Evaluating health‐related quality of life in patients with polycystic liver disease and determining the impact of symptoms and liver volume

Polycystic liver disease (PLD) follows a progressive course ultimately leading to severe hepatomegaly and mechanical complaints in a subset of patients. It is still unknown to what extent this compromises health-related quality of life (HRQL). Our aim was to determine HRQL in PLD patients and investigate its association with concurrent abdominal symptoms and liver volume. Pooled data of 92 severe PLD patients from two randomized clinical trials were used for our cross-sectional analysis. HRQL was assessed using the generic short-form health survey (SF-36) resulting in eight scale scores and the summarizing physical (PCS) and mental component score (MCS). Subsequently, these were compared with the general population. Abdominal symptoms were measured with a standardized, 7-point scale questionnaire in 54 patients. We dichotomized symptoms for absence or presence and compared them with the component scores. Finally, a possible correlation between liver volume and HRQL was explored. Demographics showed severe polycystic livers (mean 4906 ± 2315 ml). PCS was significantly lower compared with the general population (P < 0.001), in contrast with a similar MCS (P = 0.82). PLD patients had statistically significant (P < 0.05) diminished physical functioning, role physical, general health, vitality and social functioning scores. Upper- and lower abdominal pain and dyspnoea were significantly associated with a reduced PCS (P < 0.01). No correlation was found between liver volume and HRQL. Polycystic liver disease patients had significantly lower HRQL in the physical dimension compared with the general population. Abdominal pain and dyspnoea had a significant impact on this physical dimension of HRQL.

Somatostatin analog therapy for severe polycystic liver disease: results after 2 years

We showed in a randomized double-blinded placebo-controlled clinical trial that octreotide long-acting repeatable depot.® (OctLAR(®)) for 12 months reduces kidney and liver growth in autosomal dominant polycystic kidney patients with severe polycystic liver disease (PLD) and liver growth in patients with severe isolated PLD. We have now completed an open-label extension for one additional year to assess safety and clinical benefits of continued use of OctLAR for 2 years (O → O) and examined drug effect in the placebo group who crossed over to OctLAR in Year 2 (P → O). The primary end point was change in total liver volume (TLV) measured by magnetic resonance imaging (MRI); secondary end points were changes in total kidney volume (TKV) measured by MRI, glomerular filtration rate (GFR), quality of life (QOL), safety, vital signs and laboratory parameters. Forty-one of 42 patients received OctLAR (n = 28) or placebo (n = 14) in Year 1 and received OctLAR in Year 2 (maximum dose 40 mg). Patients originally randomized to placebo (P → O) showed substantial reduction in TLV after treatment with OctLAR in Year 2 (Δ% -7.66 ± 9.69%, P = 0.011). The initial reduction of TLV in the OctLAR group (O → O) was maintained for 2 years (Δ% -5.96 ± 8.90%), although did not change significantly during Year 2 (Δ% -0.77 ± 6.82%). OctLAR inhibited renal enlargement during Year 1 (Δ% +0.42 ± 7.61%) in the (O → O) group and during Year 2 (Δ% -0.41 ± 9.45%) in the (P → O) group, but not throughout Year 2 (Δ% +6.49 ± 7.08%) in the (O → O) group. Using pooled analyses of all individuals who received OctLAR for 12 months, i.e. in Year 1 for O → O patients and Year 2 for P → O patients, average reduction in TLV was -6.08 ± 7.58% (P = 0.001) compared to net growth of 0.9 ± 8.35% in the original placebo group. OctLAR-treated individuals continued to experience improvements in QOL in Year 2, although overall physical and mental improvements were not significant during Year 2 compared to Year 1. Changes in GFR were similar in both groups. Over 2 years, OctLAR significantly reduced the rate of increase in TLV and possibly the rate of increase in TKV.

Randomized Clinical Trial of Long-Acting Somatostatin for Autosomal Dominant Polycystic Kidney and Liver Disease

There are no proven, effective therapies for polycystic kidney disease (PKD) or polycystic liver disease (PLD). We enrolled 42 patients with severe PLD resulting from autosomal dominant PKD (ADPKD) or autosomal dominant PLD (ADPLD) in a randomized, double-blind, placebo-controlled trial of octreotide, a long-acting somatostatin analogue. We randomly assigned 42 patients in a 2:1 ratio to octreotide LAR depot (up to 40 mg every 28+/-5 days) or placebo for 1 year. The primary end point was percent change in liver volume from baseline to 1 year, measured by MRI. Secondary end points were changes in total kidney volume, GFR, quality of life, safety, vital signs, and clinical laboratory tests. Thirty-four patients had ADPKD, and eight had ADPLD. Liver volume decreased by 4.95%+/-6.77% in the octreotide group but remained practically unchanged (+0.92%+/-8.33%) in the placebo group (P=0.048). Among patients with ADPKD, total kidney volume remained practically unchanged (+0.25%+/-7.53%) in the octreotide group but increased by 8.61%+/-10.07% in the placebo group (P=0.045). Changes in GFR were similar in both groups. Octreotide was well tolerated; treated individuals reported an improved perception of bodily pain and physical activity. In summary, octreotide slowed the progressive increase in liver volume and total kidney volume, improved health perception among patients with PLD, and had an acceptable side effect profile.

ERK1/2-Dependent Vascular Endothelial Growth Factor Signaling Sustains Cyst Growth in Polycystin-2 Defective Mice

Severe polycystic liver disease can complicate adult dominant polycystic kidney disease, a genetic disease caused by defects in polycystin-1 (Pkd1) or polycystin-2 (Pkd2). Liver cyst epithelial cells (LCECs) express vascular endothelial growth factor (VEGF) and its receptor, VEGFR-2. We investigated the effects of VEGF on liver cyst growth and autocrine VEGF signaling in mice with Pkd1 and Pkd2 conditional knockouts. We studied mice in which Pkd1 or Pkd2 were conditionally inactivated following exposure to tamoxifen; these mice were called Pkd1(flox/-):pCxCreER (Pkd1KO) and Pkd2(flox/-):pCxCreER (Pkd2KO). Pkd1KO and Pkd2KO mice developed liver defects; their LCECs expressed VEGF, VEGFR-2, hypoxia-inducible factor (HIF)-1alpha, phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2), and proliferating cell nuclear antigen (PCNA). In Pkd2KO but not Pkd1KO mice, exposure to the VEGFR-2 inhibitor SU5416 significantly reduced liver cyst development, liver/body weight ratio, and expression of pERK and PCNA. VEGF secretion and phosphorylation of ERK1/2 and VEGFR-2 were significantly increased in cultured LCECs from Pkd2KO compared with Pkd1KO mice. Inhibition of protein kinase A (PKA) reduced VEGF secretion and pERK1/2 expression. Addition of VEGF to LCECs from Pkd2KO mice increased phosphorylated VEGFR-2 and phosphorylated mitogen signal-regulated kinase (MEK) expression and induced phosphorylation of ERK1/2; this was inhibited by SU5416. Expression of HIF-1alpha increased in parallel with secretion of VEGF following LCEC stimulation. VEGF-induced cell proliferation was inhibited by the MEK inhibitor U1026 and by ERK1/2 small interfering RNA. The PKA-ERK1/2-VEGF signaling pathway promotes growth of liver cysts in mice. In Pkd2-defective LCECs, PKA-dependent ERK1/2 signaling controls HIF-1alpha-dependent VEGF secretion and VEGFR-2 signaling. Autocrine and paracrine VEGF signaling promotes the growth of liver cysts in Pkd2KO mice. VEGF inhibitors might be used to treat patients with polycystic liver disease.

Fulminant Liver Failure in a Patient Affected by Polycystic Liver Disease and Liver Metastases from Breast Carcinoma

Polycystic liver disease (PLD) is a rare, congenital, benign condition characterized by the presence of multiple bile-duct-derived epithelial cysts in the liver parenchyma. The disease is usually asymptomatic, but cyst growth can result in complications such as ascites, esophageal varices, jaundice and hepatic failure. The exact mechanism leading to cyst growth is unclear, but estrogenic stimulation and paracrine action of vascular endothelial growth factor (VEGF) are thought to play a role in the growth of cyst epithelium. We report a case of acute liver failure in a young woman with PLD and liver metastases from breast carcinoma. No data are available in the literature about metastatic liver involvement in PLD patients affected by breast cancer. The prognosis of patients with liver metastases is generally poor but fulminant liver failure is a very rare occurrence. Estrogen stimulation seems to be a risk factor for breast cancer and severe PLD. In the reported case, the presence of either the cysts or the metastatic lesions may have resulted in more extensive liver damage. The adoption of drugs selected in relation to their hepatic toxicity together with careful monitoring of liver function is warranted in the management of breast cancer patients affected by PLD, in order to reduce the risk of liver failure.

Abnormal hepatocystin caused by truncating PRKCSH mutations leads to autosomal dominant polycystic liver disease.

Mutations in protein kinase C substrate 80K-H (PRKCSH), encoding for the protein hepatocystin, cause autosomal dominant polycystic liver disease (PCLD), which is clinically characterized by the presence of multiple liver cysts. PCLD has been documented in families from Europe (Netherlands, Belgium, Finland) as well as from the United States. In this article, we report results from extensive mutational analysis of the PRKCSH gene in a group of 14 PCLD families and 65 singleton cases of Dutch and Finnish descent with multiple simple liver cysts. We identified PRKCSH mutations in 12 families and in 3 sporadic cases. In 8 of 10 Finnish families we detected the 1437+2delTG splice-site mutation. In Dutch families, we found 2 other mutations that affect correct splicing of PRKCSH: 292+1 G>C (2 families) and 1338-2 A>G (1 family). In another Dutch family, we detected a novel deletion (374-375delAG) in exon 6, predicting an abnormal shortened protein. Investigation of the carrier haplotypes identified a common founder chromosome in unrelated individuals in each of the 3 identified splice-site mutations. In 2 Finnish families with dominantly inherited PCLD, and in 62 of 65 sporadic cases with multiple simple liver cysts, we failed to demonstrate any PRKCSH mutation. This corroborates the notion that autosomal dominant PCLD is genetically heterogeneous. In conclusion, we propose that, on the basis of our results, genetic screening for PRKCSH gene mutations should be limited to patients either with a positive family history for PCLD or who have severe polycystic liver disease.