Liver involvement in autosomal-dominant polycystic kidney disease: therapeutic dilemma

Congenital abnormalities and hepatoblastoma: a report from the Children's Oncology Group (COG) and the Utah Population Database (UPDB)

Beckwith-Wiedemann Syndrome (BWS) and familial adenomatous polyposis (FAP) are known to predispose to hepatoblastoma (HB). A case-control study was conducted through the Children's Oncology Group (COG) to study the association of HB with isolated congenital abnormalities. Cases (N = 383) were diagnosed between 2000 and 2008. Controls (N = 387) were recruited from state birth registries, frequency matched for sex, region, year of birth, and birth weight. Data on congenital abnormalities among subjects and covariates were obtained by maternal telephone interview. Odds ratios (OR) and 95% confidence intervals (CI) describing the association between congenital abnormalities with HB, adjusted for sex, birth weight, maternal age and maternal education, were calculated using unconditional logistic regression. There was a significant association of HB with kidney, bladder, or sex organ abnormalities (OR = 4.75; 95% CI: 1.74-13) which appeared to be specific to kidney/bladder defects (OR = 4.3; 95% CI: 1.2-15.3) but not those of sex organs (OR = 1.24; 95% CI: 0.37-4.1). Elevated but non-significant ORs were found for spina bifida or other spinal defects (OR = 2.12; 95% CI: 0.39-11.7), large or multiple birthmarks (OR = 1.33; 95% CI: 0.81-2.21). The results were validated through the Utah Population Database (UPDB), a statewide population-based registry linking birth certificates, medical records, and cancer diagnoses. In the UPDB, there were 29 cases and 290 population controls matched 10:1 on sex and birth year. Consistent with the COG findings, kidney/bladder defects were associated with hepatoblastoma. These results confirm the association of HB with kidney/bladder abnormalities.

Symptomatic polycystic liver disease treated with transcatheter hepatic arterial embolization and inferior vena cava stenting: a case report

Autosomal-dominant polycystic kidney disease is frequently complicated by polycystic liver disease. Some patients with polycystic liver disease have a full-stomach sensation and intractable ascites. We report a 56-year-old woman with polycystic liver disease waiting to receive a liver transplant, with a chief complaint of a full-stomach sensation and refractory ascites, wherein the transcatheter hepatic arterial embolization and inferior vena cava stenting were begun simultaneously, and the signs were favorably alleviated. It is important to recognize the risk of liver failure after the complete embolization of both the right and left hepatic arteries; however, performance of transcatheter hepatic arterial embolization and inferior vena cava stent placement also are indicated for patients awaiting a liver transplant for early alleviation of symptoms.

Conditional mesenchymal disruption of pkd1 results in osteopenia and polycystic kidney disease

Conditional deletion of Pkd1 in osteoblasts using either Osteocalcin(Oc)-Cre or Dmp1-Cre results in defective osteoblast-mediated postnatal bone formation and osteopenia. Pkd1 is also expressed in undifferentiated mesenchyme that gives rise to the osteoblast lineage. To examine the effects of Pkd1 on prenatal osteoblast development, we crossed Pkd1^flox/flox and Col1a1(3.6)-Cre mice, which has been used to achieve selective inactivation of Pkd1 earlier in the osteoblast lineage. Control Pkd1^flox/flox and Pkd1^flox/+, heterozygous Col1a1(3.6)-Cre;Pkd1^flox/+ and Pkd1^flox/null, and homozygous Col1a1(3.6)-Cre;Pkd1^flox/flox and Col1a1(3.6)-Cre;Pkd1^flox/null mice were analyzed at ages ranging from E14.5 to 8-weeks-old. Newborn Col1a1(3.6)-Cre;Pkd1^flox/null mice exhibited defective skeletogenesis in association with a greater reduction in Pkd1 expression in bone. Conditional Col1a1(3.6)-Cre;Pkd1^flox/+ and Col1a1(3.6)-Cre;Pkd1^flox/flox mice displayed a gene dose-dependent decrease in bone formation and increase in marrow fat at 6 weeks of age. Bone marrow stromal cell and primary osteoblast cultures from homozygous Col1a1(3.6)-Cre;Pkd1^flox/flox mice showed increased proliferation, impaired osteoblast development and enhanced adipogenesis ex vivo. Unexpectedly, we found evidence for Col1a1(3.6)-Cre mediated deletion of Pkd1 in extraskeletal tissues in Col1a1(3.6)-Cre;Pkd1^flox/flox mice. Deletion of Pkd1 in mesenchymal precursors resulted in pancreatic and renal, but not hepatic, cyst formation. The non-lethality of Col1a1(3.6)-Cre;Pkd1^flox/flox mice establishes a new model to study abnormalities in bone development and cyst formation in pancreas and kidney caused by Pkd1 gene inactivation.

Ascites complicating unilateral nephrectomy and peritoneal dialysis catheter implantation in a patient with massive polycystic kidney and liver disease

Peritoneal dialysis (PD) is a well-established therapeutic option for patients with polycystic kidney disease. However, in patients with massive polycystic kidney and liver disease, subclinical hepatic venous outflow obstruction may elicit the appearance of ascites after implantation of a peritoneal catheter. The case of a patient who developed ascites after implantation of a PD catheter and further lowering of abdominal pressure after unilateral nephrectomy is discussed.

2-Hydroxyestradiol slows progression of experimental polycystic kidney disease

Male gender is a risk factor for progression of polycystic kidney disease (PKD). 17β-Estradiol (E2) protects experimentally, but clinical use is limited by adverse effects. Novel E2 metabolites provide many benefits of E2 without stimulating the estrogen receptor, and thus may be safer. We hypothesized that E2 metabolites are protective in a model of PKD. Studies were performed in male control Han:SPRD rats, and in cystic males treated with orchiectomy, 2-methoxyestradiol, 2-hydroxyestradiol (2-OHE), or vehicle, from age 3 to 12 wk. Cystic rats exhibited renal functional impairment (∼50% decrease in glomerular filtration and renal plasma flow rates, P < 0.05) and substantial cyst development (20.5 ± 2.0% of cortex area). 2-OHE was the most effective in limiting cysts (6.0 ± 0.7% of cortex area, P < 0.05 vs. vehicle-treated cystic rats) and preserving function, in association with suppression of proliferation, apoptosis, and angiogenesis markers. Downregulation of p21 expression and increased expression of Akt, the mammalian target of rapamycin (mTOR), and some of its downstream effectors were significantly reversed by 2-OHE. Thus, 2-OHE limits disease progression in a cystic rodent model. Mechanisms include reduced renal cell proliferation, apoptosis, and angiogenesis. These effects may be mediated, at least in part, by preservation of p21 and suppression of Akt and mTOR. Estradiol metabolites may represent a novel, safe intervention to slow progression of PKD.

Positron emission tomography in the diagnostic pathway for intracystic infection in adpkd and "cystic" kidneys. a case series

Background

Intracystic infection, in Autosomal Dominant Polycystic Kidney Disease (ADPKD) and in kidneys with multiple cysts, is a diagnostic and therapeutic challenge, as conventional imaging techniques may not discriminate among "complicated" cysts (infection, bleeding, neoplasia), and as the clinical picture may be attenuated, in particular in early phases. Positron Emission Tomography with fluorodeoxyglucose (FDG-PET) was recently suggested as a tool to detect infection in ADPKD, in single cases and small series.

The aim of the study was to report on the role of FDG-PET in the work-up of 10 cases of suspected cystic infections, affected by ADPKD or with multiple kidney cysts.

Methods

Observational study. Review of clinical charts and of the imaging data since the use of FDG-PET for detecting cystic infections (2008-2010).

Results

In 2008-2010, 6 patients with ADPKD and 4 with multiple kidney cysts were referred for suspected intracystic infections (3 males, 7 females, aged 55-83 years, in all CKD stages); in one case the imaging was done in the work-up of a complicated "uremic" cyst. The clinical picture, the usual inflammatory markers and/or the conventional imaging techniques did not allow conclusive diagnosis at referral or during follow-up (ultrasounds in all, CT in 8/10). Nine patients displayed inflammatory signs (increase in C-reactive protein and other biochemical markers) and constitutional symptoms (fever in 9/10).

FDG-PET was positive in 6 cases (5 kidney and 1 liver cyst), was repeated during follow-up in 4 patients and was negative in 4 cases. In the positive cases, FDG-PET guided the therapeutic choices; in particular, the duration of therapy was supported by imaging data in the 4 cases with multiple scans. No relapse was recorded after discontinuation of antibiotic therapy in the treated patients. The negative cases did not develop clinical signs of cystic infection over follow-up.

Conclusion

In this case series, the largest prospective one so far published and the only one including different types of renal cysts, FDG-PET is confirmed as a promising diagnostic tool for detecting intracystic infection in ADPKD and in multiple kidney cysts, and a potential guide for tailoring therapy. Further larger and multicenter studies are needed to evaluate the cost-benefit ratio and the limits of this imaging technique in the clinical setting.

Biologic and clinical features of benign solid and cystic lesions of the liver

The widespread use of imaging analyses, either routinely or to evaluate symptomatic patients, has increased the detection of liver lesions (tumors and cysts) in otherwise healthy individuals. Although some of these incidentally discovered masses are malignant, most are benign and must be included in the differential diagnosis. The management of benign hepatic tumors ranges from conservative to aggressive, depending on the nature of the lesions. New imaging modalities, increased experience of radiologists, improved definition of radiologic characteristics, and a better understanding of the clinical features of these lesions have increased the accuracy of diagnoses and reduced the need for invasive diagnostic tests. These advances have led to constant adjustments in management approaches to benign hepatic lesions. We review the biologic and clinical features of some common hepatic lesions, to guide diagnosis and management strategies.

PPAR-gamma agonist ameliorates kidney and liver disease in an orthologous rat model of human autosomal recessive polycystic kidney disease

In autosomal recessive polycystic kidney disease (ARPKD), progressive enlargement of fluid-filled cysts is due to aberrant proliferation of tubule epithelial cells and transepithelial fluid secretion leading to extensive nephron loss and interstitial fibrosis. Congenital hepatic fibrosis associated with biliary cysts/dilatations is the most common extrarenal manifestation in ARPKD and can lead to massive liver enlargement. Peroxisome proliferator-activated receptor γ (PPAR-γ), a member of the ligand-dependent nuclear receptor superfamily, is expressed in a variety of tissues, including the kidneys and liver, and plays important roles in cell proliferation, fibrosis, and inflammation. In the current study, we determined that pioglitazone (PIO), a PPAR-γ agonist, decreases polycystic kidney and liver disease progression in the polycystic kidney rat, an orthologous model of human ARPKD. Daily treatment with 10 mg/kg PIO for 16 wk decreased kidney weight (% of body weight), renal cystic area, serum urea nitrogen, and the number of Ki67-, pERK1/2-, and pS6-positive cells in the kidney. There was also a decrease in liver weight (% of body weight), liver cystic area, fibrotic index, and the number of Ki67-, pERK1/2-, pERK5-, and TGF-β-positive cells in the liver. Taken together, these data suggest that PIO inhibits the progression of polycystic kidney and liver disease in a model of human ARPKD by inhibiting cell proliferation and fibrosis. These findings suggest that PPAR-γ agonists may have therapeutic value in the treatment of the renal and hepatic manifestations of ARPKD.

Management of an incidental liver mass

The increased use of sensitive imaging modalities has led to increased identification of the incidental liver mass (ILM). A combination of careful consideration of patient factors and imaging characteristics of the ILM enables clinicians to recommend a safe and efficient course of action. Using an algorithmic approach, this article includes pertinent clinical factors and the specific radiologic criteria of ILMs and discusses the indications for potential procedures. It is the aim of this article to assist with the development of an individualized strategy for each patient with an ILM.

Extrarenal manifestations of autosomal dominant polycystic kidney disease

Although asymptomatic in most patients, extrarenal manifestations of ADPKD may become more clinically relevant with the increasing life expectancy of affected patients. They mainly encompass cysts in other organs than the kidney (liver: 94%, seminal vesicle: 40%, pancreas: 9%, arachnoid membrane: 8%, and spinal meningeal, 2%) and connective tissue abnormalities (mitral valve prolapse: 25%, intracranial aneurysms: 8%, and abdominal hernia: 10%). Their recognition may spare the patient from other, useless investigations (eg, when an arachnoid cyst is incidentally found) or lead to the implementation of prophylactic or therapeutic measures (eg, screening, sometimes followed by the treatment of an asymptomatic intracranial aneurysm in at-risk patients, or, in the presence of a severe polycystic liver disease, avoidance from estrogens and treatment aimed to slow cyst growth).

Carbohydrate antigen 19-9 as a diagnostic marker for hepatic cyst infection in autosomal dominant polycystic kidney disease

The diagnosis of hepatic cyst infection is difficult in patients with autosomal dominant polycystic kidney disease (ADPKD). We hypothesized that carbohydrate antigen 19-9 (CA 19-9), secreted by the biliary epithelium lining the cysts, is overproduced in the case of cyst infection. In this report, we describe 3 patients with ADPKD with hepatic cyst infection, all with functioning kidney transplants, who had markedly increased serum CA 19-9 levels. Furthermore, CA 19-9 level was extremely increased in cystic fluid obtained in 2 of these individuals. Corresponding with clinical improvement, there was a marked decrease in serum CA 19-9 level in all 3 patients. To assess the potential applicability of these findings, serum CA 19-9 was measured in asymptomatic patients with ADPKD with known liver cysts and in controls without ADPKD. Although serum CA 19-9 levels were significantly higher in asymptomatic patients with ADPKD than in controls, they were markedly increased in patients with cyst infection compared with either asymptomatic ADPKD patients or controls. Immunostaining for CA 19-9 showed strong positivity in biliary tree epithelia and cysts of polycystic livers from patients with ADPKD that appeared more intense than in normal livers. Although further study is necessary, these data suggest that serum CA 19-9 level is markedly increased during liver cyst infection in kidney transplant recipients with ADPKD and has potential utility as a diagnostic marker.

Transcatheter arterial embolization therapy for a massive polycystic liver in autosomal dominant polycystic kidney disease patients

Polycystic liver is the most common extra-renal manifestation associated with autosomal dominant polycystic kidney disease (ADPKD), comprising up to 80% of all features. Patients with polycystic liver often suffer from abdominal discomfort, dyspepsia, or dyspnea; however, there have been few ways to relieve their symptoms effectively and safely. Therefore, we tried transcatheter arterial embolization (TAE), which has been used in treating hepatocellular carcinoma. We enrolled four patients with ADPKD in Seoul National University Hospital, suffering from enlarged polycystic liver. We embolized the hepatic arteries supplying the dominant hepatic segments replaced by cysts using polyvinyl alcohol particles and micro-coils. The patients were evaluated 12 months after embolization for the change in both liver and cyst volumes. Among four patients, one patient was lost in follow up and 3 patients were included in the analysis. Both liver (33%; 10%) and cyst volume (47.7%; 11.4%) substantially decreased in two patients. Common adverse events were fever, epigastric pain, nausea, and vomiting. We suggest that TAE is effective and safe in treating symptomatic polycystic liver in selected ADPKD patients.

MicroRNA15a modulates expression of the cell-cycle regulator Cdc25A and affects hepatic cystogenesis in a rat model of polycystic kidney disease

Hyperproliferation of bile duct epithelial cells due to cell-cycle dysregulation is a key feature of cystogenesis in polycystic liver diseases (PCLDs). Recent evidence suggests a regulatory role for microRNAs (miRNAs) in a variety of biological processes, including cell proliferation. We therefore hypothesized that miRNAs may be involved in the regulation of selected components of the cell cycle and might contribute to hepatic cystogenesis. We found that the cholangiocyte cell line PCK-CCL, which is derived from the PCK rat, a model of autosomal recessive polycystic kidney disease (ARPKD), displayed global changes in miRNA expression compared with normal rat cholangiocytes (NRCs). More specific analysis revealed decreased levels of 1 miRNA, miR15a, both in PCK-CCL cells and in liver tissue from PCK rats and patients with a PCLD. The decrease in miR15a expression was associated with upregulation of its target, the cell-cycle regulator cell division cycle 25A (Cdc25A). Overexpression of miR15a in PCK-CCL cells decreased Cdc25A levels, inhibited cell proliferation, and reduced cyst growth. In contrast, suppression of miR15a in NRCs accelerated cell proliferation, increased Cdc25A expression, and promoted cyst growth. Taken together, these results suggest that suppression of miR15a contributes to hepatic cystogenesis through dysregulation of Cdc25A.

Review article: the evaluation of solitary liver masses

BACKGROUND

The increasing use of imaging modalities has led to the detection of more liver masses. The differential diagnosis of a focal liver mass includes a host of benign as well as malignant conditions.

AIM

To provide a comprehensive review on the commonly encountered liver masses, and to help guide an approach to their evaluation and management.

METHODS

Pertinent literature that was identified through PubMed search and senior author's experience formed the basis of this review.

RESULTS

While most incidentally noted liver masses are benign, it may be difficult to differentiate them from those that are malignant. Furthermore, some benign lesions have malignant potential. Certain lesions such as focal nodular hyperplasia, haemangiomas and focal steatosis are often distinctly diagnosed by an imaging modality alone. The less frequently encountered hepatic adenomas are diagnosed radiologically in those with the appropriate clinical background and the absence of radiological features to suggest haemangioma or focal nodular hyperplasia.

CONCLUSIONS

A reasonable approach to the diagnosis, follow-up and management of liver masses is based on a rudimentary knowledge of their presentation, associated clinical and laboratory features, natural history and available treatment options. Most often, the so called 'incidentalomas' are benign and require patient reassurance.

Advances in management of polycystic liver disease

The focus of this review is polycystic liver disease, a genetic disorder characterized by multiple macroscopic liver cysts that initially bud from biliary epithelium but subsequently lack communication with the biliary tree. There are two main clinical presentations: polycystic liver associated with autosomal dominant polycystic kidney disease and isolated polycystic liver disease. Both of these forms of polycystic liver disease exhibit an autosomal dominant pattern of inheritance. Clinical manifestations of polycystic liver disease are related to either mass effect of the volume of hepatic cysts or to complications arising within the cysts. Polycystic liver disease rarely progresses to hepatic failure or clinical complications of portal hypertension. Management is directed at counseling patients and families, treating complications and reducing cyst load by surgical techniques: cyst fenestration, hepatic resection or, rarely, hepatic transplantation. Recent research suggests that blockade of cyst secretion or inhibition of epithelial cells might be useful in halting progression of disease--these observations are discussed in this review.

Management of polycystic liver disease

The adult forms of polycystic liver disease are characterized by autosomal dominant inheritance and numerous hepatic cysts, with or without renal involvement. Mutations in two distinct genes predispose to renal and liver cysts (PKD1 and PKD2), and mutations in two different genes yield isolated liver cysts (PRKCSH and SEC63). Mutations at certain loci of PKD1 may predispose to more severe renal cystic disease or cerebral aneurysms. Risk factors for severe hepatic cystic disease include aging, female sex, pregnancy, use of exogenous female steroid hormones, degree of renal cystic disease, or severity of renal dysfunction (in patients with mutations in PKD1 or PKD2). Although liver failure or complications of advanced liver disease is rare, some patients develop massive hepatic cystic disease and become clinically symptomatic. There is no effective medical therapy. Treatment options include cyst aspiration and sclerosis, open or laparoscopic cyst fenestration, hepatic resection, and liver transplantation.

Sirolimus reduces polycystic liver volume in ADPKD patients

The immunosuppressive agent sirolimus exerts an antiproliferative effect by inhibiting mammalian target of rapamycin (mTOR). Because excessive proliferation of the biliary epithelium is a prominent feature of the polycystic liver that accompanies autosomal dominant polycystic kidney disease (ADPKD), we hypothesized that sirolimus may benefit patients with this disorder. We retrospectively measured the volumes of polycystic livers and kidneys in ADPKD patients who had received kidney transplants and had participated in a prospective randomized trial that compared a sirolimus-containing immunosuppression regimen to a tacrolimus-containing regimen. Sixteen subjects (seven with sirolimus, nine with tacrolimus) had received abdominal imaging studies within 11 mo before and at least 7 mo after transplantation, making them suitable for our analysis. Treatment with the sirolimus regimen for an average of 19.4 mo was associated with an 11.9 +/- 0.03% reduction in polycystic liver volume, whereas treatment with tacrolimus for a comparable duration was associated with a 14.1 +/- 0.09% increase. A trend toward a greater reduction in native kidney volume was also noted in the sirolimus group compared with the nonsirolimus group. Regarding mechanism, the epithelium that lines hepatic cysts exhibited markedly higher levels of phospho-AKT, phospho-ERK, phospho-mTOR, and the downstream effector phospho-S6rp compared with control biliary epithelium. In summary, treatment with sirolimus was associated with decreased polycystic liver volume, perhaps by preventing aberrant activation of mTOR in epithelial cells lining the cysts.

Surgical management of polycystic liver disease

Adult polycystic liver disease (PCLD) is an autosomal dominant condition commonly associated with autosomal dominant polycystic kidney disease (ADPKD). However in the last decade, it has been recognized that there is a distinct form of autosomal dominant PCLD that arises without concomitant ADPKD. Early knowledge of the pathogenesis was gained from the study of hepatic cysts in patients with ADPKD. Bile duct overgrowth after embryogenesis results in cystic hepatic dilatations that are known as biliary microhamartomas or von Meyenburg complexes. Further dilatation arises from cellular proliferation and fluid secretion into these cysts. There is a variable, broad spectrum of manifestations of PCLD. Although PCLD is most often asymptomatic, massive hepatomegaly can lead to disabling symptoms of abdominal pain, early satiety, persistent nausea, dyspnea, ascites, biliary obstruction, and lower body edema. Complications of PCLD include cyst rupture and cyst infection. Also, there are associated medical problems, especially intracranial aneurysms and valvular heart disease, which clinicians need to be aware of and evaluate in patients with PCLD. In asymptomatic patients, no treatment is indicated for PCLD. In the symptomatic patient, surgical therapy is the mainstay of treatment tailored to the extent of disease for each patient. Management options include cyst aspiration and sclerosis, open or laparoscopic fenestration, liver resection with fenestration, and liver transplantation. The surgical literature discussing treatment of PCLD, including techniques, outcomes, and complication rates, are summarized in this review.

Inferior vena cava stenting: a safe and effective treatment for intractable ascites in patients with polycystic liver disease

We performed a retrospective study of seven patients with polycystic liver disease who underwent stenting of the inferior vena cava for intractable ascites. All patients had symptomatic ascites and inferior vena cava stenosis demonstrable by venography. The mean pressure gradient across the inferior vena cava stenosis before stenting was 14.5 mm Hg (range 6-25 mm Hg) and significantly decreased to a mean pressure gradient of 2.8 mm Hg (range 0-6 mm Hg, p = 0.008) after stenting. Two patients also had stenting of hepatic venous stenoses after unsuccessful inferior vena cava stenting. After a mean follow-up of 12.2 months (range 0.5-39.1 months), five of the seven patients have had maintained clinical improvement, defined as decreased symptoms, diuretic requirements, and frequency of paracentesis. Four patients have required no further intervention. The other patient was lost in follow-up. Patients with clinical improvement had an overall larger mean pressure gradient before stenting (19.2 vs. 9.8 mm Hg) and a larger Delta pressure gradient (15.8 vs. 7.8 mm Hg) compared to those in whom stenting was unsuccessful. These results suggest inferior vena cava stenting is safe and effective and should be considered as a first-line intervention in the treatment of medically intractable ascites in select patients with polycystic liver disease.

Autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease is the most prevalent, potentially lethal, monogenic disorder. It is associated with large interfamilial and intrafamilial variability, which can be explained to a large extent by its genetic heterogeneity and modifier genes. An increased understanding of the disorder's underlying genetic, molecular, and cellular mechanisms and a better appreciation of its progression and systemic manifestations have laid out the foundation for the development of clinical trials and potentially effective treatments.

Octreotide inhibits hepatic cystogenesis in a rodent model of polycystic liver disease by reducing cholangiocyte adenosine 3',5'-cyclic monophosphate

BACKGROUND AND AIMS

In polycystic liver diseases (PCLDs), increased cholangiocyte proliferation and fluid secretion are key features and cholangiocyte adenosine 3',5'-cyclic monophosphate (cAMP) is an important regulator of these processes. Thus, we assessed cAMP levels and evaluated octreotide (an analogue of somatostatin known to inhibit cAMP) in hepatic cyst growth using an in vitro model of cystogenesis and an in vivo animal model of autosomal recessive polycystic kidney disease (ARPKD), one of the PCLDs.

METHODS

Expression of somatostatin receptors (SSTRs) was assessed by reverse-transcription polymerase chain reaction and confocal microscopy in cholangiocytes from normal and polycystic kidney (PCK) rats, the ARPKD model of autosomal recessive polycystic kidney disease. Effects of octreotide on cAMP levels and cyst expansion were studied in vitro using PCK bile ducts grown in 3-dimensional culture. The effects of octreotide on hepatic and renal cystogenesis were investigated in PCK rats in vivo.

RESULTS

In cholangiocytes and serum of PCK rats, cAMP concentrations were approximately 2 times higher than in normal rats. SSTR subtypes that bind octreotide (ie, SSTR2, SSTR3, and SSTR5) were expressed in both normal and PCK cholangiocytes. In vitro, octreotide inhibited cAMP levels by 35% and reduced cyst growth by 44%. In vivo, octreotide lowered cAMP content in cholangiocytes and serum by 32%-39% and inhibited hepatic disease progression, leading to 22%-60% reductions in liver weight, cyst volume, hepatic fibrosis, and mitotic indices. Similar effects were observed in kidneys of PCK rats.

CONCLUSIONS

This preclinical study provides a strong rationale for assessing the potential value of octreotide in the treatment of PCLDs.

The hepatic fibrocystic diseases

The hepatic fibrocystic diseases present with variable intrahepatic biliary abnormalities, which range from portal tract enlargement and fibrosis to cystic formations. They may present as autosomal recessive or dominant polycystic kidney diseases, with associated dilatation of the renal collecting system, or as incompletely characterized cystic diseases. Symptoms from the liver disease often result from complications of fibrosis or dilated ducts/cyst (sludge, lithiasis, infection). The treatment is supportive, with careful attention to associated renal disease. Liver transplantation is an option in selected patients.

Intra-operative inferior vena cava syndrome in a patient with autosomal dominant polycystic kidney disease

The renal and hepatic cysts characteristic of autosomal dominant polycystic kidney disease can exert a mass effect on surrounding structures. If this involves the inferior vena cava (IVC), patients usually present with signs and symptoms characteristic of congestive heart failure. However, the absence of these signs or symptoms does not exclude a potentially hemodynamically significant IVC syndrome. This case report describes a patient with no pre-operative evidence of congestive heart failure or IVC compression, who subsequently experienced intra-operative hypotension and hypoxemia due to an IVC syndrome.

New advances in evaluation and management of patients with polycystic liver disease

Adult polycystic liver disease (APLD) is an autosomal dominant condition most commonly associated with polycystic kidney disease. However, over the last decade it has come to be recognized that APLD is a genetically heterogeneous disorder involving derangements on at least three different chromosomes. Mutations involving chromosomes 16 and 4 accounting for autosomal dominant polycystic kidney disease (ADPKD) type 1 and type 2 have been well described as have their gene products, polycystin-1 and polycystin-2. These have since been joined by a more recently recognized mutation in the short arm of chromosome 19 thought to be responsible for a much rarer form of autosomal dominant polycystic liver disease without any associated renal involvement. Despite the sometimes impressive physical and radiologic findings, only a minority of patients will progress to advanced liver disease or develop complications as a result of massive hepatomegaly. In these patients, medical management alone has proved ineffectual. Therefore, in the symptomatic APLD patient, surgical therapy remains the mainstay of therapy and includes cyst aspiration and sclerosis, fenestration with and without hepatic resection and orthotopic liver transplantation. The surgical literature on treatment of APLD, to include outcome measurements and complication rates are summarized. Additionally, we review other potential organ involvement and resultant complications.

Magnetic Resonance Imaging Evaluation of Hepatic Cysts in Early Autosomal-Dominant Polycystic Kidney Disease: The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease Cohort

The objective of this study was to investigate the prevalence of hepatic cysts by age and gender in patients with early autosomal-dominant polycystic kidney disease (ADPKD) and to determine whether hepatic cyst volume is related to renal and renal cyst volumes by using magnetic resonance imaging (MRI). A total of 230 patients with ADPKD (94 men and 136 women) who were aged 15 to 46 yr and had relatively preserved renal function were studied. MRI images of the kidney and liver were obtained to measure renal, renal cyst, and hepatic cyst volumes. These volume measurements and hepatic cyst prevalence were compared in all patients and in subgroups on the basis of gender and age (15 to 24, 25 to 34, and 35 to 46 yr). The overall prevalence of hepatic cysts was 83%; the prevalence was 58, 85, and 94% in the sequential age groups and 85% in women and 79% in men. The prevalence was related directly to renal volume (chi2 = 4.30, P = 0.04) and to renal cyst volume (chi2 = 5.59, P = 0.02). The total hepatic cyst volume was significantly greater in women than in men (a logarithmic transformation mean of 5.27 versus 1.94 ml; P = 0.003). The average hepatic cyst volume was 0.25, 5.75, and 22.78 ml in sequential age groups. Hepatic cysts are evident in 94% of patients who are older than 35 yr and in 55% of individuals who are younger than 25 yr. Hepatic cysts are more prevalent and larger in total cyst volume in women than in men. Hepatic cyst prevalence and aggregate total hepatic cyst volume increased with age.

Polycystic liver disease: experience at a teaching hospital

OBJECTIVES

This study describes the natural history of patients with polycystic liver disease, a rare disorder characterized by multiple hepatic cysts.

METHODS

Cases were identified through review of charts from a hepatology practice, a hepatobiliary surgery practice and a retrospective chart review of inpatient charts from 1990 to 2002. All patients had greater than four simple liver cysts without infectious etiology. Medical records were reviewed for history, physical examination, imaging, and laboratory data. Patients' family practitioners provided follow-up.

RESULTS

Fifty-three cases (62.3% female, 37.7% male) were identified. The mean age at diagnosis was 56.4 yr. Thirty-eight cases (71.7%) had associated polycystic kidney disease. The minority of patients were symptomatic at diagnosis (pain in 19 (36.5%), dyspnea in 5 (9.6%), and restricted mobility in 5 (9.6%) with hepatomegaly in 23 (45.1%). Follow-up information was attainable for 40 patients with a mean follow-up duration of 4.69 yr (range 0.1-15 yr). Within this subgroup, 9 patients (22.5%) had cyst bleeding, 5 (12.5%) had cyst rupture, 5 (12.5%) had cyst infection, 12 (30%) required an intervention. One patient (2.5%) developed portal hypertension, and two (5%) received a liver transplant. One patient (2.5%) died due to complications from liver cysts.

CONCLUSIONS

Most patients in this highly selected cohort were asymptomatic with normal hepatic function. Pain was the most common symptom. The natural history is variable however, with some patients developing complications including portal hypertension. Minimally invasive interventions are appropriate initially, with hepatic resection and liver transplantation reserved for those with severe symptoms or life-threatening complications.

Polycystic disease of the liver

Autosomal dominant polycystic disease is genetically heterogeneous with mutations in two distinct genes predisposing to the combination of renal and liver cysts (AD-PKD1 and AD-PKD2) and mutations in a third gene yielding isolated liver cysts (the polycystic liver disease gene). Transcription and translation of the PKD1 gene produces polycystin-1, an integral membrane protein that may serve as an extracellular receptor. Mutations occur throughout the PKD1 gene, but more severe disease is associated with N-terminal mutations. The PKD2 gene product, polycystin-2, is an integral membrane protein with molecular characteristics of a calcium-permeant cation channel. Mutations occur throughout the PKD2 gene, and severity of disease may vary with site of mutation in PKD2 and the functional consequence on the resultant polycystin-2 protein. Polycystic liver disease is genetically linked to protein kinase C substrate 80K-H (PRKCSH). The PRKCSH gene encodes hepatocystin, a protein that moderates glycosylation and fibroblast growth factor receptor signaling. More prominent in women, hepatic cysts emerge after the onset of puberty and dramatically increase in number and size through the child-bearing years of early and middle adult life. Although liver failure or complications of advanced liver disease are rare, some patients develop massive hepatic cystic disease and become clinically symptomatic. There is no effective medical therapy. Interventional and surgical options include cyst aspiration and sclerosis, open or laparoscopic cyst fenestration, hepatic resection, and liver transplantation.

Refractory hypotension and edema caused by right atrial compression in a woman with polycystic kidney disease

We present the case of a 60-year-old woman with a history of autosomal dominant polycystic kidney disease and long-standing hypertension who developed persistent hypotension. While in the hospital for the treatment of bacteriemia, the patient had low systolic blood pressures (90 to 100 mm Hg), which was thought to be the consequence of infection. After the infection was adequately controlled and the blood pressure did not improve, an echocardiogram was done to further elucidate her hypotension. It was nondiagnostic and revealed an ejection fraction of 70% with left ventricular hypertrophy. Shortly after discharge, she developed significant lower extremity edema and her blood pressure remained low. Due to the low blood pressure it was not possible to mobilize the fluid with her dialysis treatments. A repeat transthoracic echocardiogram at that time revealed that the right atrium was partially compressed throughout the cardiac cycle by polycystic hepatic tissue. This tissue invaginated up through the right hemidiaphragm. A partial liver resection was considered for the patient. Instead, right nephrectomy was performed and the blood pressure improved.

Distinct roles of transcription factors EGL-46 and DAF-19 in specifying the functionality of a polycystin-expressing sensory neuron necessary for C. elegans male vulva location behavior

Caenorhabditis elegans polycystins LOV-1 and PKD-2 are expressed in the male-specific HOB neuron, and are necessary for sensation of the hermaphrodite vulva during mating. We demonstrate that male vulva location behavior and expression of lov-1 and pkd-2 in the ciliated sensory neuron HOB require the activities of transcription factor EGL-46 and to some extent also EGL-44. This EGL-46- regulated program is specific to HOB and is distinct from a general ciliogenic pathway functioning in all ciliated neurons. The ciliogenic pathway regulator DAF-19 affects downstream components of the HOB-specific program indirectly and is independent of EGL-46 activity. The sensory function of HOB requires the combined action of these two distinct regulatory pathways.

Autosomal dominant polycystic kidney disease: MR imaging evaluation using current techniques

PURPOSE

To determine the MR imaging findings of autosomal dominant polycystic kidney disease using current imaging techniques.

MATERIALS AND METHODS

We reviewed our five-year experience with MR imaging of autosomal dominant polycystic kidney disease (ADPKD) to determine the spectrum of appearance of kidney disease, the occurrence of cysts in other abdominal organs, the size and number of cysts in the kidneys and other organs, and the association with other benign or malignant disease. Thirty patients (17 men and 13 women, age range 30 to 88 years old) with ADPKD were included in this study. All patients were examined by MR imaging including T2-weighted single-shot echo-train spin-echo and pre- and post-gadolinium chelate spoiled gradient-echo imaging.

RESULTS

All kidneys were involved with multiple, varying sized cysts scattered throughout the parenchyma. Giant renal cysts (>8 cm) were associated with pain in the only two patients who possessed them. Hemorrhage in renal cysts was observed in all kidneys with a heterogeneous pattern of involvement on non-contrast T1- and T2-weighted images, reflecting hemorrhage of varying age. The mean kidney size for the right kidney was 17.4 cm in length, 10.3 cm in transverse, and 9.4 cm in antero-posterior diameter (AP); and for the left kidney, 15.9 cm in the length, 9.3 cm in the transverse, and 9.3 cm in AP diameter. Other organs involved included the liver (22 patients), the pancreas (three patients), with two of the above-mentioned patients having both liver and pancreas cysts, and the spleen (one patient) who had both liver and splenic cysts. Massive liver involvement with large cysts was associated with abdominal pain. Malignant disease was present in five patients, including two patients with renal cell carcinoma, one with bladder cancer, one with lung cancer, and one patient with anal adenocarcinoma. Comparison of pre- and post-contrast T1-weighted images was essential to detect renal cancer.

CONCLUSION

All kidneys in patients with ADPKD had extensive, varying-sized cysts and in all cases some cysts showed evidence of hemorrhage. The liver was the second most common organ to be involved with cystic disease, in 73% of patients. Large cysts in the kidneys and liver were associated with abdominal pain.

Cystic disease in women: clinical characteristics and medical management

Autosomal dominant polycystic kidney disease (ADPKD) is a dominantly inherited systemic disorder equally inherited in men and women characterized by renal cyst development and expansion ultimately leading to renal failure. ADPKD women have a slower rate of progression to renal failure, with a later age of entry into end-stage renal disease (ESRD) as compared with men. Renal cyst growth and renal expansion are the hallmarks of ADPKD, and women will develop renal insufficiency with smaller renal volume than their male counterparts. As well, women have different rates of occurrence of renal and extrarenal complications in ADPKD. Renal complications related to ADPKD, including hypertension and gross hematuria, occur more frequently in men than in women, whereas liver cystic disease occurs earlier and more frequently in women than in men. The presence of polycystic liver disease is related to pregnancy number and oral contraceptive pill use in ADPKD women. Importantly, massive polycystic liver disease requiring surgical intervention occurs primarily in ADPKD women. ADKPD women have a highly successful reproductive course. The chance of a successful pregnancy is excellent in ADPKD women and comparable to healthy unaffected women as long as prepregnancy blood pressure and renal function are normal. Fetal complication rates are no greater than in the general population; however, maternal complication rates in ADPKD women are high with an increased frequency of new or worsening hypertension as well as an increased occurrence of preeclampsia and preterm deliveries. Finally, increasing pregnancy number has minimal or no effect on renal outcome in ADPKD women.