Adams-Oliver syndrome and hepatoportal sclerosis: occasional association or common mechanism?

Porto-sinusoidal Vascular Disease: Classification and Clinical Relevance

Non-cirrhotic portal hypertension (NCPH) is a well-recognized clinico-pathological entity, which is associated with clinical signs and symptoms, imaging, and endoscopic features of portal hypertension (PHT), in absence of cirrhosis. In patients with NCPH without known risk factors of PHT or extrahepatic portal vein thrombosis, the condition is called idiopathic non-cirrhotic portal hypertension (INCPH). There are multiple infectious, immune related causes, systemic diseases, drug and toxin exposures, haematological disorders, and metabolic risk factors that have been associated with this INCPH. However, the causal pathogenesis is still unclear. The Vascular liver disorders interest group group recently proposed porto-sinusoidal vascular disease (PSVD) as a syndromic entity, which provides definite histopathological criteria for diagnosis of NCPH (table 1). The three classical histo-morphological lesions specific for PSVD include obliterative portal venopathy, nodular regenerative hyperplasia, and incomplete septal fibrosis. The PSVD definition includes patients with portal vein thrombosis, PVT, and even those without PHT, thus broadening the scope of diagnosis to include patients who may have presented early, prior to haemodynamic changes consistent with PHT. However, this new diagnosis has pros and cons. The cons include mandating invasive liver biopsy to assess the PSVD histological triad in all patients with NCPH, an erstwhile clinical diagnosis in Asian patients. In addition, the natural history of the subclinical forms of PSVD without PHT and linear progression to develop PHT is unknown yet. In this review, we discuss the diagnosis and treatment of INCPH/PSVD, fallacies and strengths of the old and new schema, pathobiology of this disease, and clinical correlates in an Asian context. Although formulation of standardised diagnostic criteria is useful for comparison of clinical cohorts with INCPH/PSVD, prospective clinical validation in global cohorts is necessary to avoid misclassification of vascular disorders of the liver.

[Portosinusoidal vascular disorder: A paradigm shift]

The term portosinusoidal vascular disorder (PSVD) refers to a clinical-pathological entity that encompasses those patients with intrahepatic vascular damage without cirrhosis at risk of developing severe complications of portal hypertension. Numerous systemic diseases, genetic disorders, and toxic agents have been associated with this pathology, making its diagnosis an important clinical challenge. The recent description of uniform diagnostic criteria and a better understanding of its pathophysiology will allow for better identification of patients, even in early stages of the disease. Although there is currently no effective etiological treatment available, early diagnosis allows for the development of preventive strategies for some severe complications of portal hypertension.

The genetics of portal hypertension: Recent developments and the road ahead

Portal hypertension (PH), defined as a pathological increase in the portal vein pressure, has different aetiologies and causes. Intrahepatic PH is mostly secondary to the presence of underlying liver disease leading to cirrhosis, characterized by parenchymal changes with deregulated accumulation of extracellular matrix and vascular abnormalities; liver sinusoidal endothelial cells and hepatic stellate cells are key players in PH progression, able to influence each other. However, PH may also develop independently of parenchymal damage, as occur in portosinusoidal vascular disorder (PSVD), a group of clinical and histological entities characterized by portal vasculature dysfunctions. In this particular group of disorders, the pathophysiology of PH is still poorly understood. In the last years, several genetic studies, based on genome-wide association studies or whole-exome sequencing analysis, have highlighted the importance of genetic heritability in PH pathogenesis, both in cirrhotic and non-cirrhotic cases. The common PNPLA3 p.I148M variant, one of the main determinants of the susceptibility to steatotic liver disease, has also been associated with decompensation in patients with PH. Genetic variations at loci influencing coagulation, mainly the ABO locus, may directly contribute to the pathogenesis of PH. Rare genetic variants have been associated with familiar cases of progressive PSVD. In this review, we summarize the recent knowledges on genetic variants predisposing to PH development, contributing to better understand the role of genetic factors in PH pathogenesis.

Evolving Understanding of Noncirrhotic Portal Hypertension

Although cirrhosis is one of the most common causes of portal hypertension, noncirrhotic portal hypertension can result from hemodynamic perturbations occurring in the prehepatic, intrahepatic, and posthepatic circulation. Intrahepatic portal hypertension can be further subclassified relative to the hepatic sinusoids as presinusoidal, sinusoidal, and postsinusoidal. For many of these differential diagnoses, the etiology is known but the cause of idiopathic noncirrhotic portal hypertension, recently included in porto-sinusoidal vascular disease (PSVD), remains poorly understood. Herein, we discuss the diagnostic pathological features of noncirrhotic portal hypertension, with an emphasis on PSVD.

Paediatric porto-sinusoidal vascular disease: Two different clinical phenotypes with subtle histological differences

BACKGROUND AND AIMS

In paediatrics, porto-sinusoidal vascular disease (PSVD) is relatively unknown and probably underdiagnosed. We aimed to describe clinical phenotypes, histology and outcome of children diagnosed with PSVD.

METHODS

Retrospective multicentre study of children diagnosed with PSVD. Diagnosis of PSVD was based on histopathology reports; liver specimens were re-evaluated by two expert liver pathologists.

RESULTS

Sixty two children diagnosed with PSVD (M/F = 36/26, median age 6.6 years, range 3.3-10.6), from 7 centres, were included. Thirty-six presented with non-cirrhotic portal hypertension, PH, (PH-PSVD Group = 58%) while 26 had a liver biopsy because of chronic elevation of transaminases without PH (noPH-PSVD Group = 42%). On histology review, the two groups differed for the prevalence of obliterative portal venopathy (more prevalent in PH-PSVD, p = 0.005), and hypervascularised portal tracts (more common in noPH-PSVD, p = 0.039), the other histological changes were equally distributed. At multivariate analysis, platelet count ≤185 000/mm³ was the only independent determinant of PH (p < 0.001). After a median follow-up of 7 years (range 3.0-11.2), in PH-PSVD group 3/36 (8%) required TIPS placement, 5/36 (14%) developed pulmonary vascular complications of PH, and 7/36 (19%) required liver transplantation. In noPH-PSVD none progressed to PH nor had complications.

CONCLUSIONS

Paediatric patients with PSVD present with two different clinical phenotypes, one characterised by PH and one by chronic elevation of transaminases without PH. PSVD should be included among the conditions causing isolated hypertransaminasaemia. On histology, the differences between the two groups are subtle. Medium-term outcome is favourable in patients without PH; progression of the disease is observed in those with PH.

Porto-sinusoidal vascular disorder

It is well established that portal hypertension can occur in the absence of cirrhosis, as reported in patients with immune disorders, infections and thrombophilia. However, similar histological abnormalities primarily affecting the hepatic sinusoidal and (peri)portal vasculature have also been observed in patients without portal hypertension. Thus, the term porto-sinusoidal vascular disorder (PSVD) has recently been introduced to describe a group of vascular diseases of the liver featuring lesions encompassing the portal venules and sinusoids, irrespective of the presence/absence of portal hypertension. Liver biopsy is fundamental for PSVD diagnosis. Specific histology findings include nodular regenerative hyperplasia, obliterative portal venopathy/portal vein stenosis and incomplete septal fibrosis/cirrhosis. Since other conditions including alcohol-related and non-alcoholic fatty liver disease, or viral hepatitis, or the presence of portal vein thrombosis may occur in patients with PSVD, their relative contribution to liver damage should be carefully assessed. In addition to histology and clinical diagnostic criteria, imaging and non-invasive tests such as liver and spleen stiffness measurements could aid in the diagnostic workup. The introduction of PSVD as a novel clinical entity will facilitate collaborative studies and investigations into the underlying molecular pathomechanisms encompassed by this term.

Idiopathic Non-Cirrhotic Portal Hypertension and Porto-Sinusoidal Vascular Disease: Review of Current Data

Idiopathic non-cirrhotic portal hypertension (INCPH) is a clinicopathologic disease entity characterized by the presence of clinical signs and symptoms of portal hypertension (PH) in the absence of liver cirrhosis or known risk factors accountable for PH. Multiple hematologic, immune-related, infectious, hereditary and metabolic risk factors have been associated with this disorder. Still, the exact etiopathogenesis is largely unknown. The recently proposed porto-sinusoidal vascular disease (PSVD) scheme broadens the spectrum of the disease by also including patients without clinical PH who are found to have similar histopathologic findings on core liver biopsies. Three histomorphologic lesions have been identified as specific for PSVD to include obliterative portal venopathy, nodular regenerative hyperplasia and incomplete septal cirrhosis/fibrosis. However, these findings are often subtle, under-recognized and subjective with low interobserver agreement among pathologists. Additionally, the natural history of the subclinical forms of the disease remains unexplored. The clinical course is more favorable compared to cirrhosis patients, especially in the absence of clinical PH or liver dysfunction. There are no universally accepted guidelines in regard to diagnosis and treatment of INCPH/PSVD. Hence, this review emphasizes the need to raise awareness of this entity by highlighting its complex pathophysiology and clinicopathologic associations. Lastly, formulation of standardized diagnostic criteria with clinical validation is necessary to avoid misclassifying vascular diseases of the liver and to develop and implement targeted therapeutic strategies.

Short Telomeres: Cause and Consequence in Liver Disease

Short telomere syndrome is a genetically inherited syndrome resulting in premature telomere shortening. This premature shortening of telomeres can result in hematologic, pulmonary, vascular, gastrointestinal, and hepatic manifestations of disease. Identifying patients with short telomere syndrome can be a clinical challenge due to the multitude of potential manifestations and lack of widely available diagnostic tests. In this review, we will highlight hepatic manifestations of short telomere syndrome with a focus on diagnosis, testing, and potential treatments.

Porto-sinusoidal vascular disease: proposal and description of a novel entity

Portal hypertension in the absence of portal vein thrombosis and without cirrhosis, but with mild or moderate alterations of liver histology (eg, obliterative venopathy, nodular regenerative hyperplasia, or incomplete septal cirrhosis) is being increasingly recognised. Owing to the heterogeneity of causes and histological findings, a substantial number of terms have been used to describe such idiopathic non-cirrhotic portal hypertension. Patients with the same clinical and histological features exist, but without portal hypertension at the time of diagnosis. Therefore, improved criteria are needed to define this form of liver disease. Here, we propose the term porto-sinusoidal vascular disease, since all lesions found involve the portal venules or sinusoids. The definition of this entity is based on the characteristic absence of cirrhosis with or without signs of portal hypertension or histological lesions. The presence of known causes of liver disease does not rule out porto-sinusoidal vascular disease, but specific causes of vascular liver disease are excluded from its definition. The diagnosis of porto-sinusoidal vascular disease is based on liver biopsy and might include signs specific for portal hypertension with normal or mildly elevated liver stiffness values and no complete portal vein thrombosis. We provide simple diagnostic criteria, because agreement on a uniform nomenclature is an essential requirement for future collaborative studies.

Novel In-Frame Deletion Mutation in NOTCH1 in a Chinese Sporadic Case of Adams-Oliver Syndrome

Adams-Oliver syndrome (AOS) is a rare hereditary disorder characterized by aplasia cutis congenita (ACC) and terminal transverse limb defects. The etiology of AOS has remained largely unknown, although mutations in the notch receptor 1 (NOTCH1) gene are most common genetic alteration associated with this disease. In this study, we aimed to identify the case of a 6-year-old boy, who presented with large ACC of the scalp and aortic valve stenosis, suggesting the possibility of AOS. Whole-exome sequencing identified a novel, de novo, in-frame deletion in the NOTCH1 gene (NOTCH1 c.1292_1294del, p.Asn431del) in the patient. The p.Asn431del variant was evaluated by several in silico analyses, which predicted that the mutant was likely to be pathogenic. In addition, molecular modeling with the PyMOL Molecular Graphics System suggested that the NOTCH1-N431del destabilizes calcium ion chelation, leading to decreased receptor-ligand binding efficiency. Quantitative reverse transcription PCR showed further significant downregulation of the Notch target genes, hes-related family bHLH transcription factor with YRPW motif 1 (HEY1) and hes family bHLH transcription factor 1 (HES1), suggesting that this mutation causes disease through dysregulation of the Notch signaling pathway. Our study provides evidence that the NOTCH1-N431del mutation is responsible for this case of AOS. To our knowledge, this is the first report of a patient with AOS caused by NOTCH1 mutation in Asia, and this information will be useful for providing the family with genetic counseling that can help to guide their future plans.

Hepatic manifestations of telomere biology disorders

A 51-year-old Caucasian male was referred for evaluation of variceal bleeding. Laboratory tests were remarkable for mild thrombocytopenia and moderate alkaline phosphatase elevation. Synthetic liver function was well preserved. Abdominal computed tomography scan revealed moderate splenomegaly, gastric varices, and normal hepatic contour. A transjugular liver biopsy was performed revealing findings of nodular regenerative hyperplasia with no significant fibrosis or necroinflammatory activity. Hepatic venous pressure gradient was elevated at 31 mmHg, consistent with clinically significant portal hypertension. The clinical course was complicated by refractory gastric variceal bleeding requiring a surgical portosystemic shunt. Approximately seven years after the initial presentation, the patient developed progressive dyspnoea and a diagnosis of idiopathic pulmonary fibrosis was made. Contrast-enhanced echocardiogram was not suggestive of hepatopulmonary syndrome or portopulmonary hypertension. Given this new diagnosis a telomere biology disorder was suspected. A flow-fluorescence in situ hybridisation analysis for telomere length assessment revealed telomere lengths below the first percentile in both lymphocytes and granulocytes. Next generation sequencing analysis identified a heterozygous mutation involving the hTERT gene (Histidine983Threonine). The lung disease unfortunately progressed in the subsequent two years, leading to the patient's death nine years after his initial presentation with portal hypertension. During those nine years two brothers also developed idiopathic pulmonary fibrosis. The questions that arise from this case include.

Elucidating the genetic architecture of Adams-Oliver syndrome in a large European cohort

Adams–Oliver syndrome (AOS) is a rare developmental disorder, characterized by scalp aplasia cutis congenita (ACC) and transverse terminal limb defects (TTLD). Autosomal dominant forms of AOS are linked to mutations in ARHGAP31, DLL4, NOTCH1 or RBPJ, while DOCK6 and EOGT underlie autosomal recessive inheritance. Data on the frequency and distribution of mutations in large cohorts are currently limited. The purpose of this study was therefore to comprehensively examine the genetic architecture of AOS in an extensive cohort. Molecular diagnostic screening of 194 AOS/ACC/TTLD probands/families was conducted using next‐generation and/or capillary sequencing analyses. In total, we identified 63 (likely) pathogenic mutations, comprising 56 distinct and 22 novel mutations, providing a molecular diagnosis in 30% of patients. Taken together with previous reports, these findings bring the total number of reported disease variants to 63, with a diagnostic yield of 36% in familial cases. NOTCH1 is the major contributor, underlying 10% of AOS/ACC/TTLD cases, with DLL4 (6%), DOCK6 (6%), ARHGAP31 (3%), EOGT (3%), and RBPJ (2%) representing additional causality in this cohort. We confirm the relevance of genetic screening across the AOS/ACC/TTLD spectrum, highlighting preliminary but important genotype–phenotype correlations. This cohort offers potential for further gene identification to address missing heritability.

Obliterative portal venopathy: A histopathologic finding associated with chronic antibody-mediated rejection in pediatric liver allografts

The significance of post-transplant HLA DSA and chronic AMR in LT is an emerging field of study. Although OPV has previously been described as a histopathologic finding in DSA-positive adult LT recipients, it was not included in the recent Banff criteria for chronic AMR. Our aim was to describe the association between OPV and chronic AMR in pediatric LT recipients. A retrospective review of 67 liver biopsies performed between November 2014 and April 2016 in 45 pediatric LT recipients identified four patients with OPV. Clinical status, liver biochemistry, the presence of DSA, and available non-HLA antibody testing, as well as histopathologic features of chronic AMR, were assessed. All four patients with OPV had class II DSA and histopathologic features of chronic AMR based on the Banff criteria. Two patients were noted to have non-HLA antibodies. Three patients are undergoing treatment with IVIG but have persistent DSA. Two patients have graft failure and are awaiting retransplantation. In conclusion, OPV is a histopathologic finding associated with chronic AMR in pediatric LT recipients. Further studies are needed to elucidate whether OPV is reversible and/or amenable to medical therapy.

Mutations in the novel gene FOPV are associated with familial autosomal dominant and non-familial obliterative portal venopathy

BACKGROUND & AIMS

Obliterative portal venopathy (OPV) is characterized by lesions of portal vein intrahepatic branches and is thought to be responsible for many cases of portal hypertension in the absence of cirrhosis or obstruction of large portal or hepatic veins. In most cases the cause of OPV remains unknown. The aim was to identify a candidate gene of OPV.

METHODS

Whole exome sequencing was performed in two families, including 6 patients with OPV. Identified mutations were confirmed by Sanger sequencing and expression of candidate gene transcript was studied by real time qPCR in human tissues.

RESULTS

In both families, no mutations were identified in genes previously reported to be associated with OPV. In each family, we identified a heterozygous mutation (c.1783G>A, p.Gly595Arg and c.4895C>T, p.Thr1632Ile) in a novel gene located on chromosome 4, that we called FOPV (Familial Obliterative Portal Venopathy), and having a cDNA coding for 1793 amino acids. The FOPV mutations segregated with the disease in families and the pattern of inheritance was suggestive of autosomal dominant inherited OPV, with incomplete penetrance and variable expressivity. In silico analysis predicted a deleterious effect of each mutant and mutations concerned highly conserved amino acids in mammals. A deleterious heterozygous FOPV missense mutation (c.4244T>C, p.Phe1415Ser) was also identified in a patient with non-familial OPV. Expression study in liver veins showed that FOPV transcript was mainly expressed in intrahepatic portal vein.

CONCLUSIONS

This report suggests that FOPV mutations may have a pathogenic role in some cases of familial and non-familial OPV.

Adams-Oliver syndrome review of the literature: Refining the diagnostic phenotype

The Adams-Oliver syndrome (AOS) is defined as aplasia cutis congenita (ACC) with transverse terminal limb defects (TTLD). Frequencies of associated anomalies are not well characterized. Six causative genes have been identified: ARHGAP31, DOCK6, EOGT, RBPJ, NOTCH1, and DLL4. We review 385 previously described individuals (139 non-familial and 246 familial probands and family members) and add clinical data on 13 previously unreported individuals with AOS. In addition to ACC and TTLD, the most commonly associated anomalies included a wide variety of central nervous system (CNS) anomalies and congenital heart defects each seen in 23%. CNS anomalies included structural anomalies, microcephaly, vascular defects, and vascular sequelae. CNS migration defects were common. Cutis marmorata telangiectasia congenita (CMTC) was found in 19% of the study population and other vascular anomalies were seen in 14%. Hemorrhage was listed as the cause of death for five of 25 deaths reported. A relatively large number of non-familial probands were reported to have hepatoportal sclerosis with portal hypertension and esophageal varices. Non-familial probands were more likely to have additional anomalies than were familial probands. The data reported herein provide a basis for refining the diagnostic features of AOS and suggest management recommendations for probands newly diagnosed with AOS. © 2017 Wiley Periodicals, Inc.

Idiopathic Noncirrhotic Portal Hypertension: An Appraisal

Idiopathic noncirrhotic portal hypertension is a poorly defined clinical condition of unknown etiology. Patients present with signs and symptoms of portal hypertension without evidence of cirrhosis. The disease course appears to be indolent and benign with an overall better outcome than cirrhosis, as long as the complications of portal hypertension are properly managed. This condition has been recognized in different parts of the world in diverse ethnic groups with variable risk factors, resulting in numerous terminologies and lack of standardized diagnostic criteria. Therefore, although the diagnosis of idiopathic noncirrhotic portal hypertension requires clinical exclusion of other conditions that can cause portal hypertension and histopathologic confirmation, this entity is under-recognized clinically as well as pathologically. Recent studies have demonstrated that variable histopathologic entities with different terms likely represent a histologic spectrum of a single entity of which obliterative portal venopathy might be an underlying pathogenesis. This perception calls for standardization of the nomenclature and formulation of widely accepted diagnostic criteria, which will facilitate easier recognition of this disorder and will highlight awareness of this entity.

Idiopathic non-cirrhotic portal hypertension: a review

Idiopathic non-cirrhotic portal hypertension (INCPH) is a rare disease characterized of intrahepatic portal hypertension in the absence of cirrhosis or other causes of liver disease and splanchnic venous thrombosis. The etiology of INCPH can be classified in five categories: 1) immunological disorders (i.e. association with common variable immunodeficiency syndrome, connective tissue diseases, Crohn’s disease, etc.), 2) chronic infections, 3) exposure to medications or toxins (e.g. azathioprine, 6- thioguanine, arsenic), 4) genetic predisposition (i.e. familial aggregation and association with Adams-Oliver syndrome and Turner disease) and 5) prothrombotic conditions (e.g. inherited thrombophilias myeloproliferative neoplasm antiphospholipid syndrome). Roughly, INCPH diagnosis is based on clinical criteria and the formal exclusion of any other causes of portal hypertension. A formal diagnosis is based on the following criteria: 1) presence of unequivocal signs of portal hypertension, 2) absence of cirrhosis, advanced fibrosis or other causes of chronic liver diseases, and 3) absence of thrombosis of the hepatic veins or of the portal vein at imaging. Patients with INCPH usually present with signs or symptoms of portal hypertension such as gastro-esophageal varices, variceal bleeding or splenomegaly. Ascites and/or liver failure can occur in the context of precipitating factors. The development of portal vein thrombosis is common. Survival is manly limited by concomitant disorders. Currently, treatment of INCPH relies on the prevention of complications related to portal hypertension, following current guidelines of cirrhotic portal hypertension. No treatment has been studied aimed to modify the natural history of the disease. Anticoagulation therapy can be considered in patients who develop portal vein thrombosis.

Haploinsufficiency of the NOTCH1 Receptor as a Cause of Adams-Oliver Syndrome With Variable Cardiac Anomalies

BACKGROUND

Adams-Oliver syndrome (AOS) is a rare disorder characterized by congenital limb defects and scalp cutis aplasia. In a proportion of cases, notable cardiac involvement is also apparent. Despite recent advances in the understanding of the genetic basis of AOS, for the majority of affected subjects, the underlying molecular defect remains unresolved. This study aimed to identify novel genetic determinants of AOS.

METHODS AND RESULTS

Whole-exome sequencing was performed for 12 probands, each with a clinical diagnosis of AOS. Analyses led to the identification of novel heterozygous truncating NOTCH1 mutations (c.1649dupA and c.6049_6050delTC) in 2 kindreds in which AOS was segregating as an autosomal dominant trait. Screening a cohort of 52 unrelated AOS subjects, we detected 8 additional unique NOTCH1 mutations, including 3 de novo amino acid substitutions, all within the ligand-binding domain. Congenital heart anomalies were noted in 47% (8/17) of NOTCH1-positive probands and affected family members. In leukocyte-derived RNA from subjects harboring NOTCH1 extracellular domain mutations, we observed significant reduction of NOTCH1 expression, suggesting instability and degradation of mutant mRNA transcripts by the cellular machinery. Transient transfection of mutagenized NOTCH1 missense constructs also revealed significant reduction in gene expression. Mutant NOTCH1 expression was associated with downregulation of the Notch target genes HEY1 and HES1, indicating that NOTCH1-related AOS arises through dysregulation of the Notch signaling pathway.

CONCLUSIONS

These findings highlight a key role for NOTCH1 across a range of developmental anomalies that include cardiac defects and implicate NOTCH1 haploinsufficiency as a likely molecular mechanism for this group of disorders.

Obliterative portal venopathy: a clinical and histopathological review

Non-cirrhotic portal hypertension (NCPH) is characterized by the elevation of the portal pressure in the absence of cirrhosis. Obliterative portal venopathy (OPV) as a cause of NCPH is being increasingly diagnosed, especially after recent reports of its occurrence in patients with HIV using didanosine. Patients usually present with episodes of variceal hemorrhage and other features of portal hypertension including jaundice, ascites, encephalopathy and hepatopulmonary syndrome. Hepatic synthetic function is typically well preserved and the laboratory evaluation in OPV patients typically reveals only mild nonspecific hematological abnormalities chiefly related to hypersplenism. Its diagnosis remains a challenge and patients are often mistakenly diagnosed as having cirrhosis. Despite the increasing recognition of OPV, its etiology and pathogenesis are still unclear. A number of etiologies have been proposed including genetic predisposition, recurrent bacterial infections, HIV infection and highly active antiretroviral therapy, an altered immune response, hypercoagulability, and exposure to chemicals and certain medications. Histopathological evaluation remains critical in excluding cirrhosis and other causes of portal hypertension, and is the only way of definitively establishing the diagnosis of OPV. Clinicians should have a high index of suspicion for OPV in patients who present with variceal bleeding and splenomegaly and who do not have other features of cirrhosis. The purpose of this review is to summarize the known etiologies for OPV and its associated clinical aspects and correlations, and to also provide ample histophotomicrographs of OPV to aid in the diagnosis. It will also help raise awareness of this entity amongst pathologists and clinicians alike.

Hepatoportal sclerosis in childhood: descriptive analysis of 12 patients

Hepatoportal sclerosis (HPS) is defined as sclerosis of portal areas in the absence of cirrhosis. There is little information about HPS in children in the literature. The aim of this study was to describe the clinical presentation, associated disorders, laboratory characteristics and outcome of children who were diagnosed as HPS. This study included 12 children diagnosed as HPS by the Pathology Department between 2005 and 2011. Data were collected from the gastroenterology clinic charts retrospectively, including demographics, presentation characteristics, laboratory data and recent status of patients. Twelve patients were enrolled (6 girls, 6 boys). The median age of patients was 13.5 yr. Median age at the time of biopsy was 11 yr. Four patients had splenomegaly, 3 had esophageal varices, one had hepatopulmonary syndrome and had been transplanted. Smooth muscle antibody was found positive in 4 patients, without autoimmune hepatitis findings in liver biopsy. One patient had celiac disease and another patient had positive celiac disease serology but pathology findings. Another patient had Turner's syndrome. Mean follow-up time was 39 months (3.3 yr) after biopsy. Hepatoportal sclerosis does not necessarily present with portal hypertension in children.

The current clinical aspects of idiopathic portal hypertension

IDIOPATHIC PORTAL HYPERTENSION (IPH) COMPRISES DISORDERS DEVELOPING INCREASED PORTAL PRESSURE IN THE ABSENCE OF CIRRHOSIS: the clear mechanisms to explain this disease are still not well recognized. IPH usually suggests a benign prognosis, but sometimes is complicated with severe hemorrhage due to ruptured esophageal varices, or massive splenomegaly. Conventional treatments for those complications for patients with cirrhosis usually works when diverted to patients with IPH, although some of those patients might require liver transplantation if the treatment fails. However, there are few consistent treatment strategies for IPH itself, its complications or the indications for liver transplantation. In this mini review, we summarize the clinical manifestations and several potential theories to explain the etiology, as well as the current treatment options for IPH.

Management of hepatic vascular diseases

Primary damage to hepatic vessels is rare. (i) Hepatic arterial disorders, related mostly to iatrogenic injury and occasionally to systemic diseases, lead to ischemic cholangiopathy. (ii) Hepatic vein or inferior vena cava thrombosis, causing primary Budd-Chiari syndrome, is related typically to a combination of underlying prothrombotic conditions, particularly myeloproliferative neoplasms, factor V Leiden, and oral contraceptive use. The outcome of Budd-Chiari syndrome has markedly improved with anticoagulation therapy and, when needed, angioplasty, stenting, TIPS, or liver transplantation. (iii) Extrahepatic portal vein thrombosis is related to local causes (advanced cirrhosis, surgery, malignant or inflammatory conditions), or general prothrombotic conditions (mostly myeloproliferative neoplasms or factor II gene mutation), often in combination. Anticoagulation at the early stage prevents thrombus extension and, in 40% of the cases, allows for recanalization. At the late stage, gastrointestinal bleeding related to portal hypertension can be prevented in the same way as in cirrhosis. (iv) Sinusoidal obstruction syndrome (or venoocclusive disease), caused by agents toxic to bone marrow progenitors and to sinusoidal endothelial cells, induces portal hypertension and liver dysfunction. Decreasing the intensity of myeloablative regimens reduces the incidence of sinusoidal toxicity. (v) Obstruction of intrahepatic portal veins (obliterative portal venopathy) can be associated with autoimmune diseases, prothrombotic conditions, or HIV infection. The disease can eventually be complicated with end-stage liver disease. Extrahepatic portal vein obstruction is common. Anticoagulation should be considered. (vi) Nodular regenerative hyperplasia is induced by the uneven perfusion due to obstructed sinusoids, or portal or hepatic venules. It causes pure portal hypertension.

Adams-Oliver syndrome and portal hypertension: fortuitous association or common mechanism?

Adams-Oliver syndrome (AOS) is a rare condition defined by combination of cutis aplasia and transverse limb abnormalities. Some authors have described a possible association between this syndrome and portal hypertension (PH) due to hepatoportal sclerosis (HPS). We present a boy with AOS who developed a progressive splenomegaly and hypersplenism at the age of 2 months, and was admitted for acute gastrointestinal bleeding (GI) at the age of 9 months. Subsequently, we documented an extrahepatic portal vein obstruction and esophageal varices. After several episodes of cataclysmic upper GI bleeding a mesentero-portal shunt (MPS) was performed at 10 months. The shunt thrombosed, and after three failed attempts of thrombectomy, it was removed. One month later a splenorenal shunt was performed, and this closed spontaneously by 3 years. The patient suffered from ischemic stroke after placing the first shunt, and has spastic diplegia, left frontal lobe epilepsy, hyperactivity and attention deficit disorder, and severe psychomotor delay. At 11 years and he presented with chronic liver failure and hyperammonemia and coagulopathy. We hypothesize that there may be an early embryonic vascular abnormality (vascular disruption) that may explain these vascular phenomena.

Bone morphogenetic protein receptor 2 in patients with idiopathic portal hypertension

In idiopathic portal hypertension (IPH) typical vascular lesions are present in the branches of the portal vein or in the perisinusoidal area of the liver. Similar histological alterations have been reported in the pulmonary vasculature of patients with idiopathic pulmonary artery hypertension (IPAH). As IPAH is associated with mutations of the bone morphogenetic protein receptor 2 (BMPR2) gene, the aim of this study was to investigate whether this association might also be found in patients with IPH. Twenty-three samples belonging to 21 unrelated caucasian patients with IPH followed in the hepatic haemodynamic laboratory of the Hospital Clinic in Barcelona were included in the study. All patients were studied for the entire open reading frame and splice site of the BMPR2 gene by direct sequencing and multiple ligation probe amplification (MLPA) in order to detect large deletions/duplications. None of the 23 patients had pulmonary artery hypertension. Four patients presented one single nucleotide polymorphism (SNP) in intron 5, four patients had a SNP in exon 12 and a SNP in exon 1 was found in two cases. Two patients had both intron 5 and exon 12 polymorphisms. All SNPs were previously described. Except for these three SNPs, neither mutations nor rearrangements have been identified in the BMPR2 gene in this population. We did not detect mutations or rearrangements in the coding region of the BMPR2 gene in our patients with IPH. These findings suggest that, in contrast to IPAH, mutations in BMPR2 are not involved in the pathogenesis of IPH.

Idiopathic noncirrhotic portal hypertension

Idiopathic noncirrhotic portal hypertension (INCPH) is characterized by an increased portal venous pressure gradient in the absence of a known cause of liver disease and portal vein thrombosis. In contrast to the high prevalence of this disorder in India, INCPH is a rare disease in the Western world. The etiology of INCPH can be divided in five categories: chronic infections, exposure to medication or toxins, thrombophilia, immunological disorders, and genetic disorders. Multifactorial etiology can also be encountered. Chronic abdominal infection is incriminated as the most important etiological factor in Eastern patients and thrombophilia in Western patients. The majority of patients with INCPH initially present with signs or complications of portal hypertension (mainly variceal bleeding and splenomegaly). These patients usually have preserved liver function. Liver function impairment occurs mainly in the context of intercurrent conditions. Patients with INCPH are often clinically and radiologically misdiagnosed as liver cirrhosis, so that a liver biopsy is indispensable to discriminate cirrhosis from INCPH. Histopathological characteristics of INCPH are heterogeneous, demonstrating overlap between several pathological entities (e.g., hepatoportal sclerosis, nodular regenerative hyperplasia, and incomplete septal cirrhosis). Even though hemodynamical changes in INCPH patients are not comparable to those in cirrhotics, prophylaxis and treatment of variceal bleeding are recommended to be similar. Anticoagulation therapy must be considered only in patients who develop portal vein thrombosis. INCPH has been considered a disorder with a relatively benign disease course. However, liver failure, hepatic encephalopathy, and hepatopulmonary syndrome can occur and are considered indications for liver transplantation.

Adams-Oliver syndrome: Case report

Introduction. Adams-Oliver syndrome is characterized by congenital aplasia of the vertex skin of the skull in combination with skull and transverse limb defects. Case Outline. We presented a 5-month old female infant with Adams-Oliver syndrome manifested as cutis marmorata, dilated scalp veins and limb reduction defects. Clinical manifestation also included thumb hypoplasia and extreme hypoplasia of other fingers, with agenesis of all toes on both feet. Echocardiogram revealed foramen ovale apertum. Venography showed dilated malformed scalp and neck veins, predominantly on the right side. On the basis of the clinical features and extended investigation we confirmed Adams-Oliver syndrome in the presented patient. Conclusion. We recommended prenatal diagnosis in case of future pregnancies, ultrasound examination, and follow-up of foetal anomalies.

[Adams-Oliver syndrome: a case with minimal expression]

Adams-Oliver syndrome is a rare congenital anomaly characterized by aplasia cutis congenita (ACC) and variable degrees of terminal transverse limb defects. We report on a neonatal case with the sporadic form of the disease with minimal expression, illustrating the wide spectrum of clinical expression in Adams-Oliver syndrome. We also review the literature and highlight the different pathogenetic hypotheses of this syndrome.

Paediatric chronic liver diseases: how to investigate and follow up? Role of imaging in the diagnosis of fibrosis

Chronic liver diseases are rare in children, but encompass a wide spectrum of disorders that may all be complicated by liver fibrosis and therefore by portal hypertension. They may be classified according to the level of portal flow obstruction: prehepatic, intrahepatic or suprahepatic. Most of them, except presinusoidal diseases, may progress to cirrhosis that carries additional risks of impaired liver function and development of hepatocellular carcinoma. Imaging plays an important role in guiding the diagnosis and biopsy and for follow-up during treatment. US, with high-frequency transducers and Doppler, is the first modality of choice, directs the rest of the investigations and guides interventional radiology. MDCT has made great progress and has replaced angiography for diagnostic purposes. MRI is indicated for parenchyma and nodule characterization and for biliary tract evaluation. To avoid liver biopsy, several elasticity imaging techniques have been developed and have to be evaluated for accuracy and convenience in children. The role of each modality with main imaging findings is described in extrahepatic portal vein obstruction, hepatoportal sclerosis, congenital hepatic fibrosis, cirrhosis and Budd-Chiari syndrome.

The spectra of clinical phenotypes in aplasia cutis congenita and terminal transverse limb defects

The combination of aplasia cutis congenita (ACC) and terminal transverse limb defects (TTLD) is often referred to as the eponymous Adams-Oliver syndrome (AOS). The molecular basis of this disorder remains unknown, although the common occurrence of cardiac and vascular anomalies suggests a primary defect of vasculogenesis. Through the description of three previously unreported affected individuals, ascertained through the Adams-Oliver Syndrome European Consortium, we illustrate the phenotypic variability characteristically observed within extended families with AOS. Taken in combination with a detailed review of the available literature, we provide evidence for distinct clinical entities within the ACC/TTLD spectrum, which may reflect genetic heterogeneity within this spectrum of disorders.

Adams-Oliver syndrome: further evidence of an autosomal recessive variant

Adams-Oliver syndrome is characterized by aplasia cutis congenita and variable degrees of terminal transverse limb defects. Other associated anomalies were described in the syndrome. Most described cases follow an autosomal dominant pattern of inheritance. Sporadic and autosomal recessive cases, however, were reported. In this study, we report on three Egyptian patients with Adams-Oliver syndrome from three different families. The parents were normal and consanguineous in all three families. There was history of similarly affected sibs for two cases. These findings denote autosomal recessive inheritance. The reported cases had typical skull and limb anomalies with cutis marmorata telangiectatica congenita. We observed additional rare manifestations in the form of microcephaly, psychomotor retardation, epilepsy, eye anomalies and atrophic skin lesions. MRI of the brain in one of the studied cases revealed retrocerebellar cyst and mild asymmetrical cerebellar hypoplasia, which to our knowledge, were not previously reported in Adams-Oliver syndrome. The results of this study provide further evidence of clinical and genetic heterogeneity and support the presence of autosomal recessive variant of Adams-Oliver syndrome.

Clinical characteristics of idiopathic portal hypertension

Idiopathic portal hypertension is one of the interesting causes of portal hypertension. Even in very developed medical centers, this disorder is still one of the most important misdiagnoses of clinical practice. To inexperienced physicians, presenting esophageal varices and upper gastrointestinal bleeding usually prompt an unfortunate diagnosis of cirrhosis. A heterogenous clinical presentation and progression of this disorder should be recognized by physicians, and management should be directed towards some specific problems confined to this disorder. Although a genetic basis and other factors are implicated in its pathogenesis, exact underlying mechanism(s) is (are) unknown. In this review, we discuss the heterogeneity of idiopathic portal hypertension, its etiopathogenesis, clinical presentation and management issues. With the expectation of an excellent prognosis, a practicing gastroenterologist should be aware that “not all varices mean cirrhosis”.

Aplasia cutis congenita, terminal limb defects and falciform retinal folds: confirmation of a distinct syndrome of vascular disruption

We describe a son of consanguineous parents with congenital scalp defects, transverse limb abnormalities, hypoplasia of the corpus callosum and bilateral falciform retinal folds. Aplasia cutis congenita with transverse limb defects are features of Adams-Oliver syndrome, which is usually inherited as an autosomal dominant condition. The association of bilateral retinal folds and brain abnormalities with scalp defects and terminal limb defects has only once been previously described. It is possible that these cases represent a severe variant of Adams-Oliver syndrome. We, however, suggest that they may characterize a new, distinct, autosomal recessive syndrome, involving vascular disruption.

Adams-Oliver syndrome: clinical description of a four-generation family and exclusion of five candidate genes

We present a Belgian Adams-Oliver syndrome (AOS) family with 10 affected individuals over four generations, of which six were available for this study. Clinical symptoms observed in these patients were very variable as previously reported in other families and included large areas of alopecia on the vertex of the skull and serious limb reduction defects with agenesis of all toes of one foot. To identify the disease-causing gene, we sequenced the MSX1, CART1, P63 (P73L), RUNX2, and HOXD13 genes in this family and nine previously reported families, but no disease-causing mutations were found. Further investigation is ongoing in these families in order to identify the genetic cause of AOS.