Multilineage hemopoietic stem cell defects in Budd Chiari syndrome

An Update on the Management of Budd-Chiari Syndrome

Budd-Chiari syndrome (BCS) is an uncommon condition, caused by obstruction to hepatic venous outflow. It is largely underdiagnosed, and a high index of suspicion is required for any patient with unexplained portal hypertension. The understanding of its etiology and pathology is improving with advances in diagnostic techniques. Recent studies reported an identifiable etiology in > 80% of cases. Myeloproliferative neoplasm (MPN) is the most common etiology, and genetic studies help in diagnosing latent MPN. Better cross-sectional imaging helps delineate the site of obstruction accurately. The majority of BCS patients are now treated by endovascular intervention and anticoagulation which have improved survival in this disease. Angioplasty of hepatic veins/inferior vena cava remains under-utilized at present. While surgical porto-systemic shunts are no longer done for BCS, liver transplantation is reserved for select indications. Some of the unresolved issues in the current management of BCS are also discussed in this review.

Epidemiological Characteristics and Etiology of Budd-Chiari Syndrome in Upper Egypt

Background and Objectives

Budd-Chiari syndrome (BCS) is a rare disorder caused by obstruction to hepatic venous outflow. It affects all races, usually during the third or fourth decade of life. Higher prevalence had being evident in developing countries. The aim of the present study was to clarify sociodemographic features, clinical, radiological presentations, and etiology of BCS among Upper Egyptian patients.

Patients and Methods

This retrospective cohort study enrolled 50 Upper Egyptian Patients with confirmed primary BCS. Liver, coagulation, and thrombophilia workup profiles were performed as anticardiolipin antibodies, lupus anticoagulant, protein C, protein S, and antithrombin III assays. Factor V Leiden and JAK2 mutations were assessed. Full radiological assessment was done.

Results

Fifty patients were included. There were 28 males (56%) and 22 females (44%) with mean age (32.5 ± 11.1 years). The etiological factor was not identified in 22% of cases (n=11). Isolated factor C deficiency was found in 26% (n=13) with male predominance 39.3% and protein S deficiency in 10% (n=5). Factor V Leiden mutation was the etiology in 5 patients (10%). Membranous web and antiphospholipid syndrome each were the etiology in 8% (n=4). Behςet’s disease was diagnosed in 4% (n=2). Cases of liver cirrhosis(LC) were 41/50(82%)they were :33/50(66%) LC child class C, 8 /50(16%)  LC child class B, and 0/50 (0%) LC child class A. Abdominal pain was the most common symptom (96%), and ascites was the most common sign (82%). Obstruction of hepatic veins was present in 80%.

Conclusion

BCS in Upper Egyptian patients was mainly occurred in males in the third and fourth decade of life, mostly with liver cirrhosis. The most common etiology is isolated protein C deficiency followed by Factor V Leiden mutation and isolated protein S deficiency. Hepatic veins obstruction was the most common pattern of vascular involvement.

Low frequency of V617F mutation in JAK2 gene in Indian patients with hepatic venous outflow obstruction and extrahepatic portal venous obstruction

BACKGROUND

Hepatic venous outflow tract obstruction (HVOTO) and extrahepatic portal venous obstruction (EHPVO) are important causes of portal hypertension and related complications in India. Both these conditions result from splanchnic venous thrombosis. In recent years, a V617F somatic mutation in Janus kinase 2 (JAK2) gene which is highly specific for myeloproliferative disorders has been detected in 40 % to 50 % and 30 % to 35 % of Western patients with HVOTO and EHPVO, respectively. However, data on this mutation in these conditions from Asian countries are limited.

METHODS

We looked for JAK2 V617F mutation in Indian patients with HVOTO (n = 40, median age 31 [range 17-51] years, 21 female) and EHPVO (n = 50, median age 23 [15-70] years, 25 female) by using two separate methods. Both the methods involved polymerase chain reaction using allele-specific primers. Positive results on one or both of these techniques were confirmed using DNA sequencing.

RESULTS

None of the 40 patients with HVOTO and only 1 of 50 patients with EHPVO was found to have JAK2 V617F mutation. In the one patient who was found to have this mutation, both the PCR methods and DNA sequencing showed positive results.

CONCLUSION

Hypercoagulability associated with JAK2 V617F mutation and associated chronic myeloproliferative disorders was not a major cause of HVOTO and EHPVO in this population.

Extrahepatic portal vein obstruction and portal vein thrombosis in special situations: Need for a new classification

Extrahepatic portal vein obstruction is a vascular disorder of liver, which results in obstruction and cavernomatous transformation of portal vein with or without the involvement of intrahepatic portal vein, splenic vein, or superior mesenteric vein. Portal vein obstruction due to chronic liver disease, neoplasm, or postsurgery is a separate entity and is not the same as extrahepatic portal vein obstruction. Patients with extrahepatic portal vein obstruction are generally young and belong mostly to Asian countries. It is therefore very important to define portal vein thrombosis as acute or chronic from management point of view. Portal vein thrombosis in certain situations such as liver transplant and postsurgical/liver transplant period is an evolving area and needs extensive research. There is a need for a new classification, which includes all areas of the entity. In the current review, the most recent literature of extrahepatic portal vein obstruction is reviewed and summarized.

Epidemiological aspects of Budd-Chiari in Egyptian patients: A single-center study

AIM: To describe the socio-demographic features, etiology, and risk factors for Budd-Chiari syndrome (BCS) in Egyptian patients.

METHODS: Ninety-four Egyptian patients with confirmed primary Budd-Chiari syndrome were presented to the Budd-Chiari Study Group (BCSG) and admitted to the Tropical Medicine Department of Ain Shams University Hospital (Cairo, Egypt). Complete clinical evaluation and laboratory investigations, including a thrombophilia workup and full radiological assessment, were performed to determine underlying disease etiologies.

RESULTS: BCS was chronic in 79.8% of patients, acute or subacute in 19.1%, and fulminant in 1.1%. Factor V Leiden mutation (FVLM) was the most common etiological cause of disease (53.1%), followed by mutation of the gene encoding methylene tetrahydrofolate reductase (MTHFR) (51.6%). Current or recent hormonal treatment was documented in 15.5% of females, and BCS associated with pregnancy was present in 17.2% of females. Etiology could not be determined in 8.5% of patients. Males had significantly higher rates of MTHFR gene mutation and Behçet’s disease, and females had significantly higher rates of secondary antiphospholipid antibody syndrome. A highly significant positive relationship was evident between the presence of Behçet’s disease and inferior vena caval occlusion, either alone or combined with occlusion of the hepatic veins (P < 0.0001).

CONCLUSION: FVLM is the most common disease etiology and MTHFR the second most common in Egyptian BCS patients. BCS etiology tends to vary with geographic region.

Portal vein thrombosis, revisited

This review article aims to discuss the aetiology, pathophysiology, clinical presentation, diagnostic workup and management of portal vein thrombosis, either as a primary vascular liver disease in adults and children, or as a complication of liver cirrhosis. In addition, indications and limits of anticoagulant therapy are discussed in detail.

Vascular disorders of the liver

This guideline has been approved by the American Association for the Study of Liver Diseases (AASLD) and represents the position of the association.

Changing spectrum of Budd-Chiari syndrome in India with special reference to non-surgical treatment

AIM: To evaluate patterns of obstruction, etiological spectrum and non-surgical treatment in patients with Budd-Chiari syndrome in India.

METHODS: Forty-nine consecutive cases of Budd-Chiari syndrome (BCS) were prospectively evaluated. All patients with refractory ascites or deteriorating liver function were, depending on morphology of inferior vena cava (IVC) and/or hepatic vein (HV) obstruction, triaged for radiological intervention, in addition to anticoagulation therapy. Asymptomatic patients, patients with diuretic-responsive ascites and stable liver function, and patients unwilling for surgical intervention were treated symptomatically with anticoagulation.

RESULTS: Mean duration of symptoms was 41.5 ± 11.2 (range = 1-240) mo. HV thrombosis (HVT) was present in 29 (59.1%), IVC thrombosis in eight (16.3%), membranous obstruction of IVC in two (4%) and both IVC-HV thrombosis in 10 (20.4%) cases. Of 35 cases tested for hypercoagulability, 27 (77.1%) were positive for one or more hypercoagulable states. Radiological intervention was technically successful in 37/38 (97.3%): IVC stenting in seven (18.9%), IVC balloon angioplasty in two (5.4%), combined IVC-HV stenting in two (5.4%), HV stenting in 11 (29.7%), transjugular intrahepatic portosystemic shunt (TIPS) in 13 (35.1%) and combined TIPS-IVC stenting in two (5.4%). Complications encountered in follow-up: death in five, re-stenosis of the stent in five (17.1%), hepatic encephalopathy in two and hepatocellular carcinoma in one patient. Of nine patients treated medically, two showed complete resolution of HVT.

CONCLUSION: In our series, HVT was the predominant cause of BCS. In the last five years with the availability of sophisticated tests for hypercoagulability, etiologies were defined in 85.7% of cases. Non-surgical management was successful in most cases.

Familial polycythemia vera with Budd-Chiari syndrome in childhood

Polycythemia vera is a myeloproliferative disorder that, in most cases, occurs sporadically with a median age at presentation of 60 years. Familial cases are very rare and usually manifest in elderly family members. The Budd-Chiari syndrome, characterized by the obstruction and occlusion of the suprahepatic veins, is a rare typical complication in polycythemia vera patients. To date, only two children or adolescents with polycythemia vera and Budd-Chiari syndrome have been described. Here, we report an 11-year-old girl with Budd-Chiari syndrome as the initial symptom of familial polycythemia vera, which was also found in the girl's grandmother. Details of the diagnostic procedures used and the clinical course are reported. The patient underwent orthotopic liver transplantation and is being treated with hydroxyurea. The available literature on familial polycythemia vera and polycythemia vera in childhood with and without Budd-Chiari syndrome is reviewed.

ATP-dependent GSH and glutathione S-conjugate transport in skate liver: role of an Mrp functional homologue

Multidrug resistance-associated proteins 1 and 2 (Mrp1 and Mrp2) are thought to mediate low-affinity ATP-dependent transport of reduced glutathione (GSH), but there is as yet no direct evidence for this hypothesis. The present study examined whether livers from the little skate (Raja erinacea) express an Mrp2 homologue and whether skate liver membrane vesicles exhibit ATP-dependent GSH transport activity. Antibodies directed against mammalian Mrp2-specific epitopes labeled a 180-kDa protein band in skate liver plasma membranes and stained canaliculi by immunofluorescence, indicating that skate livers express a homologous protein. Functional assays of Mrp transport activity were carried out using (3)H-labeled S-dinitrophenyl-glutathione (DNP-SG). DNP-SG was accumulated in skate liver membrane vesicles by both ATP-dependent and ATP-independent mechanisms. ATP-dependent DNP-SG uptake was of relatively high affinity [Michaelis-Menten constant (K(m)) = 32 +/- 9 microM] and was cis-inhibited by known substrates of Mrp2 and by GSH. Interestingly, ATP-dependent transport of (3)H-labeled S-ethylglutathione and (3)H-labeled GSH was also detected in the vesicles. ATP-dependent GSH transport was mediated by a low-affinity pathway (K(m) = 12 +/- 2 mM) that was cis-inhibited by substrates of the Mrp2 transporter but was not affected by membrane potential or pH gradient uncouplers. These results provide the first direct evidence for ATP-dependent transport of GSH in liver membrane vesicles and support the hypothesis that GSH efflux from mammalian cells is mediated by members of the Mrp family of proteins.

Pathogenesis of liver fibrosis: role of oxidative stress

In the liver, the progressive accumulation of connective tissue, a complex and dynamic process termed fibrosis, represents a very frequent event following a repeated or chronic insult of sufficient intensity to trigger a "wound healing"-like reaction. The fibrotic process recognises the involvement of various cells and different factors in bringing about an excessive fibrogenesis with disruption of intercellular contacts and interactions and of extracellular matrix composition. However, Kupffer cells, together with recruited mononuclear cells, and hepatic stellate cells are by far the key-players in liver fibrosis. Their cross-talk is triggered and favoured by a series of chemical mediators, with a prominent role played by the transforming growth factor beta. Both expression and synthesis of this inflammatory and pro-fibrogenic cytokine are mainly modulated through redox-sensitive reactions. Further, involvement of reactive oxygen species and lipid peroxidation products can be clearly demonstrated in other fundamental events of hepatic fibrogenesis, like activation and effects of stellate cells, expression of metalloproteinases and of their specific inhibitors. The important outcome of such findings as regards the pathogenesis of liver fibrosis derives from the observation of a consistent and marked oxidative stress condition in many if not all chronic disease processes affecting hepatic tissue. Hence, reactive oxidant species likely contribute to both onset and progression of fibrosis as induced by alcohol, viruses, iron or copper overload, cholestasis, hepatic blood congestion.

Flow cytometric analysis of autonomous growth of erythroid precursors in liquid culture detects occult polycythemia vera in the Budd-Chiari syndrome

BACKGROUND/AIMS

Hepatic vein thrombosis (Budd-Chiari syndrome) is associated with various hypercoagulable states, such as polycythemia vera (PV), presence of the lupus anticoagulant, paroxysmal nocturnal hemoglobinuria (PNH) and deficiencies of antithrombin III, protein C and protein S. In recent years, it has become evident that patients with the Budd-Chiari syndrome may have more than one risk factor that may cause a state of hypercoagulability. The aim of the current study was to assess the prevalence of occult PV in patients with Budd-Chiari syndrome using a novel method for the detection of spontaneous erythroid growth.

METHODS

Twenty-two patients with Budd-Chiari syndrome were evaluated. As controls, we studied normal donors and four patients with liver cirrhosis and five patients with right-side heart failure, two conditions that in part mimic Budd-Chiari syndrome. The presence of PV was determined by flow cytometric analysis of autonomous growth of erythroid precursors. Patients were considered as having occult PV if they had spontaneous erythroid cell growth in the absence of erythropoietin and with no features of overt PV.

RESULTS

Cells from ten patients with Budd-Chiari syndrome demonstrated spontaneous erythroid cell growth; eight patients (32%) were found to have occult PV and two patients had overt PV. None of the controls had spontaneous erythroid growth. Of the eight Budd-Chiari patients with occult PV, six had one or more additional recognized hypercoagulable states. Seven patients (32%) had protein C deficiency, six patients (27%) had activated protein C resistance, five (23%) had anti-cardiolipin antibodies, five (23%) had antithrombin III deficiency, and four patients (18%) had protein S deficiency. Three patients (14%) were homozygous to methyltetra hydrofolate reductase and ten (45.5%) were heterozygous. One patient had PNH. Overall, in 12 patients there were two or more combined risk factors.

CONCLUSIONS

Using a flow cytometric analysis of autonomous growth of erythroid precursors we found a clear correlation between Budd-Chiari syndrome and occult PV.

Gastrointestinal manifestations of Behcet's disease

Behcet's disease (BD) is a multisystem, chronic, relapsing vasculitis of unknown origin that affects nearly all organs and systems. While recurrent oral ulcerations are a "sine qua non" of BD, the frequency of extra-oral parts of the gastrointestinal involvement varies widely in different countries. The most frequent extra-oral sites of gastrointestinal involvement are the ileocecal region and the colon. The liver (except with Budd-Chiari syndrome), pancreas, and spleen are rarely involved. The symptoms associated with these extra-oral manifestations of BD are abdominal pain, nausea, vomiting, diarrhea with or without blood, and constipation. The lesions typically are resistant to medical treatment and frequently recur with surgical treatment. We review the literature regarding the gastrointestinal and hepatobiliary systems in BD. Also, we present a patient who had BD complicated with radiologically-proven hepatic veins involvement (Budd-Chiari syndrome) and complete occlusion of hepatic portion of inferior vena cava and who had a good response to colchicine and penicillin treatment.

Centrilobular and perisinusoidal fibrosis in experimental congestive liver in the rat

BACKGROUND/AIMS

The pathogenesis of congestive hepatic fibrosis is known to be a reaction of hepatic stromal cells following prolonged congestive heart failure or hepatic outflow obstruction. However, little is known about the fibrotic process itself. This study documents the hepatic morphology and ultrastructure of the fibrotic processes in an experimental model of congestive hepatic fibrosis in rats.

METHODS

In this model we ligated the abdominal portion of the inferior vena cava in the space between the diaphragm and liver, and observed liver morphology 24 h, 1 week and 6 weeks after the operation. The cytoskeletal components of the hepatic stellate cells and myofibroblasts were identified by immunohistochemistry for glial fibrillary acidic protein (GFAP) and a-smooth muscle actin (a-SM actin). Extracellular matrices of reticulin fibers and fibronectin were localized using silver impregnation and immunohistochemical staining.

RESULTS

Soon after ligation of the vena cava, foci of cells at variable stages of necrosis appeared in the centrilobular areas, the topographical localization of which was highly variable within the liver. The fibrotic processes were subclassified into three stages. In the first stage (24 h after ligation), abundant neutrophils, macrophages and GFAP-positive stellate cells appeared, but a-SM actin-positive cells were not detected in the necrotic areas. In the second stage (1 week after ligation), the GFAP-positive cells disappeared, but a-SM actin-positive myofibroblasts appeared. In the third stage (6 weeks after ligation), a large number of a-SM actin-positive myofibroblasts were observed, and there was heavy deposition of connective tissue proteins, such as reticulin fibers and fibronectin, in centrilobular areas. Two interesting observations were that: (1) the distribution of centrilobular necrosis was highly variable within the liver, and (2) the fibrosis was confined to focal centrilobular areas involving the perivenular sinusoidal area without periportal fibrosis.

CONCLUSIONS

These findings suggest that GFAP-positive stellate cells are transformed into a-SM actin-positive myofibroblasts, and these myofibroblasts produce extracellular matrix proteins in centrilobular sinusoidal areas under congestive conditions.

ATP-dependent transport of reduced glutathione on YCF1, the yeast orthologue of mammalian multidrug resistance associated proteins

The transport systems involved in the export of cellular reduced glutathione (GSH) have not been identified, although recent studies implicate a role for some of the multidrug resistance associated proteins (MRP), including MRP1 and MRP2. The present study examined the hypothesis that the yeast orthologue of MRP, Ycf1p, mediates ATP-dependent GSH transport. [3H]GSH transport was measured in vacuolar membrane vesicles isolated from a control strain of Saccharomyces cerevisiae (DTY165), the isogenic DTY167 strain that lacks a functional Ycf1p, and in DTY167 transformed with a 2-micrometer plasmid vector containing YCF1. GSH transport in control vacuolar membrane vesicles was mediated largely by an ATP-dependent, low affinity pathway (Km = 15 +/- 4 mM). ATP-dependent [3H]GSH transport was cis-inhibited by substrates of the yeast Ycf1p transporter and inhibited by 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, probenecid, and sulfinpyrazone, inhibitors of MRP1 and MRP2, but was minimally affected by membrane potential or pH gradient uncouplers. In contrast, ATP-dependent GSH transport was not seen in vacuolar membrane vesicles isolated from the DTY167 yeast strain without a functional Ycf1p but was restored to near wild-type levels in the DTY167 strain transformed with YCF1 and expressing the vacuolar Ycf1p transporter. On the other hand, expression and functional activity of a bile acid transporter, Bat1p, and of the V-type ATPase were similar in all three yeast strains. These results provide direct evidence for ATP-dependent low affinity transport of GSH by the yeast Ycf1p transporter. Because of the structural and functional homology between Ycf1p and MRP1 and MRP2, these data support the hypothesis that GSH efflux from mammalian cells is mediated by these membrane proteins.

Proposal of a new nomenclature for Budd-Chiari syndrome: hepatic vein thrombosis versus thrombosis of the inferior vena cava at its hepatic portion

Budd-Chiari syndrome (BCS) was initially defined as a symptomatic occlusion of the hepatic veins, but subsequent reports on various obliterative changes that occur in the hepatic portion of the inferior vena cava (IVC) and hepatic vein orifices have resulted in a broadened and ambiguous definition. Membranous obstruction of the inferior vena cava has been regarded by many as a congenital vascular malformation, but its relation to the classical BCS has remained obscure. With modern imaging and recent histological study of new cases, membranous obstruction of the IVC is now considered to be a sequela to thrombosis. How to classify various forms of occlusion and stenosis of the IVC and hepatic vein ostia is a major challenge. In this review, we emphasize that primary hepatic vein thrombosis (classical Budd-Chiari) and an obliterative disease predominantly affecting the hepatic portion of the IVC, both of which account for most patients with venous outflow block, are clinically quite different. In the West, the former is more common than the latter, which constitutes the vast majority of cases of outflow block in developing countries such as Nepal, South Africa, China, and India. The latter is frequently complicated by hepatocellular carcinoma (HCC), and primary hepatic vein thrombosis is not. The major cause of thrombosis is a hypercoagulable state in hepatic vein thrombosis, but more of the latter cases are idiopathic. The clinical presentation of the latter is milder, and onset is frequently inapparent, whereas the former is more severe, sometimes causing acute hepatic failure. Markedly enlarged subcutaneous veins over the body trunk characterize the latter. We propose that these two disorders be clinically distinguished with a suggested term "obliterative hepato-cavopathy" for the latter against classical BCS.