Idiopathic noncirrhotic portal hypertension

Evaluation of the histologic and immunohistochemical (CD34, glutamine synthetase) findings in idiopathic non-cirrhotic portal hypertension (INCPH)

AIM

Idiopathic non-cirrhotic portal hypertension (INCPH) is a vascular disorder of uncertain origin. Diagnosis can be challenging on liver biopsy. Despite diverse histomorphologic findings documented in literature, studies on the frequency of these findings are lacking. This study aims to assess both the histomorphologic features and the immunoexpression patterns of CD34 and glutamine synthetase (GS) in liver biopsies and searched for their contribution to the pathologic diagnosis of INCPH.

MATERIALS AND METHODS

Hematoxylin-eosin, CD34, and GS-stained liver needle biopsy sections of 16 patients clinically diagnosed with INCPH were retrospectively analyzed. Histologic findings such as portal vein narrowing, obliteration, or loss were grouped as major findings, while portal vein herniation, hypervascularized portal tracts, and periportal abnormal vessels were grouped as minor findings, and their frequency were evaluated. Periportal endothelial CD34 stained areas were measured via ocular micrometer. The distribution of GS immunoexpression was evaluated. Eighteen healthy liver donor biopsies were evaluated as controls.

RESULTS

In INCPH cases, 58% of portal tracts showed major findings, compared to 15% in the control group (p < 0.001). Minor findings were observed in 16% of INCPH cases and 7% of controls (p = 0.014). The number of portal tracts with histologic findings is significantly higher in INCPH than in control liver biopsies. Abnormal portal tract distribution, like being close to each other, was seen in 75% of INCPH cases but not in controls (p < 0.001). Nodular regenerative hyperplasia (NRH) was present in 31% of cases. Periportal CD34 expression was higher in INCPH, and affected areas were larger than in controls (p < 0.001). Irregular GS staining, i.e. GS staining with patchy distribution in zone 3, and/or periportal and zone 2 hepatocytes, was found in 62% of INCPH cases, while controls showed the usual pattern (p < 0.001).

CONCLUSION

In the biopsy diagnosis of INCPH, in addition to the presence of major histologic findings and the amount of portal tracts displaying these features, the expression of endothelial CD34 in periportal areas, and irregular hepatocellular GS expression can also be considered as supporting feature.

Dissociation in hepatic vein pressure gradient, liver stiffness measurement and complications in histological subtypes of porto-sinusoidal vascular disease

BACKGROUND AND AIMS

Portosinusoidal vascular disease (PSVD) is a broad term encompassing varied histological patterns with changes in portal tracts and sinusoids without cirrhosis. We aimed to assess whether there is any clinical and pathological difference among the various histological categories of PSVD.

PATIENTS AND METHODS

This study included liver biopsy cases classified as PSVD (2020-2022). Clinical and laboratory parameters were obtained from the electronic records. PSVD cases were histologically categorised as obliterative portal venopathy (OPV), OPV with fibrosis (OPV-F), incomplete septal cirrhosis (ISC), nodular regenerative hyperplasia (NRH), mega sinusoids with fibrosis (MSF) and unclassified. Follow-up complications were recorded.

RESULTS

PSVD categories were OPV (45 (26%)), OPV-F (37 (21.4%)), ISC (20 (11.6%)), NRH (19 (11%)), MSF (19 (11%)) and unclassified (33 (19%)). Elevated hepatic venous pressure gradient (HVPG) was noted in OPV-F (10 (IQR: 12-14.7)) and ISC (12 (IQR: 9-14)) mm Hg with higher fibrosis quantity in liver tissue and elevated procollagen III aminoterminal propeptide, which correlated with HVPG. On immunohistochemistry, OPV-F and ISC showed lesser expression of ADAMT13 in liver biopsies (p<0.001). On follow-up, ascites development was more in OPV-F and ISC than in other categories (p=0.001). Higher liver stiffness measurement (LSM) values were recorded in MSF and NRH, compared with other categories, but it did not correlate with fibrosis in liver biopsy.

CONCLUSIONS

OPV-F and ISC had higher HVPG, fibrosis, and more ascites development on follow-up than the other categories of PSVD, and all are not the same. In contrast, MSF and NRH have spuriously high LSM.

Molecular Mechanisms Underlying Vascular Liver Diseases: Focus on Thrombosis

Vascular liver disorders (VLDs) comprise a wide spectrum of clinical-pathological entities that primarily affect the hepatic vascular system of both cirrhotic and non-cirrhotic patients. VLDs more frequently involve the portal and the hepatic veins, as well as liver sinusoids, resulting in an imbalance of liver homeostasis with serious consequences, such as the development of portal hypertension and liver fibrosis. Surprisingly, many VLDs are characterized by a prothrombotic phenotype. The molecular mechanisms that cause thrombosis in VLD are only partially explained by the alteration in the Virchow's triad (hypercoagulability, blood stasis, and endothelial damage) and nowadays their pathogenesis is incompletely described and understood. Studies about this topic have been hampered by the low incidence of VLDs in the general population and by the absence of suitable animal models. Recently, the role of coagulation imbalance in liver disease has been postulated as one of the main mechanisms linked to fibrogenesis, so a novel interest in vascular alterations of the liver has been renewed. This review provides a detailed analysis of the current knowledge of molecular mechanisms of VLD. We also focus on the promising role of anticoagulation as a strategy to prevent liver complications and to improve the outcome of these patients.

Systemic Sclerosis and Idiopathic Portal Hypertension: Report of a Case and Review of the Literature

Simple Summary

The presence of liver involvement in systemic sclerosis (SSc) is considered atypical, besides the eventual coexistence of other autoimmune hepatic disorders. However, the occurrence of syndromes called idiopathic portal hypertension (IPH) and regenerative nodular hyperplasia (RNH) have been anecdotally reported in the literature. We described a case of SSc complicated by IPH and we reviewed the literature on the topic. No specific SSc pattern linked to IPH emerged, even though the reports often described IPH in patients with limited skin subset SSc. Coexistence of prothrombotic states and overlap with other hepatic diseases could facilitate IPH onset. In spite of IPH being a rare condition, the rheumatologists should consider IPH as a possible hepatic complication in SSc patients.

Abstract

The presence of liver involvement in systemic sclerosis (SSc) is considered atypical, besides the possible coexistence of other autoimmune hepatic disorders. However, the occurrence of portal hypertension and, more specifically, of the syndromes called idiopathic portal hypertension (IPH) and regenerative nodular hyperplasia (RNH) have been anecdotally reported in the literature for SSc patients. We described a case of SSc woman complicated by IPH; moreover, we reviewed the literature on the topic. A 61-year-old female SSc patient was admitted to our hospital because of the onset of ascites. SSc, as a limited skin subset of disease with anticentromere antibodies, was diagnosed 11 years previously, with no significant visceral involvement. We excluded possible causes of portal hypertension, namely chronic infections, autoimmune hepatic diseases, neoplasia, thrombosis of portal vein, and Budd–Chiari syndrome. Finally, IPH was diagnosed. A review of the literature identified a number of case reports or case series that described IPH in the course of SSc. No specific SSc pattern linked to IPH emerged, even though reports from the literature often described the limited skin subset. Coexistence of prothrombotic states and overlap with other hepatic diseases could facilitate IPH onset. Besides being a rare condition, the onset of IPH in SSc patients is an occurrence that should be taken into account.

Identification and clinical significance of nodular regenerative hyperplasia in primary sclerosing cholangitis

BACKGROUND AND AIM

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by inflammation and fibrosis of intrahepatic and extrahepatic bile ducts. PSC is frequently associated with inflammatory bowel disease (IBD). Nodular regenerative hyperplasia (NRH) can occur in IBD with the use or even in the absence of thiopurine treatment. We aimed to study the significance of the presence of NRH and obliterative portal venopathy (OPV), both causes of non-cirrhotic portal hypertension (NCPH), in patients having PSC.

METHODS

Patients with PSC and concurrent NRH on liver biopsy were identified from the digital pathology database covering the period 2003-2019. Evaluation of liver biopsy and the original diagnoses were confirmed on review based on standard histological features diagnostic for NRH and OPV. Clinical and laboratory data were obtained from electronic medical records.

RESULTS

Thirty-one patients (21 male, 10 female; median age at biopsy 40.1 years) were included in the study. Twelve (38.7%) patients had OPV in addition to NRH on the liver biopsy. Nineteen (61.2%) patients had IBD including 11 with Crohn's disease (CD), 7 with ulcerative colitis (UC), and 1 with indeterminate colitis. Thirteen (41.9%) patients had evidence of portal hypertension, 10 (32.2%) with esophageal varices, 4 (12.9%) with history of variceal bleeding, 6 (19.3%) with ascites, and 14 (12.9%) with splenomegaly. Eleven (35.4%) patients had a cirrhotic-appearing liver on imaging. Twelve (38.7%) patients had a history of prior or current thiopurine use.

CONCLUSIONS

The current study suggests that NRH with or without OPV independently occurs in patients having PSC and may lead to NCPH, even in the absence of concurrent IBD and/or thiopurine therapy.

Antibody-mediated rejection of the liver allograft: An update and a clinico-pathological perspective

Antibody-mediated rejection after liver transplantation is an under-recognised cause of allograft injury. While definitions of acute and chronic antibody-mediated rejection have increased clinical awareness, timely identification and management of antibody-mediated rejection remain difficult because of complexities in diagnosis and histopathology, lack of treatment protocols, and unclear long-term outcomes. While recent cohort studies assessing the importance of donor-specific antibodies have aided in its diagnosis, literature on the treatment of antibody-mediated rejection in liver transplantation remain limited to case reports and small series. Further increasing the awareness and timely recognition of antibody-mediated rejection post-liver transplantation is crucial in order to stimulate future research and the development of protocols for its diagnosis and treatment. This review will summarise recent advances in the clinical diagnosis and treatment of antibody-mediated rejection in liver transplantation, as well as some of the histopathologic features (on liver biopsy tissue) of acute and chronic antibody-mediated rejection.

Congenital hepatic fibrosis and its mimics: a clinicopathologic study of 19 cases at a single institution

Background

Congenital hepatic fibrosis (CHF) is a rare inherited form of ductal plate malformation associated with polycystic kidney disease. The diagnosis requires histopathologic confirmation, but can be challenging to distinguish from other undefined fibrocystic liver diseases. We aimed to describe the clinicopathologic features of congenital hepatic fibrosis (CHF), with comparisons to other entities that may clinically and/or histologically mimic CHF.

Methods

Nineteen cases that carried a clinical and/or histologic impression of CHF were identified at our institution, of which the histology was reassessed and reappraised into two categories: CHF (n=13) and mimics (n=6). The clinicopathologic features between the two groups were analyzed and compared.

Results

The CHF group was further sub-classified into those with clinical suspicion (CHF-c, n=8) and those as incidental histology findings (CHF-i, n=5). Patients of CHF-i were much older than CHF-c or mimics (P<0.05). Male and female were equally affected. Six of 8 CHF-c (66.7%) had concurrent kidney diseases, including 5 polycystic kidney diseases. Five of 6 mimics (83.3%) had various kidney diseases, including nephronophthisis, Alport syndrome, renal agenesis, and nephrolithiasis. None of the CHF-i patients had kidney disease, but 3 were associated with hepatic carcinomas. Histology analysis demonstrated characteristic triads (bile duct abnormalities, portal vein hypoplasia, and fibrosis) in all CHF cases. One mimic had paucity of intrahepatic bile ducts, while the other 5 mimics showed abnormal portal veins and nodular regenerative hyperplasia consistent with hepatoportal sclerosis (HPS).

Conclusions

Our study demonstrates classic histology triad of CHF despite a wide spectrum of clinical presentations. HPS is unexpectedly a clinical mimicker of CHF, which can be distinguished histologically.

Porto-sinusoidal vascular disease with portal hypertension versus liver cirrhosis: differences in imaging features on CT and hepatobiliary contrast-enhanced MRI

PURPOSE

To differentiate the computed tomography (CT) and magnetic resonance imaging (MRI) features of porto-sinusoidal vascular disease (PSVD) and liver cirrhosis (LC).

METHODS

In this retrospective case-control study of patients with PSVD matched in a 1:3 ratio with LC patients according to liver function, initial diagnosis and time to final diagnosis were analyzed. Imaging features on CT and the parenchymal enhancement on hepatobiliary phase of hepatobiliary agent-enhanced MRI (HBA-MRI) were compared using a generalized linear mixed model. Focal hepatic lesions in the PSVD group were analyzed.

RESULTS

In total, 43 PSVD patients and 129 LC patients were included. Among PSVD patients, 72.1% were initially misdiagnosed with LC. PSVD patients had a longer diagnostic delay than LC patients (32 months vs. 4 months; p < 0.001). Liver surface nodularity was less common in the PSVD group than in the LC group (16.3% vs. 89.2%, p < 0.001). Increased caudate-to-right lobe ratio, heterogeneous parenchymal enhancement, and portal vein abnormalities were more frequently noted in the PSVD group than in the LC group (all p < 0.001). The grade of portal hypertension was significantly higher in the PSVD group than in the LC group (p < 0.001), and they also had brighter parenchymal enhancement during the hepatobiliary phase of HBA-MRI (p < 0.001). In the PSVD group, 14% patients had at least one focal hepatic lesion, primarily a focal nodular hyperplasia (FNH)-like nodule.

CONCLUSIONS

Some imaging features on CT and HBA-MRI can distinguish PSVD from LC. Benign focal lesions, most commonly FNH-like nodules, can develop in PSVD.

A case of systemic lupus erythematosus with marked ascites due to idiopathic non-cirrhotic portal hypertension

A 43-year-old-woman admitted to our department because of abdominal pain, abdominal distension, pain on both inner thighs and blurred vision lasting for 3 months. Pancytopenia and positive anti-double stranded DNA (dsDNA) antibodies were noted 5 years prior to her hospitalisation. On admission, the patient was diagnosed with systemic lupus erythematosus (SLE) with retinal vasculitis, panniculitis, cholecystitis and enteritis. The ultrasound test revealed a large amount of ascites, splenomegaly, a hypoechoic band in the liver, and portal hypertension with mildly elevated hepatic venous wedge pressure (15 mmHg). Liver biopsy showed no evidence of hepatitis, cholangitis or liver cirrhosis, leading to the diagnosis of idiopathic non-cirrhotic portal hypertension (INCPH). Prednisolone (PSL) at a daily dose of 50 mg and intravenous cyclophosphamide pulse therapy (IVCY) were initiated for SLE, while diuretics were administered for transudative ascites associated with INCPH. Although these symptoms temporarily improved, 2 months later, SLE and ascites effusion aggravated again, and portal vein thrombosis was confirmed by computed tomography. After increasing the dose of IVCY and adding an anticoagulant agent, all symptoms improved, allowing a reduction of the PSL dose. In the present case, the exacerbation of INCPH was associated with the exacerbation of SLE and the occurrence of portal thrombosis, suggesting an autoimmune and thrombotic mechanism of INCPH. On the other hand, splenomegaly, oesophageal varices, the hypoechoic band remained unchanged, suggesting the established organised INCPH was refractory to immunosuppressive agents.

Key histopathologic features in idiopathic noncirrhotic portal hypertension: an interobserver agreement study and proposal for diagnostic criteria

Histologic features of idiopathic noncirrhotic portal hypertension (INCPH), loosely termed as obliterative portal venopathy (OPV), are heterogenous, often subtle, and overlap with other entities. To this date, no consensus histopathologic diagnostic criteria have been established for INCPH. For these reasons, rendering a reproducible consensus histologic diagnosis of OPV on a liver biopsy may often be challenging even for experienced hepatopathologists. We report herein a two-phase interobserver agreement study on the diagnosis of OPV and assessed the relative value of histologic features in 104 liver biopsies in distinguishing between INCPH and non-INCPH with the goal to obtain a consensus on specific practical diagnostic criteria. Six hepatopathologists blinded to clinical information and original pathologic diagnosis reviewed internet-based case study sets with high-resolution whole-slide images. The initial interobserver agreement on OPV was expectedly low, but significantly improved (moderate agreement in most categories) upon adopting a consensus view recognizing portal vein sclerosis as the only strong independent histologic predictor for INCPH, and that contrary to the conventional view, aberrant portal/periportal vessels does not significantly contribute to the positive assignment of OPV status. We propose a three-tiered classification with diagnostic criteria to facilitate the histologic assignment of OPV status for the evaluation of INCPH. Furthermore, we have validated the performance of the proposed criteria either based on histology alone or coupled with clinicopathologic correlation. This classification may aid in practical histologic assessment of liver biopsies with or without portal hypertension and help to improve diagnostic consistency and accuracy.

Hepatopulmonary Syndrome in an Adolescent With Insidious Hypoxia and Small Intrahepatic Portal Venous Shunts: Posttransplant Benefit From Sildenafil

We report a patient without known preexisting liver disease who presented with hepatopulmonary syndrome (HPS) due to aberrant intrahepatic portal venous development leading to portosystemic shunting. Liver transplantation resulted in resolution of portal hypertension and HPS and sildenafil was safely tolerated in the treatment of persistent fatigue and hypoxemia. Twelve months later, patient has normal allograft function and has returned to normal activity.

Non-cirrhotic portal hypertension related to azathioprine therapy in a patient with Crohn's disease

Azathioprine is widely used for the treatment of Crohn’s disease (CD). Few cases from Western countries have reported idiopathic non-cirrhotic portal hypertension (NCPH) related to thiopurine therapy in patients with inflammatory bowel disease. Idiopathic NCPH is a rare hepatic condition with intrahepatic portal hypertension but no evidence of cirrhosis or chronic liver disease. Patients with idiopathic NCPH present with symptoms of portal hypertension such as thrombocytopenia, splenomegaly and esophageal varices. We report a case of idiopathic NCPH in a 51-year-old male patient with CD who had been taking azathioprine for 5 years. He was admitted due to esophageal variceal bleeding along with splenomegaly and thrombocytopenia. Evaluation of cirrhosis or chronic liver disease showed normal-range results as estimated by FibroScan evaluation, laboratory examination for autoimmune hepatitis or viral hepatitis, and liver biopsy. This case may suggest the need for careful monitoring for manifestations of portal hypertension in Asian patients with inflammatory bowel disease receiving thiopurine treatment.

Aberrant von Willebrand factor expression of sinusoidal endothelial cells and quiescence of hepatic stellate cells in nodular regenerative hyperplasia and obliterative portal venopathy

AIMS

Nodular regenerative hyperplasia (NRH) and obliterative portal venopathy (OPV), entities that comprise idiopathic non-cirrhotic portal hypertension (INCPH), are under-recognised diseases of uncertain aetiology and the diagnosis can be easily missed on liver biopsy. The expression of CD34 and von Willebrand factor (vWF) in liver sinusoidal endothelial cells (LSEC) and alpha-smooth muscle actin (ASMA) in hepatic stellate cells (HSCs) is unknown in NRH and OPV. We sought to investigate the pathogenesis and potential immunomarkers that might aid in making the diagnosis of NRH and OPV.

METHODS AND RESULTS

Immunohistochemical (IHC) staining for CD34, vWF and ASMA was performed in clinically and histologically well-characterised NRH (n = 15) and OPV (n = 47) liver specimens. Among the 47 OPV cases, 37 (78.7%) had concurrent features of NRH. CD34 positive staining was mainly confined to small vessels in the portal tracts and LSECs in periportal areas, a finding similar to that in non-NRH/OPV livers. However, expression of vWF in LSECs was positive in the compressed sinusoids of NRH and in a patchy or geographic pattern, particularly prominent in the perivenular areas and dilated sinusoids of OPV cases. HSCs were negative for ASMA in all NRH and OPV cases.

CONCLUSION

Our findings indicate that NRH may be a subtle but common concurrent morphological feature in OPV. The aberrant expression of vWF in LSECs suggests that endothelial injury may play a role in the pathogenesis, which may thus aid in the recognition and diagnosis of NRH and OPV, particularly when confronted with otherwise apparent normal liver histology on needle biopsy.