Spectrum of histopathological changes in patients with non-cirrhotic portal fibrosis

Role of splenic hepatic elastography ratio in differentiating non-cirrhotic portal fibrosis and chronic liver disease in children and adolescents

BACKGROUND

Differentiation of Non-cirrhotic Portal Fibrosis (NCPF) from chronic liver disease (CLD) in children and adolescents with portal hypertension (PHT) is challenging especially in cases where liver stiffness measurement (LSM) and hepatic venous pressure gradient are higher. This objective of the current study was to evaluate the diagnostic accuracy of the splenic stiffness measurement (SSM)/LSM ratio in the diagnosis of NCPF.

METHODS

From January 2019 to December 2023, consecutive children and adolescents of 6 months to 18 years of age with PHT (CLD and NCPF) were prospectively enrolled. Transient elastography (TE) for SSM and LSM, upper gastrointestinal endoscopy (UGIE), liver biopsy/trans-jugular liver biopsy, abdominal imaging, and laboratory evaluation were done. The relationship of TE parameters for diagnosis of NCPF and CLD was evaluated. Receiver-operating characteristic (ROC) statistics were applied using R Studio-4.2.2 statistical software.

RESULTS

One hundred and forty seven with CLD and 27 patients with NCPF were evaluated. Median age was 10.0 (IQR 2.4-14.0) years; 68.4% were males. The AUROC of SSM/LSM ratio was better (0.992, 95%CI 0.982-1.0001) than LSM (0.945, 95%CI0.913-0.977) and SSM (0.626, 95%CI0.258-0.489) for the diagnosis of NCPF. SSM/LSM ratio cut-off of 3.67 predicted NCPF with an excellent sensitivity (100%), specificity (95.9%), and diagnostic accuracy (95.91%). The AUROC of SSM/LSM ratio was excellent and outperformed other TE parameters in the subgroups, i.e., LSM between 10 and 20 kPa (0.982, 95%CI 0.947-1.000), without clinically significant varices (CSV) (1.000, 95%CI 1.000-1.000) and with CSV (0.993, 95%CI 0.983-1.000). Diagnostic performance of SSM/LSM Ratio was better than LSM for discriminating NCPF from CLD using McNemar test (p = 0.01).

CONCLUSION

The SSM/LSM ratio is an excellent tool in differentiating NCPF from CLD.

Histopathological features of idiopathic portal hypertension: A systematic review and meta-analysis

BACKGROUND

Portal hypertension (PH) is a clinically significant entity that could present with life-threatening gastrointestinal bleeding. Cirrhosis is the most common cause of PH, with well-documented histopathology and etiology. However, in idiopathic portal hypertension (IPH), no single histopathologic finding is associated with PH. Our systematic review aims to identify and summarize the prevalence of the common histological findings of IPH.

METHODS

We systematically searched PubMed, Cochrane CENTRAL, Web of Science, and Scopus till 1ST March 2022 for studies describing the histopathological features of IPH. Data were extracted from eligible studies and pooled as events rate and 95% confidence interval (CI) using binary random-effects model by open meta-analyst software.

RESULTS

We included 23 retrospective studies with a total sample size of 813 patients. The overall incidence of nodular regenerative hyperplasia was 38.6%, 59.8% for portal fibrosis, 51.3% for periportal fibrosis, 39.3% for perisinusoidal fibrosis, 89.8% for portal vein sclerosis, 42.2% for portal inflammation, 53.3% for mega-sinusoids, 39.5% for thickening of portal vein branches, 93.8% for narrowing of portal veins, 53.3% for hepatic veins/venous outflow obstruction, 51.4% for aberrant portal/periportal vessels, 42.4% for shunt vessel, 50.9% for ductular proliferation, and 16.3% for steatosis.

CONCLUSION

Due to the relatively non-pathognomonic and non-specific nature of IPH, a combination of different histological features such as the portal and periportal fibrosis, portal vein sclerosis, mega-sinusoids, narrowing of portal veins, hepatic venous outflow obstruction, aberrant portal or periportal vessels, and ductular proliferation may be of value in diagnosing IPH as the incidence rate of these features was at approximately 50%.

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.

Recent Advances in the Pathogenesis and Clinical Evaluation of Portal Hypertension in Chronic Liver Disease

In chronic liver disease, hepatic stellate cell activation and degeneration of liver sinusoidal endothelial cells lead to structural changes, which are secondary to fibrosis and the presence of regenerative nodules in the sinusoids, and to functional changes, which are related to vasoconstriction. The combination of such changes increases intrahepatic vascular resistance and causes portal hypertension. The subsequent increase in splanchnic and systemic hyperdynamic circulation further increases the portal blood flow, thereby exacerbating portal hypertension. In clinical practice, the hepatic venous pressure gradient is the gold-standard measure of portal hypertension; a value of ≥10 mm Hg is defined as clinically significant portal hypertension, which is severe and is associated with the risk of liver-related events. Hepatic venous pressure gradient measurement is somewhat invasive, so evidence on the utility of risk stratification by elastography and serum biomarkers is needed. The various stages of cirrhosis are associated with different outcomes. In viral hepatitis-related cirrhosis, viral suppression or elimination by nucleos(t)ide analog or direct-acting antivirals results in recompensation of liver function and portal pressure. However, careful follow-up should be continued, because some cases have residual clinically significant portal hypertension even after achieving sustained virologic response. In this study, we reviewed the current and future prospects for portal hypertension.

Noninvasive differentiation of porto-sinusoidal vascular disorder from cirrhosis: a systematic review

BACKGROUND

Porto-sinusoidal vascular disorder (PSVD) is one of the common causes of portal hypertension and has overlapping features with early cirrhosis. The differentiation of PSVD from cirrhosis requires a liver biopsy, which is invasive and has potential complications. This systematic review aimed at summarizing the current evidence on the performance of noninvasive modalities for differentiating PSVD from cirrhosis.

METHODS

A comprehensive search of electronic databases of MEDLINE, Embase, and Scopus was conducted from 2000 to October 2022 for the studies comparing the elastographic and radiological features of PSVD and cirrhosis, using liver biopsy as the gold standard.

RESULTS

A total of 12 studies were included in the systematic review. Transient elastography (TE) as a modality was studied in five studies, MR elastography (MRE) in two, contrast CT in two, Contrast CT and MRI in two, and ARFI in only one. Both TE and MRE showed a significantly lower liver stiffness measurement and a higher splenic stiffness measurement with a higher SSM/LSM ratio with PSVD, compared to cirrhosis. Among the radiological features, focal nodular hyperplasia-like lesions, portal vein abnormalities (intrahepatic and extrahepatic), and a larger spleen size favored a diagnosis of PSVD. In contrast, surface nodularity and atrophy of segment IV with a segment I hypertrophy favored a diagnosis of cirrhosis.

CONCLUSION

Elastography and cross-sectional imaging can help differentiate PSVD from early cirrhosis with good accuracy. Further studies are required to assess the diagnostic role of a combination of both modalities.

Splenic-hepatic elastography index is useful in differentiating between porto-sinusoidal vascular disease and cirrhosis in patients with portal hypertension

INTRODUCTION

In patients with portal hypertension (PH), the differential diagnosis between porto-sinusoidal vascular disease (PSVD) and cirrhosis is challenging. This study aims to evaluate the diagnostic accuracy of the SSM/LSM index in the diagnosis of PSVD.

METHODS

Prospective study of patients with PH and PSVD or cirrhosis. Transient liver and spleen elastography were performed and the ratio between spleen stiffness measurement (SSM) and liver stiffness measurement (LSM) was calculated. The relation of SSM/LSM with the diagnosis of PSVD was evaluated.

RESULTS

Forty-four patients with PSVD and 44 patients with cirrhosis were evaluated. Median age was 57.5 (IQR 49.0-64.5) years, 66.3% were males. In patients with PSVD, median SSM was 59.4 (33.5-77.7) kPa, median LSM was 6.2 (5.2-10.2) kPa and median SSM/LSM was 5.62 (3.15-9.68). In patients with cirrhosis, median SSM was 47.3 (24.3-60.3) kPa, median LSM was 27.8 (17.7-53.9) kPa and median SSM/LSM was 1.55 (1.06-3.24). The SSM/LSM AUROC was 0.940 (p<0.001). Using 2 as a cut-off, we obtained good sensitivity (86.5%), specificity (92.7%), and accuracy (89.7%) for the diagnosis of PSVD.

CONCLUSION

The SSM/LSM index is useful in the differential diagnosis between liver cirrhosis and PSVD. Using the cut-off of 2 we achieved a good sensitivity and specificity for diagnosing PSVD.

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.

Liver Stiffness by Transient Elastography to Detect Porto-Sinusoidal Vascular Liver Disease With Portal Hypertension

BACKGROUND AND AIMS

Porto-sinusoidal vascular liver disease (PSVD) is a rare cause of portal hypertension. PSVD is still often misdiagnosed as cirrhosis, emphasizing the need to improve PSVD diagnosis strategies. Data on liver stiffness measurement using transient elastography (TE-LSM) in PSVD are limited. The aim of this study was to evaluate the accuracy of TE-LSM to discriminate PSVD from cirrhosis in patients with signs of portal hypertension.

APPROACH AND RESULTS

Retrospective multicenter study comparing TE-LSM in patients with PSVD, according to Vascular Liver Disease Interest Group criteria, with patients with compensated biopsy-proven cirrhosis associated with alcohol (n = 117), HCV infection (n = 110), or NAFLD (n = 46). All patients had at least one sign of portal hypertension among gastroesophageal varices, splenomegaly, portosystemic collaterals, history of ascites, or platelet count < 150 × 10⁹ /L. The 77 patients with PSVD included in the test cohort had lower median TE-LSM (7.9 kPa) than the patients with alcohol-associated, HCV-related, and NAFLD-related cirrhosis (33.8, 18.2, and 33.6 kPa, respectively; P < 0.001). When compared with cirrhosis, a cutoff value of 10 kPa had a specificity of 97% for the diagnosis of PSVD with a 85% positive predictive value. A cutoff value of 20 kPa had a sensitivity of 94% for ruling out PSVD with a 97% negative predictive value. Of the patients, 94% were well-classified. Even better results were obtained in a validation cohort including 78 patients with PSVD.

CONCLUSIONS

This study including a total of 155 patients with PSVD and 273 patients with cirrhosis demonstrates that TE-LSM < 10 kPa strongly suggests PSVD in patients with signs of portal hypertension. Conversely, when TE-LSM is >20 kPa, PSVD is highly unlikely.

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.

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.

Liver stiffness measurement in patients with nodular regenerative hyperplasia undergoing magnetic resonance elastography

PURPOSE

Nodular regenerative hyperplasia (NRH) may mimic cirrhosis at imaging. We aim to investigate the effect of NRH on liver stiffness measurement (LSM) obtained with magnetic resonance elastography (MRE).

METHODS

This retrospective, Institutional Review Board-approved study included 37 subjects with NRH (Group 1) and no or minimal fibrosis (F0-F1), a control group (Group 2) made of 30 subjects with non-advanced fibrosis (F0-F2), and a control group (Group 3) made of 30 subjects with advanced fibrosis (F3-F4), all with available MRE. LSM was measured in each subject along with assessment of hepatic morphological features of cirrhosis and signs of portal hypertension. The significance of the difference in mean LSM between Group 1 and 2 and between Group 1 and 3 was evaluated using the Mann-Whitney U test. The difference in distribution of imaging features among groups was assessed using the Pearson χ2 or Fisher exact test.

RESULTS

The mean ± SD LSM in Group 1 (3.56 ± 1.10 kPa) was significantly higher compared to Group 2 (2.91 ± 0.52 kPa, P = 0.019) and significantly lower compared to Group 3 (7.18 ± 2.08 kPa, P < 0.001). Twelve (32%) patients with NRH had LSM ≥ 4.11 kPa, and 6 (16%) patients had LSM ≥ 4.71 kPa. Surface nodularity (P = 0.032) and caudate lobe hypertrophy (P = 0.004) were more commonly visualized in Group 1 than in Group 2. At least one feature of portal hypertension was observed in 16 (43%) NRH subjects.

CONCLUSION

NRH may increase the LSM obtained with MRE and may represent a confounding factor when using liver stiffness for the non-invasive diagnosis of fibrosis.

TIPSS for variceal bleeding in patients with idiopathic non-cirrhotic portal hypertension: comparison with patients who have cirrhosis

BACKGROUND

In patients with idiopathic non-cirrhotic portal hypertension (INCPH), the usual recommended strategy for management of variceal bleeding is the same as that in cirrhosis. However, this policy has been challenged by the different natural history between INCPH and cirrhosis.

AIM

To compare outcomes after transjugular intrahepatic portosystemic shunt (TIPSS) between INCPH and cirrhotic patients admitted for variceal bleeding.

METHODS

Between March 2001 and September 2015, 76 consecutive patients with biopsy-proven INCPH undergoing TIPSS for variceal bleeding in a tertiary-care centre were included. 76 patients with cirrhotic portal hypertension receiving TIPSS for variceal bleeding, and matched for age, sex, Child-Pugh class, stent type and index year of TIPSS creation served as controls.

RESULTS

Patients with INCPH, compared to those with cirrhosis, had significantly lower mortality (11% vs 36% at 5 years, adjusted HR, 0.37; 95% CI 0.15-0.87, P = 0.022), overt hepatic encephalopathy (16% vs 33% at 5 years, adjusted HR, 0.35; 95% CI 0.16-0.75, P = 0.007) and hepatic impairment, despite similar rates of further bleeding (33% vs 32% at 5 years, adjusted HR, 0.72; 95% CI 0.36-1.44, P = 0.358), and shunt dysfunction (35% vs 36% at 5 years, adjusted HR, 0.84; 95% CI 0.41-1.72, P = 0.627). These findings were consistent across different relevant subgroups.

CONCLUSIONS

Patients with INCPH treated with TIPSS for variceal bleeding had similar progression of portal hypertension (further bleeding and shunt dysfunction) but fewer complications of liver disease (overt hepatic encephalopathy and hepatic insufficiency) and lower mortality rate compared with cirrhotic patients with comparable liver function.