Porto-sinusoidal Vascular Disease Research Articles

Application of liver biopsy in etiological diagnosis of unexplained portal hypertension: Porto-sinusoidal vascular disease should not be ignored.

The diagnostic value of liver biopsy has been confirmed in patients with abnormal liver test results; however, little data are available on its application in patients with portal hypertension. This study aimed to investigate the utility of liver biopsy for the etiological diagnosis of unexplained portal hypertension, and explore the clinical and pathological characteristics of each etiology. A retrospective observational analysis was conducted on 1367 patients who underwent liver biopsy at the Second Hospital of Nanjing from 2017 to 2019. Of these, 188 patients with unexplained portal hypertension were enrolled. The clinical and pathological characteristics were collected and reassessed in a multidisciplinary team meeting. Among these patients, 174 (92.6%, 174/188) had a definite etiological diagnosis through liver biopsy. The main etiologies were autoimmune hepatitis in 47 patients (25%, 47/188), autoimmune hepatitis-primary biliary cirrhosis overlap syndrome in 41 patients (21.8%, 41/188), and porto-sinusoidal vascular disease (PSVD) in 40 patients (21.3%, 40/188). Compared to liver cirrhosis, PSVD patients were younger and the liver function damage of which was subtler. The widths of portal vein diameter were widest in PSVD but the liver stiffness measurement were almost normal. Splenomegaly was common in PSVD, but ascites were less frequent than in autoimmune hepatitis (25.0% vs 51.1%, P = .013). Based on the histological patterns, we found that cholestatic liver diseases such as primary biliary cirrhosis, autoimmune hepatitis-primary biliary cirrhosis overlap syndrome, and progressive familial intrahepatic cholestasis could lead to non-cirrhotic portal hypertension, while vascular liver diseases such as PSVD and Budd-Chiari syndrome could also show fibrous proliferation as the disease progresses. Liver biopsy is safe and valuable for etiological diagnosis of unexplained portal hypertension. Cirrhosis is the leading cause of portal hypertension, and porto-sinusoidal vascular diseases should also be considered. Clinical features may be helpful in suggesting the cause; however, pathological examination is still indispensable for disease diagnosis and progression assessment.

Porto-Sinusoidal Vascular Disease: A New Nomenclature Different from Idiopathic Non-Cirrhotic Portal Hypertension.

Porto-sinusoidal vascular disease (PSVD) as a novel clinical conception was modified on the basis of idiopathic non-cirrhotic portal hypertension (INCPH). This study aimed to compare the clinical, biochemical histological features and prognosis between the diagnostic criteria for PSVD and that of INCPH. A total of 65 patients who underwent liver biopsies were analyzed retrospectively. The clinical, pathological and prognosis date were reviewed and screened according to the latest diagnostic criteria of PSVD and INCPH. A total of 65 patients were diagnosed with PSVD, of which 31 (47.69%) also fulfilled INCPH criteria. Specific histological and specific clinical portal hypertension (PH) signs were found in 34 (52.31%) and 30 (46.15%) of the patients, respectively. PSVD patients showed higher LSM levels (11.45 (6.38, 18.08) vs. 7.90 (6.70, 13.00), p = 0.039) than the INCPH patients. INCPH patients had a higher cumulative incidence of liver-related complications than the PSVD patients (86.95% vs. 35.71%, log-rank p < 0.001). Novel PSVD criteria facilitate early diagnosis. PSVD patients with other liver diseases may have higher LSM values. Disease progression and survival outcomes are correlated with PH in PSVD patients.

Plea to radiologists: Please consider Mahvash disease when encountering an enlarged pancreas.

Radiologists play a key role in establishing an early and accurate diagnosis, especially for rare diseases. Mahvash disease (OMIM 619290) is an autosomal recessive hereditary disease caused by inactivating mutations of the glucagon receptor and its main clinical consequences are pancreatic neuroendocrine tumors and in some cases, porto-sinusoidal vascular disease and portal hypertension. Untreated Mahvash disease can be lethal. The diagnosis of Mahvash disease has almost always been delayed in the past due to radiologists' unawareness of or unfamiliarity with the unique imaging features of Mahvash disease which are moderately to enormously enlarge pancreas with preserved pancreas contour and parenchyma without vascular involvement or lymphadenopathy. These features help differentiate Mahvash disease from other etiologies of diffusely enlarged pancreas such as diffuse pancreatic ductal carcinoma, diffuse pancreatic lymphoma, and autoimmune pancreatitis. Invoking Mahvash disease in the differential diagnosis of an enlarged pancreas has recently been shown to facilitate early diagnosis. To prevent missing the diagnosis of this significant disease, I sincerely ask radiologists to consider Mahvash disease in their differential diagnoses of diffusely enlarged pancreas.

Clinical characteristics and natural history of porto-sinusoidal vascular disease: A cohort study of 234 patients in China.

Porto-sinusoidal vascular disease (PSVD) is an under-recognized and under-diagnosed disease. The purpose of this study was to investigate the clinical features and prognosis of PSVD. The patients who underwent liver biopsies were analyzed retrospectively. The clinical and pathological data were reviewed and screened according to the latest diagnostic criteria of PSVD. A total of 234 patients were diagnosed as PSVD, including 103 patients presented with portal hypertension (PH) and 131 patients without PH. At baseline, the alanine aminotransferase (ALT) and γ-glutamyl transpeptidase (GGT) levels were higher in the no-PH group. The liver stiffness increased in the PH group. In histological review, obliterative portal venopathy, sinusoidal dilatation and architectural disturbance were more common in the PH group, while portal tract abnormalities were more widely distributed in the no-PH group. After a median follow-up of 43.6 months, the survival rate of patients with baseline liver decompensation was 76.0%, and that of patients at a liver compensated stage in the PH group was 98.7%. First variceal bleeding occurred in 13.8% of patients with gastric-oesophageal varices. None of the patients in the no-PH group developed portal hypertension during follow-up. PSVD can manifest as PH or mild liver enzyme abnormalities. There are significant differences in pathological features among patients with different clinical manifestations. Recurrent ascites are the main cause of death in PSVD patients. However, patients without PH have a slow disease progression, with recurrent elevated GGT levels being their main clinical feature.

Clinicopathological features of Sjogren's syndrome complicated with liver injury

Objective: To study the clinicopathological features of Sjogren's syndrome (SS) with liver injury and to improve the understanding of this disease. Methods: Forty-nine patients with SS complicated with liver injury were collected from Beijing Ditan Hospital, Capital Medical University from October 2008 to January 2022. All patients underwent ultrasound-guided liver biopsy, and all specimens were stained with HE. The histopathologic characteristics were observed and the pathologic indexes were graded. Immunohistochemical stains for CK7, CK19, CD38, MUM1 and CD10 were performed by EnVision method; and special histochemical stains for reticulin, Masson's trichrome, Rhodanine, Prussian blue, periodic acid Schiff (PAS) and D-PAS stains were conducted. Results: The age of patients ranged from 31 to 66 years, including 3 males and 46 females. SS combined with drug-induced liver injury was the most common (22 cases, 44.9%), followed by autoimmune liver disease (13 cases, 26.5%, including primary biliary cholangitis in eight cases, autoimmune hepatitis in 3 cases, and PBC-AIH overlap syndrome in 2 cases), non-alcoholic fatty liver disease (NAFLD, 9 cases, 18.4%) and other lesions (5 cases, 10.2%; including 3 cases of nonspecific liver inflammation, 1 case of liver amyloidosis, and 1 case of porto-sinusoidal vascular disease). Among them, 28 cases (57.1%) were associated with obvious interlobular bile duct injury, mainly in SS combined with PBC group and drug-induced liver injury group. Twenty-three cases (46.9%) were associated with hepatocyte steatosis of varying degrees. In SS with autoimmune liver disease group, ISHAK score, degree of fibrosis bile duct injury, bile duct remodeling, lymphocyte infiltration of portal area, and plasma cell infiltration, MUM1 and CD38 expression; serum ALP and GGT, IgM; elevated globulin; positive AMA, proportion of AMA-M2 positive and IgM positive were all significantly higher than those in other groups(all P<0.05). Serum ALT, direct bilirubin and SSA positive ratio in SS combined with drug liver group were significantly higher than those in other groups(all P<0.05). The serum total cholesterol level in SS combined with PBC group (P=0.006) and NALFD group (P=0.011) were significantly higher than those in other groups (P<0.05). Conclusions: The pathologic manifestations of SS patients with liver injury are varied. The inflammatory lesions of SS patients with autoimmune liver disease are the most serious, and the inflammatory lesions of SS patients with non-alcoholic fatty liver disease and non-specific inflammation are mild. Comprehensive analysis of liver histopathologic changes and laboratory findings is helpful for the diagnosis of SS complicated with different types of liver injury.

Protocolo diagnóstico de la afectación hepática en las enfermedades autoinmunes sistémicas

Systemic autoimmune diseases are conditions in which there is an alteration of the immune system that is chronic and with multisystemic involvement. Due to its central role in metabolism, the liver is often affected to varying degrees. There are different mechanisms that can explain this involvement. First, immune dysregulation itself can lead to direct liver toxicity (antibody formation, T cell-mediated injury), as well as the development of primary liver disease (autoimmune hepatitis, primary biliary cholangitis). Second, patients with autoimmune diseases can develop different forms of hepatic vascular involvement such as porto-sinusoidal vascular disease, sinusoidal obstruction syndrome, Budd-Chiari syndrome, or the onset of hepatic ischemia within vasculitis. Finally, the drugs used in the treatment of systemic autoimmune disease can produce hepatotoxicity through different mechanisms, some of which are not fully known.

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

Background and aimsPortosinusoidal 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...

Pre-emptive transjugular intrahepatic portosystemic shunt in pediatric cystic fibrosis-related liver disease and portal hypertension: prospective long-term results.

Portal hypertension (PHT) and its sequelae are the most clinically important manifestations in cystic fibrosis-related liver disease (CFLD). This paper aimed to evaluate the safety and efficacy of a pre-emptive transjugular intrahepatic portosystemic shunt (TIPS) to prevent PHT-related complications in pediatric patients with CFLD. This was a prospective single-arm study on pediatric patients with CFLD, signs of PHT, and preserved liver function who underwent a pre-emptive TIPS in a single tertiary CF center between 2007 and 2012. The long-term safety and clinical efficacy were assessed. A pre-emptive TIPS was performed on seven patients with a mean age of 9.2 years (± standard deviation: 2.2). The procedure was technically successful in all patients, with an estimated median primary patency of 10.7 years [interquartile range (IQR) 0.5-10.7)]. No variceal bleeding was observed during the median follow-up of 9 years (IQR 8.1-12.9). In two patients with advanced PHT and rapidly progressive liver disease, severe thrombocytopenia could not be stopped. Subsequent liver transplantation revealed biliary cirrhosis in both patients. In the remaining patients with early PHT and milder porto-sinusoidal vascular disease, symptomatic hypersplenism did not occur, and liver function remained stable until the end of the follow-up. Inclusion for pre-emptive TIPS was discontinued in 2013 following an episode of severe hepatic encephalopathy. TIPS is a feasible treatment with encouraging long-term primary patency to avoid variceal bleeding in selected patients with CF and PHT. However, as the progression of liver fibrosis, thrombocytopenia, and splenomegaly is inevitable, the clinical benefits due to pre-emptive placement appear to be minor.

Liver Transplantation in a Woman with Mahvash Disease

SummaryMahvash disease is an exceedingly rare genetic disorder of glucagon signaling characterized by hyperglucagonemia, hyperaminoacidemia, and pancreatic α-cell hyperplasia. Although there is no known definitive treatment, octreotide has been used to decrease systemic glucagon levels. We describe a woman who presented to our medical center after three episodes of small-volume hematemesis. She was found to have hyperglucagonemia and pancreatic hypertrophy with genetically confirmed Mahvash disease and also had evidence of portal hypertension (recurrent portosystemic encephalopathy and variceal hemorrhage) in the absence of cirrhosis. These findings established a diagnosis of portosinusoidal vascular disease, a presinusoidal type of portal hypertension previously known as noncirrhotic portal hypertension. Liver transplantation was followed by normalization of serum glucagon and ammonia levels, reversal of pancreatic hypertrophy, and resolution of recurrent encephalopathy and bleeding varices.

Liver disease in germline mutations of telomere-related genes: Prevalence, clinical, radiological, pathological features, outcome, and risk factors.

Germline mutations of telomere-related genes (TRG) induce multiorgan dysfunction, and liver-specific manifestations have not been clearly outlined. We aimed to describe TRG mutations-associated liver diseases. Retrospective multicenter analysis of liver disease (transaminases > 30 IU/L and/or abnormal liver imaging) in patients with TRG mutations. Main measurements were characteristics, outcomes, and risk factors of liver disease in a TRG mutations cohort. The prevalence of liver disease was compared to a community-based control group (n = 1190) stratified for age and matched 1:3 for known risk factors of liver disease. Among 132 patients with TRG mutations, 95 (72%) had liver disease, with associated lung, blood, skin, rheumatological, and ophthalmological TRG diseases in 82%, 77%, 55%, 39%, and 30% of cases, respectively. Liver biopsy was performed in 52/95 patients, identifying porto-sinusoidal vascular disease in 48% and advanced fibrosis/cirrhosis in 15%. After a follow-up of 21 months (12-54), ascites, hepato-pulmonary syndrome, variceal bleeding, and HCC occurred in 14%, 13%, 13%, and 2% of cases, respectively. Five-year liver transplantation-free survival was 69%. A FIB-4 score ≥ 3·25 and ≥1 risk factor for cirrhosis were associated with poor liver transplantation-free survival. Liver disease was more frequent in patients with TRG mutations than in the paired control group [80/396, (20%)], OR 12.9 (CI 95%: 7.8-21.3, p < 0.001). TRG mutations significantly increase the risk of developing liver disease. Although symptoms may be mild, they may be associated with severe disease. Porto-sinusoidal vascular disease and cirrhosis were the most frequent lesions, suggesting that the mechanism of action is multifactorial.

A case of porto-sinusoidal vascular disease

Introduction: Porto-sinusoidal vascular syndrome is characterised by specific histological changes that do not include cirrhosis, with or without portal hypertension. Patients are usually asymptomatic until development of portal hypertension complications. Case description: A 69-year-old female with history of JAK2 positive essential thrombocythemia (ET) was referred to internal medicine consultation due to elevated liver enzymes. The patient had no previous history of liver disease. Seven months earlier, she had an ischaemic stroke and started treatment with atorvastatin. After discontinuing medication, liver enzymes returned to normal and atorvastatin-related drug-induced liver disease (DILI) was presumed. During a follow-up visit, iron deficiency anaemia was detected and an endoscopic study was performed. It revealed a gastric varix actively bleeding, which was successfully treated with cyanoacrylate. Two months later, the patient was admitted due to a new episode of variceal bleeding, and a portal hypertension complementary study was made. Discussion: Although the pathogenesis of porto-sinusoidal vascular disease (PSVD) remains poorly understood, vascular changes within the liver have been associated with several predisposing conditions, such as hypercoagulable states. Patients with ET, especially those with JAK2 mutation, are known to be at increased risk of non-cirrhotic vein thrombosis. Concerning PSVD, the association is not clear but it is believed that both PSVD and myeloproliferative neoplasms share a common denominator: a state characterised by hypercoagulability, inflammation, endothelial dysfunction and, in some cases, portal hypertension. Conclusion: Portal hypertension without cirrhosis is a rare condition, presenting diagnostic challenges and significant impact on the patient’s prognosis.

The non-invasive evaluation of liver involvement in patients with cystic fibrosis: A prospective study.

Porto-sinusoidal vascular disease (PSVD) has been described as the prominent pathology in liver explants of patients with cystic fibrosis (CF), but data outside the transplant setting are lacking. We aimed to investigate the prevalence of portal hypertension (PH) in CF-associated liver disease (CFLD) and develop an algorithm to classify liver involvement in CF patients. This is a cross-sectional study of consecutive paediatric and adult patients in a tertiary centre between 2018 and 2019, who underwent ultrasound, liver (LSM) and spleen stiffness (SSM) measurement. CFLD was defined according to physical examination, liver tests and ultrasound findings. PSVD was likely if there were PH signs in the absence of advanced chronic liver disease (CF-ACLD, LSM <10 kPa). A historical cohort was used to validate the prognostic significance of the new definitions. Fifty (27.5%) patients met CFLD criteria. At least one sign of PH was found in 47 (26%) patients, but most (81%) had LSM <10 kPa and were likely to have PSVD; only 9 (5%) had CF-ACLD. PSVD and CFLD (LSM <10 kPa) co-existed in most (23/36) cases. In the historical cohort (n = 599 patients), likely PSVD and CFLD+PH were independently associated with a 2-fold and 3.5-fold increase in mortality compared to patients without PH, respectively. In 34 patients with SSM, values <21 and >50 kPa accurately diagnosed specific signs of PH. PSVD is the prevailing cause of PH in CF patients. We developed a new diagnostic algorithm based on clinical and elastosonography criteria to classify liver involvement in patients with CF.

Diagnostic performance of transient elastography in differentiation between porto-sinusoidal vascular liver disease and compensated cirrhosis.

The efficacy of transient elastography (TE) in the differential diagnosis between porto-sinusoidal vascular disease (PSVD) and compensated cirrhosis has not been sufficiently studied. We aimed to investigate the diagnostic performance of TE and identify histological lesions associated with liver stiffness. We conducted a retrospective cohort study including patients with PSVD and cirrhosis (Child-Turcotte-Pugh class A) and healthy subjects. Both the PSVD and cirrhotic patients had at least one sign of PH. The area under the receiver operating characteristic curve (AUROC) was used for differentiation. Ninety-two patients with PSVD (median age: 53 years, 33% male), 100 patients with compensated cirrhosis and 101 healthy subjects were included. The median TE-LSM in the PSVD patients (10.0 [7.0-13.0] kPa) was significantly lower than that in the cirrhotic patients (21.0 [15.0-28.0] kPa, p < .001) but was significantly higher than that in the healthy subjects (5.1 [4.6-6.0] kPa, p < .001). The AUROCs of TE-LSM for the discrimination of PSVD from the cirrhosis and healthy subjects were 0.886 (95% CI: 0.833-0.928) and 0.913 (95% CI: 0.864-0.949), respectively. The sensitivity and specificity to discriminate PSVD from compensated cirrhosis were 78.3% and 82.0%, respectively, at a cut-off of 13.6 kPa. Furthermore, portal fibrosis and aberrant cytokeratin 7 expression of centrilobular hepatocytes were significantly associated with higher TE-LSM (≥10.0 kPa). TE-LSM can be used to differentiate PSVD from compensated cirrhosis. Pathological features in association with increased liver stiffness are identified.

Porto-sinusoidal Vascular Disease: What Radiologists Should Know

Porto-sinusoidal vascular disease (PSVD) is a rare hepatic vascular disorder that can cause portal hypertension. Its diagnosis can be challenging, as its clinical manifestations can overlap with those of liver cirrhosis. However, radiological imaging can provide valuable clues to differentiate PSVD from liver cirrhosis. This review aims to identify imaging findings that suggest PSVD in cross-sectional imaging and ultrasound elastography, enabling the suggestion of a liver biopsy that is essential for diagnosis of PSVD.

Application of ultrasonography-elastography score to suspect porto-sinusoidal vascular disease in patients with portal vein thrombosis

BackgroundPorto-sinusoidal vascular disease (PSVD) and portal vein thrombosis (PVT) are causes of portal hypertension characterized respectively by an intrahepatic and a pre-hepatic obstacle to the flow in the portal system. As PVT may be a consequence of PSVD, in PVT patients at presentation, a pre-existing PSVD should be suspected. In these patients the identification of an underlying PSVD would have relevant implication regarding follow-up and therapeutic management, but it could be challenging. In this setting ultrasonography may be valuable in differential diagnosis. The aim of the study was to use ultrasonography to identify parameters to discriminate between PSVD and “pure” PVT and then to suspect PVT secondary to a pre-existing PSVD. MethodsFifty-three patients with histologically proven PSVD and forty-eight patients affected by chronic PVT were enrolled and submitted to abdominal ultrasonography with elastography by acoustic radiation force impulse (ARFI). ResultsARFI was higher and superior mesenteric vein (SMV) diameter was wider in PSVD patients than in PVT patients. Thus, a prognostic score was obtained as linear combinations of the two parameters with a good discrimination capacity between PSVD and PVT (the area under the curve = 0.780; 95% confidence interval: 0.690-0.869). ConclusionsA score based on ARFI and SMV diameter may be useful to suspect an underlying PSVD in patients with PVT and to identify a subgroup of patients to be submitted to liver biopsy.

SAT-542 - Coagulation profile in adult patients with porto-sinusoidal vascular disease

SAT-542 - Coagulation profile in adult patients with porto-sinusoidal vascular disease

THU-323 - Role of gut-derived endotoxins in porto-sinusoidal vascular disease

THU-323 - Role of gut-derived endotoxins in porto-sinusoidal vascular disease

THU-285 - Clinical features, histology and outcome of pediatric porto-sinusoidal vascular disease

THU-285 - Clinical features, histology and outcome of pediatric porto-sinusoidal vascular disease

Azathioprine-induced porto-sinusoidal vascular disease complicated with esophageal varices in Crohn's disease patient - Case report.

Journal Article Accepted manuscript Azathioprine-induced porto-sinusoidal vascular disease complicated with esophageal varices in Crohn’s disease patient – Case report Get access Tomotaka Yazaki, Tomotaka Yazaki Department of Internal Medicine II, Shimane University Faculty of Medicine 89-1 Enya-cho, Izumo, Shimane 693-8501, JapanDivision of Hepatology, Shimane University Hospital 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan Search for other works by this author on: Oxford Academic PubMed Google Scholar Kousaku Kawashima, Kousaku Kawashima Department of Internal Medicine II, Shimane University Faculty of Medicine 89-1 Enya-cho, Izumo, Shimane 693-8501, JapanInflammatory Bowel Disease Center, Shimane University Hospital 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan Address for correspondence: Kousaku Kawashima, MD, PhD, Department of Internal Medicine II, Shimane University Faculty of Medicine, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan, Tel: +81-853-20-2190; Fax: +81-853-20-2187, Email: kk461223@med.shimane-u.ac.jp https://orcid.org/0000-0002-5815-0066 Search for other works by this author on: Oxford Academic PubMed Google Scholar Shunji Ishihara Shunji Ishihara Department of Internal Medicine II, Shimane University Faculty of Medicine 89-1 Enya-cho, Izumo, Shimane 693-8501, JapanInflammatory Bowel Disease Center, Shimane University Hospital 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Crohn's and Colitis, jjad066, https://doi.org/10.1093/ecco-jcc/jjad066 Published: 17 April 2023 Article history Received: 13 March 2023 Published: 17 April 2023

Portal vein thrombosis, hepatic decompensation, and survival in patients with porto-sinusoidal vascular disease and portal hypertension.

Porto-sinusoidal vascular disease (PSVD) is a novel nomenclature to describe non-cirrhotic portal hypertension and characteristic histology without portal vein thrombosis (PVT). It is a more inclusive definition than the previously well-recognized entity idiopathic non-cirrhotic portal hypertension. There is a paucity of data on PSVD patients. A total of 33 patients diagnosed with PSVD and portal hypertension (PH) between 2005 and 2021 were included. Data were retrieved from electronic medical record system and analyzed. Of the 33 patients, 6 (18%) occurred in post-transplant allograft liver. After a median follow-up of 96months (interquartile range, IQR [52, 139]), 14 deaths occurred (42%), 4 directly related to decompensated liver disease. The Kaplan-Meier survival estimates at 1, 5, and 10years were 94%, 87% and 58%. PVT occurred in 10 patients (30%). The Nelson-Aalen cumulative risk estimate for PVT at 1, 5 and 10years were 16%, 25% and 48%. The median model for end-stage liver disease and Child-Pugh score at initial presentation were 8 (IQR [7-12]) and 5 [5-6], and increased to 13 [8, 18] and 7 [5, 8], respectively, at the end of follow-up. Of the 11 patients who presented with splenomegaly and no specific sign of PH, 7 (64%) developed varices and 3 (27%) ascites at a median follow-up of 100months. PSVD with PH is not a benign entity. Mortality, PVT and hepatic decompensation are common. Patients with PSVD must be closely monitored, including those who only have non-specific clinical signs (e.g., splenomegaly) of PH.