Pyrrolizidine alkaloids-induced hepatic sinusoidal obstruction syndrome: Pathogenesis, clinical manifestations, diagnosis, treatment, and outcomes

Histological evaluation of pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome: Correlation with Drum Tower Severity Scoring

BACKGROUND

Hepatic sinusoidal obstruction syndrome induced by pyrrolizidine alkaloids (PA-HSOS) is a complication of drug-induced liver damage. Few studies have examined the relationship between pathological changes and clinical circumstances in PA-HSOS. The Drum Tower Severity Scoring System (DTSS) was developed using prognostic indicators from clinical treatment outcomes. We hypothesized that the severity of pathological damage is consistent with DTSS.

AIMS

We aimed to improve our understanding and assessment of vascular liver injury disease histopathology by studying larger sample sizes of human histopathological samples. We also wanted to confirm the link between histopathological findings and DTSS.

METHODS

The study included 62 patients with PA-HSOS who underwent transjugular liver biopsy. Their hepatic pathological tissues were evaluated. Analyses of linear regression and Spearman's correlation were employed to examine the relationship between DTSS and pathological characteristics.

RESULTS

Clinical performance and the DTSS score were used to determine histopathological severity. The sinusoidal congestion area (SCA), central venous endothelial injury (CVEI), and fibrinoid exudation in congestion foci (FECF) were significant indicators. SCA was linearly related to the DTSS score.

CONCLUSION

Our findings show that hepatic pathological characteristics correlate with DTSS scores in PA-HSOS. SCA, CVEI, and FECF may be helpful for determining PA-HSOS severity.

Chinese guideline for the diagnosis and treatment of drug-induced liver injury: an update

Drug-induced liver injury (DILI) is an important adverse drug reaction that can lead to acute liver failure or even death in severe cases. Currently, the diagnosis of DILI still follows the strategy of exclusion. Therefore, a detailed history taking and a thorough and careful exclusion of other potential causes of liver injury is the key to correct diagnosis. This guideline was developed based on evidence-based medicine provided by the latest research advances and aims to provide professional guidance to clinicians on how to identify suspected DILI timely and standardize the diagnosis and management in clinical practice. Based on the clinical settings in China, the guideline also specifically focused on DILI in chronic liver disease, drug-induced viral hepatitis reactivation, common causing agents of DILI (herbal and dietary supplements, anti-tuberculosis drugs, and antineoplastic drugs), and signal of DILI in clinical trials and its assessment.

Gynura segetum induces hepatic sinusoidal obstruction syndrome in a child: A case report

RATIONALE

Hepatic sinusoidal obstruction syndrome (HSOS), which includes hepatic stasis and portal hypertension, is a rare vascular disorder of the liver. It is often associated with hematopoietic stem cell transplantation. It is also possible to treat this disease using Chinese herbal medicines that contain pyrrolizidine alkaloids (PAs). This disease is extremely rare in children and poses a serious threat to their health. To our knowledge, this is the first case of HSOS in a child with PAs.

PATIENT CONCERNS

We report a 4-year-old boy suffering from abdominal pain, hepatomegaly, massive ascites, elevated liver enzyme level, and severe portal hypertension as a result of the consumption of Gynura segetum (also known as Tusanqi in Chinese, a traditional herbal medicine containing PAs).

DIAGNOSES

The child was finally diagnosed with PA-HSOS based on pathological diagnosis and imaging examination.

INTERVENTION

With active symptomatic and supportive care and sequential anticoagulation therapy, the abdominal distension and liver function improved in the patient.

OUTCOMES

The patient was eventually recovered. The levels of liver enzymes, hemoglobin, and bilirubin were normal, and the international normalized ratio fluctuated between 2.0 and 3.0 during 1-year follow-up after discharge.

LESSONS

This case report emphasizes the prevention of Chinese herb-induced liver injury in children and the importance of active long-term sequential anticoagulant therapy to reduce the progressive damage of PA-HSOS in the liver.

Anticoagulant therapy likely increases risk of bleeding in Gynura segetum-induced hepatic sinus obstruction syndrome

This study aimed to analyze the clinical characteristics of Gynura segetum (Tusanqi)-induced hepatic sinusoidal obstruction syndrome (HSOS) and the benefits and risks of anticoagulant therapy for Tusanqi-induced HSOS. This was a retrospective analysis of 49 patients with Tusanqi-induced HSOS who were treated with anticoagulation or standard therapy between July 2006 and December 2022. Clinical manifestations included abdominal pain (n = 47) and peritoneal or pleural effusion (n = 46); 2 patients died. Nineteen patients requested standard medical treatment, while 30 were treated with anticoagulants. HSOS resolved within 6 months in 22 patients but did not resolve in 27 patients. The resolution rate was higher in the anticoagulant than standard treatment group (P = .037). Logistic regression analysis revealed that a history of chronic liver disease or treatment increased the risk of poor outcomes. Bleeding complications occurred in 6 patients in the anticoagulant treatment group. Early diagnosis and anticoagulant treatment are beneficial for rapid recovery after Tusanqi-induced HSOS. However, anticoagulant treatment is associated with the risk of multisite bleeding.

Diagnosis, toxicological mechanism, and detoxification for hepatotoxicity induced by pyrrolizidine alkaloids from herbal medicines or other plants

Pyrrolizidine alkaloids (PAs) are one type of phytotoxins distributed in various plants, including many medicinal herbs. Many organs might suffer injuries from the intake of PAs, and the liver is the most susceptible one. The diagnosis, toxicological mechanism, and detoxification of PAs-induced hepatotoxicity have been studied for several decades, which is of great significance for its prevention, diagnosis, and therapy. When the liver was exposed to PAs, liver sinusoidal endothelial cells (LSECs) loss, hemorrhage, liver parenchymal cells death, nodular regeneration, Kupffer cells activation, and fibrogenesis occurred. These pathological changes classified the PAs-induced liver injury as acute, sub-acute, and chronic type. PAs metabolic activation, mitochondria injury, glutathione (GSH) depletion, inflammation, and LSECs damage-induced activation of the coagulation system were well recognized to play critical roles in the pathological process of PAs-induced hepatotoxicity. A lot of natural compounds like glycyrrhizic acid, (-)-epicatechin, quercetin, baicalein, chlorogenic acid, and so on were demonstrated to be effective in alleviating PAs-induced liver injury, which rendered them huge potential to be developed into therapeutic drugs for PAs poisoning in clinics. This review presents updated information about the diagnosis, toxicological mechanism, and detoxification studies on PAs-induced hepatotoxicity.

Primary Budd-Chiari syndrome versus sinusoidal obstruction syndrome: a review

Budd-Chiari syndrome (BCS) and sinusoidal obstruction syndrome (SOS) are two major vascular disorders of the liver, of which both can cause portal hypertension related complications, but their locations of obstruction are different. BCS refers to the obstruction from the hepatic vein to the junction between the inferior vena cava and right atrium, which is the major etiology of post-sinusoidal portal hypertension; by comparison, SOS is characterized as the obstruction at the level of hepatic sinusoids and terminal venulae, which is a cause of sinusoidal portal hypertension. Both of them can cause hepatic congestion with life-threatening complications, especially acute liver failure and chronic portal hypertension, and share some similar features in terms of imaging and clinical presentations, but they have heterogeneous risk factors, management strategy, and prognosis. Herein, this paper reviews the current evidence and then summarizes the difference between primary BCS and SOS in terms of risk factors, clinical features, diagnosis, and treatment.

Analysis of potential risks of clinical application of Yi Dian Hong and its proprietary Chinese medicines: A review

Yi Dian Hong, belonging to the Asteraceae family, finds widespread use in traditional Chinese medicine for its effectiveness in clearing heat, detoxifying, promoting blood circulation, reducing swelling, and cooling the blood. Modern medical research has revealed that Yi Dian Hong and its proprietary Chinese medicines possess biological functions such as inhibiting tumor-specific angiogenesis and regulating immune-related molecules. However, studies have identified that the primary component of Yi Dian Hong contains pyrrolizidine alkaloids (PAs), a toxic substance with potential risks to the liver, lungs, genes, and a propensity for carcinogenicity. Many countries impose strict controls on the content of PAs in herbal medicines and products. Unfortunately, China currently lacks relevant content standards, thereby introducing greater clinical application risks. To ensure the safety of clinical use of Yi Dian Hong, this review will analyze the risk associated with Yi Dian Hong and its proprietary Chinese medicines in clinical applications based on the PAs content in these medicines and provide recommendations.

Transjugular intrahepatic portosystemic shunt for the treatment of hepatic sinusoidal obstruction syndrome caused by pyrrolizidine alkaloids: A multicenter retrospective study

Purpose

To assess the impact of transjugular intrahepatic portosystemic shunt (TIPS) on clinical outcomes and liver histology in patients with hepatic sinusoidal obstruction syndrome (HSOS) caused by pyrrolizidine alkaloids (PA), and compare these results with those of patients who received supportive treatment alone.

Materials and methods

From June 2015 to August 2022, 164 patients diagnosed with PA-HSOS in six tertiary care centers were retrospectively included in this study and divided into TIPS group (n = 69) and supportive treatment (ST) group (n = 95). The main endpoint was to determine whether TIPS placement could improve survival in PA-HSOS patients. The clinical symptoms associated with portal hypertension were also evaluated in this study. Additionally, a small TIPS-subgroup of 7 patients received liver biopsies before and after TIPS for histological analysis.

Results

The incidence of death was markedly lower in the TIPS group than in the ST group (log-rank p = 0.026). Multivariate Cox model revealed that group assignment (hazard ratio (HR) 5.146; 95 % confidence interval (CI) 1.587-16.687; p = 0.006), total bilirubin (HR 1.029; 95 % CI 1.020-1.038; p < 0.001), and INR (HR 13.291; 95 % CI 3.637-48.566; p < 0.001) were independent predictors for mortality. In addition, TIPS placement reduced the risk of complications associated with portal hypertension but did not increase the rate of overt hepatic encephalopathy (log-rank p = 0.731). Furthermore, six of 7 TIPS patients receiving liver biopsies improved after TIPS placement, and one patient developed fibrosis.

Conclusions

TIPS placement decreased the mortality and risk of complications associated with portal hypertension. Histological evaluation in a few patients showed a potential improvement by TIPS.

Rifaximin Prevents Intestinal Barrier Dysfunction and Alleviates Liver Injury in MCT-induced HSOS Mice

OBJECTIVE

Rifaximin is an effective component of treatment strategies for liver and intestinal diseases. However, the efficacy of rifaximin in hepatic sinusoidal obstruction syndrome (HSOS) has not been explored. The present study aimed to investigate the efficacy and mechanism of rifaximin in HSOS.

METHODS

An HSOS model was established in mice through the administration of monocrotaline (MCT, 800 mg/kg), and part of the HSOS mice were intragastrically administered with rifaximin. Then, the efficacy of rifaximin in HSOS was evaluated based on the liver pathological findings, liver proinflammatory cytokines, and alanine aminotransferase and aspartate aminotransferase levels. The Ussing chamber was used to evaluate the intestinal permeability, and tight junction (TJ) proteins were measured by Western blotting and real-time polymerase chain reaction to evaluate the intestinal barrier integrity. Then, the serum proinflammatory cytokine levels were evaluated by enzyme-linked immunosorbent assay. Afterwards, an in vitro experiment was performed to determine the relationship between rifaximin and TJ proteins.

RESULTS

Rifaximin effectively alleviated the MCT-induced HSOS liver injury, suppressed the expression of liver proinflammatory cytokines, and reduced the serum levels of tumor necrosis factor-alpha and interleukin-6. Furthermore, rifaximin reduced the intestinal permeability, improved the intestinal barrier integrity, and promoted the expression of TJ proteins.

CONCLUSION

The results revealed that the intestinal barrier integrity was destroyed in MCT-induced HSOS. The significant alleviation of MCT-induced HSOS induced by rifaximin might be correlated to the repairment of intestinal barrier integrity via the regulation of the TJ protein expression.

Andrographolide attenuated MCT-induced HSOS via regulating NRF2-initiated mitochondrial biogenesis and antioxidant response

Hepatic sinusoidal obstruction syndrome (HSOS) is a death-dealing liver disease with a fatality rate of up to 67%. In the study present, we explored the efficacy of andrographolide (Andro), a diterpene lactone from Andrographis Herba, in ameliorating the monocrotaline (MCT)-induced HSOS and the underlying mechanism. The alleviation of Andro on MCT-induced rats HSOS was proved by biochemical index detection, electron microscope observation, and liver histological evaluation. Detection of hepatic ATP content, mitochondrial DNA (mtDNA) copy number, and protein expression of nuclear respiratory factor-1 (NRF1) and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PPARGC1A) demonstrated that Andro strengthened mitochondrial biogenesis in livers from MCT-treated rats. Chromatin immunoprecipitation assay exhibited that Andro enhanced the occupation of nuclear factor erythroid 2-related factor 2 (NFE2L2, also known as NRF2) in the promoter regions of both PPARGC1A and NRF1. Andro also activated the NRF2-dependent anti-oxidative response and alleviated liver oxidative injury. In Nrf2 knock-out mice, MCT induced more severe liver damage, and Andro showed no alleviation in it. Furthermore, the Andro-activated mitochondrial biogenesis and anti-oxidative response were reduced in Nrf2 knock-out mice. Contrastingly, knocking out Kelch-like ECH-associated protein 1 (Keap1), a NRF2 repressor, reduced MCT-induced liver damage. Results from co-immunoprecipitation, molecular docking analysis, biotin-Andro pull-down, cellular thermal shift assay, and surface plasmon resonance assay showed that Andro hindered the NRF2-KEAP1 interaction via directly binding to KEAP1. In conclusion, our results revealed that NRF2-dependent liver mitochondrial biogenesis and anti-oxidative response were essential for the Andro-provided alleviation of the MCT-induced HSOS. Graphical Headlights: 1. Andro alleviated MCT-induced HSOS via activating antioxidative response and promoting mitochondrial biogenesis. 2. Andro-activated antioxidative response and mitochondrial biogenesis were NRF2-dependent. 3. Andro activated NRF2 via binding to KEAP1.

Transjugular intrahepatic portosystemic shunt for pyrrolidine alkaloids-induced hepatic sinusoidal obstruction syndrome: a retrospective cohort study

BACKGROUND

This study aimed to investigate the efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) in the treatment of patients with pyrrolidine alkaloids-induced hepatic sinusoidal obstruction syndrome (PA-HSOS).

METHODS

Patients diagnosed with PA-HSOS and treated in Ningbo No.2 Hospital between November 2017 and October 2022 were enlisted in this retrospective cohort study.

RESULTS

This cohort comprised a total of 22 patients with PA-HSOS, of which 12 patients received TIPS treatment and 10 patients experienced conservative treatment. The median follow-up duration was 10.5 months. Baseline characteristics existed with no significant difference between the two groups. No operation failures or any TIPS-associated intraoperative complications were observed after TIPS. In the TIPS group, the portal venous pressure was substantially decreased from 25.3 ± 6.3 mmHg to 14.4 ± 3.5 mmHg after TIPS ( P  = 0.002). Compared with preoperative, the ascites after TIPS were significantly subsided ( P  = 0.001) and there existed a considerable decrease in Child-Pugh score. At the end of follow-up, 5 patients died, involving 1 in the TIPS group and 4 in the conservative treatment group. The median survival time was 13 (3-28) months in the TIPS group and 6.5 (1-49) months in the conservative treatment group, respectively. The survival analysis demonstrated that the total survival time of TIPS group was longer than that of the conservative treatment group, no statistical significance was observed ( P  = 0.08).

CONCLUSION

TIPS may be a secure and effective therapeutic strategy for PA-HSOS patients who do not respond to conservative treatment.

Prognostic risk factors for patients with hepatic sinusoidal obstruction syndrome caused by pyrrolizidine alkaloids

Pyrrolizidine alkaloids induced hepatic sinusoidal obstruction syndrome (PA-HSOS) often occurs after consuming herbs or a dietary supplement containing the plant Tu-San-Qi. Limited data exists to identify patients with fatal outcomes for early interventions. We aimed to analyze the predictors for 3-month survival. We retrospectively enrolled PA-HSOS patients in 5 hospitals and extracted data from the onset of PA-HSOS to 36 months. Outcome measurements were 3-month and 36-month survival rates, baseline prognostic predictors for survival, and the effects of anticoagulant therapy. Among 49 enrollees, the median age was 60 and 49% male. At the onset of PA-HSOS, patients with Child-Turcotte-Pugh (CTP) class of A, B, or C were 8.2% (4/49), 42.8% (21/49) and 49.0% (24/49), respectively. None of them received a transjugular intrahepatic portosystemic shunt or a liver transplant. The 3-month and 36-month survival rates were 86% and 76%, respectively. Compared to the CTP class A or B, class C at baseline independently predicted lower survival rates at both 3 and 36 months. However, anticoagulation therapy treatment within the first 3 months independently predicted significantly higher survival rates at both time points. CTP class C and anticoagulant therapy were the independent predictors for short-term and long-term survival. Anticoagulant therapy could decrease mortality rate of CTP class C patients. The greatest benefit of anticoagulant evaluated by 3-month survival rate was in patients with CTP class C compared with those without treatment (93% vs 40%, P = .009). There were no bleeding complications reported in patients treated with the anticoagulant.

Gut microbiota-derived tryptophan metabolites alleviate liver injury via AhR/Nrf2 activation in pyrrolizidine alkaloids-induced sinusoidal obstruction syndrome

BACKGROUND AND AIMS

Hepatic sinusoidal obstruction syndrome (HSOS) is caused by toxic injury, such as pyrrolizidine alkaloids, to the liver sinusoidal endothelial cells, and the gut microbiota may be involved. However, the specific role and underlying mechanism of gut microbiota in HSOS is unknown.

METHODS

HSOS model was established by gavage of monocrotaline (MCT) in rats. Fecal microbiota transplantation (FMT) with HSOS-derived or healthy gut flora was also conducted to validate the role of gut microflora in MCT-induced liver injury. The microbial 16 s rRNA analysis and untargeted metabolomics analysis in the faeces were performed to identify HSOS-related flora and metabolites. Finally, by supplementation with specific tryptophan metabolites, such as indole-3-acetaldehyde (IAAld) and indole acetic acid (IAA), we further confirmed the role of tryptophan metabolism in HSOS and the role of the AhR/Nrf2 pathway in MCT-induced liver injury.

RESULTS

MCT induced HSOS-like liver injury in rats with significantly altered gut microbiota. Particularly, some tryptophan-metabolizing bacteria reduced in MCT-treated rats, such as Bacteroides, Bifidobacterium, Lactobacillus and Clostridium, and accompanied by a decrease in microbial tryptophan metabolic activity and a series of tryptophan derivatives. Restoring the gut microbiota via FMT improved MCT-induced liver damage, while HSOS-derived gut microbiota aggravated the liver injury induced by MCT. Supplementation with microbial tryptophan derivatives (IAAld or IAA), or 6-formylindolo(3,2-b)carbazole (Ficz, an AhR agonist) could activate the AhR/Nrf2 signaling pathway, thereby attenuating the MCT-induced liver oxidative stress and liver sinusoidal endothelial cells injury.

CONCLUSIONS

Gut microbiota plays a critical role in MCT-induced HSOS, with inadequate microbial tryptophan metabolism in the gut and consequently a lower activity of the AhR/Nrf2 signaling pathway in the liver, which should be a potential target for the management of HSOS.

Clinicopathological characteristics and diagnosis of hepatic sinusoidal obstruction syndrome caused by Tusanqi - Case report and literature review

Tusanqi-induced hepatic sinusoidal obstruction syndrome (HSOS) is caused by exposure to pyrrolizidine alkaloids (PAs) and manifests as abdominal distension, liver pain, ascites, jaundice, and hepatomegaly. Pathologically, hepatic congestion and sinusoidal occlusion are observed in HSOS. We summarized the clinical characteristics of 124 patients with HSOS caused by Tusanqi in China between 1980 and 2019, along with those of 831 patients from seven English case series. The main clinical manifestations of PA-HSOS included abdominal pain, ascites, and jaundice. Common imaging features included characteristic heterogeneous density, slender hepatic veins, and other nonspecific changes. The acute stage is primarily manifested as hepatic sinus congestion and necrosis. Meanwhile, the persistence of hepatic sinus congestion and the onset of perisinusoidal fibrosis were observed during the repair stage. Finally, the persistence of hepatic sinusoidal fibrosis and resultant central hepatic vein occlusion were observed in the chronic stage. The new Nanjing standard for PA-HSOS incorporates the history of PA consumption and imaging features and eliminates weight gain and the serum total bilirubin value. Preliminary clinical validation of the Nanjing standard for PA-HSOS diagnosis revealed a sensitivity and specificity of 95.35 and 100%, respectively.

Chromatographic Methods for Detection and Quantification of Pyrrolizidine Alkaloids in Flora, Herbal Medicines, and Food: An Overview

Pyrrolizidine alkaloids (PAs) are natural toxins produced by some plants that gained special interest due to their potential hazardous effects in humans and animals. These substances have been found in wild flora, herbal medicines and food products raising health concerns. Recently, maximum concentration levels of PAs were established for some food products; however, maximum daily intake frequently surpasses the upper limit set by the competent authorities posing a health risk. Given the scarcity or absence of occurrence data on PAs in many products, there is an urgent need to measure their levels and establish safety intake levels. Analytical methods have been reported to detect and quantify PAs in different matrices. The commonly used chromatographic methodologies provides accurate and reliable results. Analytical methods include diverse steps as extraction and sample preparation procedures that are critical for sensitivity and selectivity of the analytical method. Great efforts have been directed toward optimization of extraction procedures, clean up and chromatographic conditions to improve recovery, reduce matrix effects, and achieve low limits of detection and quantification. Therefore, this paper aims to give a general overview about the occurrence of PAs in flora, herbal medicines, and foodstuff; and discuss the different chromatographic methodologies used for PAs analysis, namely extraction and sample preparation procedures and chromatographic conditions.

Transjugular Intrahepatic Portosystemic Shunt Benefits for Hepatic Sinusoidal Obstruction Syndrome Associated with Consumption of Gynura Segetum: a Propensity Score-Matched Analysis

PURPOSE

Pyrrolidine alkaloids-related hepatic sinusoidal obstruction syndrome (PA-HSOS) is associated with a high mortality rate without standardized therapy. The efficacy of transjugular intrahepatic portosystemic shunts (TIPS) remains controversial. The study aimed to explore the risk factors influencing the clinical response in patients with PA-HSOS related to Gynura segetum (GS) to assess the disease prognosis at an early stage and to evaluate the efficacy of TIPS in these patients.

METHODS

This study retrospectively enrolled patients diagnosed with PA-HSOS between January 2014 and June 2021 with a clear history of exposure to GS. Univariate and multivariate logistic regression analyses were used to evaluate the risk factors influencing the clinical response in patients with PA-HSOS. Propensity score matched (PSM) was performed to compensate for differences in baseline characteristics between patients with and without TIPS. The primary outcome was the clinical response defined as the disappearance of ascites with normal total bilirubin levels and/or a reduction of elevated transaminase levels < 50% within 2 weeks.

RESULTS

A total of 67 patients were identified in our cohort with a clinical response rate of 58.2%. Of these, thirteen patients were assigned to the TIPS group and 54 to the conservative treatment group. Logistic regression analysis revealed that TIPS treatment (P = 0.047), serum globulin levels (P = 0.043), and prothrombin time (P = 0.001) were independent factors influencing clinical response. After PSM, there was a higher long-term survival rate of patients (92.3% vs. 51.3%, P = 0.021) and a shorter hospital stay (P = 0.043), but a high trend in hospital costs (P = 0.070) in the TIPS group. The 6-month survival probability in patients undergoing TIPS therapy was more than ninefold higher than in patients without receiving that treatment [hazard ratio (95% CI) = 9.304 (4.250, 13.262), P < 0.05].

CONCLUSIONS

TIPS therapy may be an effective treatment option for patients with GS-related PA-HSOS.

Neonatal Hemochromatosis: Systematic Review of Prenatal Ultrasound Findings—Is There a Place for MRI in the Diagnostic Process?

Neonatal hemochromatosis (NH) is an uncommon, severe disorder that results in fetal loss or neonatal death due to liver failure. NH is currently regarded as the phenotypic expression of gestational alloimmune liver disease (GALD). The diagnosis of NH-GALD is rarely prenatally established. In addition to providing a systematic review of the prenatal features that are identifiable using ultrasound (US) and MRI, we suggest a prenatal diagnosis algorithm for use in suspected NH during the first affected pregnancy. From a total of 586 database entries identified in PubMed, Google Scholar, and ResearchGate, we selected 18 studies published from 1993 to 2021 that reported maternal medical and obstetric history, prenatal ultrasound findings, and postpartum outcomes. We investigated the ultrasound and MRI features of these studies, along with the outcome due to this condition. A total of 74 cases were identified. The main reported prenatal US finding was fetal growth restriction (FGR) (33%), followed by oligohydramnios (13%) and hydrops fetalis (13%), with 13% cases described as uneventful. Other rare prenatal findings were fetal anemia, ascites, and abnormal fetal liver and spleen. Most pregnancies ended with fetal/perinatal death or therapeutic interruption of pregnancy. Favorable evolution with treatment (ensanguine transfusion and intravenous immunoglobulin (IVIG)) was reported for only 7% of fetuses. Using T2-weighted MRI, fetal extrahepatic siderosis confirmed prenatally in two cases and postnatally in 11 cases. IVIG treatment throughout subsequent pregnancies was found to significantly improve fetal prognosis. MRI should be indicated in selected cases of oligohydramnios, fetal hydrops, fetal hepatomegaly, ascites, or unexplained FGR or anemia after ruling out all other more frequently encountered conditions. MRI can be used to detect iron overload in the liver and extrahepatic siderosis.

Mid- to long-term outcomes of initial transjugular intrahepatic portosystemic shunt versus anticoagulation for pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome

BACKGROUND

Anticoagulation therapy (AT) is often used as the initial treatment for pyrrolizidine alkaloid (PA)-induced hepatic sinusoidal obstruction syndrome (HSOS). However, transjugular intrahepatic portosystemic shunt (TIPS) is an alternative treatment. This study aimed to determine the mid- to long-term outcomes of TIPS versus AT as the initial treatment for PA-induced HSOS.

METHODS

We retrospectively analyzed the clinical data of 61 patients with PA-induced HSOS that were collected between November 2015 and July 2021. The patients were allocated to the TIPS group ( n = 20) or the AT group ( n = 41). These two groups were divided into subgroups according to the severity grading. The clinical data of the patients in both groups were analyzed. Cumulative survival rates were calculated and compared between the two groups and among the subgroups.

RESULTS

The clinical symptoms and signs improved or stabilized in 100% of the patients following TIPS and in 85% of the patients following AT at discharge ( P = 0.166). The mortality rate was 0.0% in the TIPS group and 34.1% in the AT group ( P = 0.005). The patients were followed up for 2-69 months (mean, 26.3 ± 20.5 months). In the mild- and moderate-grade subgroups, there was no difference in the cumulative survival rate between the TIPS and AT groups ( P = 0.589 and P = 0.364, respectively). In the severe and very severe-grade subgroups, the cumulative survival rate was higher in the TIPS group than in the AT group ( P = 0.018 and P = 0.025, respectively).

CONCLUSION

AT is a suitable initial treatment for mild or moderate PA-induced HSOS, whereas TIPS should be considered the appropriate initial treatment for severe or very severe PA-induced HSOS.

Hepatic Venous Occlusion Type of Budd–Chiari Syndrome versus Pyrrolizidine Alkaloid-Induced Hepatic Sinusoidal Obstructive Syndrome: A Multi-Center Retrospective Study

(1) Background: Hepatic venous occlusion type of Budd–Chiari syndrome (BCS-HV) and pyrrolizidine alkaloid-induced hepatic sinusoidal obstructive syndrome (PA-HSOS), share similar clinical features, and imaging findings, leading to misdiagnoses; (2) Methods: We retrospectively analyzed 139 patients with BCS-HV and 257 with PA-HSOS admitted to six university-affiliated hospitals. We contrasted the two groups by clinical manifestations, laboratory tests, and imaging features for the most valuable distinguishing indicators.; (3) Results: The mean patient age in BCS-HV is younger than that in PA-HSOS (p < 0.05). In BCS-HV, the prevalence of hepatic vein collateral circulation of hepatic veins, enlarged caudate lobe of the liver, and early liver enhancement nodules were 73.90%, 47.70%, and 8.46%, respectively; none of the PA-HSOS patients exhibited these features (p < 0.05). DUS showed that 86.29% (107/124) of patients with BCS-HV showed occlusion of the hepatic vein, while CT or MRI showed that only 4.55%(5/110) patients had this manifestation (p < 0.001). Collateral circulation of hepatic veins was visible in 70.97% (88/124) of BCS-HV patients on DUS, while only 4.55% (5/110) were visible on CT or MRI (p < 0.001); (4) Conclusions: In addition to an established history of PA-containing plant exposure, local hepatic vein stenosis and the presence of collateral circulation of hepatic veins are the most important differential imaging features of these two diseases. However, these important imaging features may be missed by enhanced CT or MRI, leading to an incorrect diagnosis.

Enoxaparin attenuates pyrrolizidine alkaloids-induced hepatic sinusoidal obstruction syndrome by inhibiting oncostatin M expression

BACKGROUND AND AIMS

The definitive treatment for pyrrolizidine alkaloids (PAs)-induced hepatic sinusoidal obstruction syndrome (HSOS) is not available. The effectiveness of anticoagulation therapy remains controversial. The efficacy of low molecular weight heparin (LMWH) should be investigated in patients and animal models, and the underlying mechanism should be explored.

METHODS

The prognosis of patients with PAs-HSOS who received anticoagulation therapy was retrospectively analysed. The effect of enoxaparin on the liver injury was determined in animal models of monocrotaline (MCT)-induced HSOS was determined, and the underlying mechanism was investigated using a murine model.

RESULTS

The cumulative survival rate of patients with PAs-induced HSOS was 60.00% and 90.90% in the non-anticoagulation group and anticoagulation group. Enoxaparin attenuated liver injury effectively in a rat model of MCT-induced HSOS. Additionally, the improvement of severe liver injury was observed in MCT-treated mice after the administration of enoxaparin (40 mg/kg). The alleviation of liver injury was observed in mice with hepatocyte-specific deletion of oncostatin M (Osm^△Hep ). In MCT-treated mice administrated with enoxaparin, no significant differences in liver injury were observed between Osm^△Hep mice and Osm^flox/flox mice. Additionally, adenovirus-mediated overexpression of Osm resulted in severe liver injury in MCT-induced mice after the administration of enoxaparin.

CONCLUSIONS

LMWH attenuated severe liver injury in patients with PAs-Induced HSOS and animal models of MCT-induced HSOS, which provides a rationale for the application of anticoagulation therapy.

Transjugular intrahepatic portosystemic shunt for portal hypertension: 30 years experience from China

Liver diseases are a major cause of illness and death worldwide. In China, liver diseases, primarily viral hepatitis, affect approximately 300 million people, thus having a major impact on the global burden of liver diseases. Portal hypertension is the most severe complication of chronic liver diseases, including ascites, hepatic encephalopathy and bleeding from gastroesophageal varices. Transjugular intrahepatic portosystemic shunt (TIPS) represents a very effective treatment of these complications. Since its introduction 30 years ago in China, the use of TIPS has evolved and has played an increasingly important role in the management of the complications of portal hypertension. This review will focus on the history, current application and management of complications of TIPS in China.

Hepatic sinusoidal obstruction syndrome induced by tacrolimus following liver transplantation: Three case reports

BACKGROUND

Hepatic sinusoidal obstruction syndrome (HSOS) is a rare complication in solid organ transplant recipients, especially in liver transplantation recipients. However, the consequences of HSOS occurrence are pernicious, which could result in severe liver or renal failure, and even death. In addition to previously reported azathioprine and acute rejection, tacrolimus is also considered as one predisposing factor to induce HSOS after liver transplantation, although the underlying mechanism remains unclear.

CASE SUMMARY

In this study, we reported three cases of tacrolimus-related HSOS after liver transplantation. The diagnosis of HSOS was firstly based on the typical symptoms including ascites, painful hepatomegaly and jaundice. Furthermore, the features of patchy enhancement on portal vein and delayed phase of abdominal enhanced computed tomography were suspected of HSOS and ultimately confirmed by liver biopsy and histological examination in two patients. A significant decrease in ascites and remission of clinical symptoms of abdominal distention and pain were observed after withdrawal of tacrolimus.

CONCLUSION

Tacrolimus-induced HSOS is a scarce but severe complication after liver transplantation. It lacks specific symptoms and diagnostic criteria. Timely diagnosis of HSOS is based on clinical symptoms, radiological and histological examinations. Discontinuation of tacrolimus is the only effective treatment. Transplantation physicians should be aware of this rare complication potentially induced by tacrolimus.

Agreement between Wedged Hepatic Venous Pressure and Portal Pressure in Hepatic Sinusoidal Obstruction Syndrome

Background: Wedge hepatic vein pressure (WHVP) accurately estimates the portal pressure (PP) in chronic sinusoidal portal hypertension patients. Whether this applies to patients with acute portal hypertension due to hepatic sinusoidal obstruction syndrome (HSOS) is unclear. Our aim was to assess the agreement between WHVP and PP in patients with HSOS by comparing them to decompensated cirrhosis patients. Methods: From December 2013 to December 2021, patients with pyrrolidine alkaloid-induced HSOS (PA-HSOS) receiving hepatic venous pressure gradient (HVPG) measurement and transjugular intrahepatic portosystem shunt (TIPS) were retrospectively collected and matched with those of patients with virus- or alcohol-related cirrhosis as a cirrhosis group. Pearson’s correlation (R), intraclass correlation coefficient (ICC), scatter plots, and the Bland−Altman method were performed for agreement evaluation. Results: A total of 64 patients were analyzed (30 PA-HSOS and 34 cirrhosis groups). The correlation between WHVP and PP was moderate in the PA-HSOS group (R: 0.58, p = 0.001; ICC: 0.68, p = 0.002) but good in the cirrhosis group (R: 0.81, p < 0.001; ICC: 0.90, p < 0.001). The percentage of patients with inconsistent WHVP and PP in the two groups was 13 (43.3%) and 15 (26.5%) (p = 0.156), respectively, and an overestimation of PP was more common in the PA-HSOS group (33.3% vs. 2.9%, p = 0.004). HVPG and portal pressure gradient (PPG) consistency was poor in both groups (R: 0.51 vs. 0.26; ICC: 0.65 vs. 0.41; p < 0.05). Conclusions: WHVP in patients with PA-HSOS did not estimate PP as accurately as in patients with virus- or alcohol-related cirrhosis, which was mainly due to PP overestimation.

Effects of bicyclol on hepatic sinusoidal obstruction syndrome induced by Gynura segetum

BACKGROUND

The intake of Gynura segetum, a traditional Chinese medicine, may be induce hepatic sinusoidal obstruction syndrome (HSOS). It has a high mortality rate based on the severity of the disease and the absence of therapeutic effectiveness. Therefore, the current study was designed to investigate the effects of bicyclol on HSOS induced by Gynura segetum and the potential molecular mechanisms.

METHODS

Gynura segetum (30 g/kg) was administered for 4 weeks in the model group, while the bicyclol pretreatment group received bicyclol (200 mg/kg) administration. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholesterol (CHO), triglyceride (TG), and liver histological assays were detected to assess HSOS. The gene expressions of cytochrome P450 (CYP450) isozymes were quantified by real-time PCR. Moreover, hepatocellular apoptosis was detected using the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, then apoptosis and autophagy-related markers were determined using Western blot.

RESULTS

As a result, bicyclol pretreatment is notably protected against Gynura segetum-induced HSOS, as observed by reducing serum ALT levels, inhibiting the reduction in CHO and TG levels, and alleviating the histopathological changes. Bicyclol pretreatment inhibited the changes in mRNA levels of CYP450 isozymes (including the increase in CYP2a5 and decrease in CYP2b10, 2c29, 2c37, 3a11, and 7b1). In addition, the upregulation of Bcl-2 and the downregulation of LC3-II/LC3-I proteins expression in HSOS were inhibited with bicyclol pretreatment.

CONCLUSION

Bicyclol exerted a protective effect against HSOS induced by Gynura segetum, which could be attributed to the regulated expressions of CYP450 isozymes and alleviated the downregulation of autophagy.

Combined Hepatotoxicity and Toxicity Mechanism of Intermedine and Lycopsamine

Pyrrolizidine alkaloids (PAs) are common constituents of plants and have serious hepatotoxicity. Intermedine (Im) and lycopsamine (La) are two monoesters of PAs that frequently coexist in the PA-containing plants (e.g., comfrey and tea). The present study aimed to explore the combined hepatotoxicity and toxicity mechanism of the Im and La mixture. In vitro, the combined cytotoxicity of the Im and La mixture on human hepatocytes (HepD) was examined by CCK-8, colony formation, wound healing, and Annexin V/PI staining assays. The combination of Im and La inhibited the ability of HepD cells to proliferate, colonize, and migrate and induced hepatocytes apoptosis in a dose-dependent manner. In addition to significantly causing a burst of intracellular reactive oxygen species (ROS), mitochondrial apoptosis, and endoplasmic reticulum (ER) stress, the Im and La mixture can also cause an increase in intracellular Ca2+, triggering the PERK/eIF2α/ATF4/CHOP apoptosis pathway. This study provided the first direct evidence that the combined PAs induced hepatotoxicity through ER-mediated apoptosis. These results supplemented the basic toxicity data for the combined PAs and provided a new perspective for the risk assessment of combined PA toxicity.

Difference between type 2 gastroesophageal varices and isolated fundic varices in clinical profiles and portosystemic collaterals

BACKGROUND

There is significant heterogeneity between gastroesophageal varices (GOV2) and isolated gastric varices (IGV1). The data on the difference between GOV2 and IGV1 are limited.

AIM

To determine the etiology, clinical profiles, endoscopic findings, imaging signs, portosystemic collaterals in patients with GOV2 and IGV1.

METHODS

Medical records of 252 patients with gastric fundal varices were retrospectively collected, and computed tomography images were analyzed.

RESULTS

Significant differences in routine blood examination, Child–Pugh classification and MELD scores were found between GOV2 and IGV1. The incidence of peptic ulcers in patients with IGV1 (26.55%) was higher than that of GOV2 (11.01%), while portal hypertensive gastropathy was more commonly found in patients with GOV2 (22.02%) than in those with IGV1 (3.54%). Typical radiological signs of cirrhotic liver were more commonly observed in patients with GOV2 than in those with IGV1. In patients with GOV2, the main afferent vessels were via the left gastric vein (LGV) (97.94%) and short gastric vein (SGV) (39.18%). In patients with IGV1, the main afferent vessels were via the LGV (75.61%), SGV (63.41%) and posterior gastric vein (PGV) (43.90%). In IGV1 patients with pancreatic diseases, spleno-gastromental-superior mesenteric shunt (48.15%) was a major collateral vessel. In patients with fundic varices, the sizes of gastric/esophageal varices were positively correlated with afferent vessels (LGVs and PGVs) and efferent vessels (gastrorenal shunts). The size of the esophageal varices was negatively correlated with gastrorenal shunts in GOV2 patients.

CONCLUSION

Significant heterogeneity in the etiology and vascular changes between GOV2 and IGV1 is useful in making therapeutic decisions.

Development of a Drum Tower Severity Scoring (DTSS) system for pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome

BACKGROUND AND AIMS

There has been no reliable severity system based on the prognosis to guide therapeutic strategies for patients with pyrrolizidine alkaloid (PA)-induced hepatic sinusoidal obstruction syndrome (HSOS). We aimed to create a novel Drum Tower Severity Scoring (DTSS) system for these patients to guide therapy.

METHODS

172 Patients with PA-HSOS who received supportive care and anticoagulation therapy in Nanjing Drum Tower Hospital from January 2008 to December 2020 were enrolled and analyzed retrospectively. These patients were randomized into a training or validation set in a 3:1 ratio. Next, we established and validated the newly developed DTSS system.

RESULTS

Analysis identified a predictive formula: logit (P) = 0.004 × aspartate aminotransferase (AST, U/L) + 0.019 × total bilirubin (TB, μmol/L) - 0.571 × fibrinogen (FIB, g/L) - 0.093 × peak portal vein velocity (PVV, cm/s) + 1.122. Next, we quantified the above variables to establish the DTSS system. For the training set, the area under the ROC curve (AUC) (n = 127) was 0.787 [95% confidence interval (CI) 0.706-0.868; p < 0.001]. With a lower cut-off value of 6.5, the sensitivity and negative predictive value for predicting no response to supportive care and anticoagulation therapy were 94.7% and 88.0%, respectively. When applying a high cut-off value of 10.5, the specificity was 92.9% and the positive predictive value was 78.3%. For the validation set, the system performed stable with an AUC of 0.808.

CONCLUSIONS

The DTSS system can predict the outcome of supportive care and anticoagulation in PA-HSOS patients with satisfactory accuracy by evaluating severity, and may have potential significance for guiding therapy.

1,2-Dehydropyrrolizidine Alkaloids: Their Potential as a Dietary Cause of Sporadic Motor Neuron Diseases

Sporadic motor neuron diseases (MNDs), such as amyotrophic lateral sclerosis (ALS), can be caused by spontaneous genetic mutations. However, many sporadic cases of ALS and other debilitating neurodegenerative diseases (NDDs) are believed to be caused by environmental factors, subject to considerable debate and requiring intensive research. A common pathology associated with MND development involves progressive mitochondrial dysfunction and oxidative stress in motor neurons and glial cells of the central nervous system (CNS), leading to apoptosis. Consequent degeneration of skeletal and respiratory muscle cells can lead to death from respiratory failure. A significant number of MND cases present with cancers and liver and lung pathology. This Perspective explores the possibility that MNDs could be caused by intermittent, low-level dietary exposure to 1,2-dehydropyrrolizidine alkaloids (1,2-dehydroPAs) that are increasingly recognized as contaminants of many foods consumed throughout the world. Nontoxic, per se, 1,2-dehydroPAs are metabolized, by particular cytochrome P450 (CYP450) isoforms, to 6,7-dihydropyrrolizines that react with nucleophilic groups (-NH, -SH, -OH) on DNA, proteins, and other vital biochemicals, such as glutathione. Many factors, including aging, gender, smoking, and alcohol consumption, influence CYP450 isoform activity in a range of tissues, including glial cells and neurons of the CNS. Activation of 1,2-dehydroPAs in CNS cells can be expected to cause gene mutations and oxidative stress, potentially leading to the development of MNDs and other NDDs. While relatively high dietary exposure to 1,2-dehydroPAs causes hepatic sinusoidal obstruction syndrome, pulmonary venoocclusive disease, neurotoxicity, and diverse cancers, this Perspective suggests that, at current intermittent, low levels of dietary exposure, neurotoxicity could become the primary pathology that develops over time in susceptible individuals, along with a tendency for some of them to also display liver and lung pathology and diverse cancers co-occurring with some MND/NDD cases. Targeted research is recommended to investigate this proposal.

Constructing vascularized hepatic tissue by cell-assembled viscous tissue sedimentation method and its application for vascular toxicity assessment

In vitro Construction of the liver sinusoidal structure using artificial tissue is an important but worthwhile challenge, particularly for assessing the risk of diseases such as sinusoidal obstruction syndrome (SOS). Current models are unsuitable for evaluating the toxicity because of lacking sinusoidal capillary. In this study, we developed a vascularized hepatic tissue (VHT) using a unique tissue engineering technique, the cell assembled viscous tissue by sedimentation (CAViTs) method. The "viscous bodies" created using the CAViTs method exhibited significant self-assembly within 6 h after seeding, promoting cell-cell interaction. The level of albumin secreted by the VHT was four times higher than that of 2D-coculture and maintained for 1 month. The gene expression pattern of the VHT was closer to that of total human liver, compared with the 2D system. Quantitative evaluations of the vascular structure of VHT treated with two typical SOS-inducing compounds, monocrotaline and retrorsine, revealed higher sensitivity (IC₅₀ = 40.35 µM), 19.92 times higher than the cell-viability assay. Thus, VHT represents an innovative in vitro model that mimics the vessel network structure and could become a useful tool for the early screening of compounds associated with a risk of vascular toxicity. STATEMENT OF SIGNIFICANCE: Mimicking sinusoidal structures in in vitro liver model is important to consider from the perspective of predicting hepatotoxicity such like sinusoidal obstruction syndrome (SOS). However, it was difficult to reconstruct the vascular structure within the hepatocyte-rich environment. In this study, we constructed a vascularized hepatic tissue in a high-throughput manner by a unique method using collagen and heparin, and evaluated its applicability to toxicity assessment. Vessel morphology analysis of the model treated by monocrotaline, which is a well-known SOS-inducing compound, could predict the toxicity with higher sensitivity. To the best of our knowledge, this is the first report to provide vascularized hepatic tissues using sinusoidal endothelial cells at least for demonstrating applicability to the evaluation of SOS induction risk.

Clinical Features and CT Imaging Analysis of Hepatic Sinuscase-Syndrome and Budd–Chiari Syndrome

Objective

This study aimed to analyze the clinical features and computed tomography (CT) manifestations of hepatic sinusoidal obstruction syndrome (HSOS) induced by Gynura segetum, a Chinese herbal medicine, so as to improve the clinical understanding and diagnosis of the disease.

Methods

Relevant clinical and laboratory parameters and CT imaging data of 20 patients with HSOS confirmed by liver biopsy were retrospectively analyzed and compared with 16 patients with Budd-Chiari syndrome (BCS).

Results

Levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and glutamyl transpeptidase increased significantly (p < 0.05) in HSOS patients compared to the BCS patients, while the albumin level and prothrombin time, which are indicators of liver synthesis function, decreased and prolonged significantly, respectively. All 20 patients with HSOS had manifestations of ascites and heterogeneous hypoattenuation on CT, including 18 cases (90%) with heterogeneous enhancement (characteristic map-like enhancement), 17 (85%) with hepatomegaly, 18 (90%) with gallbladder wall oedema, and 16 (80%) with stenosis of main hepatic veins and characteristic “clover-like” enhancement at the second porta hepatis.

Conclusion

Both HSOS and BCS are post-sinusoidal portal hypertension, but have different etiologies and durations. Although they both cause liver congestion, the clinical manifestation of HSOS is acute liver injury. The CT manifestations are characterized by ascites, map-like enhancement and heterogeneous hypoattenuation of the liver parenchyma, and stenosis of the main hepatic veins. BCS is often found in the stage of decompensated liver cirrhosis, resulting in liver shrinkage, splenomegaly, and ascites.

Herb-Induced Liver Injury—A Challenging Diagnosis

Herb-induced liver injury (HILI) can be caused by supplements containing herbs, natural products, and products used in traditional medicine. Herbal products’ most common adverse reaction is hepatotoxicity. Almost every plant part can be used to make herbal products, and these products can come in many different forms, such as teas, powders, oils, creams, capsules, and injectables. HILI incidence and prevalence are hard to estimate and vary from study to study because of insufficient large-scale prospective studies. The diagnosis of HILI is a challenging process that requires not only insight but also a high degree of suspicion by the clinician. HILI presents with unspecific symptoms and is a diagnosis of exclusion. For diagnosis, it is necessary to make a causality assessment; the Council for International Organizations of Medical Sciences assessment is the preferred method worldwide. The most effective treatment is the suspension of the use of the suspected herbal product and close monitoring of liver function. The objective of this review is to highlight the necessary steps for the clinician to follow to reach a correct diagnosis of herb-induced liver injury. Further studies of HILI are needed to better understand its complexity and prevent increased morbidity and mortality.

Hepatotoxicity of Pyrrolizidine Alkaloid Compound Intermedine: Comparison with Other Pyrrolizidine Alkaloids and Its Toxicological Mechanism

Pyrrolizidine alkaloids (PAs) are common secondary plant compounds with hepatotoxicity. The consumption of herbal medicines and herbal teas containing PAs is one of the main causes of hepatic sinusoidal obstruction syndrome (HSOS), a potentially life-threatening condition. The present study aimed to reveal the mechanism underlying the cytotoxicity of intermedine (Im), the main PA in Comfrey. We evaluated the toxicity of the retronecine-type PAs with different structures to cell lines derived from mammalian tissues, including primary mouse hepatocytes, human hepatocytes (HepD), mouse hepatoma-22 (H₂₂) and human hepatocellular carcinoma (HepG2) cells. The cytotoxicity of Im to hepatocyte was evaluated by using cell counting kit-8 assay, colony formation experiment, wound healing assay and dead/live fluorescence imaging. In vitro characterization showed that these PAs were cytotoxic and induced cell apoptosis in a dose-dependent manner. We also demonstrated that Im induced cell apoptosis by generating excessive reactive oxygen species (ROS), changing the mitochondrial membrane potential and releasing cytochrome c (Cyt c) before activating the caspase-3 pathway. Importantly, we directly observed the destruction of the cell mitochondrial structure after Im treatment through transmission electron microscopy (TEM). This study provided the first direct evidence of Im inducing hepatotoxicity through mitochondria-mediated apoptosis. These results supplemented the basic toxicity data of PAs and facilitated the comprehensive and systematic evaluation of the toxicity caused by PA compounds.

Timing and efficacy of transjugular intrahepatic portosystemic shunt in patients with pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome

There is no specific treatment for pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome (PA-HSOS). It is not clear when transjugular intrahepatic portosystemic shunt (TIPS) should be implemented in PA-HSOS patients. This study aimed to evaluate the timing of TIPS using total bilirubin (TBIL) as a measure, and to investigate efficacy of TIPS. We retrospectively analyzed the medical records of 10 PA-HSOS patients, among whom 4 patients had received TIPS (TIPS group), and the remaining patients were assigned to the internal medicine group. In the TIPS group, the TBIL level before TIPS was 84.4 ± 45.2 µmol/L (> 3 mg/dL), and TBIL levels were increased to different degrees after TIPS. With the extension of time, serum TBIL levels gradually decreased, and no liver failure occurred. With regards to the short-term outcomes, 3 patients recovered, 1 developed chronic illness and 0 died in the TIPS group. Moreover, 0 patients recovered, 5 developed chronic illness and 1 died in the internal medicine group. The rank sum test of group design revealed significant differences in clinical outcomes (P = 0.02). It was suggested that when the internal medicine effect of PA-HSOS patients is poor, TIPS should be considered, which is no trestricted to the limit of 3 mg/dL TBIL. It was also found TIPS effectively promote the recovery of liver function and reduce the occurrence of chronicity.

Pyrrolizidine Alkaloid-Induced Hepatotoxicity Associated with the Formation of Reactive Metabolite-Derived Pyrrole-Protein Adducts

Pyrrolizidine alkaloids (PAs) with 1,2-unsaturated necine base are hepatotoxic phytotoxins. Acute PA intoxication is initiated by the formation of adducts between PA-derived reactive pyrrolic metabolites with cellular proteins. The present study aimed to investigate the correlation between the formation of hepatic pyrrole-protein adducts and occurrence of PA-induced liver injury (PA-ILI), and to further explore the use of such adducts for rapidly screening the hepatotoxic potency of natural products which contain PAs. Aqueous extracts of Crotalaria sessiliflora (containing one PA: monocrotaline) and Gynura japonica (containing two PAs: senecionine and seneciphylline) were orally administered to rats at different doses for 24 h to investigate PA-ILI. Serum alanine aminotransferase (ALT) activity, hepatic glutathione (GSH) level, and liver histological changes of the treated rats were evaluated to assess the severity of PA-ILI. The levels of pyrrole-protein adducts formed in the rats' livers were determined by a well-established spectrophotometric method. The biological and histological results showed a dose-dependent hepatotoxicity with significantly different toxic severity among groups of rats treated with herbal extracts containing different PAs. Both serum ALT activity and the amount of hepatic pyrrole-protein adducts increased in a dose-dependent manner. Moreover, the elevation of ALT activity correlated well with the formation of hepatic pyrrole-protein adducts, regardless of the structures of different PAs. The findings revealed that the formation of hepatic pyrrole-protein adducts-which directly correlated with the elevation of serum ALT activity-was a common insult leading to PA-ILI, suggesting a potential for using pyrrole-protein adducts to screen hepatotoxicity and rank PA-containing natural products, which generally contain multiple PAs with different structures.

Metabolic Toxification of 1,2-Unsaturated Pyrrolizidine Alkaloids Causes Human Hepatic Sinusoidal Obstruction Syndrome: The Update

Saturated and unsaturated pyrrolizidine alkaloids (PAs) are present in more than 6000 plant species growing in countries all over the world. They have a typical heterocyclic structure in common, but differ in their potential toxicity, depending on the presence or absence of a double bond between C1 and C2. Fortunately, most plants contain saturated PAs without this double bond and are therefore not toxic for consumption by humans or animals. In a minority of plants, however, PAs with this double bond between C1 and C2 exhibit strong hepatotoxic, genotoxic, cytotoxic, neurotoxic, and tumorigenic potentials. If consumed in error and in large emouns, plants with 1,2-unsaturated PAs induce metabolic breaking-off of the double bonds of the unsaturated PAs, generating PA radicals that may trigger severe liver injury through a process involving microsomal P450 (CYP), with preference of its isoforms CYP 2A6, CYP 3A4, and CYP 3A5. This toxifying CYP-dependent conversion occurs primarily in the endoplasmic reticulum of the hepatocytes equivalent to the microsomal fraction. Toxified PAs injure the protein membranes of hepatocytes, and after passing their plasma membranes, more so the liver sinusoidal endothelial cells (LSECs), leading to life-threatening hepatic sinusoidal obstruction syndrome (HSOS). This injury is easily diagnosed by blood pyrrolizidine protein adducts, which are perfect diagnostic biomarkers, supporting causality evaluation using the updated RUCAM (Roussel Uclaf Causality Assessment Method). HSOS is clinically characterized by weight gain due to fluid accumulation (ascites, pleural effusion, and edema), and may lead to acute liver failure, liver transplantation, or death. In conclusion, plant-derived PAs with a double bond between C1 and C2 are potentially hepatotoxic after metabolic removal of the double bond, and may cause PA-HSOS with a potential lethal outcome, even if PA consumption is stopped.

Quantification of Usaramine and Its N-oxide Metabolite in Rat Plasma Using Liquid Chromatography-Tandem Mass Spectrometry

A sensitive, fast and robust liquid chromatography--tandem mass spectrometry (LC–MS-MS) method was developed and validated for the determination of usaramine (URM) and usaramine N-oxide (UNO) in rat plasma. The separation was conducted on an ACQUITY UPLC BEH C₁₈ Column (50 × 2.1 mm, 1.7 μm) and gradient eluted with mobile phase A (0.1% formic acid with 5 mM ammonium acetate in water) and B (0.1% formic acid in acetonitrile/methanol, 9/1, v/v). The method was linear over the range of 1–2,000 ng/mL for both analytes. The validated method was applied to investigate the pharmacokinetic behaviors and sex differences of URM and its N-oxide metabolite in rats. After intravenous administration of URM at 1 mg/kg, the AUC_0-t values for URM and UNO were 363 ± 65 and 172 ± 32 ng/mL*h in male rats, while 744 ± 122 and 30.7 ± 7.4 ng/mL*h in females, respectively. The clearance of URM was significantly higher in male rats than in females (2.77 ± 0.50 vs 1.35 ± 0.19 L/h/kg, P < 0.05). After oral administration of URM at 10 mg/kg, the AUC_0-t values of URM and UNO were 1,960 ± 208 and 1,637 ± 246 ng/mL*h in male rats, while 6,073 ± 488 and 300 ± 62 ng/mL*h in females, respectively. The oral bioavailability of URM in female rats (81.7%) was much higher than in males (54.0%). In conclusion, sex-based differences were observed in the pharmacokinetics, N-oxide metabolism and oral bioavailability of URM.

The Food Contaminants Pyrrolizidine Alkaloids Disturb Bile Acid Homeostasis Structure-Dependently in the Human Hepatoma Cell Line HepaRG

Pyrrolizidine alkaloids (PAs) are a group of secondary plant metabolites being contained in various plant species. The consumption of contaminated food can lead to acute intoxications in humans and exert severe hepatotoxicity. The development of jaundice and elevated bile acid concentrations in blood have been reported in acute human PA intoxication, indicating a connection between PA exposure and the induction of cholestasis. Additionally, it is considered that differences in toxicity of individual PAs is based on their individual chemical structures. Therefore, we aimed to elucidate the structure-dependent disturbance of bile acid homeostasis by PAs in the human hepatoma cell line HepaRG. A set of 14 different PAs, including representatives of all major structural characteristics, namely, the four different necine bases retronecine, heliotridine, otonecine and platynecine and different grades of esterification, was analyzed in regard to the expression of genes involved in bile acid synthesis, metabolism and transport. Additionally, intra- and extracellular bile acid levels were analyzed after PA treatment. In summary, our data show significant structure-dependent effects of PAs on bile acid homeostasis. Especially PAs of diester type caused the strongest dysregulation of expression of genes associated with cholestasis and led to a strong decrease of intra- and extracellular bile acid concentrations.

Hepatic sinusoidal obstruction syndrome caused by the ingestion of Gynura segetum in a patient with alcoholic cirrhosis: a case report

Hepatic sinusoidal obstruction syndrome (HSOS) is a rare hepatic vascular disorder characterized by intrahepatic congestion, liver injury, and post-sinusoidal portal hypertension, and it is frequently associated with hematopoietic stem cell transplantation. In this study, we observed a case of HSOS associated with the ingestion of Gynura segetum, a pyrrolizidine alkaloid (PA)-containing Chinese herb, in a patient with alcoholic cirrhosis. The patient was a 43-year-old man with chief complaints of physical asthenia and a loss of appetite for more than a month. The diagnosis of HSOS combined with alcoholic cirrhosis was confirmed via the histopathological examination of liver tissues. With proper supportive and symptomatic care and anticoagulation therapy using low-molecular-weight heparin, the patient’s condition was stabilized. Because of its nonspecific symptoms in the early stage and a lack of information about PA consumption, PA-induced HSOS (PA-HSOS) has been long neglected, especially in patients with underlying liver diseases. Early identification and intervention are critical for optimizing outcomes. Further efforts are needed to supervise the use of PA-containing herbal medicines and identify accurate biomarkers for PA-HSOS.

Pyrrolizidine alkaloids from the seeds of Scleropyrum wallichianum

Two new pyrrolizidine alkaloids, sclerwalins A and B (1 and 2), and one known 9-O-E-hydroxysenecioylretronecine (3) were first isolated from the seeds of Scleropyrum wallichianum. Their chemical structures were elucidated by extensive 1 D NMR and 2 D NMR (HSQC, HMBC, COSY, and ROESY), MS and IR spectra. Cytotoxicities of all isolates were evaluated against five human tumor cell lines (HL-60, A-549, SMMC-7721, MCF-7 and SW480).[Formula: see text].

Quantitative CT assessment by histogram and volume ratio in pyrrolizidines alkaloids-induced hepatic sinusoidal obstruction syndrome

OBJECTIVE

To quantitatively assess hypoattenuation volume ratio and hepatic parenchymal hypoattenuation on contrast enhanced computed tomography (CECT) in patients with pyrrolizidines alkaloids (PAs)-induced hepatic sinusoidal obstruction syndrome (HSOS), and evaluate the correlations of the CT-based quantitative values with clinical factors.

METHODS

Thirty-five patients with PAs-induced HSOS who underwent CECT were retrospectively enrolled. The ratio of hypoattenuation volume to total liver volume, and changes in damaged area-to-normal liver density ratio (ΔDR) derived from histogram on portal venous phase were quantitatively measured. Heterogeneous hypoattenuation (CT score) scored by hypoattenuation volume ratio and ΔDR were calculated. The correlation between imaging findings and clinical factors was analyzed using Pearson correlation test.

RESULTS

Liver function tests were abnormal in most patients, the mean Hounsfield unit (HU) of damaged area (58.68 ± 17.3) was significantly lower (P < 0.001) than the corresponding normal liver (82.27 ± 23.97). Heterogeneous hypoattenuation were mild in 13 patients (37 %), moderate in 16 patients (46 %), and severe in 6 patients (17 %). ΔDR derived from histogram was positively correlated (weakly to moderately) with total bilirubin (r = 0.341, P = 0.045), direct bilirubin (r = 0.385, P = 0.022), and alkaline phosphatase (r = 0.491, P = 0.003), while such correlation was not observed in hypoattenuation volume ratio. The severity of heterogeneous hypoattenuation scored by hypoattenuation volume ratio and ΔDR was positively correlated (weakly) with prothrombin time (r = 0.357, P = 0.035), international normalized ratio (r = 0.363, P = 0.032), alkaline phosphatase (r = 0.359, P = 0.034), and model for end-stage liver disease (MELD) score (r = 0.347, P = 0.041).

CONCLUSION

Heterogeneous hypoattenuation scored by volume ratio and ΔDR on CECT provides a non-invasive approach in evaluating the severity of PAs-induced HSOS.

Blood microRNA Signatures Serve as Potential Diagnostic Biomarkers for Hepatic Sinusoidal Obstruction Syndrome Caused by Gynura japonica Containing Pyrrolizidine Alkaloids

Background and Aims: The Gynura japonica-induced hepatic sinusoidal obstruction syndrome (HSOS) is closely related to pyrrolizidine alkaloids (PAs), and its prevalence has been increasing worldwide in recent years. However, no effective therapy for PA-induced HSOS in clinics is available, partially due to the failure of quick diagnosis. This study aims to identify blood microRNA (miRNA) signatures as potential biomarkers for PA-induced HSOS in clinics.

Methods: The microarray-based miRNA profiling was performed on blood samples of the discovery cohort, which consisted of nine patients with HSOS and nine healthy donors. Differentially expressed miRNAs were further confirmed using a validation cohort, which consisted of 20 independent patients with HSOS. In addition, the rat model was established through the oral administration of the total alkaloid extract from G. japonica to investigate the association of miRNA biomarkers with the progression of HSOS. Bioinformatic analyses, including GO and KEGG enrichment, receiver operating characteristics curve, and correlation analyses were conducted to evaluate the accuracy of the potential miRNA biomarkers.

Results: Three miRNAs, namely miR-148a-3p, miR-362-5p, and miR-194-5p, were overexpressed in patients and rats with PA-induced HSOS. These miRNAs were positively related to the severity of liver injury and displayed considerable diagnostic accuracy for patients with HSOS with areas under the curve over 0.87.

Conclusion: In summary, this study demonstrated that three miRNAs, hsa-miR-148a-3p, hsa-miR-362-5p, and hsa-miR-194-5p, might serve as potential biomarkers for PA-induced HSOS in clinics.

Risk factors of poor prognosis in patients with pyrrolidine alkaloid-induced hepatic sinusoidal obstruction syndrome after transjugular intrahepatic portosystemic shunt

AIMS

Transjugular intrahepatic portosystemic shunt (TIPS) is an effective method in treating patients with severe hepatic sinusoidal obstruction syndrome induced by pyrrolidine alkaloids (PA-HSOS). However, some patients still have poor postoperative prognosis. So, we aim to evaluate the predictors associated with poor outcomes in PA-HSOS patients receiving TIPS.

METHODS

Patients who were diagnosed as PA-HSOS and received TIPS in our hospital between January 2013 and April 2019 were reviewed retrospectively. Baseline information and clinical data were collected. The hazard ratios (HRs) of factors associated with poor prognosis were analyzed by Cox proportional hazard analysis. The Kaplan-Meier method was used to analyze and compare the cumulative incidence of the poor results and survival rate of patients.

RESULTS

During a median of 19.25-month follow-up, death occurred in 17 patients. We found that prothrombin time at baseline with an adjusted HR 1.110 (95% confidence interval 1.014-1.216, p = 0.024) and serum total bilirubin of 9 mg/dl 5 days after TIPS with an adjusted HR 1.114 (95% confidence interval 1.042-1.190, p = 0.001) were independent risk factors for death. The 1-year and 5-year survival rate were 86.2% and 82.1%, respectively. The 1-year survival rate in patients with prothrombin time > 17.85 s at baseline and serum total bilirubin > 9 mg/dl at 5 days after TIPS was significantly lower than that of patients below the corresponding threshold, respectively.

CONCLUSIONS

Prolonged prothrombin time at baseline and increased serum total bilirubin levels 5 days after TIPS are independent risk factors for predicting death after TIPS treatment in PA-HSOS patients.

Is sinusoidal obstructive syndrome a recurrent disease after liver transplantation? A case report

BACKGROUND

Sinusoidal obstructive syndrome (SOS) is a disease that damages hepatic sinusoidal endothelial cells, resulting in progressive occlusion and fibrosis of the lobular central vein and the occurrence of intrahepatic sinusoidal portal hypertension. However, SOS after liver transplantation (LT) is uncommon and potentially fatal. Here, we report a rare case of second-time recurrence of SOS after liver retransplantation (rLT).

CASE SUMMARY

A 22-year-old woman received a living donor LT due to SOS. Four years later, she developed abdominal distention and ascites with no apparent cause. She was diagnosed with recurrence of SOS and underwent rLT. But 2 mo post rLT, the patient suffered from aggravated jaundice and ascites again. She was diagnosed with second-time recurrence of SOS post-rLT according to computed tomography and liver pathology. After treatment with warfarin anticoagulation and immunosuppressant conversion, she gradually recovered with improvement of liver function and liver pathology. During the 17-mo follow-up period, she was in good condition with normal liver function and no ascites.

CONCLUSION

SOS can be a recurrent disease after LT, and autoimmune antibody and genetic sequencing should be screened before LT. For susceptible patients, anticoagulant drugs should be used for an extended period, and tacrolimus or other pathogenic agents should be avoided. Early diagnosis and treatment can improve the prognosis of patients and avoid graft failure or death.

Gynura segetum induces hepatic sinusoidal obstruction syndrome in mice by impairing autophagy

Purpose:

To investigate the underlying mechanism of hepatic sinusoidal obstruction syndrome (HSOS) induced by Gynura segetum by measuring autophagy in mouse models.

Methods:

The model group was administered G. segetum (30 g/kg/d) by gavage, while the normal control group was administered an equal volume of saline daily for five weeks. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic histopathological examinations, and Masson staining were performed to evaluate liver injury. Liver intercellular adhesion molecule-1 (ICAM-1) and P-selectin were evaluated by immunohistochemistry. Hepatocellular apoptosis was assessed using the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. Protein expression levels of autophagy markers were measured using Western blot analysis.

Results:

Gynura segetum was found to significantly induce liver injury compared with control mice, as evidenced by the increase of serum transaminases, a decrease in triglyceride levels, and histopathological changes in mice. Gynura segetum remarkably induced hepatocellular apoptosis and upregulated the expressions of ICAM-1 and P-selectin and also downregulated the protein expression levels of LC3, Atg12 and cytoplasmic polyadenylation element binding protein.

Conclusions:

Our results suggested that G. segetum induced liver injury with HSOS, and it was partly due to its ability to impair the autophagy pathway.

Prognostic factors for pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome: a multicenter study in China

Background

In China, one of the major causes of hepatic sinusoidal obstruction syndrome (HSOS) is the intake of herbals containing pyrrolizidine alkaloid (PA). However, prognostic factors for PA-induced HSOS are poorly understood. The aim of this study was to identify the independent prognostic factors for PA-induced HSOS using a multi-center study.

Methods

A total of 117 PA-induced HSOS patients were enrolled for data collection in three university hospitals from November 2003 to September 2018. Univariate and multivariate Cox proportional hazards analysis were used to determine prognostic factors for PA-induced HSOS.

Results

The median age of the PA-induced HSOS patients was 61 years (range, 21–88 years), and 64% of them were male. The survival rates at 1, 3, and 36 months were 89.71%, 72.60%, and 69.19%, respectively. Significant differences in prothrombin time (PT), international normalized ratio, total bilirubin, severity grading [new criteria for severity grading of hematopoietic stem cell transplantation (HSCT)-related HSOS in adults] were found between patients who survived and those who died. Univariate and multivariate survival analysis using Cox’s regression model demonstrated low serum albumin (<35 g/L), elevated serum urea (>8.2 mmol/L) and severe or very severe HSOS (European Society for Blood and Marrow Transplantation 2016 criteria) were independent prognostic factors of survival.

Conclusions

Serum albumin, serum urea, and severity grading were independent prognostic factors for patients with PA-induced HSOS, and can contribute to identifying potentially high-risk patients for early effective intervention.

Trial registration

ChiCTR-DRD-17010709 (www.chictr.org.cn).

Low molecular weight heparin in the treatment of pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome: five case reports

Hepatic sinusoidal obstruction syndrome (HSOS) can be caused by the intake of pyrrolizidine alkaloids (PAs). The disease has a high mortality rate, a poor prognosis and limited treatment options. Managing pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome (PA-HSOS) is a significant challenge for hepatologists. This case report describes five patients with PA-HSOS that were treated with low molecular weight heparin (LMWH) between 2014 and 2019. All five patients had a history of taking PA-containing herbal preparations before the onset of the disease. They all met the Nanjing diagnostic criteria and were diagnosed with PA-HSOS. Symptomatic treatment was administered to all five patients. In addition to symptomatic treatment, all five patients were treated with LMWH for approximately 8–21 days. After treatment, their ascites disappeared, symptoms improved and the hepatic venous blood flow had improved compared with before treatment. There was no obvious discomfort during the 6 months of follow-up. LMWH may play a useful role in the early treatment of PA-HSOS. Therefore, for patients in the early stages of PA-HSOS, in addition to symptomatic treatment, early anticoagulant intervention can be attempted to improve patient prognosis under close monitoring of coagulation.

Clinical characteristics, CT signs, and pathological findings of Pyrrolizidine alkaloids-induced sinusoidal obstructive syndrome: a retrospective study

BACKGROUND

One major etiology of hepatic sinusoidal obstruction syndrome (HSOS) in China is the intake of pyrrolizidine alkaloids (PAs). Since PAs-induced HSOS is a rare disease that has not been clearly characterized until now, the aim of this study was to investigate clinical characteristics, CT features, and pathological findings of PA-induced HSOS.

METHODS

This retrospective cohort study included 116 patients with PAs-induced HSOS and 68 patients with Budd-Chiari syndrome from Jan 2006 to Sep 2016. We collected medical records of the patients, and reviewed image features of CT, and analyzed pathological findings.

RESULTS

Common clinical manifestations of PAs-induced HSOS were abdominal distention (98.26%), ascites (100%), jaundice (52.94%), abdominal pain (36.36%). Abnormal liver function was observed in most of PAs-induced HSOS. On CT scan, common findings included: ascites, hepatomegaly, the thickening of gallbladder wall, pleural effusion, patchy liver enhancement, and heterogeneous hypoattenuation. Most of the patients had a low ascitic total protein (< 25 g/L) and a high SAAG (≥ 11.0 g/L). In acute stage, pathologic features were massive sinusoidal dilatation, sinusoidal congestion, the extravasation of erythrocytes, hepatocellular necrosis, the accumulation of macrophages, the deposition of hemosiderin. In subacute stage, complete loss of pericentral hepatocytes, sinusoidal dilatation, the deposition of pigment granules were observed.

CONCLUSIONS

The PAs-induced HSOS patients displayed distinct clinical characteristics, imaging features, and pathological findings, which provided some evidences for the diagnosis of PAs-induced HSOS.

TRIAL REGISTRATION

ChiCTR-DRD-17010709.