Sinusoidal obstruction syndrome

Hepatic veno-occlusive disease with asparaginase products: a review of cases reported to the FDA adverse event reporting system and published in the literature

Multiple asparaginase products have been approved by the United States (US) Food and Drug Administration (FDA) for the treatment of acute lymphoblastic leukemia in pediatric and adult patients. Hepatic veno-occlusive disease (VOD) is a potentially life-threatening disorder resulting from damage to the liver sinusoidal endothelial cells. To evaluate this safety concern with asparaginase (i.e. Asparlas, Oncaspar, Rylaze, and Erwinaze) use, we performed a postmarketing review of hepatic VOD reports retrieved from the FDA Adverse Event Reporting System database and literature with these four products. We identified 55 cases of hepatic VOD following exposure to asparaginase products. The median time to onset of hepatic VOD from the first dose of asparaginase was 18 days (interquartile range 13-24 days). Notably, 80% (44/55) of cases reported grades 3-5 VOD per the Common Terminology Criteria for Adverse Events. Although patients received asparaginase with standard chemotherapeutic agents known to induce VOD, case-level data indicates that asparaginase products may have contributed to hepatic VOD. Asparaginase products are associated with hepatotoxicity and thrombosis, suggesting a plausible mechanism for asparaginase-induced hepatic VOD. Based on the totality of data, including temporality and biologic plausibility, we determined hepatic VOD to be a class effect with asparaginase products. These data contributed to the addition of hepatic VOD to the hepatoxicity warning in the US Prescribing Information for asparaginase class products.

Gadoxetic acid-enhanced magnetic resonance imaging in the assessment of hepatic sinusoidal obstruction syndrome in a mouse model

BACKGROUND

Neoadjuvant chemotherapy can cause hepatic sinusoidal obstruction syndrome (SOS) in patients with colorectal cancer liver metastases and increases postoperative morbidity and mortality.

AIM

To evaluate T₁ mapping based on gadoxetic acid-enhanced magnetic resonance imaging (MRI) for diagnosis of hepatic SOS induced by monocrotaline.

METHODS

Twenty-four mice were divided into control (n = 10) and experimental (n = 14) groups. The experimental groups were injected with monocrotaline 2 or 6 days before MRI. MRI parameters were: T1 relaxation time before enhancement; T1 relaxation time 20 minutes after enhancement (T_1post); a reduction in T1 relaxation time (△T₁%); and first enhancement slope percentage of the liver parenchyma (ESP). Albumin and bilirubin score was determined. Histological results served as a reference. Liver parenchyma samples from the control and experimental groups were analyzed by western blotting, and organic anion transporter polypeptide 1 (OATP1) was measured.

RESULTS

T_1post, △T₁%, and ESP of the liver parenchyma were significantly different between two groups (all P < 0.001) and significantly correlated with the total histological score of hepatic SOS (r = -0.70, 0.68 and 0.79; P < 0.001). △T₁% and ESP were positively correlated with OATP1 levels (r = 0.82, 0.85; P < 0.001), whereas T_1post had a negative correlation with OATP1 levels (r = -0.83; P < 0.001).

CONCLUSION

T₁ mapping based on gadoxetic acid-enhanced MRI may be useful for diagnosis of hepatic SOS, and MRI parameters were associated with OATP1 levels.

Intrinsic Causes of Nonfibrotic Portal Hypertension-A Clinicopathologic Review of 56 Patients

Aim: The differential diagnosis of intrinsic nonfibrotic conditions that may lead to portal hypertension include hepatoportal sclerosis (HPS), nodular regenerative hyperplasia (NRH), and sinusoidal obstruction syndrome (SOS). In this article, we characterize the clinical features and outcome of these lesions when they manifest as portal hypertension. Methods: Data was collected through retrospective patient medical records. Results: Patients (HPS: 28, NRH: 17, SOS: 11) were identified more frequently in recent years. All groups presented with signs and symptoms of portal hypertension. All patients had complex medical histories. An elevated serum alkaline phosphatase occurred in all groups and an elevated bilirubin with SOS. Imaging of the liver with HPS and NRH suggested cirrhosis, which was not seen with SOS. 11%, 12%, and 9% of patients in the HPS, NRH, and SOS respectively, underwent transjugular intrahepatic portosystemic shunt placement to manage the complications of portal hypertension, while 43%, 24%, and 36% of patients respectively, received a liver transplant. Conclusions: Patients with HPS, NRH, and SOS had complex medical histories, likely contributing to the development of these lesions. They are recognized more frequently now. In contrast to HPS and NRH, SOS occurred in liver transplant recipients, was associated with elevated serum bilirubin, and imaging did not suggest the presence of advanced fibrosis/cirrhosis. Liver transplantation appeared to be a viable treatment for complications related to HPS and NRH. Retransplantation for SOS yielded mixed results. HPS, SOS, and NRH should be considered when evaluating liver specimens from patients with unexplained nonfibrotic portal hypertension. Key message: Intrinsic nonfibrotic causes of portal hypertension appear to be increasing in frequency. The differential diagnosis includes NRH, HPS, and SOS. These conditions are associated with complex diseases and possibly due to treatments. Pathologists need to be aware of this differential diagnosis when presented with liver biopsies performed to assess portal hypertension.

Liver Late Effects in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

A pediatric normal tissue effects in the clinic (PENTEC) comprehensive review of patients with childhood cancer who received radiation therapy (RT) to the liver was performed to develop models that may inform RT dose constraints for the liver and improve risk forecasting of toxicities.

METHODS AND MATERIALS

A systematic literature search was performed to identify published data on hepatic toxicities in children. Treatment and outcome data were extracted and used to generate normal tissue complication probability (NTCP) models. Complications from both whole and partial liver irradiation were considered. For whole liver irradiation, total body irradiation and non-total body irradiation treatments were considered, but it was assumed that the entire liver received the prescribed dose. For partial liver irradiation, only Wilms tumor flank field RT could be analyzed. However, a prescribed dose assumption could not be applied, and there was a paucity of analyzable liver dosimetry data. To associate the dose-volume exposures with the partial volume complication data from flank irradiation, liver dose-volume metrics were reconstructed for Wilms tumor flank RT using age-specific computational phantoms as a function of field laterality and superior extent of the field.

RESULTS

The literature search identified 2103 investigations pertaining to hepatic sinusoidal obstructive syndrome (SOS) and liver failure in pediatric patients. All abstracts were screened, and 241 articles were reviewed in full by the study team. A model was developed to calculate the risk of developing SOS after whole liver RT. RT dose (P = .006) and receipt of nonalkylating chemotherapy (P = .01) were significant. Age <20 years at time of RT was borderline significant (P = .058). The model predicted a 2% risk of SOS with zero RT dose, 6.1% following 10 Gy, and 14.5% following 20 Gy to the whole liver (modeled as the linear-quadratic equivalent dose in 2-Gy fractions [α/β = 3 Gy]). Patients with Wilms tumor treated with right flank RT had a higher observed rate of SOS than patients receiving left flank RT, but data were insufficient to generate an NTCP model for partial liver irradiation. From the phantom-based dose reconstructions, mean liver dose was estimated to be 2.16 ± 1.15 Gy and 6.54 ± 2.50 Gy for left and right flank RT, respectively, using T10-T11 as the superior field border and a prescription dose of 10.8 Gy (based on dose reconstruction). Data were sparse regarding rates of late liver injury after RT, which suggests low rates of severe toxicity after treatment for common pediatric malignancies.

CONCLUSIONS

This pediatric normal tissue effects in the clinic (PENTEC) review provides an NTCP model to estimate the risk of hepatic SOS as a function of RT dose following whole liver RT and quantifies the range of mean liver doses from typical Wilms tumor flank irradiation fields. Patients treated with right flank RT had higher rates of SOS than patients treated with left flank RT, but data were insufficient to develop a model for partial liver irradiation. Risk of SOS was estimated to be approximately ≤6% in pediatric patients receiving whole liver doses of <10 Gy.

Evaluation of Circulating Endothelial Cells as Direct Marker of Endothelial Damage in Allo-Transplant Recipients at High Risk of Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome

Sinusoidal obstruction syndrome (SOS), also known as veno-occlusive disease (VOD), is a rare but potentially fatal complication following allogenic hematopoietic cell transplantation (allo-HCT). Timely identification of SOS/VOD to allow for prompt treatment is critical, but identifying a VOD-predictive biomarker remains challenging. Given the pivotal role of endothelial dysfunction in SOS/VOD pathophysiology, the CECinVOD study prospectively evaluated levels of circulating endothelial cells (CECs) in patients undergoing allo-HCT with a myeloablative conditioning (MAC) regimen to investigate the potential of CEC level in predicting and diagnosing SOS/VOD. A total of 150 patients from 11 Italian bone marrow transplantation units were enrolled. All participants were age >18 years and received a MAC regimen, putting them at elevated risk of developing SOS/VOD. Overall, 6 cases of SOS/VOD (4%) were recorded. CECs were detected using the Food and Drug Administration-approved CellSearch system, an immunomagnetic selection-based platform incorporating ferrofluid nanoparticles and fluorescent-labeled antibodies, and were defined as CD146+, CD105+, DAPI+, or CD45-. Blood samples were collected at the following time points: before (T0) and at the end of conditioning treatment (T1), at neutrophil engraftment (T2), and at 7 to 10 days postengraftment (T3). For patients who developed VOD, additional samples were collected at any suspected or proven VOD onset (T4) and weekly during defibrotide treatment (T5 to T8). A baseline CEC count >17/mL was associated with an elevated risk of SOS/VOD (P = .04), along with bilirubin level >1.5 mg/mL and a haploidentical donor hematopoietic stem cell source. Postconditioning regimen (T1) CEC levels were elevated (P = .02), and levels were further increased at engraftment (P < .0001). Additionally, patients developing SOS/VOD after engraftment, especially those with late-onset SOS/VOD, showed a markedly higher relative increase (>150%) in CEC count. Multivariate analysis supported these findings, along with a high Endothelial Activation and Stress Index (EASIX) score at engraftment (T2). Finally, CEC kinetics corresponded with defibrotide treatment. After the start of therapy (T4), CEC levels showed an initial increase in the first week (T5), followed by a progressive decrease during VOD treatment (T6 and T7) and a return to pre-SOS/VOD onset levels at resolution of the complication. This prospective multicenter study reveals a low incidence of SOS/VOD in high-risk patients compared to historical data, in line with recent reports. The results from the CECinVOD study collectively confirm the endothelial injury in allo-HCT and its role in in the development of SOS/VOD, suggesting that CEC level can be a valuable biomarker for diagnosing SOS/VOD and identifying patients at greater risk of this complication, especially late-onset SOS/VOD. Furthermore, CEC kinetics may support treatment strategies by providing insight into the optimal timing for discontinuing defibrotide treatment.

sVEGF-R1 in acute non-infectious toxicity syndromes after pediatric allogeneic hematopoietic stem cell transplantation

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (HSCT) is challenged by acute non-infectious toxicities, including sinusoidal obstruction syndrome (SOS), engraftment syndrome (ES) and capillary leak syndrome (CLS) among others. These complications are thought to be driven by a dysfunctional vascular endothelium, but the pathophysiological mechanisms remain incompletely understood, and the diagnoses are challenged by purely clinical diagnostic criteria that are partly overlapping, limiting the possibilities for progress in this field. There is, however, increasing evidence suggesting that these challenges may be met through the development of diagnostic biomarkers to improve diagnostic accuracy of pathogenetically homogenous entities, improved pre-transplant risk assessment and the early identification of patients with increased need for specific treatment. Soluble vascular endothelial growth factor receptor-1 (sVEGF-R1) is emerging as an important biomarker of endothelial damage in patients with trauma and sepsis but has not been studied in HSCT.

OBJECTIVES

To investigate sVEGF-R1 as a marker of endothelial damage in pediatric HSCT patients by exploring associations with SOS, CLS, ES, and acute graft-versus-host disease (aGvHD).

METHODS

We prospectively included 113 children undergoing myeloablative HSCT and measured sVEGF-R1 in plasma samples obtained weekly during the early period of transplantation and 3 months post-transplant.

RESULTS

All over, sVEGF-R1 levels were significantly increased from day +7 after graft infusion, peaking at day +30, most pronounced in patients receiving busulfan. Patients considered to be at increased risk of SOS and therefore commenced on prophylactic defibrotide had significantly elevated levels of sVEGF-R1 before start of conditioning (446 pg/mL vs. 281 pg/mL, p = 0.0035), and this treatment appeared to stabilize sVEGF-R1 levels compared to patients not treated with defibrotide. Thirteen (11.5%) children meeting the modified Seattle criteria for SOS at median day +8 (1-18), had significantly elevated sVEGF-R1 levels on day +14 (489 pg/mL vs. 327 pg/mL, p = 0.007). In contrast. sVEGF-R1 levels in the much broader group of patients (45.1%) meeting EBMT-SOS criteria, including patients with very mild disease, did not overall differ in sVEGF-R1 levels, but higher sVEGF-R1 levels were seen in EBMT-SOS patients with an increased need for diuretic treatment. Importantly, sVEGF-R1 levels were not associated with ES and CLS but were significantly increased on day +30 in patients with grade III-IV aGvHD (OR = 4.2 pr. quartile, p = 0.023).

CONCLUSION

VEGF-R1 levels are found to be increased in pediatric patients developing SOS, reflecting the severity of morbidity. sVEGF-R1 were unassociated with both CLS and ES. The potential of sVEGF-R1 as a clinically useful biomarker for SOS should be further explored to improve pre-transplant SOS-risk assessment, SOS-severity grading, and to guide treatment.

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.

Metformin pretreatment ameliorates busulfan-induced liver endothelial toxicity during haematopoietic stem cell transplantation

The success of Haematopoietic cell transplantation (HCT) is often limited by regimen-related toxicity (RRT) caused by conditioning regimen drugs. Among different conditioning drugs, busulfan (Bu) and treosulfan (Treo), although widely used in HCT, exhibit different toxicity profiles, the mechanism of which is still unclear. Here we investigated the effects of Bu and Treo in endothelial cells. While both Bu and Treo induced DNA damage in endothelial cells, we observed Bu alone to induce oxidative stress and sustained activation of phospho-ERK1/2, leading to apoptosis. However, Treo-treated cells exhibited no oxidative stress/apoptosis of endothelial cells. Screening of pharmacological inhibitors of both ROS and p-ERK revealed that metformin effectively ameliorates Bu-mediated toxicity in endothelial cells. In Balb/c mice, we observed a significant reduction in bone marrow endothelial cells in Bu-treated mice compared to Treo-treated mice. Further, liver sinusoidal endothelial cells (LSEC) was damaged by Bu, which is implicated in liver vasculature and their functional capacity to uptake FITC-albumin. However, Treo-treated mice liver vasculature was morphologically and functionally normal. When mice were pretreated with metformin followed by Bu, LSECs damage was ameliorated morphologically and functionally. Bone marrow transplants done on these mice did not affect the engraftment of donor cells.

Complications of Cancer Therapy in Children: A Comprehensive Review of Body Imaging Findings

ABSTRACT

Complications of cancer therapy in children can result in a spectrum of toxicities that can affect any organ system and result in a range of morbidity. Complications may occur at the initiation of therapy or years following treatment. Although childhood cancer remains rare, increasing survival rates means more children are living longer following their treatment. Radiologists often play an important role in the diagnosis and evaluation of these complications, and thus, awareness of their imaging findings is essential to guide management and avoid misdiagnosis. This second part of a 2-part review aims to illustrate the typical body imaging findings of cancer therapy-related toxicities, including both early and late treatment effects. The article also discusses the differential diagnosis of imaging findings, highlighting pearls and pitfalls in making the appropriate diagnosis.

Melatonin attenuates monocrotaline-induced hepatic sinusoidal obstruction syndrome in rats via activation of Sirtuin-3

Melatonin possesses potent hepatoprotective properties, but it remains to be elucidated whether melatonin has a therapeutic effect on monocrotaline (MCT)-induced hepatic sinusoidal obstruction syndrome (HSOS). In this study, male Sprague Dawley rats were intraperitoneally injected with melatonin or the same volume of vehicle at 0 and 24 h after MCT intragastric administration. Next, hematoxylin-eosin staining and electron microscopy were performed to evaluate the hepatic sinusoidal injury of rats. Endothelial cell marker RECA-1 was observed by immunohistochemistry. Hepatic oxidative stress was analyzed by detecting malondialdehyde, glutathione S-transferase, and reactive oxygen species. Assessment of liver function was carried out by analysis of serum aspartate aminotransferase, alanine aminotransferase, total bilirubin, and albumin levels. Real-time polymerase chain reaction and Western blot analysis were used to identify liver Sirtuin-3 (SIRT3) and active matrix metallopeptidase 9 (MMP-9) expression. Besides, liver sinusoidal endothelial cells (LSECs) were used for the in vitro functional verification experiment. Specifically, liver histology of the melatonin-treated groups showed that the pathological damages caused by MCT were significantly attenuated, total HSOS scores were decreased, and the elevation of serum hyaluronic acid observed in the model group was also reduced. Moreover, melatonin treatment also improved the survival of rats after partial hepatectomy. Administration of melatonin ameliorated MCT-induced LSECs injury, hepatic oxidative stress, and hepatic dysfunction. Furthermore, melatonin treatment increased SIRT3 expression while attenuating MMP-9 activity in liver tissues. Cell experiment also demonstrated that SIRT3 might mediate the protective effect of melatonin on LSECs. Collectively, our study provided the potential rationale for the application of melatonin for the prevention of MCT-induced HSOS.

Unusual Progressive Hepatic Echogenicity of the Pediatric Liver Following Intravenous Sonographic Contrast Administration

Contrast-enhanced ultrasound is a valuable tool to evaluate liver lesions in a pediatric patient cohort. Unusual progressive hepatic echogenicity (UPHE) is a self-limiting phenomenon noted in a cohort of children after administration of ultrasonographic contrast agents (UCAs). UPHE appears initially as heterogeneous branching similar to portal venous gas, culminating in a diffuse globular appearance. The etiology of UPHE is unclear and may be from underlying hepatic microvascular disease or altered gut permeability. This case series describes pediatric patients with UPHE following UCA bolus and discusses its potential mechanisms in children.

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.

Predictive factors of collateral vessel development induced by oxaliplatin-based chemotherapy

BACKGROUND AND AIM

Oxaliplatin can lead to hepatic sinusoidal injury, called hepatic sinusoidal obstruction syndrome (SOS), resulting in portal hypertension-related complications. This could worsen the clinical course of the patients treated with oxaliplatin. Early diagnosis is challenging. We explored predictive markers of oxaliplatin-induced collateral vessels.

METHODS

Patients who received oxaliplatin-based chemotherapy were retrospectively screened. We evaluated their laboratory findings and spleen size on computed tomography immediately before oxaliplatin-based chemotherapy and after 6 months of treatment. The primary outcome was collateral vessel development, as a surrogate marker for oxaliplatin-induced SOS in patients who underwent oxaliplatin-based chemotherapy. The secondary outcome was the identification of factors that predicted the development of collateral vessels.

RESULTS

We enrolled 161 patients who received oxaliplatin-based chemotherapy. They had a median age of 69 years, and 63.3% were men. Collateral vessels developed in nine (5.6%) patients during the study period. After oxaliplatin-based chemotherapy, the spleen size increased in 104 patients (64.6%), with a ≥ 30% increase in 19.4% of the patients. Univariate analysis showed that the Fibrosis-4 (FIB-4) index (≥ 1.76; OR 9.17), aspartate aminotransferase:platelet ratio index (APRI) (≥ 0.193; OR 9.62), cumulative dose of oxaliplatin (≥ 1000 mg; OR 8.43), and increase in spleen size (≥ 30%; OR 6.01) were significant risk factors for collateral vessel development. Multivariate analysis after stepwise selection revealed that the FIB-4 index and spleen size were significant independent predictive factors.

CONCLUSION

A ≥ 1.76 increase in the FIB-4 index and a ≥ 30% increase in spleen size after 6 months of oxaliplatin-based chemotherapy were significant predictive markers for collateral vessel development.

Endothelial Dysfunction Syndromes after Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only therapy with a curative potential for a variety of malignant and non-malignant diseases. The major limitation of the procedure is the significant morbidity and mortality mainly associated with the development of graft versus host disease (GVHD) as well as with a series of complications related to endothelial injury, such as sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD), transplant-associated thrombotic microangiopathy (TA-TMA), etc. Endothelial cells (ECs) are key players in the maintenance of vascular homeostasis and during allo-HSCT are confronted by multiple challenges, such as the toxicity from conditioning, the administration of calcineurin inhibitors, the immunosuppression associated infections, and the donor alloreactivity against host tissues. The early diagnosis of endothelial dysfunction syndromes is of paramount importance for the development of effective prophylactic and therapeutic strategies. There is an urgent need for the better understanding of the pathogenetic mechanisms as well as for the identification of novel biomarkers for the early diagnosis of endothelial damage. This review summarizes the current knowledge on the biology of the endothelial dysfunction syndromes after allo-HSCT, along with the respective therapeutic approaches, and discusses the strengths and weaknesses of possible biomarkers of endothelial damage and dysfunction.

Transjugular Intrahepatic Portosystemic Shunt in Liver Transplant Recipients: Outcomes in Six Adult Patients

OBJECTIVES

Transjugular intrahepatic portosystemic shunt (TIPS) is regularly used in treatment of clinically significant portal hypertension. Liver transplant recipients are, however, rarely indicated for the procedure. The study retrospectively examines the results of TIPS placement in 6 patients after OLT.

METHODS

4 males and 2 females (aged 36 to 62 years), treated with TIPS between 2007 a 2018, were included in the study. 5 patients had previously undergone liver transplantation for liver graft cirrhosis, 1 patient for Budd-Chiari syndrome. The piggyback caval reconstruction technique was selected in 4/6 cases. PH developed after OLT due to the recurrence of underlying liver condition and sinusoidal obstruction syndrome in half of the cases, respectively. Indications for TIPS were refractory ascites in 4 cases and variceal bleeding in 2 cases.

RESULTS

Standard TIPS technique was used and technical success was achieved in all cases with a procedure-related complication in 1 patient. One patient died shortly after TIPS placement. The remaining patients all reported regression of clinically significant PH. Late complications appeared in 2 patients. Liver retransplantation after TIPS creation was performed in 1 case. Median TIPS patency was 55 months. 2/6 patient continue to thrive with a patent shunt.

CONCLUSIONS

Transjugular intrahepatic portosystemic shunt in OLT recipients is technically feasible. Favorable clinical outcomes were reported particularly in patients treated for sinusoidal obstruction syndrome who were indicated to TIPS for refractory ascites.

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.

Hepatic venous pressure gradient in sinusoidal obstruction syndrome: diagnostic value and link with histological lesions

Background & Aims

Liver sinusoidal obstruction syndrome (SOS) is a well-established complication of myeloablative conditioning regimens used in hematopoietic stem cell transplantation. Hepatic venous pressure gradient (HVPG) >10 mmHg was described as an accurate diagnostic tool for SOS in the 1990s. However, epidemiology and presentation of SOS have dramatically changed. Moreover, elementary histological lesions influencing HVPG are unknown.

Methods

We retrospectively analyzed the charts of all patients who underwent transjugular liver biopsy with HVPG measurement for a clinical suspicion of SOS at our center. Two expert pathologists unaware of the presence or absence of SOS reviewed all liver samples and graded elementary histological lesions according to a semi-quantitative scoring defined a priori.

Results

Out of the 77 included patients, the 30 patients with SOS had higher HVPG than the 47 patients without SOS (median 14 mmHg [IQR 10-18], vs. 6 mmHg [3-9], respectively p <0.001). HVPG >10 mmHg had a specificity of 78% and a positive predictive value of 66% for the diagnosis of SOS. However, almost 40% of the patients with SOS had an HVPG ≤10 mmHg. HVPG correlated with sinusoidal congestion (r = 0.57; p = 0.001) and hepatocyte necrosis (r = 0.42; p = 0.02), but not with other lesions.

Conclusion

Even though HVPG is higher in patients with SOS, low HVPG values do not rule out SOS. Thus, HVPG cannot be used alone, and should be combined with transjugular liver biopsy, for the diagnosis of SOS.

Lay summary

Hepatic venous pressure gradient >10 mmHg has been described as an accurate tool for the diagnosis of liver sinusoidal obstruction syndrome after hematopoietic stem cell transplantation. This study shows that the sensitivity and specificity of hepatic venous pressure gradient measurement for sinusoidal obstruction syndrome are insufficient, so that liver pressure measurement should be combined with a liver biopsy in this setting.

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HVPG is significantly higher in patients with sinusoidal obstruction syndrome than in those with other liver injuries.

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A 10 mmHg threshold is associated with low PPV (66%) and low sensitivity (63%).

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HVPG measurement should be combined with transjugular liver biopsy when sinusoidal obstruction syndrome is suspected.

A Systematic Review and Meta-Analysis of Studies of Defibrotide Prophylaxis for Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome

BACKGROUND AND OBJECTIVES

Defibrotide is approved to treat severe veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) after haematopoietic cell transplantation in patients aged > 1 month in the European Union and for VOD/SOS with renal/pulmonary dysfunction post-haematopoietic cell transplantation in the United States. This meta-analysis estimated the incidence and risk of VOD/SOS after intravenous defibrotide prophylaxis using the published literature.

METHODS

PubMed, Embase and Web of Science were searched through 30 November 2021 for defibrotide studies in VOD/SOS "prevention" or "prophylaxis," excluding phase I studies, case reports, studies with fewer than ten patients and reviews.

RESULTS

The search identified 733 records; 24 met inclusion criteria, of which 20 (N = 3005) evaluated intravenous defibrotide for VOD/SOS prophylaxis. Overall VOD/SOS incidence with intravenous defibrotide was 5%, with incidences of 5% in adults and 8% in paediatric patients. In eight studies with data on intravenous defibrotide prophylaxis vs controls (e.g. heparin, no prophylaxis), VOD/SOS incidence in controls was 16%. The risk ratio for developing VOD/SOS with defibrotide prophylaxis vs controls was 0.30 (95% confidence interval 0.12-0.71; p = 0.006).

CONCLUSIONS

This analysis suggests a low incidence of VOD/SOS following intravenous defibrotide prophylaxis, regardless of age group, and a lower relative risk for VOD/SOS with defibrotide prophylaxis vs controls in patient populations at high risk of VOD/SOS.

Living Donor Liver Transplantation for Hepatic Venoocclusive Disease/Sinusoidal Obstruction Syndrome Originating from Hematopoietic Stem Cell Transplantation

Background

Venoocclusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is a life-threatening hematopoietic stem cell transplantation (HSCT) complication. Cases of mild and moderate VOD/SOS are self-limiting; however, the mortality for severe VOD/SOS has reached 80%. Recently, defibrotide became available and has been used for VOD/SOS; however, the outcome for patients with severe VOD/SOS is not satisfactory, and liver transplantation is attempted in these severe cases.

Method

We describe a case of living donor liver transplantation (LDLT) for acute liver failure secondary to VOD/SOS that originates from HSCT.

Result

Liver regeneration after LDLT was impaired, and several infections were developed before liver regeneration completion. Our patient suffered sepsis and finally died of multiorgan failure.

Conclusion

Severe VOD/SOS originating from HSCT is associated with a very poor prognosis. The liver transplantation outcome for VOD/SOS has not been satisfied, but it may provide long-term survival if successful. We considered liver transplantation as a therapeutic option, especially in cases where sufficient graft volume is secured, considering impaired liver regeneration under bone marrow suppression after HSCT.

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.

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.

Sinusoidal obstruction syndrome as a manifestation of acute antibody-mediated rejection after liver transplantation

Antibody-mediated rejection (AMR) after liver transplantation is uncommon but, when present, manifests as graft dysfunction. We report the case of a 54-year-old woman who developed portal hypertension with pleural effusion and ascites secondary to sinusoidal obstruction syndrome (SOS) due to acute AMR following an ABO-matched liver transplantation for autoimmune cirrhosis and hepatocellular carcinoma. Initial immunosuppression comprised basiliximab, decreasing prednisone, tacrolimus, and mycophenolate mofetil. After 1 month, she presented with the massive pleural effusion, slight ascites, and normal liver tests. After excluding common causes of pleural effusion, we performed a liver biopsy that showed atypical rejection with the involvement of large centrilobular veins partially occluded by marked endotheliitis and lax fibrosis suggestive of SOS. Direct immunofluorescence study of C4d showed diffuse endothelial sinusoidal staining, and de novo donor-specific anti-human leukocyte antigen antibodies were detected in his blood. Thus, we diagnosed AMR focused on centrilobular veins and initiated treatment with defibrotide, steroid pulses, and diuretics. However, this was ineffective, and the pleural effusion only resolved when plasmapheresis and intravenous immunoglobulin were started. This case shows that AMR can cause SOS with portal hypertension and present with a pleural effusion, and as such, it should be suspected after excluding other more common causes of effusion.

Anatomic and Clinical Pathology Characterization of Drug-Induced Sinusoidal Obstruction Syndrome (Veno-Occlusive Disease) in Cynomolgus Macaques

Sinusoidal obstruction syndrome (SOS) is a unique form of liver injury that occurs after exposure to chemotherapeutic drugs and toxins. The diagnosis of SOS in humans remains a challenge as the clinical criteria have low specificity and there are no reliable noninvasive biomarkers. The mechanism of injury is believed to be damage to liver endothelial cells, primarily sinusoidal endothelial cells (SECs), which leads to sinusoidal dilation, central venous fibrosis, and/or nodular regeneration. Nonclinical data suggest that this uncommon liver toxicity can be recapitulated in cynomolgus monkeys, and it is critical that pathologists are familiar with its characteristic clinicopathologic features. Elevations in liver enzymes, in particular aspartate aminotransferase, associated with isolated thrombocytopenia, should raise the suspicion of SEC injury for specific drug classes. Characterization of liver microscopic findings in monkeys benefits from the use of appropriate stains, such as reticulin stain, and VEGFR2 and CD34 immunohistochemical (IHC) stains. CD41 IHC demonstrates platelet accumulation in injured sinusoids, the likely cause of thrombocytopenia commonly reported in SOS. In conclusion, this report provides a comprehensive characterization of the pathology findings of drug-induced SOS in monkeys with the objectives of ensuring appropriate nonclinical recognition of the liability and informing clinical development strategy and monitoring.

Oxaliplatin-induced hepatic sinusoidal obstruction syndrome

Oxaliplatin (OXA) is a third-generation platinum anticancer drug that is mainly used for the treatment of metastatic colorectal cancer (CRC). Of note, hepatic sinusoidal obstruction syndrome (HSOS) induced by OXA has become a key concern for patients with CRC receiving chemotherapy with OXA in recent years. Splenomegaly, thrombocytopenia, abnormal liver function, and portal hypertension are some of the main clinical characteristics seen in patients with OXA-induced HSOS. Previous studies have suggested that oxidative stress, inflammatory damage, liver fibrosis, and platelet aggregation and adhesion may be involved in the pathogenesis of OXA-induced HSOS. Currently, there are no specific drugs for prevention and treatment of OXA-induced HSOS. In this review, we summarized the epidemiology, pathological characteristics, clinical predictive indicators, related mechanisms, possible prevention and treatment of OXA-related HSOS.

Tu-San-Qi (Gynura japonica): the culprit behind pyrrolizidine alkaloid-induced liver injury in China

Herbs and dietary supplement-induced liver injury (HILI) is the leading cause of drug-induced liver injury in China. Among different hepatotoxic herbs, the pyrrolizidine alkaloid (PA)-producing herb Gynura japonica contributes significantly to HILI by inducing hepatic sinusoidal obstruction syndrome (HSOS), a liver disorder characterized by hepatomegaly, hyperbilirubinemia, and ascites. In China, G. japonica has been used as one of the plant species for Tu-San-Qi and is often misused with non-PA-producing Tu-San-Qi (Sedum aizoon) or even San-Qi (Panax notoginseng) for self-medication. It has been reported that over 50% of HSOS cases are caused by the intake of PA-producing G. japonica. In this review, we provide comprehensive information to distinguish these Tu-San-Qi-related herbal plant species in terms of plant/medicinal part morphologies, medicinal indications, and chemical profiles. Approximately 2156 Tu-San-Qi-associated HSOS cases reported in China from 1980 to 2019 are systematically reviewed in terms of their clinical manifestation, diagnostic workups, therapeutic interventions, and outcomes. In addition, based on the application of our developed mechanism-based biomarker of PA exposure, our clinical findings on the definitive diagnosis of 58 PA-producing Tu-San-Qi-induced HSOS patients are also elaborated. Therefore, this review article provides the first comprehensive report on 2214 PA-producing Tu-San-Qi (G. japonica)-induced HSOS cases in China, and the information presented will improve public awareness of the significant incidence of PA-producing Tu-San-Qi (G. japonica)-induced HSOS and facilitate future prevention and better clinical management of this severe HILI.

CONTRAST-ENHANCED COMPUTED TOMOGRAPHIC FINDINGS OF APPARENTLY CLINICALLY NORMAL CHEETAH (ACINONYX JUBATUS) LIVERS

Hepatic veno-occlusive disease (VOD) is a significant cause of morbidity and mortality in captive cheetahs (Acinonyx jubatus), and the appearance of this disease in humans by computed tomography (CT) has been well described. Contrast-enhanced CT abdominal scans of cheetahs without evidence of hepatic disease (n = 5) were reviewed retrospectively to describe the normal appearance of cheetah livers as an aid to antemortem VOD diagnosis. Despite having no clinical signs, clinical pathology abnormalities, or hepatic biopsy histopathology supportive of VOD, all five cheetahs had at least one VOD consistent finding on CT. The results of this study suggest that given the progressive and potentially subclinical nature of VOD, CT could serve as a noninvasive screening tool and be used to monitor disease progression.

Genetic Predictors for Sinusoidal Obstruction Syndrome-A Systematic Review

Sinusoidal obstruction syndrome (SOS) is a potentially life-threatening complication after hematopoietic stem cell transplantation (HSCT) or antineoplastic treatment without HSCT. Genetic variants were investigated for their association with SOS, but the evidence is inconclusive. We performed a systematic literature review to identify genes, gene variants, and methods of association analyses of genetic markers with SOS. We identified 23 studies after HSCT and 4 studies after antineoplastic treatment without HSCT. One study (4%) performed whole-exome sequencing (WES) and replicated the analysis in an independent cohort, 26 used a candidate-gene approach. Three studies included >200 participants (11%), and six were of high quality (22%). Variants in 34 genes were tested in candidate gene studies after HSCT. Variants in GSTA1 were associated with SOS in three studies, MTHFR in two, and CPS1, CTH, CYP2B6, GSTM1, GSTP1, HFE, and HPSE in one study each. UGT2B10 and LNPK variants were identified in a WES analysis. After exposure to antineoplastic agents without HSCT, variants in six genes were tested and only GSTM1 was associated with SOS. There was a substantial heterogeneity of populations within and between studies. Future research should be based on sufficiently large homogenous samples, adjust for covariates, and replicate findings in independent cohorts.

Macrophages contribute to liver repair after monocrotaline-induced liver injury via SDF-1/CXCR4

Monocrotaline (MCT) administration induces liver injury in rodents that mimics the pathology of human sinusoidal obstruction syndrome. MCT-induced SOS models are used to investigate the mechanism of injury and optimize treatment strategies. However, the processes underlying liver repair are largely unknown. Specifically, the role of macrophages, the key drivers of liver repair, has not been elucidated. The current study aimed to examine the role of macrophages in the repair of MCT-induced liver injury in male C57/BL6 mice. Maximal liver injury occurred at 48 h post-MCT treatment, followed by repair at 120 h post-treatment. Immunofluorescence analysis revealed that CD68⁺ macrophages were recruited to the injured regions after MCT treatment. This was associated with the decreased expression of genes related to a pro-inflammatory macrophage phenotype and the increased expression of those associated with a reparative macrophage phenotype during the repair phase. The results also revealed that stromal cell-derived factor-1 (SDF-1) and its receptor C-X-C chemokine receptor-4 (CXCR4) were upregulated, and CD68⁺ macrophages were co-localized with CXCR4 expression. Treatment of mice with AMD3100, a CXCR4 antagonist, delayed liver repair and increased the expression of genes related to a pro-inflammatory macrophage phenotype. In contrast, SDF-1 treatment stimulated liver repair and increased the expression of genes related to a reparative macrophage phenotype. The results suggested that macrophages accumulate in the liver and repair damaged tissue after MCT treatment, and that the SDF-1-CXCR4 axis is involved in this process.

Idiopathic Non-Cirrhotic Portal Hypertension and Porto-Sinusoidal Vascular Disease: Review of Current Data

Idiopathic non-cirrhotic portal hypertension (INCPH) is a clinicopathologic disease entity characterized by the presence of clinical signs and symptoms of portal hypertension (PH) in the absence of liver cirrhosis or known risk factors accountable for PH. Multiple hematologic, immune-related, infectious, hereditary and metabolic risk factors have been associated with this disorder. Still, the exact etiopathogenesis is largely unknown. The recently proposed porto-sinusoidal vascular disease (PSVD) scheme broadens the spectrum of the disease by also including patients without clinical PH who are found to have similar histopathologic findings on core liver biopsies. Three histomorphologic lesions have been identified as specific for PSVD to include obliterative portal venopathy, nodular regenerative hyperplasia and incomplete septal cirrhosis/fibrosis. However, these findings are often subtle, under-recognized and subjective with low interobserver agreement among pathologists. Additionally, the natural history of the subclinical forms of the disease remains unexplored. The clinical course is more favorable compared to cirrhosis patients, especially in the absence of clinical PH or liver dysfunction. There are no universally accepted guidelines in regard to diagnosis and treatment of INCPH/PSVD. Hence, this review emphasizes the need to raise awareness of this entity by highlighting its complex pathophysiology and clinicopathologic associations. Lastly, formulation of standardized diagnostic criteria with clinical validation is necessary to avoid misclassifying vascular diseases of the liver and to develop and implement targeted therapeutic strategies.

Liver transplantation for rare liver diseases and rare indications for liver transplant

Liver transplantation (LT) is currently considered the gold standard treatment for end-stage liver failure. Compared to the first decades of its use, LT is associated with lower comorbidity and mortality, with a 5-year survival over 70%. Worldwide, liver cirrhosis and hepatocellular carcinoma represent the major indications to LT. However, almost 1% of LT is performed for rare diseases or rare indications, which include non-hepatocellular malignancy, vascular disorders, metabolic and congenital liver disorders. These diseases can lead to hepatocellular necrosis, biliary tree abnormality and/or hepatomegaly. Most of these diseases are not associated with liver failure but in highly selected patients, LT represent an effective therapy improving the overall survival and quality of life. Rare indications for LT often overlap with rare diseases. However, rare LT indications for non-rare diseases are rising in the last decades, especially for benign primary liver tumor, colon rectal liver metastasis, neuroendocrine liver metastasis, and cholangiocarcinoma (CCA). Non-rare diseases with rare indication for LT and rare adult disease with an indication for LT are categorized and discussed in detail, focusing on some disorders for which the literature provides a more definitive evidence base. Early referral to a transplant center is encouraged to provide an effective therapeutic option in these non-standard indications for LT.

Veno-occlusive Disease in HSCT Patients: Consensus-based Recommendations for Risk Assessment, Diagnosis, and Management by the GITMO Group

Variation in clinical practice affects veno-occlusive disease management, mainly in patients who undergo allogeneic hematopoietic stem cell transplantation. Disputes about diagnostic criteria, treatment, and prophylaxis, due to the lack of high-quality data, are at the base of this variability. With the aim of limiting inconsistency in clinical care, thus improving both patient outcomes and data collection reliability, the Italian Society of Stem cell transplant (Gruppo Italiano Trapianto Midollo Osseo e Terapia Cellulare) launched a collaborative effort to formulate recommendations based on integration of available evidence and expert's consensus. A systematic method, according to US National Institute of Health guidelines and Italian National System for Guidelines, was used. Twenty-nine recommendations were approved with a strong (20) or weak (9) level of agreement, while 26 were rejected. In particular, the panel pointed out the need to achieve an early diagnosis, encouraging the adoption of European Society for Blood and Marrow Transplantation criteria and the prompt use of ultrasonography. Moreover, our experts strongly recommended in favor of prophylactic use of ursodeoxycholic acid. As soon as a veno-occlusive disease diagnosis is established, treatment with defibrotide should be started for at least 21 days. A number of areas of uncertainty, particularly concerning risk stratification and use of diagnostic tools such as elastography has been identified and discussed.

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.

Recent progress in the use of microRNAs as biomarkers for drug-induced toxicities in contrast to traditional biomarkers: A comparative review

microRNAs (miRNAs) are small non-coding RNAs with 18-25 nucleotides. They play key regulatory roles in versatile biological process including development and apoptosis, and in disease pathogenesis, for example carcinogenesis, by negatively regulating gene expression. miRNAs often exhibit characteristics suitable for biomarkers such as tissue-specific expression patterns, high stability in serum/plasma, and change in abundance in circulation immediately after toxic injury. Since the discovery of circulating miRNAs in extracellular biological fluids in 2008, there have been many reports on the use of miRNAs as biomarkers for various diseases including cancer and organ injury in humans and experimental animals. In this review article, we have summarized the utility and limitation of circulating miRNAs as safety/toxicology biomarkers for specific tissue injuries including liver, skeletal muscle, heart, retina, and pancreas, by comparing them with conventional protein biomarkers. We have also covered the discovery of miRNAs in serum/plasma and their stability, the knowledge of which is essential for understanding the kinetics of miRNA biomarkers. Since numerous studies have reported the use of these circulating miRNAs as safety biomarkers with high sensitivity and specificity, we believe that circulating miRNAs can promote pre-clinical drug development and improve the monitoring of tissue injuries in clinical pharmacotherapy.

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).

Contrast-Enhanced Ultrasound Imaging Features of Focal Chemotherapy-Induced Sinusoidal Injury in Patients With Colorectal Cancer: Initial Experience

OBJECTIVES

Increasing studies have reported focal chemotherapy-induced sinusoidal injury (CSI) mimicking colorectal liver metastasis (CRLM) on imaging studies, resulting in unnecessary lobectomy. This study aimed to investigate the contrast-enhanced ultrasound (CEUS) imaging features of focal CSI.

METHODS

We retrospectively evaluated 16 patients who had a pathologic diagnosis of focal CSI and underwent CEUS between January 2013 and January 2019. The images were compared with those obtained from 27 patients with CRLM.

RESULTS

On CEUS, 14 (87.5%) focal CSIs showed heterogeneous isoenhancement, 1 (6.3%) peripheral hyperenhancement, and 1 (6.3%) homogeneous hyperenhancement during the arterial phase. Compared with the adjacent liver parenchyma, the initial enhancement time of focal CSI was earlier in 2 (12.5%), simultaneous in 9 (56.3%), and later in 5 (31.3%) patients. In the portal and late phases, all of the focal CSI cases showed hypoenhancement compared with the adjacent liver parenchyma. Focal CSI had the following CEUS findings, which were different from those of CRLM: (1) heterogeneous isoenhancement in the arterial phase (87.5% versus 0%; P < .001); (2) an initial enhancement time later than that of the liver parenchyma (mean ± SD, 0.5 ± 1.5 versus -1.5 ± 1.9; P < .001); (3) a longer time to peak (30.5 ± 5.6 versus 22.5 ± 4.4 seconds; P < .001); and (4) a later time to wash-out (51.0 ± 12.5 versus 35.0 ± 6.2 seconds; P = .002).

CONCLUSIONS

Focal CSI usually shows heterogeneous isoenhancement in arterial phase and hypoenhancement in portal and late phases on CEUS, with slow contrast wash-in and wash-out, which can be helpful in the differential diagnosis with CRLM.

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.

Serum Gamma Glutamyl transferase is a predictor of recurrence after R0 hepatectomy for patients with colorectal cancer liver metastases

Objectives:

Gamma glutamyl-transpeptidase (GGT) has been shown as a prognostic marker in many cancers. The aim of this study was to explore whether serum GGT could predict tumor recurrence in patients with liver-confined colorectal cancer liver metastases (CRCLM) undergoing R0 resection.

Methods:

We reviewed patients who had underwent liver surgery for CRCLM. Patients with liver-only metastases that underwent R0 resection were included. Pre-operative serum GGT were classified into either high or low using a cut-off value of 33 U/L for female and 51 U/L for male. Relapse-free survival (RFS) was compared in relation to GGT and other clinicopathological factors.

Results:

Of the 350 patients included, 108 (30.9%) had a high serum GGT. Patients with metachronous liver metastases, number of metastases ⩾2, size of the largest metastasis ⩾3 cm, or a history of neoadjuvant chemotherapy had a higher GGT level (p = 0.001, 0.027, 0.001, and 0.002, respectively). In survival analyses, patients with a high GGT had a shorter RFS than those with a low GGT, with a median RFS of 11.8 versus 30.3 months (p < 0.001). RFS was also associated with the number of metastases, size of the largest metastasis and the delivery of neoadjuvant chemotherapy. In multivariate analysis, GGT remained an independent prognostic factor of RFS.

Conclusions:

Our study demonstrates that the serum GGT level before liver surgery is an adverse prognostic factor of RFS for patients with liver-confined CRCLM.

Effect of Sirolimus levels between days 11 and 20 after allogeneic stem cell transplantation on the risk of hepatic sinusoidal obstruction syndrome

Sinusoidal obstruction syndrome (SOS) is a serious complication of hematopoietic stem cell transplantation (HSCT). Sirolimus plus tacrolimus is an accepted regimen for graft-versus-host disease (GVHD) prophylaxis, with both agents implicated as risk factors for SOS. We analyzed 260 consecutive patients who underwent allogeneic HSCT following myeloablative conditioning using total body irradiation (TBI)-based (n = 151) or chemotherapy only (n = 109) regimens, with sirolimus plus tacrolimus for GVHD prophylaxis. SOS occurred in 28 patients at a median of 22 (range, 12-58) days. Mean sirolimus trough levels were higher between days 11 and 20 following transplant in patients who developed SOS (10.3 vs. 8.5 ng/ml, P = 0.008), with no significant difference in mean trough levels between days 0 and 10 (P = 0.67) and days 21-30 (P = 0.37). No differences in mean tacrolimus trough levels during the same time intervals were observed between those developing SOS and others. On multivariable analysis, a mean sirolimus trough level ≥ 9 ng/ml between days 11 and 20 increased the risk of SOS (hazard ratio 3.68, 95% CI: 1.57-8.67, P = 0.003), together with a longer time from diagnosis to transplant (P = 0.004) and use of TBI (P = 0.006). Our results suggest that mean trough sirolimus levels ≥ 9 ng/mL between days 11 and 20 post transplant may increase the risk of SOS and should be avoided.

Chemotherapy-associated liver injury in colorectal cancer

Patients with colorectal cancer (CRC) have benefited significantly from advances in multimodal treatment with significant improvements in long-term survival. More patients are currently being treated with surgical resection or ablation following neoadjuvant or adjuvant chemotherapy. However, several cytotoxic agents that are administered routinely have been linked to liver toxicities that impair liver function and regeneration. Recognition of chemotherapy-related liver toxicity emphasizes the importance of multidisciplinary planning to optimize care. This review aims to summarize current data on multimodal treatment concepts for CRC, provide an overview of liver damage caused by commonly administered chemotherapeutic agents, and evaluate currently suggested protective agents.

Editorial for "Non-Gaussian Diffusion Models and T1rho Quantification in the Assessment of Hepatic Sinusoidal Obstruction Syndrome in Rats"

LEVEL OF EVIDENCE

5 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:1122-1123.

Biological Activities of Rhamnan Sulfate Extract from the Green Algae Monostroma nitidum (Hitoegusa)

Monostroma nitidum is a green single-cell layered algae that grows on the southwest coast of Japan. It is often used for salad ingredients, boiled tsukudani, soups, etc., due to its health benefits. M. nitidum is composed of many cell aggregates, and the various substances that fill the intercellular space are dietary fibers, vitamins, and minerals. Rhamnan sulfate (RS), a sulfated polysaccharide, is main the component of the fiber extracted from M. nitidum. Recently, some biological properties of RS have been demonstrated by in vitro and in vivo studies that probably protect human subjects from viruses and ameliorate vascular dysfunction caused by metabolic disorders, especially lifestyle-related diseases. In this review, we focus on the antithrombotic effects of RS and introduce its antiviral and other biological activities.

Endothelial cell function and endothelial-related disorders following haematopoietic cell transplantation

Use of haematopoietic cell transplantation (HCT) in the treatment of haematologic and neoplastic diseases may lead to life-threatening complications that cause substantial morbidity and mortality if untreated. In addition to patient- and disease-related factors, toxicity associated with HCT puts patients at risk for complications that share a similar pathophysiology involving endothelial cells (ECs). Normally, the endothelium plays a role in maintaining homeostasis, including regulation of coagulation, vascular tone, permeability and inflammatory processes. When activated, ECs acquire cellular features that may lead to phenotypic changes that induce procoagulant, pro-inflammatory and pro-apoptotic mediators leading to EC dysfunction and damage. Elevated levels of coagulation factors, cytokines and adhesion molecules are indicative of endothelial dysfunction, and endothelial damage may lead to clinical signs and symptoms of pathological post-HCT conditions, including veno-occlusive disease/sinusoidal obstruction syndrome, graft-versus-host disease, transplant-associated thrombotic microangiopathy and idiopathic pneumonia syndrome/diffuse alveolar haemorrhage. The endothelium represents a rational target for preventing and treating HCT complications arising from EC dysfunction and damage. Additionally, markers of endothelial damage may be useful in improving diagnosis of HCT-related complications and monitoring treatment effect. Continued research to effectively manage EC activation, injury and dysfunction may be important in improving patient outcomes after HCT.

Diagnosis and Treatment of VOD/SOS After Allogeneic Hematopoietic Stem Cell Transplantation

Hepatic veno-occlusive disease (VOD) or sinusoidal obstruction syndrome (SOS) is a rare complication characterized by hepatomegaly, right-upper quadrant pain, jaundice, and ascites, occurring after high-dose chemotherapy, hematopoietic stem cell transplantation (HSCT) and, less commonly, other conditions. We review pathogenesis, clinical appearance and diagnostic criteria, risk factors, prophylaxis, and treatment of the VOD occurring post-HSCT. The injury of the sinusoidal endothelial cells with loss of wall integrity and sinusoidal obstruction is the basis of development of postsinusoidal portal hypertension responsible for clinical syndrome. Risk factors associated with the onset of VOD and diagnostic tools have been recently updated both in the pediatric and adult settings and here are reported. Treatment includes supportive care, intensive management, and specific drug therapy with defibrotide. Because of its severity, particularly in VOD with associated multiorgan disease, prophylaxis approaches are under investigation. During the last years, decreased mortality associated to VOD/SOS has been reported being it attributable to a better intensive and multidisciplinary approach.

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.