Clinical effects of recombinant thrombomodulin and defibrotide on sinusoidal obstruction syndrome after allogeneic hematopoietic stem cell transplantation

Utility of liver stiffness measurement in the diagnosis of sinusoidal obstruction syndrome/veno-occlusive disease after hematopoietic stem cell transplantation

PURPOSE

We aimed to assess the role of liver stiffness measurement (LSM), evaluated using transient elastography (TE), for the diagnosis of sinusoidal obstruction syndrome (SOS)/veno-occlusive disease (VOD), a complication of hematopoietic stem cell transplantation (HSCT).

METHODS

In this retrospective study, ultrasonography (US) and LSM were performed on 86 adult patients (55 men and 31 women) undergoing HSCT between January 2016 and December 2022. Characteristics and changes in liver stiffness (LS) were compared between patients with and without SOS/VOD.

RESULTS

Of the 86 patients, 14 were diagnosed with SOS/VOD. A significant increase in LS (ranging from 12.6 to 55.1 kPa, median 23.8 kPa) compared to pre-HSCT values was observed in all patients who developed SOS/VOD. The area under the receiver operating characteristic curve (AUROC) for the diagnosis of SOS/VOD was 0.9663 (0.933-0.995) for LS ≥ 17.4 kPa after HSCT. Post-transplant LS exceeded 17.4 kPa in all 14 patients in the SOS/VOD group (100%) and in seven patients in the non-SOS/VOD group (9.7%). The sensitivity and specificity were 100% and 90.3%, respectively. AUROC for the diagnosis of SOS/VOD was 0.973 (0.943-1.000) for LS increase ≥  + 12.6 kPa from baseline after HSCT. The change of ≥  + 12.6 kPa from baseline was observed in all 14 patients in the SOS/VOD group (100%) and in four patients in the non-SOS/VOD group (5.6%). The sensitivity and specificity were 100% and 94.4%, respectively.

CONCLUSION

LSM using TE may contribute to establishing the diagnosis of SOS/VOD after HSCT.

HokUS-10 scoring system predicts the treatment outcome for sinusoidal obstruction syndrome after allogeneic hematopoietic stem cell transplantation

Hepatic sinusoidal obstruction syndrome (SOS) is a severe and life-threatening complication after allogeneic hematopoietic stem cell transplantation (HSCT). We conducted a multi-center retrospective study to evaluate the utility of our ultrasonographic scoring system for the diagnosis of SOS (HokUS-10) in predicting SOS-related mortality (SOS-RM). We analyzed a total of 42 patients who developed SOS after HSCT. The cumulative incidences of SOS-RM, non-relapse mortality (NRM), and overall survival at day 180 after the diagnosis of SOS were 26.4%, 28.8% and 54.5%, respectively. The area under the receiver operating characteristic curve analysis showed that the optimal cut-off value of HokUS-10 total score to predict SOS-RM was 8 points after the treatment of SOS. In the individual HokUS-10 score, ascites and portal vein flow-related scores (PV mean velocity and PV flow direction) after the treatment of SOS were shown as significant risk factors for SOS-RM. Our study suggested that US findings after the treatment can predict the treatment outcomes for SOS.

Idiopathic hypereosinophilic syndrome with hepatic sinusoidal obstruction syndrome: A case report and literature review

BACKGROUND

Hypereosinophilic syndrome (HES) is classified as primary, secondary or idiopathic. Idiopathic HES (IHES) has a variable clinical presentation and may involve multiple organs causing severe damage. Hepatic sinusoidal obstruction syndrome (HSOS) is characterized by damage to the endothelial cells of the hepatic sinusoids of the hepatic venules, with occlusion of the hepatic venules, and hepatocyte necrosis. We report a case of IHES with HSOS of uncertain etiology.

CASE SUMMARY

A 70-year-old male patient was admitted to our hospital with pruritus and a rash on the extremities for > 5 mo. He had previously undergone antiallergic treatment and herbal therapy in the local hospital, but the symptoms recurred. Relevant examinations were completed after admission. Bone marrow aspiration biopsy showed a significantly higher percentage of eosinophils (23%) with approximately normal morphology. Ultrasound-guided hepatic aspiration biopsy indicated HSOS. Contrast-enhanced computed tomography (CT) of the upper abdomen showed hepatic venule congestion with hydrothorax and ascites. The patient was initially diagnosed with IHES and hepatic venule occlusion. Prednisone, low molecular weight heparin and ursodeoxycholic acid were given for treatment, followed by discontinuation of low molecular weight heparin due to ecchymosis. Routine blood tests, biochemical tests, and imaging such as enhanced CT of the upper abdomen and pelvis were reviewed regularly.

CONCLUSION

Hypereosinophilia may play a facilitating role in the occurrence and development of HSOS.

Efficacy and Safety of Recombinant Thrombomodulin for the Prophylaxis of Veno-Occlusive Complication in Allogeneiccit Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

BACKGROUND

Hepatic veno-occlusive disease (VOD), also termed as sinusoidal obstruction syndrome (SOS), is a lethal complication after hematopoietic stem cell transplantation (HSCT). Various factors put patients undergoing allogeneic HSCT at an increased risk for VOD. Thrombomodulin (TM) is an important factor which has a wide range of effects, including anticoagulant, anti-inflammatory, angiogenic, and protective effect, on endothelial cells. It plays a role in preventing excessive coagulation and thrombosis by binding with thrombin and inhibiting the coagulation cascade. There are a limited number of options for the prevention of this fatal complication. Recombinant thrombomodulin (rTM), an endothelial anticoagulant co-factor, as prophylactic therapy might be able to prevent veno-occlusive complications after stem cell transplantation.

METHODS

A literature search was performed on PubMed, Embase, and Web of Science. We used the following Mesh terms and Emtree terms, "Hepatic Veno-Occlusive Diseases" OR "Sinusoidal Obstruction" OR "Stem Cell Transplantations " AND "Thrombomodulin" from the inception of data up to April 1, 2021. The PICO (Patient/Population, Intervention, Comparison and Outcomes) framework was used for the literature search.

RESULTS

For the VOD incidence after HSCTstem cell transplantation, the result was in favor of rTM with a risk ratio (RR) of 0.53 (I² = 0%, 95% confidence interval [CI] = 0.32-0.89). The incidence of transplant-associated thrombotic microangiopathy (TA-TMA) after HSCT was reduced in rTM group. The RR for incidence of TA-TMA was 0.48 (I² = 62%, 95% CI = 0.20-1.17) favoring rTM. The RR for incidence of graft-versus-host disease (GvHD) was also lower in rTM group, 0.48 (I² = 64%, 95% CI = 0.32-0.72).

CONCLUSION

In our meta-analysis, we evaluate the efficacy and safety of rTM in the prevention of SOS after HSCT. According to our results, rTM use led to a significant reduction in SOS episodes, TA-TMA, and GvHD after HSCT.

Oxaliplatin-related Portal Hypertension Complicated with Esophageal Varices and Refractory Massive Ascites

Oxaliplatin, widely used as a chemotherapy drug for colorectal cancer, is known to cause various adverse reactions. In particular, special attention for the development of portal hypertension associated with porto-sinusoidal vascular disease is necessary, as it is a serious adverse life-threating reaction, although rare. We herein report a case of oxaliplatin-related portal hypertension that developed several years after oxaliplatin administration and led to esophageal varices and refractory massive ascites. Clinical physicians should be aware of the possibility of oxaliplatin-induced portal hypertension and its possible development over a long period after discontinuation of the drug.

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.

Allogeneic hematopoietic cell transplantation using fludarabine plus myeloablative busulfan and melphalan confers promising survival in high-risk hematopoietic neoplasms: a single-center retrospective analysis

OBJECTIVES

Optimal selection of pretransplant conditioning is crucially vital for improving survival and quality-of-life of patients who receive allogeneic hematopoietic cell transplantation (allo-HCT), particularly in those with high-risk diseases. In this study, we evaluated the efficacy and safety of recently-developed reduced-toxicity myeloablative regimen that combines fludarabine, intravenous busulfan, and melphalan (FBM).

METHODS

We conducted a single-center retrospective analysis of 39 patients (23 with myeloid neoplasms and 16 with lymphoid neoplasms), with a median age of 50 (range, 17-68) years, who underwent their first allo-HCT using the FBM regimen. Graft types were bone marrow in 11, peripheral blood in 11, and cord blood in 17 patients. Cyclosporine- or tacrolimus-based graft-versus-host disease (GVHD) prophylaxis was administered. The primary end point of the study was the overall survival rate at 2-year after transplantation.

RESULTS

After a median follow-up of 910 days for the surviving patients, 2-year overall survival was 62% for the entire cohort; 73% in the low-to-intermediate-risk group and 44% in the high-to-very high-risk group classified by the refined CIBMTR Disease Risk Index. Cumulative incidences of engraftment, grade II-IV acute GVHD, chronic GVHD, relapse, and non-relapse mortality were 95%, 56%, 56%, 31%, and 17%, respectively.

CONCLUSION

These results suggest that our FBM regimen can be applied to allo-HCT using various graft types and yields acceptable outcomes with relatively low non-relapse mortality in both myeloid and lymphoid neoplasms. Also, we observed a promising survival in the group of patients with high-risk diseases, warranting more accumulation of patients and longer follow-up.

Thrombomodulin as a Physiological Modulator of Intravascular Injury

Thrombomodulin (TM), which is predominantly expressed on the endothelium, plays an important role in maintaining vascular homeostasis by regulating the coagulation system. Intravascular injury and inflammation are complicated physiological processes that are induced by injured endothelium-mediated pro-coagulant signaling, necrotic endothelial- and blood cell-derived damage-associated molecular patterns (DAMPs), and DAMP-mediated inflammation. During the hypercoagulable state after endothelial injury, TM is released into the intravascular space by proteolytic cleavage of the endothelium component. Recombinant TM (rTM) is clinically applied to patients with disseminated intravascular coagulation, resulting in protection from tissue injury. Recent studies have revealed that rTM functions as an inflammatory regulator beyond hemostasis through various molecular mechanisms. More specifically, rTM neutralizes DAMPs, including histones and high mobility group box 1 (HMGB1), suppresses excessive activation of the complement system, physiologically protects the endothelium, and influences both innate and acquired immunity. Neutrophil extracellular traps (NETs) promote immunothrombosis by orchestrating platelets to enclose infectious invaders as part of the innate immune system, but excessive immunothrombosis can cause intravascular injury. However, rTM can directly and indirectly regulate NET formation. Furthermore, rTM interacts with mediators of acquired immunity to resolve vascular inflammation. So far, rTM has shown good efficacy in suppressing inflammation in various experimental models, including thrombotic microangiopathy, sterile inflammatory disorders, autoimmune diseases, and sepsis. Thus, rTM has the potential to become a novel tool to regulate intravascular injury via pleiotropic effects.

Advances in the diagnosis and treatment of disseminated intravascular coagulation in haematological malignancies

Haematological malignancies, including acute leukaemia and non-Hodgkin lymphoma, are one of the underlying diseases that frequently cause disseminated intravascular coagulation (DIC), an acquired thrombotic disorder. Concomitant DIC is associated with the severity of the underlying disease and poor prognosis. The Japanese Society on Thrombosis and Hemostasis released the new DIC diagnostic criteria in 2017. This criteria include coagulation markers such as soluble fibrin and the thrombin-antithrombin complex to more accurately evaluate the hypercoagulable state in patients. Among several groups of anticoagulants available, recombinant human soluble thrombomodulin is most frequently used to treat DIC caused by haematological malignancies in Japan. DIC is remitted in parallel with the improvement of the underlying haematological diseases; thus, there is room for debate regarding whether the treatment of DIC would improve the prognosis of patients. Haematopoietic stem cell transplantation as well as the recently introduced chimeric antigen receptor (CAR)-T-cell therapy are innovative therapies to produce a cure in a subset of patients with haematological malignancies. However, coagulopathy frequently occurs after these therapies, which limits the success of the treatment. For example, DIC is noted in approximately 50% of patients after CAT-T-cell therapy in conjunction with cytokine release syndrome. Hematopoietic stem cell transplantation (HSCT) causes endotheliitis, which triggers coagulopathy and the development of potentially lethal complications, such as sinusoidal obstruction syndrome/veno-occlusive disease and transplant-associated thrombotic microangiopathy. This review article describes the pathogenesis, clinical manifestation, diagnosis, and treatment of DIC caused by haematological malignancies, CAR-T-cell therapy, and HSCT.

Effects of recombinant thrombomodulin therapy and soluble human leukocyte antigen-G levels during hematopoietic stem cell transplantation

BACKGROUND

Conditioning chemotherapies for hematopoietic stem cell transplantation (HSCT), especially those that include total body irradiation, can result in serious complications such as graft-versus-host disease (GVHD). Human leukocyte antigen G (HLA-G) is a non-classical class I molecule with multiple immunoregulatory functions.

METHODS

We measured interleukin (IL)-10, transforming growth factor (TGF)β₁, and soluble HLA-G (sHLA-G) in HSCT patients and examined the relationship between sHLA-G levels and acute GVHD (aGVHD). Additionally, we investigated the effect of recombinant soluble thrombomodulin (rTM) therapy on sHLA-G levels. Our study cohort included 135 patients who underwent allogeneic HSCT at several institutions in Japan.

RESULTS

Serum levels of IL-10 and TGFβ₁ exhibited no significant changes following HSCT. In contrast, levels of sHLA-G were significantly increased at days 21 and 28 post-HSCT. For patients with confirmed complications, the frequency of aGVHD was significantly lower in those with a > 2.8-fold increase in sHLA-G levels at day 28 relative to day 7 post-HSCT. sHLA-G levels in patients who received rTM therapy were significantly higher at days 21 and 28 post-HSCT compared with those in patients who did not receive rTM therapy.

CONCLUSION

These data suggest that HLA-G/sHLA-G participate in prevention of GVHD, and that rTM may prevent aGVHD following HSCT by promoting elevation of sHLA-G.