Veno-occlusive Research Articles

Application of artificial intelligence and machine learning for risk stratification acute kidney injury among hematopoietic stem cell transplantation patients: PCRRTICONIC AI Initiative Group Meeting Proceedings.

Acute kidney injury (AKI) is a frequent, severe complication of hematopoietic stem cell transplantation (HSCT) and is associated with an increased risk of morbidity and mortality. Recent advances in artificial intelligence (AI) and machine learning (ML) have showcased their proficiency in predicting AKI, projecting disease progression, and accurately identifying underlying etiologies. This review examines the central aspects of AKI post-HSCT, veno-occlusive disease (VOD) in HSCT recipients, discusses present-day applications of artificial intelligence in AKI, and introduces a proposed ML framework for the early detection of AKI risk.

The benefits of prophylactic defibrotide: Are the tides turning?

Veno-occlusive disease (VOD) is a life-threatening endotheliopathy that can occur after stem cell transplant (SCT). Numerous risk factors contribute to the development of VOD during SCT, and the role of prophylactic defibrotide (DF) in mitigating these risks remains unclear. We compare not only the incidence of VOD development, but also the severity of VOD and survival outcomes between patients who did and did not develop VOD and did or did not receive prophylactic DF. In this single-center retrospective study of 58 pediatric SCT patients from 2008 to 2022, we compare the demographics, risk profiles, and outcomes within three cohorts: Group 1: prophylactic DF and no VOD (n=5), Group 2: prophylactic DF and development of VOD (n=6), and Group 3: treatment DF for patients who developed VOD (n=47). Patients with VOD who did not receive prophylactic DF had higher severity classification of disease at onset (very severe 80.9% vs. 66.7%, p=.592) and at maximum severity (very severe 89.4% vs. 83.3%, p=.532), as opposed to mild, moderate, or severe categorization compared to those who did not receive prophylactic DF. Patients who developed VOD and did not receive prophylactic DF had a lower 1-year survival probability compared to those who received prophylactic DF and still developed VOD (51.1% vs. 75% alive at 1year, excluding the two subjects without adequate follow-up time, p=.266). Although, not statistically significant in our small retrospective study, there is potential overall survival and decreased VOD severity benefits of prophylactic DF.

Elevation of NT-proBNP Levels in Pediatric and Young Adult Hematopoietic Stem Cell Transplant Patients with Endotheliopathy

Background/Objectives: Hematopoietic stem cell transplantation (HSCT) in pediatric and young adult (YA) patients can lead to endotheliopathy, such as thrombotic microangiopathy (TMA), sinusoidal obstruction syndrome (SOS), and diffuse alveolar hemorrhage (DAH). Natriuretic peptides have been studied as markers of endotheliopathy and critical illness. We hypothesized that an elevation in NT-proBNP was associated with the development of endotheliopathy (DAH, SOS, or TMA) in the first 100 days following HSCT in pediatric and YA patients. Methods: IRB-exempt status was obtained. This retrospective case–control study reviewed HSCT at our institution from 2016 to 2020. Cases were selected based on an endotheliopathy diagnosis in the first 100 days after HSCT. Cases were matched with controls. Baseline and near-event NT-proBNP levels were compared between cases and matched controls. The effect of NT-proBNP levels on developing endotheliopathy was estimated using conditional logistic regression. Results: Sixty-two patients were included (31 cases, 31 controls). Near-event NT-proBNP was significantly higher in cases compared to controls (median: 473 vs. 187 pg/mL, p = 0.03, Wilcoxon rank–sum test), in contrast to comparison in baseline NT-proBNP (median: 86 vs. 86 pg/mL, p = 0.51). After adjusting for covariates, an association between near-event NT-proBNP and odds of developing endotheliopathy did not achieve statistical significance. However, trends from most common transplant indications suggested an association between an elevated near-event NT-proBNP level and endotheliopathy, particularly in acute lymphoblastic leukemia (ALL) patients. Conclusions: NT-proBNP should be studied further as a biomarker for endotheliopathy in pediatric and YA patients undergoing HSCT. This may be particularly relevant for patients undergoing HSCT for ALL.

Safety and feasibility of umbilical cord blood transplantation in children with neuronal ceroid lipofuscinosis: a retrospective study.

Ceroid lipofuscinosis neuronal (CLN) encompasses rare inherited neurodegenerative disorders that present in childhood with clinical features including epilepsy, psychomotor delay, progressive vision loss, and premature death. Published experience utilizing umbilical cord blood transplant (UCBT) for these disorders is limited. This retrospective analysis includes patients with CLN (2, 3, and 5) who underwent UCBT from 2012 to 2020. All subjects (n = 8) received standard-of-care myeloablative conditioning. Four also enrolled in clinical trial NCT02254863 and received intrathecal DUOC-01 cells posttransplant. Median age at UCBT was 5.9 years. All subjects achieved neutrophil engraftment with >95% donor chimerism at a median of 28.5 days. Sinusoidal obstructive syndrome was not observed. Severe acute graft-versus-host disease occurred in 12.5%. Other complications included autoimmune hemolytic anemia (25%) and viral reactivation/infection (62.5%). No transplant-related mortality was observed. Two CLN2 patients died, 1 from progressive disease and 1 from unknown cause at days +362 and +937, respectively. With median follow-up of 8 years, overall survival at 100 days and 24 months was 100% and 88%, respectively. Three of 4 CLN3 subjects stabilized Hamburg motor and language scores. While UCBT appears safe and feasible in these patients, given the variable expression and natural history, extended follow-up and further studies are needed to elucidate the potential impact of UCBT on clinical outcomes.

Idiopathic pulmonary hypertension in an adult with patent foramen ovale

The article is devoted to the clinical case of combined idiopathic pulmonary hypertension with an open foramen ovale of the atrial septum in a young man of 21 years old with progressive decrease in lung ventilation function. The relationship of pulmonary arterial hypertension with an open foramen ovale of the atrial septum is nearly not described in the literature, as it is rarely found in clinical practice. According to the classification, pulmonary hypertension is divided into idiopathic (primary), secondary and pulmonary hypertension caused by other causes. In the pathogenesis of any PAH, an important role belongs to a complex of vascular changes. Verification of vascular changes is carried out histologically. Variants of idiopathic pulmonary hypertension are plexiform and thrombotic arteriopathy, veno-occlusive disease, capillary hemangiomatosis. An open foramen ovale as a structural anomaly of the adult heart (a vestige of embryonic blood circulation) causes a variety of hemodynamic disorders that can affect the pathogenesis of pulmonary hypertension. Because of this, preclinical observation of a combination of plexiform and thrombotic arteriopathy with a patent foramen ovale of the interatrial septum in a young man of 21 years old and an attempt to determine the role of an open oval window in the progression of pulmonary hypertension and its effect on treatment is of interest. The diagnosis of idiopathic pulmonary hypertension was made based on the clinical picture, laboratory parameters, echocardiography and histological examination of pulmonary vessels. The article discusses the importance of a patent foramen ovale in the pathogenesis of idiopathic pulmonary hypertension.

Genetic testing in pulmonary hypertension in adults and children

Abstract Pathogenic genetic variants have been found in patients with different forms of pulmonary arterial hypertension (PAH). Our aim was to define the genetic background of patients with idiopathic PAH (IPAH), heritable PAH (HPAH), pulmonary veno-occlusive disease (PVOD) and PAH associated with congenital heart disease (PAH-CHD); both in adult and pediatric age. REHAP and REHIPED are Spanish, voluntary, multicenter registries that include patients with PAH. REHAP started in 2007 and includes patients over 18 years of age. REHIPED started in 2009 and collects patients between 2 months and 18 years of age. Patients with IPAH, HPAH, PVOD and PAH-CHD who have undergone a genetic testing were included. 413 adults and 122 children were analyzed. From 2011, Sanger sequencing and multiplex ligation-dependent probe amplification were used to detect genetic variants in the BMPR2, TBX4, and KCNK3 genes. Since 2014, a next generation sequencing (NGS) panel of 21 genes was applied. In 2017 this panel was expanded to cover 35 genes, and in 2019, it was expanded to 37 genes. Since 2020, whole-exome sequencing has been applied for the previously followed-up patients without known pathogenic/likely pathogenic (P/LP) genetic variants, and for each incident case. There was a statistically significant difference (p 0.031) in the etiologies among adults and children. The etiologies in adults were 242 (59%) IPAH, 25 (6%) HPAH, 83 (20%) PAH-CHD, 63 (15%) PVOD. The etiologies in children were 66 (54%) IPAH, 8 (7%) HPAH, 38 (31%) PAH-CHD, and 10 (8%) PVOD. The genetic testing had a variant in 121 (29%) adults (56% pathogenic, 9% likely pathogenic, 32% VUS) and 63 (52%) children (65% pathogenic, 16% LP, 19% VUS) (adults vs children p < 0.001). BMPR2 was the most frequent variant in both populations, followed by EIF2AK4. Patients with HAPH and PVOD are more likely to have a genetic variant, while PAH-CHD are the less likely to have one; both in adults and children (p<0.001). The etiology was reclassified after the genetic testing in 13% adults and 19% children (p 0.08); including 6 adults and 4 children initially classified as IPAH and then diagnosed of PVOD when a P/LP variant was found in EIF2AK4. Also, 5 children were initially diagnosed as IPAH and then reclassified as multisystemic disorders (4 NFU1 and 1 MECP2) In conclusion, a significant number of patients with PAH have a variant in genetic testing, especially if they are diagnosed in pediatric age. BMPR2 is the most frequent variant in our cohort, followed by EIF2AK4. Knowing the genetic background of our patients enables a better classification and understanding of the disease. This is especially important in patients initially diagnosed of PAHI who are then classified as PVOD. Also, knowing the genetic background may help develop new treatments in the future.

Fluid Overload in Children Following Hematopoietic Cell Transplant: A Comprehensive Review.

Fluid overload significantly increases morbidity and mortality in critically ill children. Following hematopoietic cell transplant (HCT), children are at a high risk of fluid accumulation due to essential increased fluid intake for nutrition, blood products, and antimicrobials. In addition, many complications predispose these children to capillary leak and fluid overload (FO), such as sinusoidal obstruction syndrome, engraftment syndrome, sepsis, and acute kidney injury (AKI). FO > 10% occurs in nearly half of children following HCT and is associated with a lower PICU survival rate. In addition, in children with acute respiratory failure post HCT, each 1% increase in cumulative fluid balance on d 3 increases the odds of PICU mortality by 3%. Furthermore, FO worsens AKI. Tools such as the renal angina index and urinary biomarkers such as neutrophil gelatinase-associated lipocalin can help identify patients at risk of AKI and FO. Early detection, prevention, and intervention are crucial to improving outcomes in this population. Management strategies include fluid restriction, diuretics, and continuous kidney replacement therapy (CKRT) when FO exceeds 10% and other measures have failed.

Inotuzumab Ozogamicin and Low-Intensity Chemotherapy in Older Patients With Newly Diagnosed CD22+ Philadelphia Chromosome-Negative B-Cell Precursor Acute Lymphoblastic Leukemia.

The use of inotuzumab ozogamicin (InO), a conjugated anti-CD22 monoclonal antibody, is becoming a promising frontline treatment for older patients with ALL. EWALL-INO is an open-label prospective multicenter phase II trial (ClinicalTrials.gov identifier: NCT03249870). Patients age 55 years and older with newly diagnosed CD22+ Philadelphia chromosome-negative (Ph-) B-cell precursor (BCP) ALL were eligible. After a prephase, a first induction consisting of vincristine, dexamethasone, and three injections of InO (0.8 mg/m2 day 1, 0.5 mg/m2 day 8/day 15) was followed by a second induction combining cyclophosphamide, dexamethasone, and two injections of InO (0.5 mg/m2 day 1/day 8). Responders received up to six cycles of chemotherapy consolidation and 18-month chemotherapy maintenance. Allotransplant was allowed after three consolidations. The primary end point was 1-year overall survival (OS). Between December 2017 and March 2022, 131 patients (median age 68 years) were included. Three patients died during induction 1 (n = 130), two from multiple organ failure and one from hemorrhage, and none during induction 2 (n = 120). After induction 2, 90% of the patients achieved complete remission (CR) or CR with incomplete platelet recovery (CRp) and 80% had measurable residual disease (MRD2) <10-4. Among responders (n = 119), 47 relapsed and 14 died in CR/CRp. One-year OS, relapse-free survival (RFS), and cumulative incidence of relapse (CIR) rates were 73.2%, 66%, and 25%, respectively. High-risk cytogenetics and lower CD22 expression (<70%) were associated with worse OS, while both high-risk cytogenetics and MRD2 ≥10-4 were associated with lower RFS and higher CIR. The 10 allotransplanted patients had very favorable outcomes (90% 2-year OS/RFS and no relapse). Only one nonfatal sinusoidal obstructive syndrome was documented during the study. Our results support InO's use in first-line regimens for older patients with CD22+ Ph- BCP-ALL.

Refractory Thrombocytopenia is the Earliest Diagnostic Criterion for Sinusoidal Obstruction Syndrome in Children.

Sinusoidal obstruction syndrome (SOS) is a life-threatening complication of hematopoietic stem cell transplantation (HSCT), whose diagnostic criteria changed over time to achieve a timelier diagnosis. Recently, pediatric-specific criteria presented by the European Society for Blood and Marrow Transplantation (pEBMT) incorporated transfusion-refractory thrombocytopenia (RT) as an early indicator of SOS in children. However, a comparison of all individual diagnostic parameters belonging to pEBMT and former SOS diagnostic criteria has never been performed. This retrospective study conducted at a pediatric tertiary care hospital analyzed all pediatric HSCT cases diagnosed with SOS among 170 children transplanted from 2009 to 2023. Eleven patients developed SOS during this period (incidence: 11/170, 6.5%). pEBMT, Seattle, and Baltimore criteria were retrospectively applied to the 11 cases and compared, showing that RT was the earliest fulfilled parameter (median onset: 6d post-HSCT). pEBMT and Seattle criteria identified 11/11 SOS cases, with pEBMT leading to an earlier diagnosis. RT typically manifested before diagnosis, with significantly higher platelet transfusion requirements before diagnosis than after. RT is the earliest satisfied criterion in pediatric SOS and typically occurs in the initial stages of the disease before diagnosis. Further research is needed to identify additional early indicators of pediatric SOS.

Total Marrow and Lymphoid Irradiation (TMLI) Is Associated with Good Early Outcomes in Patients Undergoing Matched Sibling Donor and Haplo-identical Transplants for Acute Lymphoblastic Leukemia

Total marrow and lymphoid irradiation [TMLI] can deliver higher doses of irradiation without increased toxicity. This study evaluated TMLI and Cyclophosphamide in patients undergoing stem cell transplantation for acute lymphoblastic leukemia [ALL] . Fifty-eight patients underwent matched related, unrelated or haplo-identical donor transplant using TMLI. The graft source was PBSC in all while GVHD prophylaxis consisted of cyclosporine with methotrexate or post-transplant cyclophosphamide. The median age was 20 years [range: 5 - 49] and included 20 children. Engraftment occurred in 56 [96.5%] at median of 15 days [range: 12 - 23] with 2 early deaths. Sinusoidal obstruction syndrome [SOS] was seen in 10 patients while hemorrhagic cystitis and cardiac dysfunction occurred in 2 patients each. Cumulative incidence of grade II - IV acute GVHD was 23.6% while grade III - IV was 10.9%. Chronic GVHD was seen in 46.9% while relapse was seen in 10 patients [17.2%]. The 2-year overall survival [OS] was 65.9 ± 6.8% and 2-year disease free survival [DFS] was 59 ± 6.7%. Outcomes were compared with 52 patients who received either Cy/TBI or Flu/Bu4 for conditioning during the same period. Engraftment rates and time to engraftment were similar. Acute GVHD [p = 0.002], regimen related toxicity [p = 0.043] and Day 100 non-relapse mortality [p = 0.020] were significantly lower with TMLI. TMLI was associated with better OS [p = 0.004] and DFS [p = 0.005] for haplo-identical transplants. Better DFS was seen with TMLI in patients with high-risk disease [p = 0.007] and disease status > CR1 [p = 0.041]. The use of TMLI and cyclophosphamide is associated with good outcomes in patients undergoing HSCT for ALL especially with haploidentical stem cell transplants.

S4475 Veno-Occlusive Disease as a Rare Complication of Ipilimumab and Nivolumab

S4475 Veno-Occlusive Disease as a Rare Complication of Ipilimumab and Nivolumab

GCN2 kinase activation mediates pulmonary vascular remodeling and pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is characterized by progressive increase of pulmonary vascular resistance and remodeling that result in right heart failure. Recessive mutations of EIF2AK4 gene (encoding general control nonderepressible 2 kinase, GCN2) are linked to heritable pulmonary veno-occlusive disease (PVOD) in patients but rarely in patients with PAH. The role of GCN2 kinase activation in the pathogenesis of PAH remains unclear. Here, we show that GCN2 was hyperphosphorylated and activated in pulmonary vascular endothelial cells (ECs) of hypoxic mice, monocrotaline-treated rats, and patients with idiopathic PAH. Unexpectedly, loss of GCN2 kinase activity in Eif2ak4-/- mice with genetic disruption of the kinase domain induced neither PVOD nor pulmonary hypertension (PH) but inhibited hypoxia-induced PH. RNA-sequencing analysis suggested endothelin-1 (Edn1) as a downstream target of GCN2. GCN2 mediated hypoxia-induced Edn1 expression in human lung ECs via HIF-2α. Restored Edn1 expression in ECs of Eif2ak4-/- mice partially reversed the reduced phenotype of hypoxia-induced PH. Furthermore, GCN2 kinase inhibitor A-92 treatment attenuated PAH in monocrotaline-treated rats. These studies demonstrate that GCN2 kinase activation mediates pulmonary vascular remodeling and PAH at least partially through Edn1. Thus, targeting GCN2 kinase activation is a promising therapeutic strategy for treatment of PAH in patients without EIF2AK4 loss-of-function mutations.

Early defibrotide therapy and risk factors for post-transplant veno-occlusive disease/sinusoidal obstruction syndrome in childhood.

Veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is a life-threatening complications of hematopoietic cell transplantation (HCT). We studied the impact of early defibrotide (DF) therapy on the outcomes of pediatric patients with VOD/SOS after transplantation, focusing on recent immunotherapies. A total of 111 pediatric patients who underwent HCT for malignant disease between February 2017 and March 2023 at Kyushu University Hospital were included. Among 111 patients of less than 20years of age who underwent HCT for malignancy at a single institution between 2017 and 2023, VOD/SOS occurred in 25 (23%) patients. VOD/SOS developed more frequently in the post-DF era (2020-2023, n=58) than in the pre-DF era (31% vs. 13%, p=.04). The proportion of patients with relapsed/refractory acute lymphoblastic leukemia (ALL) was higher in the post-DF era than in the pre-DF era (44% vs. 8%, p=.04). Early DF therapy that was started at two European Society for Blood and Marrow Transplantation diagnostic criteria reduced the severity of VOD/SOS (p<.01) in comparison to non-early therapy started at less than two criteria. A multivariate analysis indicated that a history of cytokine release syndrome (odds ratio [OR]=10.4, p=.01) and juvenile myelomonocytic leukemia (OR=8.98, p=.04), but not an endothelial activation and stress index (EASIX) score of greater than 0.85, were independent risk factors for VOD/SOS. Early DF therapy improves the severity and survival outcomes of post-transplant VOD/SOS in children. However, its incidence is increasing in the era of immunotherapy for progressive diseases.

A Phase I First-in-Human Study of ABBV-011, a Seizure-Related Homolog Protein 6-Targeting Antibody-Drug Conjugate, in Patients with Small Cell Lung Cancer.

Seizure-related homolog protein 6 (SEZ6) is a novel target expressed in small cell lung cancer (SCLC). ABBV-011, a SEZ6-targeted antibody conjugated to calicheamicin, was evaluated in a phase I study (NCT03639194) in patients with relapsed/refractory SCLC. We report initial outcomes of ABBV-011 monotherapy. ABBV-011 was administered intravenously once every 3 weeks during dose escalation (0.3-2 mg/kg) and expansion. Patients with SEZ6-positive tumors (≥25% of tumor cells with ≥1+ staining intensity by IHC) were preselected for expansion. Safety, tolerability, antitumor activity, and pharmacokinetics were evaluated. As of August 2022, 99 patients received ABBV-011 monotherapy [dose escalation, n = 36; Japanese dose evaluation, n = 3; dose expansion, n = 60 (1 mg/kg, n = 40)]; the median age was 63 years (range, 41-79 years). Also, 32%, 41%, and 26% of patients received 1, 2, and ≥3 prior therapies, respectively. The maximum tolerated dose was not reached through 2.0 mg/kg. The most common treatment-emergent adverse events were fatigue (50%), nausea (42%), and thrombocytopenia (41%). The most common hepatic treatment-emergent adverse events were increased aspartate aminotransferase (22%), increased γ-glutamyltransferase (21%), and hyperbilirubinemia (17%); two patients experienced veno-occlusive liver disease. The objective response rate was 19% (19/98). In the 1-mg/kg dose-expansion cohort (n = 40), the objective response rate was 25%; the median response duration was 4.2 months (95% confidence interval, 2.6-6.7); and the median progression-free survival was 3.5 months (95% confidence interval, 1.5-4.2). ABBV-011 1.0 mg/kg every 3 weeks monotherapy was well tolerated and demonstrated encouraging antitumor activity in heavily pretreated patients with relapsed/refractory SCLC. SEZ6 is a promising novel SCLC target and warrants further investigation.

Clinical analysis of allogeneic hematopoietic cell transplantation in 9 patients with hematological malignancies complicated by Gilbert's syndrome

From January 1, 2013, to March 1, 2024, nine patients with hematological malignancies complicated by Gilbert's syndrome in Peking University People's Hospital underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). The patients comprised seven male and two female cases, with a median age of 38 (13-60) years old. Among them, three cases were acute myeloid leukemia, three cases were acute lymphocytic leukemia, two cases were myelodysplastic syndrome, and one case was chronic myelomonocytic leukemia. None of the patients had viral hepatitis. Of the nine cases, seven cases received the Bu-Cy+ATG regimen, while the other two cases received the TBI-Cy+ATG regimen (Bu, busulfan; Cy, cyclophosphamide; ATG, antithymocyte immunoglobulin; and TBI, total body irradiation). All patients achieved neutrophil engraftment, and eight received platelet engraftment. The median total bilirubin level was 45.4 (22.5-71.2) μmol/L before transplantation and 22.0 (18.0-37.2) μmol/L on -1d of preconditioning. The total bilirubin level on +20d after the transplantation of eight patients decreased compared with the baseline level before transplantation. Moreover, one patient had a transient increase in the total bilirubin level on +5d after transplantation, which was considered to be attributed to the toxicity of Bu. No patients were complicated by hepatic veno-occlusive disease. The median follow-up time was 739 (42-2 491) days. During the follow-up period, one patient died of recurrence, and the remaining eight patients had disease-free survival events.

The spectrum of systemic sclerosis-associated pulmonary hypertension: Insights from the ASPIRE registry

There are limited data assessing the spectrum of systemic sclerosis-associated pulmonary hypertension (PH). Data for 912 systemic sclerosis patients assessed between 2000and 2020 were retrieved from the Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre (ASPIRE) registry and classified based on 2022 European Society of Cardiology/European Respiratory Society(ESC/ERS) guidelines and multimodality investigations. Reduction in pulmonary vascular resistance (PVR) diagnostic threshold to >2WU resulted in a 19% increase in precapillary PH diagnoses. Patients with PVR ≤2WU had superior survival to PVR >2-3WU which was similar to PVR >3-4WU. Survival in pulmonary arterial hypertension (PAH) was superior to PH associated with lung disease. However, patients with mild parenchymal disease on CT had similar characteristics and outcomes to patients without lung disease. Combined pre- and postcapillary PH had significantly poorer survival than isolated postcapillary PH. Patients with mean pulmonary arterial wedge pressure (PAWP) 13-15mmHg had similar haemodynamics and left atrial volumes to those with PAWP>15mmHg. Unclassified-PH had more frequently dilated left atria and higher PAWP than PAH. Although Unclassified-PH had a similar survival to No-PH, 36% were subsequently diagnosed with PAH or PH associated with left heart disease. The presence of 2-3 radiological signs of pulmonary veno-occlusive disease was noted in 7% of PAH patients and was associated with worse survival. Improvement in incremental shuttle walking distance of ≥30m following initiation of PAH therapy was associated with superior survival. PAH patients diagnosed after 2011 had greater use of combination therapy and superior survival. A number of systemic sclerosis PH phenotypes can be recognized and characterized using haemodynamics, lung function and multimodality imaging.

Mechanisms underlying age-associated exacerbation of pulmonary veno-occlusive disease.

Pulmonary veno-occlusive disease (PVOD) is a rare but severe form of pulmonary hypertension characterized by the obstruction of pulmonary arteries and veins, causing increased pulmonary artery pressure and leading to right ventricular (RV) heart failure. PVOD is often resistant to conventional pulmonary arterial hypertension (PAH) treatments and has a poor prognosis, with a median survival time of 2-3 years after diagnosis. We previously showed that the administration of a chemotherapy agent mitomycin C (MMC) in rats mediates PVOD through the activation of the eukaryotic initiation factor 2 (eIF2) kinase protein kinase R (PKR) and the integrated stress response (ISR), resulting in the impairment of vascular endothelial junctional structure and barrier function. Here, we demonstrate that aged rats over 1 year exhibit more severe vascular remodeling and RV hypertrophy than young adult rats following MMC treatment. This is attributed to an age-associated elevation of basal ISR activity and depletion of protein phosphatase 1, leading to prolonged eIF2 phosphorylation and sustained ISR activation. Pharmacological blockade of PKR or ISR mitigates PVOD phenotypes in both age groups, suggesting that targeting the PKR/ISR axis could be a potential therapeutic strategy for PVOD.

Hepatic Sinusoidal Disorders.

Hepatic sinusoids are highly specialized microcirculatory conduits within the hepatic lobules that facilitate liver functions. The sinusoids can be affected by various disorders, including sinusoidal dilatation, sinusoidal obstruction syndrome (SOS), sinusoidal cellular infiltration, perisinusoidal infiltration, and endothelial neoplasms, such as hemangioendothelioma and angiosarcoma. While these disorders, particularly SOS and neoplasms, can be life threatening, their clinical manifestation is often nonspecific. Patients may present with right upper quadrant pain, jaundice, hepatomegaly, ascites, splenomegaly, and unexplained weight gain, although the exact manifestation depends on the cause, severity, and duration of the disease. Ultimately, invasive tests may be necessary to establish the diagnosis. A comprehensive understanding of imaging manifestations of various sinusoidal disorders contributes to early diagnosis and can help radiologists detect subclinical disease. Additionally, specific imaging features may assist in identifying the cause of the disorder, leading to a more focused and quicker workup. For example, a mosaic pattern of enhancement of the liver parenchyma is suggestive of sinusoidal dilatation; peripheral and patchy reticular hypointensity of the liver parenchyma on hepatobiliary MR images is characteristic of SOS; and associated diffuse multiple hyperintensities on diffusion-weighted images may be specific for malignant sinusoidal cellular infiltration. The authors provide an overview of the pathogenesis, clinical features, and imaging appearances of various hepatic sinusoidal disorders, with a special emphasis on SOS. ©RSNA, 2024 Supplemental material is available for this article.

Rationale for Hepatitis C Virus Treatment During Hematopoietic Stem Cell Transplant in the Era of Novel Direct-Acting Antivirals.

Untreated hepatitis C (HCV) infection in patients undergoing hematopoietic stem cell transplantation (HSCT) can lead to worse outcomes. Traditionally, HSCT patients infected with HCV would wait until after immune reconstitution to receive HCV therapy, as the oncologic urgency of transplant would not allow time for a full preceding treatment course of HCV therapy. However, in the era of newer direct-acting antivirals (DAAs), we propose that concomitant treatment of HCV while undergoing HSCT is safe and feasible, while keeping in mind potential drug-drug interactions. A literature review was performed to summarize the available data on the impact of HCV on patients undergoing HSCT. Drug-drug interactions for DAA's and pertinent HSCT drugs were evaluated using Lexicomp online® and http://hep-druginteractions.org . During HSCT, HCV appears to be a conditional risk factor for sinusoidal obstruction syndrome and a potential risk factor for graft versus host disease, both of which are associated with increased mortality. HCV reactivation and exacerbation may impact the use of chemotherapeutics, but available studies haven't shown impact specifically on HSCT. Limited case reports exist but demonstrate safe and effective use DAAs during HSCT. These, along with a drug-drug interaction review demonstrate agents such as sofosbuvir/velpatasvir and glecaprevir/pibrentasvir are promising DAAs for use in HSCT. HCV infection may worsen outcomes for patients undergoing HSCT. Concomitant treatment of HCV during HSCT using newer DAAs appears feasible and may improve patient morbidity and mortality, however large-scale studies are needed to further support this practice.

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.