Heparanase polymorphisms: influence on incidence of hepatic sinusoidal obstruction syndrome in children undergoing allogeneic hematopoietic stem cell transplantation

Genetic Susceptibility in Endothelial Injury Syndromes after Hematopoietic Cell Transplantation and Other Cellular Therapies: Climbing a Steep Hill

Hematopoietic stem cell transplantation (HSCT) remains a cornerstone in the management of patients with hematological malignancies. Endothelial injury syndromes, such as HSCT-associated thrombotic microangiopathy (HSCT-TMA), veno-occlusive disease/sinusoidal obstruction syndrome (SOS/VOD), and capillary leak syndrome (CLS), constitute complications after HSCT. Moreover, endothelial damage is prevalent after immunotherapy with chimeric antigen receptor-T (CAR-T) and can be manifested with cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). Our literature review aims to investigate the genetic susceptibility in endothelial injury syndromes after HSCT and CAR-T cell therapy. Variations in complement pathway- and endothelial function-related genes have been associated with the development of HSCT-TMA. In these genes, CFHR5, CFHR1, CFHR3, CFI, ADAMTS13, CFB, C3, C4, C5, and MASP1 are included. Thus, patients with these variations might have a predisposition to complement activation, which is also exaggerated by other factors (such as acute graft-versus-host disease, infections, and calcineurin inhibitors). Few studies have examined the genetic susceptibility to SOS/VOD syndrome, and the implicated genes include CFH, methylenetetrahydrofolate reductase, and heparinase. Finally, specific mutations have been associated with the onset of CRS (PFKFB4, CX3CR1) and ICANS (PPM1D, DNMT3A, TE2, ASXL1). More research is essential in this field to achieve better outcomes for our patients.

Biomarkers for early complications post hematopoietic cell transplantation: Insights and challenges

Hematopoietic cell transplantation is an established curative treatment option for various hematological malignant, and non-malignant diseases. However, the success of HCT is still limited by life-threatening early complications post-HCT, such as Graft Versus Host Disease (GVHD), Sinusoidal Obstruction Syndrome (SOS), and transplant-associated microangiopathy, to name a few. A decade of research in the discovery and validation of novel blood-based biomarkers aims to manage these early complications by using them for diagnosis or prognosis. Advances in this field have also led to predictive biomarkers to identify patients' likelihood of response to therapy. Although biomarkers have been extensively evaluated for different complications, these are yet to be used in routine clinical practice. This review provides a detailed summary of various biomarkers for individual early complications post-HCT, their discovery, validation, ongoing clinical trials, and their limitations. Furthermore, this review also provides insights into the biology of biomarkers and the challenge of obtaining a universal cut-off value for biomarkers.

Heparanase wildtype is associated with a reduced incidence of transplant-associated systemic vasculopathies

Some of the early complications of hematopoietic stem cell transplantation (HSCT) concerning the small vessels can be summarized as transplant-associated systemic vasculopathies (TASV). One enzyme known to play a major role in inflammation, tissue remodeling, and repair processes as well as tumor metastasis is heparanase (HPSE). HPSE genetic variants have recently been associated with significant influence on the risk of developing certain TASV such as a sinusoidal obstruction syndrome. This study aimed to validate the two known HPSE single nucleotide polymorphisms (SNPs)-rs4693608 and rs4364254-as a genetic predictor of TASV in a cohort of 494 patients and were correlated retrospectively with the clinical course post-HSCT. Significant association was revealed for rs4364254, showing that the incidence of TASV (38.0% vs. 57.8%, p = .009) and in particular of acute graft-versus-host disease (aGvHD) (36.3% vs. 54.0%, p = .0138) was lower in wildtype CC carriers than in TC/TT carriers. Moreover, compared with all other genotypes, the allelic combination GG-CC had the lowest incidence of TASV (34.9% vs. 57.4%, p = .0109) and aGvHD in particular (34.9% vs. 53.5%, p = .0315). A competing risk regression analysis confirmed a significantly reduced risk for a TASV in patients with GG (subhazard ratio [SHR] = 0.670, p = .043) and CC (SHR = 0.598, p = .041) compared with the corresponding homozygote SNP as well as for allelic combinations correlated with low HPSE gene expression (SHR = 0.630, p = .016) and in correlation with clinical risk factors. In summary, our study emphasizes an association of HPSE gene SNPs with TASV, in particular with aGvHD, which could be implementable as pre-transplant risk stratification if validated prospectively.

The HPSE Gene Insulator-A Novel Regulatory Element That Affects Heparanase Expression, Stem Cell Mobilization, and the Risk of Acute Graft versus Host Disease

The HPSE gene encodes heparanase (HPSE), a key player in cancer, inflammation, and autoimmunity. We have previously identified a strong HPSE gene enhancer involved in self-regulation of heparanase by negative feedback exerted in a functional rs4693608 single-nucleotide polymorphism (SNP) dependent manner. In the present study, we analyzed the HPSE gene insulator region, located in intron 9 and containing rs4426765, rs28649799, and rs4364254 SNPs. Our results indicate that this region exhibits HPSE regulatory activity. SNP substitutions lead to modulation of a unique DNA-protein complex that affects insulator activity. Analysis of interactions between enhancer and insulator SNPs revealed that rs4693608 has a major effect on HPSE expression and the risk of post-transplantation acute graft versus host disease (GVHD). The C alleles of insulator SNPs rs4364254 and rs4426765 modify the activity of the HPSE enhancer, resulting in altered HPSE expression and increased risk of acute GVHD. Moreover, rs4426765 correlated with HPSE expression in activated mononuclear cells, as well as with CD3 levels and lymphocyte counts following G-CSF mobilization. rs4363084 and rs28649799 were found to be associated with CD34⁺ levels. Our study provides new insight into the mechanism of HPSE gene regulation and its impact on normal and pathological processes in the hematopoietic system.

Analysis of risk factors for hepatic sinusoidal obstruction syndrome following allogeneic hematopoietic stem cell transplantation in pediatric patients

Purpose

Hepatic sinusoidal obstruction syndrome (SOS) represents a serious complication following hematopoietic stem cell transplantation (HSCT). Our study aimed to investigate important risk factors of SOS in a pediatric population.

Methods

This retrospective study analyzed 105 children, adolescents and young adults who underwent allogeneic HSCT at our pediatric HSCT center in Jena. The observation period was 12 years and SOS was defined by the pediatric criteria of the European Society for Blood and Marrow Transplantation (EBMT).

Results

15 out of all 105 patients developed SOS (14.3%). The median time from HSCT to SOS diagnosis was 12 days. The mortality rate of SOS was 20.0%. In univariate analyses, we identified the significant risk factors of patient age < 1 year [odds ratio (OR) = 7.25, p = 0.037], prior treatment with gemtuzumab ozogamicin (OR = 11.00, p = 0.020), high pretransplant ferritin levels above 1500 ng/mL (OR = 4.00, p = 0.033), 2000 ng/mL (OR = 4.69, p = 0.016), and 2400 ng/mL (OR = 5.29, p = 0.005) as well as international normalized ratio (INR) ≥ 1.3 (OR = 5.91, p = 0.009). The following risk factors could be confirmed in multivariate analysis: treatment with gemtuzumab ozogamicin (OR = 9.24, p = 0.048), ferritin > 2400 ng/mL (OR = 5.74, p = 0.023), and INR ≥ 1.3 (OR = 8.02, p = 0.007).

Conclusion

Our study confirms several risk factors from the current literature. Additionally, this is the first report on the risk factor of high pretransplant INR.

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.

Correlation between heparanase gene polymorphism and susceptibility to endometrial cancer

BACKGROUND

Endometrial cancer is one of the three most common malignancies in the female genital tract. Previous studies have demonstrated the association between heparanase (HPSE, OMIM 604,724) single-nucleotide polymorphism (SNP) and cancer risk in several cancers. However, its role in endometrial cancer remains unclear. The present study investigated the effects of HPSE SNPs on the susceptibility and clinicopathological parameters in patients with endometrial cancer.

METHODS

HPSE SNPs of rs4693608 (G > A) and rs4364254 (C > T) were analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay in 270 endometrial cancer patients and 320 healthy controls.

RESULTS

The investigation indicated that the HPSE SNP rs4693608 with GG showed a protective effect from EC in both codominant (adjusted OR = 0.41, 95%CI = 0.21-0.81, p = .026) and recessive models (adjusted OR = 0.43, 95%CI = 0.22-0.82, p = .0076). No significant differences were found in the incidences of EC patients with the rs4364254 polymorphisms compared to controls. Moreover, a significantly increased distribution of A/A (rs4693608) was observed in patients with grade ≥ 2 (p = .03) and in patients with positive cervical invasion (p = .042) while patients with T/C (rs4364254) had lower tumor grade.

CONCLUSION

Our study suggested that HPSE SNP of rs4693608 correlated strongly with susceptibility to EC, and HPSE SNPs might be a potential biomarker for prognosis of endometrial cancer.

Mechanism of HPSE Gene SNPs Function: From Normal Processes to Inflammation, Cancerogenesis and Tumor Progression

Single Nucleotide Polymorphisms (SNPs) is the substitution of a single nucleotide, stably inherited, highly abundant, and distributed throughout the genome. Up today 9746 SNPs were found in the HPSE gene. During 12 years 21 SNPs were analyzed in normal and pathological samples. The most prominent SNPs are rs4693608, rs11099592, rs4693084, and rs4364254. These SNPs were found in correlation with heparanase mRNA and protein expression among healthy persons. Moreover, an association of the HPSE gene SNPs with inflammatory processes, cancer development and progression was detected. SNP investigation allowed the identification of strong HPSE gene enhancer in the intron 2. In normal leukocytes, heparanase binds to the enhancer region and regulates HPSE gene expression via negative feedback in rs4693608 SNP-dependent manner. In malignant cells, heparanase halted self-regulation of the enhancer region. Instead of heparanase, the helicase-like transcription factor (HLTF) binds to the regulatory region. These and subsequent studies will elucidate how modification in the HPSE enhancer region could be applied to develop new approaches for cancer treatment.

The use of defibrotide in blood and marrow transplantation

Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of conditioning during hematopoietic stem cell transplantation (HSCT) or chemotherapy without HSCT, with a historically reported mean incidence of 13.7% post-HSCT. Typical symptoms of VOD/SOS may include hyperbilirubinemia, painful hepatomegaly, weight gain, and ascites. Defibrotide, a polydisperse mixture of predominantly single-stranded polydeoxyribonucleotides, is currently the only therapy approved to treat hepatic VOD/SOS with pulmonary/renal dysfunction (ie, multiorgan dysfunction/multiorgan failure [MOD/MOF]) following HSCT in the United States and to treat severe hepatic VOD/SOS post-HSCT in the European Union. In preclinical and human studies, defibrotide has demonstrated profibrinolytic, antithrombotic, anti-inflammatory, and angio-protective actions, thus promoting an anticoagulant phenotype of the endothelium that protects and stabilizes the function of endothelial cells. In a phase 3, historically controlled, multicenter trial in adults and children with VOD/SOS and MOD/MOF (defibrotide: n = 102; controls treated before defibrotide availability: n = 32), defibrotide resulted in significantly greater day +100 survival following HSCT (38.2%) vs controls (25.0%; propensity analysis-estimated between-group difference: 23%; P = .0109). The most common adverse events (AEs) were hypotension and diarrhea; rates of common hemorrhagic AEs were similar in the defibrotide and historical control group (64% and 75%, respectively). In a phase 3 prophylaxis trial, defibrotide was found to lower incidence of VOD/SOS in children (not an approved indication) and reduce the incidence of graft-versus-host disease. This review describes the development and clinical applications of defibrotide, focusing on its on-label use in patients with VOD/SOS and MOD/MOF after HSCT.

Identification of strong intron enhancer in the heparanase gene: effect of functional rs4693608 variant on HPSE enhancer activity in hematological and solid malignancies

Heparanase is an endo-β-glucuronidase that specifically cleaves the saccharide chains of heparan sulfate (HS) proteoglycans and releases HS-bound cytokines, chemokines, and bioactive growth-promoting factors. Heparanase plays an important role in the nucleus as part of an active chromatin complex. Our previous studies revealed that rs4693608 correlates with heparanase levels and increased risk of acute and extensive chronic graft vs. host disease (GVHD). Discrepancy between recipient and donor in this SNP significantly affected the risk of acute GVHD. In the present study, we analyzed the HPSE gene region, including rs4693608, and demonstrated that this region exhibits SNPs-dependent enhancer activity. Analysis of nuclear proteins from normal leukocytes revealed their binding to DNA probe of both alleles with higher affinity to allele G. All malignant cell lines and leukemia samples disclosed a shift of the main bands in comparison to normal leukocytes. At least five additional shifted bands were bound to allele A while allele G probe was bound to only one main DNA/protein complex. Additional SNPs rs4693083, rs4693084, and rs4693609 were found in strong linkage disequilibrium (LD) with rs11099592 (exon 7). Only rs4693084 affected protein binding to DNA in cell lines and leukemia samples. As a result of the short distance between rs4693608 and rs4693084, both SNPs may be included in a common DNA/protein complex. DNA pull-down assay revealed that heparanase is involved in self-regulation by negative feedback in rs4693608-dependent manner. During carcinogenesis, heparanase self-regulation is discontinued and the helicase-like transcription factor begins to regulate this enhancer region. Altogether, our study elucidates conceivable mechanism(s) by which rs4693608 SNP regulates HPSE gene expression and the associated disease outcome.

Diagnosis and severity criteria for sinusoidal obstruction syndrome/veno-occlusive disease in pediatric patients: a new classification from the European society for blood and marrow transplantation

The advances in hematopoietic cell transplantation (HCT) over the last decade have led to a transplant-related mortality below 15%. Hepatic sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) is a life-threatening complication of HCT that belongs to a group of diseases increasingly identified as transplant-related, systemic endothelial diseases. In most cases, SOS/VOD resolves within weeks; however, severe SOS/VOD results in multi-organ dysfunction/failure with a mortality rate >80%. A timely diagnosis of SOS/VOD is of critical importance, given the availability of therapeutic options with favorable tolerability. Current diagnostic criteria are used for adults and children. However, over the last decade it has become clear that SOS/VOD is significantly different between the age groups in terms of incidence, genetic predisposition, clinical presentation, prevention, treatment and outcome. Improved understanding of SOS/VOD and the availability of effective treatment questions the use of the Baltimore and Seattle criteria for diagnosing SOS/VOD in children. The aim of this position paper is to propose new diagnostic and severity criteria for SOS/VOD in children on behalf of the European Society for Blood and Marrow Transplantation.

Defibrotide for the treatment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome with multiorgan failure

Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome (VOD/SOS), is a potentially life-threatening and unpredictable complication of hematopoietic stem cell transplantation (HSCT). Characterized by a prothrombotic-hypofibrinolytic state, VOD/SOS typically presents with hyperbilirubinemia, ascites, weight gain and painful hepatomegaly; VOD/SOS with multiorgan failure may be associated with >80% mortality. Treatment has been mainly supportive. However, defibrotide is now approved in the USA for treatment of hepatic VOD/SOS with renal or pulmonary dysfunction following HSCT and in the European Union for treatment of severe hepatic VOD/SOS post-HSCT. In vitro evidence suggests defibrotide may restore thrombotic-fibrinolytic balance at the endothelial level and protect endothelial cells. Defibrotide has demonstrated significant reduction in VOD/SOS-related mortality and resolved VOD/SOS-related symptoms, with a manageable safety profile.

Consensus Report by Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplantation Consortium Joint Working Committees: Supportive Care Guidelines for Management of Veno-Occlusive Disease in Children and Adolescents, Part 1: Focus on Investigations, Prophylaxis, and Specific Treatment

Veno-occlusive disease (VOD) is a common and potentially fatal complication in children undergoing hematopoietic cell transplantation (HCT). It occurs in about one-third of all patients undergoing transplantation and is fatal in 50% of patients with severe disease. Early intervention and specific treatment with defibrotide are associated with improved outcomes. However, there is a lack of supportive care guidelines for management of the multiorgan dysfunction seen in most cases. There is high variability in the management of VOD, which may contribute to the increased morbidity and mortality. Although there is ample research in the specific treatment of VOD, there is paucity of literature regarding the management of ascites, transfusions requirements, fluids and electrolyte dysfunction, delirium, and investigations in children with VOD. The joint working committees of the Pediatric Acute Lung Injury and Sepsis Investigators and the Pediatric Blood and Marrow Transplantation Consortium collaborated to develop a series of evidence-based supportive care guidelines for management of VOD. The quality of evidence was rated and recommendations were made using Grading of Recommendations, Assessment, Development and Evaluation criteria. This manuscript is part 1 of the series and focuses on the need to develop these guidelines; methodology used to establish the guidelines; and investigations needed for diagnosis, prophylaxis, and treatment of VOD in children.

Role of Pharmacogenetics in Hematopoietic Stem Cell Transplantation Outcome in Children

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic procedure for several congenital and acquired disorders, both malignant and nonmalignant. Despite the great improvements in HSCT clinical practices over the last few decades, complications, such as graft vs. host disease (GVHD) and sinusoidal obstructive syndrome (SOS), are still largely unpredictable and remain the major causes of morbidity and mortality. Both donor and patient genetic background might influence the success of bone marrow transplantation and could at least partially explain the inter-individual variability in HSCT outcome. This review summarizes some of the recent studies on candidate gene polymorphisms in HSCT, with particular reference to pediatric cohorts. The interest is especially focused on pharmacogenetic variants affecting myeloablative and immunosuppressive drugs, although genetic traits involved in SOS susceptibility and transplant-related mortality are also reviewed.

Sinusoidal obstruction syndrome/veno-occlusive disease: current situation and perspectives-a position statement from the European Society for Blood and Marrow Transplantation (EBMT)

Sinusoidal obstruction syndrome or veno-occlusive disease (SOS/VOD) is a potentially life-threatening complication of hematopoietic SCT (HSCT). This review aims to highlight, on behalf of the European Society for Blood and Marrow Transplantation, the current knowledge on SOS/VOD pathophysiology, risk factors, diagnosis and treatments. Our perspectives on SOS/VOD are (i) to accurately identify its risk factors; (ii) to define new criteria for its diagnosis; (iii) to search for SOS/VOD biomarkers and (iv) to propose prospective studies evaluating SOS/VOD prevention and treatment in adults and children.