Early bilirubinemia after allogeneic stem cell transplantation-an endothelial complication

Non-invasive Estimation of Microvasculopathy & Endothelial Dysfunction in Stem Cell Transplant Recipients and its Relationship with GVHD

Introduction

Microvasculopathy and endothelial dysfunction play important roles in the development of post-transplant complications, including graft-versus-host disease (GVHD). We assessed structural microvasculopathy by employing nailfold video capillaroscopy (NFVC) and endothelial dysfunction via flow-mediated dilatation (FMD) of the brachial artery in recipients of hematopoietic stem cell transplantation.

Patients and methods

Recipients of stem cell transplantation were included in this study post day+100 and divided into two cohorts. The first cohort consisted of 35 recipients of allogeneic hematopoietic stem cell transplantation (HCT) and the second cohort was comprised of 31 recipients of autologous HCT. A third cohort included 35 healthy individuals. NFVC was conducted on the second to fifth fingers of both hands using an Optilia video capillaroscope at 200× magnification, and the images were analyzed according to the European Alliance of Associations for Rheumatology (EULAR) criteria. The following parameters were used to measure vasculopathy: (a) median capillary density, derived from the capillary density of eight fingers, (b) median capillary diameter, derived from maximum capillary apical diameters of eight fingers, and (c) significant neoangiogenesis (neoangiogenesis present in ≥2 fingers). FMD of the right brachial artery was observed by high-resolution ultrasonography using the principle of post-occlusive reactive hyperemia, and video images were analyzed using edge-detecting software.

Results

The median capillary diameter was significantly higher in the allo-HCT cohort (20.56±5.17 micrometer) compared to the auto-HCT cohort (16.19±3.31 micrometer; p<0.001) and healthy controls (14.66±2.61 micrometer; p<0.001). The median capillary density was significantly lower in the allo-HCT cohort (median: 6 capillaries/mm, range: 5-9 capillaries/mm) compared to the auto-HCT cohort (median: 8.5 capillaries, range: 5-12 capillaries/mm; p<0.001) and healthy controls (median: 8 capillaries/mm, range: 7-10.5 capillaries/mm; p<0.001). The allo-HCT cohort had a higher proportion of patients with significant neoangiogenesis (86%) than the auto-HCT cohort (10%) and healthy controls (9%). The presence of significant neoangiogenesis was more frequent in the subgroup of patients with a history of GVHD (93%) compared to the subgroup of patients without any history of GVHD (57%; p=0.044). No significant differences in NFVC parameters or FMD were observed between recipients of myeloablative and reduced-intensity conditioning regimens. There was no significant difference in NFVC parameters between the auto-HCT cohort and healthy controls. There was no significant difference in FMD among the three cohorts; however, a higher proportion of patients in the allo-HCT cohort (28%) had lower FMD than those in the auto-HCT cohort (3%) and healthy controls (6%), suggesting endothelial dysfunction.

Conclusions

Our findings demonstrate the presence of structural microvasculopathy in allo-HCT recipients and suggest a possible role of alloreactivity in the pathogenesis of post-HCT microvasculopathy.

Incidence, Etiology and Prognosis of Initial Liver Injury After Allogeneic Hematopoietic Stem Cell Transplantation: A Multi-Center Retrospective Study

BACKGROUND

Liver injury post allogeneic hematopoietic stem cell transplantation (Allo-HSCT), particularly first-time occurrences, is a prevalent and severe complication.

METHODS

Clinical data from 262 patients treated at 3 medical centers in Shenzhen, China, between January 2018 and December 2021 were retrospectively collected. Risk factors and outcomes of initial liver injury post allo-HSCT were analyzed.

RESULTS

Liver injury occurred in 70.8% of patients, with drug-induced liver injury (DILI) being the most common cause. Other causes included graft-versus-host disease (GVHD) and veno-occlusive disease (VOD). Pre-transplant HBsAg positivity was a significant risk factor. Differences in the timing and survival outcomes were observed among patients with different causes and types of liver injury. Patients with VOD or hepatic aGVHD had lower overall survival compared to those with DILI or hepatic cGVHD. Patients with isolated enzyme elevation had a more favorable prognosis than those with isolated bilirubin elevation or simultaneous enzyme and bilirubin elevation.

CONCLUSION

Findings of our study serve as a crucial resource for clinicians, assisting in the challenging task of diagnosing and managing liver injuries after allo-HSCT, especially when it occurs for the first time, which may ultimately help to reduce early treatment-related mortality and enhance the long-term survival of transplant recipients.

Endothelial Activation and Stress Index in adults undergoing allogeneic hematopoietic cell transplantation with post-transplant cyclophosphamide-based prophylaxis

BACKGROUND AIMS

Post-transplant cyclophosphamide (PTCY)-based prophylaxis is becoming widespread for allogeneic hematopoietic cell transplantation (allo-HCT) performed independently of the selected donor source. In parallel, use of the Endothelial Activation and Stress Index (EASIX)-considered a surrogate parameter of endothelial activation-for predicting patient outcomes and clinical complications is gaining popularity in the allo-HCT setting.

METHODS

We first investigated whether the dynamics of EASIX after allo-HCT differ between patients receiving PTCY and patients receiving other prophylaxis. We then investigated whether the predictive capacity of EASIX persists in PTCY-based allo-HCT. A total of 328 patients transplanted between 2014 and 2020 were included, and 201 (61.2%) received PTCY.

RESULTS

EASIX trends differed significantly between the groups. Compared with patients receiving other prophylaxis, patients receiving PTCY had lower EASIX on day 0 and higher values between day 7 and day 100. In patients receiving PTCY, higher EASIX correlated significantly with higher non-relapse mortality (NRM) and lower overall survival (OS) when measured before and during the first 180 days after allo-HCT. In addition, higher EASIX scores measured at specific time points were predictors of veno-occlusive disease (VOD), transplant-associated thrombotic microangiopathy (TA-TMA) and grade 2-4 acute graft-versus-host disease (aGVHD) risk.

CONCLUSIONS

This study demonstrates how EASIX trends vary during the first 180 days after allo-HCT in patients receiving PTCY and those not receiving PTCY and validates the utility of this index for predicting NRM, OS and risk of VOD, TA-TMA and grade 2-4 aGVHD in patients receiving PTCY.

Preconditioning Modified-Easix as a Predictor of Prognosis in Allogeneic Hematopoietic Stem Cell Transplant Recipients

Allogeneic hematopoietic stem cell transplantation (alloHCT) is associated with severe complications, most of which share a common physiopathological background characterized by endothelial dysfunction. A novel risk assessment model, endothelial activation and stress index (EASIX), has been introduced as a predictor of endothelial activation. This retrospective study was performed to evaluate the predictive impact of EASIX/modified-EASIX (mEASIX) on transplant outcome. Medical records of 398 alloHCT recipients [median age: 43(17-71) years; M/F: 243/155] were examined. EASIX/mEASIX were calculated at specific time points before and after transplantation. EASIX/mEASIX were significantly associated with transplant complications including engraftment syndrome, sinusoidal obstruction syndrome, febrile neutropenia and transplant associated thrombotic microangiopathy. The probability of overall survival was significantly higher in low-preconditioning mEASIX (day -7) group (37% vs 25.2%; p = 0.008; HR: 2.057; 95% CI: 1.208-3.504). The probabilities of day30 mortality (2.9% vs 19.4%; p = 0.017; HR: 7.028; 95% CI: 1.418-34.836), day100 mortality (9% vs 33%; p = 0.004; HR: 4.469; 95% CI: 1.619-12.336) and non relapse mortality (44.8% vs 61.4%; p = 0.005; HR: 2.551; 95% CI: 1.318-4.941) were lower in low-preconditioning mEASIX (day -7) group. This retrospective cohort analysis demonstrates the significant impact of EASIX/mEASIX on transplant complications and survival. Prospective analyses are mandatory to assess the predictive role of EASIX/mEASIX in clinical practice.

EASIX Is an Accurate and Easily Available Prognostic Score in Critically Ill Patients with Advanced Liver Disease

Acute-on-chronic liver failure (ACLF) is associated with high mortality. Objective prognostic scores are important for treatment decisions. EASIX (Endothelial Activation and Stress Index) is a simple biomarker consisting of LDH, platelets, and creatinine, reflecting endothelial dysfunction after allogeneic stem cell transplantation. Considering endothelial dysfunction in the pathogenesis of ACLF, this study aimed to test the discriminative ability of EASIX in advanced liver disease. We retrospectively analysed the prognostic potential of EASIX to predict 28-day and 3-month mortality in a total of 188 liver cirrhotic patients requiring treatment at the intensive care unit. We evaluated the ability of EASIX to rule out early infections and predict the need for hemodialysis. EASIX performed moderately better than established scores in predicting 28-day mortality (AUC = 0.771) and was nearly equivalent (AUC = 0.791) to SOFA and APACHE-II in the prediction of 3-month mortality. Importantly, EASIX showed better diagnostic potential in ruling out clinically apparent infections than common proinflammatory markers (AUC = 0.861, p < 0.001) and showed suitable accuracy in predicting the need for hemodialysis (AUC = 0.833). EASIX is an accurate, objective and easily assessable biomarker for predicting mortality and complications in patients with advanced liver disease.

Role of endothelial cells in graft-versus-host disease

To date, the only curative treatment for high-risk or refractory hematologic malignancies non-responsive to standard chemotherapy is allogeneic hematopoietic transplantation (allo-HCT). Acute graft-versus-host disease (GVHD) is a donor T cell-mediated immunological disorder that is frequently fatal and the leading cause of non-relapse mortality (NRM) in patients post allo-HCT. The pathogenesis of acute GVHD involves recognition of minor and/or major HLA mismatched host antigens by donor T cells followed by expansion, migration and finally end-organ damage due to combination of inflammatory cytokine secretion and direct cytotoxic effects. The endothelium is a thin layer of endothelial cells (EC) that line the innermost portion of the blood vessels and a key regulator in vascular homeostasis and inflammatory responses. Endothelial cells are activated by a wide range of inflammatory mediators including bacterial products, contents released from dying/apoptotic cells and cytokines and respond by secreting cytokines/chemokines that facilitate the recruitment of innate and adaptive immune cells to the site of inflammation. Endothelial cells can also be damaged prior to transplant as well as by alloreactive donor T cells. Prolonged EC activation results in dysfunction that plays a role in multiple post-transplant complications including but not limited to veno-occlusive disease (VOD), transplant associated thrombotic microangiopathy (TA-TMA), and idiopathic pneumonia syndrome. In this mini review, we summarize the biology of endothelial cells, factors regulating EC activation and the role of ECs in inflammation and GVHD pathogenesis.

Preliminary Report for the Development of a Multiparameter Protocol for the Identification of Sinusoidal Obstruction Syndrome including Abdominal Ultrasound before and after Allogeneic Stem Cell Transplantation

Sinusoidal obstruction syndrome (SOS) is a rare complication after allogeneic hematopoietic stem cell transplantation (alloHSCT) caused by endothelial dysfunction. Previous definitions and diagnostic criteria for the presence of SOS include bilirubinemia, hepatomegaly and weight gain, but histological evaluation is still the only way to prove the diagnosis of SOS. However, biopsy remains an invasive technique and is therefore undesirable in the alloHSCT scenario. Hence, a non-invasive diagnostic strategy is critical. Besides thorough clinical assessment and laboratory values, ultrasound examination remains part of the diagnostic workflow in clinical routine. Previous studies defined sonographic abnormalities, which are associated with the occurrence of SOS, but a standardized protocol to perform reliable abdominal ultrasound has not been finally defined. In this study, we evaluated a multi-parameter protocol including laboratory values as well as ultrasound examination pre- and post-alloHSCT. The application of this protocol was feasible in clinical practice and achieved a high inter- and intra-rater reliability. In our population, no case of SOS was identifiable and, in line with previous studies, no changes known to be associated with SOS were detected by ultrasound examination in our cohort. Additionally, we investigated subgroups of patients partly fulfilling SOS diagnostic criteria analyzing correlations between the fulfilled criteria and aberrances in ultrasound measurements pre- and post-alloHSCT. Although statistical examination may be limited by a small sample size and missing SOS cases, hyperbilirubinemia, thrombocytopenia and weight gain showed only a coincidence with selected, enlarged liver dimensions in few patients. This may underline the fact that hepatomegaly occurs as an unspecific finding after alloHSCT. Our protocol, including the ultrasound examination pre- and post-alloHSCT and laboratory parameters, may help to rule out SOS early, but validation in a greater population and different transplantation centers is required to warrant broader appliance. Nevertheless, we aim to contribute to an elaborate and standardized work-flow in peri-alloHSCT patient care.

Endothelial cell dysfunction: a key determinant for the outcome of allogeneic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (alloSCT) carries the promise of cure for many malignant and non-malignant diseases of the lympho-hematopoietic system. Although outcome has improved considerably since the pioneering Seattle achievements more than 5 decades ago, non-relapse mortality (NRM) remains a major burden of alloSCT. There is increasing evidence that endothelial dysfunction is involved in many of the life-threatening complications of alloSCT, such as sinusoidal obstruction syndrome/venoocclusive disease, transplant-associated thrombotic microangiopathy, and refractory acute graft-versus host disease. This review delineates the role of the endothelium in severe complications after alloSCT and describes the current status of search for biomarkers predicting endothelial complications, including markers of endothelial vulnerability and markers of endothelial injury. Finally, implications of our current understanding of transplant-associated endothelial pathology for prevention and management of complications after alloSCT are discussed.