Early Fluid Overload Is Associated with an Increased Risk of Nonrelapse Mortality after Ex Vivo CD34-Selected Allogeneic Hematopoietic Cell Transplantation

Cardiovascular Management of Patients Undergoing Hematopoietic Stem Cell Transplantation: From Pretransplantation to Survivorship: A Scientific Statement From the American Heart Association

Hematopoietic stem cell transplantation can cure various disorders but poses cardiovascular risks, especially for elderly patients and those with cardiovascular diseases. Cardiovascular evaluations are crucial in pretransplantation assessments, but guidelines are lacking. This American Heart Association scientific statement summarizes the data on transplantation-related complications and provides guidance for the cardiovascular management throughout transplantation. Hematopoietic stem cell transplantation consists of 4 phases: pretransplantation workup, conditioning therapy and infusion, immediate posttransplantation period, and long-term survivorship. Complications can occur during each phase, with long-term survivors facing increased risks for late effects such as cardiovascular disease, secondary malignancies, and endocrinopathies. In adults, arrhythmias such as atrial fibrillation and flutter are the most frequent acute cardiovascular complication. Acute heart failure has an incidence ranging from 0.4% to 2.2%. In pediatric patients, left ventricular systolic dysfunction and pericardial effusion are the most common cardiovascular complications. Factors influencing the incidence and risk of complications include pretransplantation therapies, transplantation type (autologous versus allogeneic), conditioning regimen, comorbid conditions, and patient age. The pretransplantation cardiovascular evaluation consists of 4 steps: (1) initial risk stratification, (2) exclusion of high-risk cardiovascular disease, (3) assessment of cardiac reserve, and (4) optimization of cardiovascular reserve. Clinical risk scores could be useful tools for the risk stratification of adult patients. Long-term cardiovascular management of hematopoietic stem cell transplantation survivors includes optimizing risk factors, monitoring, and maintaining a low threshold for evaluating cardiovascular causes of symptoms. Future research should prioritize refining risk stratification and creating evidence-based guidelines and strategies to optimize outcomes in this growing patient population.

Early Postoperative Volume Overload is a Predictor of 1-Year Post-Transplant Mortality in Pediatric Heart Transplant Recipients

Fluid restriction and diuretic management are mainstays in the postoperative management of cardiac patients, at risk of volume overload and its deleterious effects on primary cardiac function and multi-organ systems. The importance of fluid homeostasis is further emphasized among orthotopic heart transplant recipients (OHT). We sought to investigate the relationship between postoperative volume overload, mortality, and allograft dysfunction among pediatric OHT recipients within 1-year of transplantation. This is a retrospective cohort study from a single pediatric OHT center. Children under 21 years undergoing cardiac transplantation between 2010 and 2018 were included. Cumulative fluid overload (cFO) was assessed as percent fluid accumulation adjusted for preoperative body weight. Greater than 10% cFO defined those with postoperative cFO and a comparison of postoperative cFO vs. no postoperative cFO (< 5%) is reported. 102 pediatric OHT recipients were included. Early cFO at 72 h post-OHT occurred in 14% and overall cFO at 1-week post-OHT occurred in 23% of patients. Risk factors for cFO included younger age, lower weight, and postoperative ECMO. Early cFO was associated with postoperative mortality at 1-year, OR 8.6 (95% CI 1.4, 51.6), p = 0.04, independent of age and weight. There was no significant relationship between cFO and allograft dysfunction, measured by rates of clinical rejection and cardiopulmonary filling pressures within 1-year of transplant. Early postoperative volume overload is prevalent and associated with increased risk of death at 1-year among pediatric OHT recipients. It may be an important postoperative marker of transplant survival, and this relationship warrants further clinical investigation.

Pretransplant Systemic Lipidomic Profiles in Allogeneic Stem Cell Transplant Recipients

Simple Summary

Stem cell transplantation is used in the treatment of aggressive hematological malignancies and consists of initial high-dose and potentially lethal chemotherapy, followed by rescue with the transplantation of hematopoietic stem cells. Transplantation with stem cells from a healthy donor (i.e., allogeneic stem cells) has the strongest anti-cancer effect, but also the highest risk of severe toxicity. Furthermore, the clinical status at the time of transplantation (inflammation, fluid overload) is associated with posttransplant mortality, and immune-mediated acute graft-versus-host disease (GVHD) is a potential lethal complication. Finally, lipid metabolism regulates the proliferation and survival of both malignant hematological cells and immunocompetent cells that cause GVHD. Our study shows that the pretransplant lipid profiles differ between allotransplant recipients and can be used for the subclassification of patients and possibly to identify patients with an increased risk of death due to disease relapse or treatment toxicity. The therapeutic targeting of lipid metabolism should therefore be further explored in these transplant recipients.

Abstract

Allogeneic stem cell transplantation is used in the treatment of high-risk hematological malignancies. However, this treatment is associated with severe treatment-related morbidity and mortality. The metabolic status of the recipient may be associated with the risk of development of transplant-associated complications such as graft-versus-host disease (GVHD). To better understand the impact of the lipidomic profile of transplant recipients on posttransplant complications, we evaluated the lipid signatures of patients with hematological disease using non-targeted lipidomics. In the present study, we studied pretransplant serum samples derived from 92 consecutive patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS). A total of 960 lipid biochemicals were identified, and the pretransplant lipidomic profiles differed significantly when comparing patients with and without the risk factors: (i) pretransplant inflammation, (ii) early fluid overload, and (iii) patients with and without later steroid-requiring acute GVHD. All three factors, but especially patients with pretransplant inflammation, were associated with decreased levels of several lipid metabolites. Based on the overall concentrations of various lipid subclasses, we identified a patient subset characterized by low lipid levels, increased frequency of MDS patients, signs of inflammation, decreased body mass index, and an increased risk of early non-relapse mortality. Metabolic targeting has been proposed as a possible therapeutic strategy in allotransplant recipients, and our present results suggest that the clinical consequences of therapeutic intervention (e.g., nutritional support) will also differ between patients and depend on the metabolic context.

A Clinical Review of the Different Strategies to Minimize Hemorrhagic Cystitis Associated with the Use of Post-Transplant Cyclophosphamide in an Allogeneic Transplant

Post-transplantation cyclophosphamide (PTCy) has improved hematopoietic stem cell transplantation outcomes for patients with major HLA disparities. Although PTCy in combination with calcineurin inhibitors is a successful graft-versus-host disease regimen, giving high doses of cyclophosphamide may cause hemorrhagic cystitis (HC). The strategies used to prevent HC are adapted from published data in the pre-transplantation conditioning setting. However, there is no consensus on what the optimal strategy is to prevent PTCy-associated HC. This review provides a summary of the different preventative strategies used in this setting. Based on the results published in current literature, hyperhydration is an effective preventative strategy, but it may cause fluid overload and other complications. Additionally, mesna at least 100% of the PTCy dose should be administered as a continuous infusion or frequent intermittent bolus infusion. More comparative studies between these strategies are needed to provide a definitive solution for preventing HC associated with PTCy.

Endocan in Acute Leukemia: Current Knowledge and Future Perspectives

Endocan is a soluble dermatan sulfate proteoglycan expressed by endothelial cells and detected in serum/plasma. Its expression is increased in tumors/tumor vessels in several human malignancies, and high expression (high serum/plasma levels or tumor levels) has an adverse prognostic impact in several malignancies. The p14 endocan degradation product can also be detected in serum/plasma, but previous clinical studies as well as previously unpublished results presented in this review suggest that endocan and p14 endocan fragment levels reflect different biological characteristics, and the endocan levels seem to reflect the disease heterogeneity in acute leukemia better than the p14 fragment levels. Furthermore, decreased systemic endocan levels in previously immunocompetent sepsis patients are associated with later severe respiratory complications, but it is not known whether this is true also for immunocompromised acute leukemia patients. Finally, endocan is associated with increased early nonrelapse mortality in (acute leukemia) patients receiving allogeneic stem cell transplantation, and this adverse prognostic impact seems to be independent of the adverse impact of excessive fluid overload. Systemic endocan levels may also become important to predict cytokine release syndrome after immunotherapy/haploidentical transplantation, and in the long-term follow-up of acute leukemia survivors with regard to cardiovascular risk. Therapeutic targeting of endocan is now possible, and the possible role of endocan in acute leukemia should be further investigated to clarify whether the therapeutic strategy should also be considered.

Endothelial dysfunction and vascular complications after allogeneic hematopoietic cell transplantation: an expert analysis

Allogeneic hematopoietic cell transplantation (alloHCT) is the standard of care for many diseases. However, survivors often present with serious complications resulting from acute and chronic toxicities and it is crucial to increase consciousness from treating physicians. We performed a comprehensive review of the literature and critically examined recent available data, mostly using the PubMed and Medline search engines for original articles published over the last decade. Better understanding of many alloHCT-related disorders has shown that endothelial injury and vascular damage plays a critical role. The most widely studied endothelial injury syndromes (EIS) are veno-occlusive disease/sinusoidal obstruction syndrome (SOS/VOD), graft-versus-host-disease (GVHD), and transplant-associated thrombotic microangiopathy (TA-TMA). TA-TMA, frequently underdiagnosed, needs to be clarified using certain criteria and, as a life-threatening condition, requires immediate and intensive treatment. The first-in-class complement inhibitor eculizumab has significantly improved outcomes in both the pediatric and adult population. Cardiovascular (CV) events are the second major cause of morbidity and mortality of alloHCT survivors, after GVHD. Long-term monitoring and management of CV risk is expected to also incorporate patient stratification with CV risk prediction models, early markers of vascular dysfunction or procoagulant activity, subclinical target organ damage, arterial stiffness, and subclinical atherosclerosis.

Fluid overload is associated with increased 90-day mortality in AML patients undergoing induction chemotherapy

Treatment‐related complications contribute substantially to morbidity and mortality in acute myeloid leukemia (AML) patients undergoing induction chemotherapy. Although AML patients are susceptible to fluid overload (FO) (e.g., in the context of chemotherapy protocols, during sepsis treatment or to prevent tumor lysis syndrome), little attention has been paid to its role in AML patients undergoing induction chemotherapy. AML patients receiving induction chemotherapy between 2014 and 2019 were included in this study. FO was defined as ≥5% weight gain on day 7 of induction chemotherapy compared to baseline weight determined on the day of admission. We found FO in 23 (12%) of 187 AML patients undergoing induction chemotherapy. Application of >100 ml crystalloid fluids/kg body weight until day 7 of induction chemotherapy was identified as an independent risk factor for FO. AML patients with FO suffered from a significantly increased 90-day mortality rate and FO was demonstrated as an independent risk factor for 90-day mortality. Our data suggests an individualized, weight-adjusted calculation of crystalloid fluids in order to prevent FO-related morbidity and mortality in AML patients during induction chemotherapy. Prospective trials are required to determine the adequate fluid management in this patient population.

Early bilirubinemia after allogeneic stem cell transplantation-an endothelial complication

Hyperbilirubinemia occurs frequently after allogeneic stem cell transplantation. Causes include primary liver damage and endothelial complications as major contributors. Here, we have investigated the impact of early bilirubinemia (EB) on posttransplant outcomes. Maximum total bilirubin levels (days 0-28) were categorized using maximally selected log rank statistics to identify a cut off for the endpoint non-relapse mortality (NRM) in a training cohort of 873 patients. EB above this cut off was correlated with NRM and overall survival (OS) and with pre- and posttransplant Angiopoietin-2, interleukin (IL)18, CXCL8 and suppressor of tumorigenicity-2 (ST2) serum levels, and the endothelial activation and stress index (EASIX). Clinical correlations were validated in a sample of 388 patients transplanted in an independent institution. The EB cut off was determined at 3.6 mg/dL (61.6 µM). EB predicted OS (HR 1.60, 95% CI 1.21-2.12, p < 0.001), and NRM (CSHR 2.14; 1.28-3.56, p = 0.004), also independent of typical endothelial complications such as veno-occlusive disease, refractory acute graft-versus-host disease, or transplant-associated microangiopathy. However, EB correlated with high Angiopoietin-2, EASIX-pre and EASIX-day 0, as well as increased levels of posttransplant CXCL8, IL18, and ST2. In summary, EB indicates a poor prognosis. The association of EB with endothelial biomarkers suggests an endothelial pathomechanism also for this posttransplant complication.

Stable renal function in children and adolescents with sickle cell disease after nonmyeloablative hematopoietic stem cell transplantation

BACKGROUND

Sickle cell disease (SCD) is associated with renal complications starting as early as infancy. Allogeneic hematopoietic stem cell transplant (HSCT) treatments using newer nonmyeloablative (NMA) conditioning regimens show promising results in treating SCD in the pediatric population, but renal outcome parameters after transplantation have not been described.

AIM

To describe baseline renal parameters as well as short- and long-term renal outcomes in pediatric patients with SCD who underwent NMA-HSCT.

METHODS

A retrospective chart review of pediatric patients who received NMA-HSCT in Alberta, Canada. Short-term renal outcomes evaluated were: (1) acute kidney injury (AKI), (2) fluid overload (FO), and (3) hypertension. Long-term outcomes evaluated were: (1) estimated glomerular filtration rate (eGFR) development and at last follow-up with hyperfiltration defined as eGFR ≥ 150 mL/min/1.73 m² , (2) proteinuria, and (3) hypertension.

RESULTS

The mean follow-up time was 128.6 weeks (standard deviations, 69.3). No posttransplant AKI events or FO were observed. eGFR remained > 90 mL/min/1.73 m² at last follow-up in all patients, whereas hyperfiltration was present in eight (44.4%) and four (22.2%) patients pre- and post-HSCT, respectively, which are significantly different (P < 0.0001). Consequently, median GFR was significantly higher pre-HSCT compared with 24 months HSCT (P < 0.009). Long-term hypertension post-HSCT was present in six patients (33.3%).

CONCLUSION

This study describes stable kidney function in children with SCD after NMA-HSCT without evidence of AKI or FO episodes. Rates of hyperfiltration decreased post-HSCT, which signifies that NMA-HSCT could potentially preserve long-term renal function in this population at risk of progressive chronic kidney disease. Further prospective studies are needed to confirm these novel findings.

Endothelial Activation and Stress Index (EASIX) at Admission Predicts Fluid Overload in Recipients of Allogeneic Stem Cell Transplantation

Fluid overload (FO) grade ≥2 (more than 10% weight gain from baseline) has recently been recognized as an important toxicity associated with a high rate of nonrelapse mortality in recipients of allogeneic hematopoietic cell transplantation (AHCT). The causes for FO remain unclear. We hypothesized that endothelial damage, possibly due to treatments received prior to AHCT, may be associated with this toxicity and sought to determine whether the Endothelial Activation and Stress Index (EASIX) (defined as lactate dehydrogenase [U/L] × creatinine [mg/dL]/platelets [10⁹ cells/L]) correlates with grade ≥2 FO in 2 cohorts of recipients of AHCT at our institution. We tested our hypothesis in a cohort of 145 consecutive recipients (study cohort) of AHCT transplant from HLA-haploidentical donors and validated the findings in a cohort of 449 (validation cohort) recipients of AHCT from HLA-matched donors who underwent transplantation between 2010 and 2015. Predictors of grade ≥2 FO were evaluated using competing risks regression in univariate analysis and classification and regression tree (CART) analysis in multivariate analysis. The cumulative incidence of grade ≥2 FO was estimated considering death as a competing risk. EASIX scores were evaluated based on log₂-transformed values. Optimal predictive EASIX cutoff values were determined based on receiver operating characteristics curve analysis. Grade ≥2 FO occurred in 21% and 6% of the study and validation cohorts, respectively, with the majority of these cases being diagnosed before the day of AHCT. Median log₂ EASIX score at admission was 2.4 (interquartile range [IQR], 1.3, 3.7) and 2.5 (IQR, 1.4, 3.9) in the 2 respective cohorts. In univariate analysis, high EASIX at admission was a significant predictor of grade ≥2 FO in the study (cutoff: 4.4, hazard ratio [HR] = 4.8, P < .001) and in the validation (cutoff: 4.3, HR = 4.8, P < .001) cohorts. The significant effect of EASIX persisted in multivariate CART analysis in the study (HR = 6.3, P < .001) and the validation (HR = 28, P = .002) cohorts. Additional predictors in multivariate analysis included body weight below 80 kg in recipients older than 55 years (HR = 4.5, P < .001) in the study cohort and diabetes (HR = 34, P = .001) and age >60 years (HR = 9.6, P = .04) in the validation cohort. At admission, the prevalence of EASIX score of >4.3 (18% versus 17%, P = .9) was not different between the diabetics and nondiabetics. EASIX score at admission is a significant predictor of grade ≥2 FO in recipients of AHCT from HLA-haploidentical or HLA-matched donors. Independently of EASIX, older patients with low weight were associated with increased risk of grade ≥2 FO for recipients of HLA-haploidentical transplants. For the HLA-matched cohort, diabetes and older age were associated with increased FO risk. These findings require validation in external cohorts.

Incidence and Risk Factors for Acute and Chronic Kidney Injury after Adult Cord Blood Transplantation

Although cord blood transplantation (CBT) extends allograft access, patient comorbidities, chemoradiation, and nephrotoxic medications all contribute to acute kidney injury (AKI) risk. We analyzed AKI in adult myeloablative CBT recipients who underwent transplantation from 2006 to 2017 for hematologic malignancies using cyclosporine A (CSA)/mycophenolate mofetil immunosuppression. Maximum grades of AKI were calculated using Kidney Disease: Improving Global Outcomes (grade 1, 1.5 to <2-fold; grade 2, 2 to <3-fold; or grade 3, ≥3-fold over baseline) definitions. In total, 153 patients (median 51 years [range, 23-65], 114/153 [75%] acute leukemia, 27/153 [18%] African, 88/153 [58%] cytomegalovirus seropositive, median age-adjusted hematopoietic cell comorbidity index 3 [range, 0-9], median pretransplant albumin 4.0 g/dL [range, 2.6-5.2]) underwent transplantation. The day 100 cumulative incidence of grade 1-3 AKI was 83% (95% confidence interval [CI], 77%-89%) (predominantly grade 2, median onset 40 days, range 0 to 96), and grade 2-3 AKI incidence was 54% (95% CI, 46%-62%) (median onset 43 days, range 0 to 96). Mean CSA level preceding AKI onset was high (360 ng/mL, target range 300-350). In multivariate analysis, African ancestry, addition of haploidentical CD34⁺ cells, low day -7 albumin, critical illness/intensive care admission, and nephrotoxic drug exposure (predominantly CSA and/or foscarnet) were associated with AKI. In a day 100 landmark analysis, 6% of patients with no prior AKI had chronic kidney disease (CKD) at 2 years versus 43% with prior grade 1 and 38% with prior grade 2-3 AKI (overall P= .02). Adult CBT recipients are at significant AKI risk, and AKI is associated with increased risk of CKD. Prevention strategies, early recognition, and prompt intervention are critical to mitigate kidney injury.

Allogeneic Stem Cell Transplantation with CD34+ Cell Selection

The success of allogeneic stem cell transplant is hampered by the development of acute and chronic graft-versus-host disease (GvHD) which has direct impact on treatment-related mortality and morbidity. As a result, T cell depletion through positive selection of CD34+ cells has emerged as a promising strategy to reduce acute and chronic GvHD in these patients.

In this review, we summarize the main characteristics of allogeneic stem cell transplant with CD34+ cell selection including risks of graft failure, GvHD, infection, organ toxicity, and long-term survival. Moreover, we highlight future strategies to improve the results of this platform and to consolidate its use in clinical practice.

Early fluid overload predicts higher non-relapse and overall mortality in adults after single-unit cord blood transplantation

Early fluid overload has been associated with poor transplant outcomes after allogeneic hematopoietic cell transplantation. However, its effects on the outcomes after cord blood transplantation (CBT) are unclear. We retrospectively analyzed the data of 227 adult patients who received single-unit CBT in our institute. The cumulative incidence of grade ≥2 fluid overload was 4% at day 30 after CBT with a median onset at 16 days (range, 9-30 days) after CBT. In the multivariate analysis, grade ≥2 fluid overload was significantly associated with higher non-relapse mortality (hazard ratio [HR], 5.73; P = 0.011) and overall mortality (HR, 3.81; P = 0.006). Among the entire cohort, 133 patients were treated with low-dose dopamine (0.5-2 µg/kg/min) with a median time of initiation of low-dose dopamine therapy at 10.5 days after CBT. Use of low-dose dopamine significantly increased daily urine output and decreased body weight. These data suggested that early fluid overload was significantly associated with non-relapse and overall mortality after single CBT. The early intervention of low-dose dopamine to prevent early fluid overload is a matter of future investigation for patients undergoing allogeneic hematopoietic cell transplantations (HCT), particularly for CBT.