Improved Treatment-Related Mortality and Overall Survival of Patients with Grade IV Acute GVHD in the Modern Years

Antibiotic Prophylaxis During Allogeneic Stem Cell transplantation-A Comprehensive Single Center Retrospective Analysis

BACKGROUND

Prophylactic antibiotics are still controversial during allogeneic hematopoietic stem cell transplantation (allo-HSCT). In our transplant center, we suspended antibiotic prophylaxis during allo-HSCT in 2017.

OBJECTIVE

The main objective of this study was the detailed analysis of the potentially beneficial impact of omittance of standard antibiotic prophylaxis during allo-HSCT in survival and Graft-versus-Host disease (GvHD) development, especially with consideration of confounding factors and competing events. Secondary objectives were the evaluation of the risk of severe infections and transplant-related mortality without antibiotic prophylaxis, the detailed assessment of bacterial and viral infections including multiresistant pathogens as well as occurrence of relapse in both groups. This study aims to support the development of future antibiotic strategies in allo-HSCT.

STUDY DESIGN

We retrospectively analyzed patient outcome in the time periods before (between December 2012 and February 2017) and after suspension (between March 2017 and June 2020) of antibiotic prophylaxis during allo-HSCT. Relevant clinical outcome parameters of the patients (n = 221) were collected by chart-review in the two groups (with antibiotic prophylaxis n = 101 versus without antibiotic prophylaxis n = 120). All patients were 18 years or older. Propensity score methods were used to adjust for potentially confounding patient characteristics. To address competing events, transitions between moderate/severe acute and chronic GvHD, relapse and death were analyzed using an inverse-propensity score weighted multistate modeling approach.

RESULTS

While we observed a trend towards an improved outcome in the cohort without antibiotic prophylaxis, the inverse-propensity-score-weighted analyses did not show significant differences between the two groups in overall survival (OS) (P = .811) or development of acute GvHD (aGvHD) grade 3/4 (P = .158) and chronic moderate/severe GvHD (cGvHD) (P = .686). Multistate analysis respecting competing events revealed comparable estimated probabilities without antibiotic prophylaxis versus with antibiotic prophylaxis in OS (35.0% [95% CI: 28.2%-42.7%] versus 35.3% [95% CI: 27.8%-41.1%]) as well as development of aGvHD grade 3/4 (7.7% [95% CI: 5.9%-12.2%] vs. 10.6% [95% CI: 7.7%-15.7%]) and moderate/severe cGvHD (21.0% [95% CI: 17.7%-30.0%] vs. 23.8% [95% CI: 19.6%-31.4%]). Similar analyses showed also no significant differences in relapse rate, transplant-related mortality, relapse-related mortality, or GvHD-free/relapse-free survival between the two groups. An observed increase in severe infections without antibiotic prophylaxis did not lead to a significantly higher mortality rate. Viral reactivation and detection of multiresistant bacteria were comparable, yet a higher incidence of Clostridioides difficile infections was observed in patients receiving antibiotic prophylaxis.

CONCLUSION

Our study supports previous reports of noninferiority of allo-HSCT without use of antibiotic prophylaxis with close monitoring and rapid intervention, if infection is suspected. The trend towards improved outcomes without antibiotic prophylaxis, however, might not only be due to the absence of antibiotic prophylaxis but also due to additional progresses in the field over the recent years. While the present study is too small to draw definite conclusions, these results strongly warrant further multicenter studies addressing the potential benefit of omitting antibiotic prophylaxis during allo-HSCT.

Application of CD25 and CTLA4 gene transcription levels in early prediction of acute graft-versus-host disease

Introduction

Our study investigated the potential of peripheral blood T cell CD25, CD28, and CTLA-4 gene transcription levels as predictive biomarkers for acute graft-versus-host disease (aGVHD) following allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Methods

Real-time reverse transcription fluorescent quantitative PCR (RT-qPCR) analysis was conducted on day +7, +14, and +21 post-transplantation in patients undergoing allo-HSCT.

Results

Elevated levels of CD25 and CTLA-4 mRNA were found to be associated with the occurrence of aGVHD, as well as severe and gastrointestinal aGVHD. Receiver operating characteristic (ROC) curve analysis was utilized to assess the predictive value of each biomarker. Combined analysis of CD25 and CTLA-4 mRNA levels demonstrated promising predictive potential for aGVHD.

Conclusion

Our results confirmed that the transcription levels of CD25 and CTLA-4 genes could be used as early predictive biomarkers for aGVHD post-allo-HSCT.

Non-viral pathogens of infectious diarrhoea post-allogeneic stem cell transplantation are associated with graft-versus-host disease

Infectious diarrhoea is common post-allogeneic haematopoietic stem-cell transplantation (alloHSCT). While the epidemiology of Clostridioides difficile infection (CDI) post-alloHSCT has been described, the impact of other diarrhoeal pathogens is uncertain. We reviewed all alloHSCT between 2017 and 2022 at a single large transplant centre; 374 patients were identified and included. The 1-year incidence of infectious diarrhoea was 23%, divided into viral (13/374, 3%), CDI (65/374, 17%) and other bacterial infections (16/374, 4%). There was a significant association between infectious diarrhoea within 1 year post-transplant and the occurrence of severe acute lower gastrointestinal graft-versus-host disease (GVHD, OR = 4.64, 95% CI 2.57-8.38, p < 0.001) and inferior GVHD-free, relapse-free survival on analysis adjusted for age, donor type, stem cell source and T-cell depletion (aHR = 1.64, 95% CI = 1.18-2.27, p = 0.003). When the classes of infectious diarrhoea were compared to no infection, bacterial (OR = 6.38, 95% CI 1.90-21.40, p = 0.003), CDI (OR = 3.80, 95% CI 1.91-7.53, p < 0.001) and multiple infections (OR = 11.16, 95% CI 2.84-43.92, p < 0.001) were all independently associated with a higher risk of severe GI GVHD. Conversely, viral infections were not (OR = 2.98, 95% CI 0.57-15.43, p = 0.20). Non-viral infectious diarrhoea is significantly associated with the development of GVHD. Research to examine whether the prevention of infectious diarrhoea via infection control measures or modulation of the microbiome reduces the incidence of GVHD is needed.

Allogeneic hematopoietic stem cell transplantation for pediatric acute lymphoblastic leukemia

This study was aimed to explore the prognosis of allogenic hematopoietic stem cell transplantation (allo-HSCT) in pediatric patients with acute lymphoblastic leukemia (ALL). This retrospective case series study included children with ALL who underwent allo-HSCT at Beijing Children's Hospital of Capital Medical University, Beijing, China, between January 2009 and December 2019. The outcomes included 5-year overall survival (OS) and event-free survival (EFS). A total of 75 children (52 males) were included. The median age at presentation was 5.30 years, and the median time from diagnosis to transplantation was 1.64 years. There were 15 human leukocyte antigen (HLA)-matched and 60 HLA-semi-matched transplants, 73 complete remissions (CR), and 2 MRD-positive transplants. The median follow-up time was 41 months. Out of 75 patients, 51 children survived, and 24 died/given up at the terminal stage. The 5-year OS and EFS rates were 67.77% and 57.30%, respectively, whereas the 5-year recurrence rate was 35.69%. Acute and chronic graft versus host diseases occurred in 40 and 28 cases, respectively. Children with MLL gene fusion had higher survival rates compared to other subgroups. Haplo-HSCT is not inferior to HLA-matched transplant. The children with MLL rearrangement had an acceptable 5-year OS, while complications and relapse should be monitored.

Body Surface Area-Based Dosing of Mycophenolate Mofetil in Pediatric Hematopoietic Stem Cell Transplant Recipients: A Prospective Population Pharmacokinetic Study

Mycophenolate mofetil (MMF) is commonly used for acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). However, limited population pharmacokinetic (PPK) data are available for pediatric HSCT patients. This study aimed to develop a PPK model and recommend optimal oral MMF dosage in pediatric HSCT patients. This prospective study involved pediatric HSCT patients at a tertiary academic institution. Patients received oral MMF 15-20 mg/kg twice daily for aGVHD prophylaxis and treatment. The PPK analysis was conducted using a nonlinear mixed-effects modeling method. Simulation was performed considering different body surface areas (BSAs) (0.5 m2, 1.0 m2, 1.5 m2) and dosing (400 mg/m2, 600 mg/m2, 900 mg/m2 twice daily). Based on the simulation, an optimal dosage of oral MMF was suggested. A total of 20 patients and 80 samples were included in the PPK model development. A one-compartment model with first-order absorption adequately described the pharmacokinetics of mycophenolic acid (MPA). BSA was a statistically significant covariate on Vd/F. Simulation suggested the optimal dosage of oral MMF as 900 mg/m2 twice daily, respectively. A reliable PPK model was developed with good predictive performance. This model-informed optimal MMF dosage in pediatric HSCT patients can provide valuable dosing guidance in real-world clinical practice.

Understanding and treatment of cutaneous graft-versus-host-disease

The skin is the outermost mechanical barrier where dynamic immune reactions take place and is the most commonly affected site in both acute and chronic graft-versus-host disease (GVHD). If not properly treated, pain and pruritis resulting from cutaneous GVHD can increase the risk of secondary infection due to erosions, ulcerations, and damage of underlying tissues. Furthermore, resulting disfiguration can cause distress and significantly impact patients' quality of life. Thus, a deeper understanding of skin-specific findings of GVHD is needed. This review will highlight some promising results of recent pre-clinical studies on the pathophysiology of skin GVHD and summarize the diagnostic and staging/grading procedures according to the clinical manifestations of skin GVHD. In addition, we will summarize outcomes of various GVHD treatments, including skin-specific response rates.

Graft conditioning with fluticasone propionate reduces graft-versus-host disease upon allogeneic hematopoietic cell transplantation in mice

Hematopoietic cell transplantation (HCT) treats many blood conditions but remains underused due to complications such as graft-versus-host disease (GvHD). In GvHD, donor immune cells attack the patient, requiring powerful immunosuppressive drugs like glucocorticoids (GCs) to prevent death. In this study, we tested the hypothesis that donor cell conditioning with the glucocorticoid fluticasone propionate (FLU) prior to transplantation could increase hematopoietic stem cell (HSC) engraftment and reduce GvHD. Murine HSCs treated with FLU had increased HSC engraftment and reduced severity and incidence of GvHD after transplantation into allogeneic hosts. While most T cells died upon FLU treatment, donor T cells repopulated in the hosts and appeared less inflammatory and alloreactive. Regulatory T cells (Tregs) are immunomodulatory and survived FLU treatment, resulting in an increased ratio of Tregs to conventional T cells. Our results implicate an important role for Tregs in maintaining allogeneic tolerance in FLU-treated grafts and suggest a therapeutic strategy of pre-treating donor cells (and not the patients directly) with GCs to simultaneously enhance engraftment and reduce GvHD upon allogeneic HCT.

Acute graft-versus-host disease

Acute graft-versus-host disease (GVHD) is a common immune complication that can occur after allogeneic haematopoietic cell transplantation (alloHCT). Acute GVHD is a major health problem in these patients, and is associated with high morbidity and mortality. Acute GVHD is caused by the recognition and the destruction of the recipient tissues and organs by the donor immune effector cells. This condition usually occurs within the first 3 months after alloHCT, but later onset is possible. Targeted organs include the skin, the lower and upper gastrointestinal tract and the liver. Diagnosis is mainly based on clinical examination, and complementary examinations are performed to exclude differential diagnoses. Preventive treatment for acute GVHD is administered to all patients who receive alloHCT, although it is not always effective. Steroids are used for first-line treatment, and the Janus kinase 2 (JAK2) inhibitor ruxolitinib is second-line treatment. No validated treatments are available for acute GVHD that is refractory to steroids and ruxolitinib, and therefore it remains an unmet medical need.

Risk and promise: an 11-year, single-center retrospective study of severe acute GVHD in pediatric patients undergoing allogeneic HSCT for nonmalignant diseases

Background

Hematopoietic stem cell transplantation (HSCT) is the only curative option for many nonmalignant hematopoietic-derived diseases in pediatric patients. Survival after HSCT has improved in recent years and resulted in a 90% survival rate and cure in some nonmalignant diseases. Graft-vs.-host disease (GVHD) remains a frequent and major complication of HSCT, and a leading cause of morbidity and mortality. Prognosis of patients with high-grade GVHD is dismal, with survival rates varying from 25% in the adult population to 55% in pediatric patients.

Methods

The main aim of this study is to evaluate the incidence, risk factors, and outcome of severe acute GVHD (AGVHD) in pediatric patients with nonmalignant diseases, following allogeneic HSCT. Clinical and transplant data were retrospectively collected for all pediatric patients who underwent allogeneic HSCT for nonmalignant diseases at the Hadassah Medical Center between 2008 and 2019. Patients who developed severe AGVHD were compared with those who did not.

Results

A total of 247 children with nonmalignant diseases underwent 266 allogeneic HSCTs at Hadassah University Hospital over an 11-year period. Seventy-two patients (29.1%) developed AGVHD, 35 of them (14.1%) severe AGVHD (grade 3-4). Significant risk factors for developing severe AGVHD were unrelated donor (p < 0.001), mismatch donor (p < 0.001), and the use of peripheral blood stem cells (PBSCs) (p < 0.001). Survival rates of pediatric patients with severe AGVHD was 71.4%, compared with 91.9% among those with mild (grade 1-2) AGVHD and 83.4% among patients without AGVHD (p = 0.067).

Conclusions

These results demonstrate a high survival rate in pediatric patients with nonmalignant diseases despite severe GVHD. Significant mortality risk factors found in these patients were the source of donor PBSC (p = 0.016) and poor response to steroid treatment (p = 0.007).

Late Effects of Severe Acute Graft-versus-Host Disease on Quality of Life, Medical Comorbidities, and Survival

Grade III-IV acute graft-versus-host disease (aGVHD) is associated with high short-term morbidity and mortality following allogeneic hematopoietic cell transplantation (HCT). The long-term effects after recovery from grade III-IV aGVHD are unknown. This study aimed to analyze late medical comorbidities, quality of life, nonrelapse mortality, and survival in patients treated for grade III-IV aGVHD. Chart review identified late effects, and patients were asked to complete annual surveys to collect patient-reported outcomes. Outcomes were compared between patients with grade 0-I aGVHD and grade III-IV aGVHD who underwent HCT between 2001 and 2019 and survived for at least 1 year post-transplantation. Patients with a history of grade III-IV aGVHD (n = 192) had significantly higher rates of late medical comorbidities (P < .001) and worse physical (P = .01) and mental (P = .04) functioning compared with patients with grade 0-I aGVHD (n = 615). Patients who survived for >1 year post-transplantation and had prior grade III-IV aGVHD also had worse 5-year overall survival (77.5% versus 83.6%; P = .006) and higher nonrelapse mortality (19.2% versus 10.6%; P < .001) compared with those with a history of grade 0-I aGVHD. No between-group difference was found in cumulative incidence of chronic GVHD. Patients who recover from severe aGVHD remain vulnerable to developing late comorbidities. These patients would likely benefit from continued monitoring and supportive care in an attempt to prevent late effects and improve survival.

Multi-institutional development and validation of a novel histologic grading system for colonic graft-versus-host disease

Graft-versus-host disease (GVHD) remains a major complication for patients who have undergone hematopoietic stem cell transplantation. The Lerner system is the most widely used histologic grading score for gastrointestinal GVHD but its clinic utility is debated. The aim of our study was to develop a novel histologic grading system for gastrointestinal GVHD that incorporates independent evaluation of both apoptotic counts and crypt destruction. Colonic biopsies taken to assess for GVHD were retrospectively assessed for: Crypt damage (No crypt dropout or ulceration-0; crypt dropout without ulceration-1; ulceration-2) and crypt apoptotic counts (No apoptosis-0; 1-6 apoptotic bodies per 10 contiguous crypts-1; >6apoptotic bodies per 10 contiguous crypts-2). The two scores were added together to get an overall grade (0-4). Alternative apoptotic cutoff points were examined. An apoptotic cutoff of >9 apoptotic bodies per 10 contiguous crypts marginally improved the area under the curve (AUC), but the AUCs from the resulting novel grade calculations were not significantly different (p = 0.10). Lerner grading was also applied. The study group consisted of an initial analysis cohort (n = 191) and a second validation cohort from a separate institution (n = 97). In the initial analysis cohort, our histologic grading system provided prognostic stratification for GVHD-related death within 6 months (p = 0.0004, AUC = 0.705). The Lerner system performed similarly in terms of providing prognostic stratification for GVHD-related death (p = 0.0001, AUC = 0.707). In the external validation cohort, our histologic grading system was not associated with GVHD-related death (p = 0.14, AUC = 0.621), but the Lerner system was associated with GVHD-related death (p = 0.048, AUC = 0.663). While our grading system may have some advantages compared to the Lerner system, due to lack of reproducibility we do not currently recommend widespread adoption of this system. Nonetheless, we present a standardized tool for assessing both apoptosis and crypt damage. Future studies assessing alternative histologic grading systems with external validation and further examination the lower apoptotic threshold for GVHD diagnosis are warranted.

Increased risk of nonrelapse mortality post T-cell-replete haploidentical stem cell transplantation in patients with recurrence of acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) causes significant morbidity and mortality. While most studies focus on classic or late aGVHD, some patients with previous aGVHD achieve complete remission and later develop another episode of aGVHD. Data on recurrence of aGVHD (RaGVHD) are lacking. This study aimed to identify the incidence, risk factors, and impacts of RaGVHD after T-cell-replete haploidentical hematopoietic cell transplantation (haplo-HCT) without posttransplantation cyclophosphamide. We evaluated patients with RaGVHD after haplo-HCT between 2017 and 2019 and compared their outcomes to those of patients with no aGVHD and those of patients with one episode of de novo aGVHD. Of 199 patients included in the analysis, 45 experienced 50 cases of RaGVHD with a 1-year cumulative incidence of 19.0% (95% CI: 14.5-24.6). Grade III-IV aGVHD was more common in RaGVHD than in previous aGVHD (22.2% vs 4.4%, p = 0.01). Female donor to male recipient was strongly associated with RaGVHD (HR: 2.5, p = 0.009). The most common death in patients with RaGVHD was GVHD-related, which was different from controls who mostly died from relapse (p =0.008). RaGVHD was an independent risk factor for chronic GVHD (HR: 2.6, p = 0.006) and nonrelapse mortality (HR: 2.4, p = 0.019) and a significant predictor of lower GVHD relapse-free survival (HR: 1.9, p = 0.020) and cGVHD relapse-free survival (HR: 2.1, p = 0.007). In conclusion, clinical manifestations and negative impacts of RaGVHD needs to be recognized independently. This article is protected by copyright. All rights reserved.

Improved Therapeutic Approaches are Needed to Manage Graft-versus-Host Disease

Allogeneic haematopoietic stem cell transplantation (alloHSCT) offers a potentially curative therapy for patients suffering from diseases of the haematopoietic system but requires a high level of expertise and is both resource intensive and expensive. A frequent and life-threatening complication is graft-versus-host disease (GvHD). Acute GvHD (aGvHD) generally causes skin, gastrointestinal and liver symptoms, but chronic GvHD (cGvHD) has a different pathophysiology and may affect nearly every organ or tissue of the body. In Europe, GvHD prophylaxis is generally a calcineurin inhibitor in combination with methotrexate, with high-dose systemic steroids used for advanced GvHD treatment. Between 39% and 59% of alloHSCT patients will develop aGvHD and around 36–37% will develop cGvHD. Steroid response decreases with increasing disease severity, which in turn leads to an increase in non-relapse mortality. GvHD imposes a financial burden on healthcare systems, significantly increasing post-alloHSCT costs. Increased GvHD disease severity magnifies this. Balancing immunosuppression to control the GvHD whilst maintaining a degree of immunocompetence against infection is critical. European GvHD guidelines acknowledge the lack of evidence to support a standard second-line therapy, and improved long-term outcomes and quality-of-life (QoL) remain an unmet need. Evidence generation for potential treatments is challenging. Issues to overcome include choice of comparator (extensive off-label usage); blinding; selection of relevant patient-reported outcome measures (PROMs); and rarity of the condition, which may infeasibly increase timescales to achieve clinical and statistical relevance.

Targeting the CD27-CD70 Pathway to Improve Outcomes in Both Checkpoint Immunotherapy and Allogeneic Hematopoietic Cell Transplantation

Immune checkpoint inhibitor therapies and allogeneic hematopoietic cell transplant (alloHCT) represent two distinct modalities that offer a chance for long-term cure in a diverse array of malignancies and have experienced many breakthroughs in recent years. Herein, we review the CD27-CD70 co-stimulatory pathway and its therapeutic potential in 1) combination with checkpoint inhibitor and other immune therapies and 2) its potential ability to serve as a novel approach in graft-versus-host disease (GVHD) prevention. We further review recent advances in the understanding of GVHD as a complex immune phenomenon between donor and host immune systems, particularly in the early stages with mixed chimerism, and potential novel therapeutic approaches to prevent the development of GVHD.

Is it time to reconsider prophylactic antimicrobial use for hematopoietic stem cell transplantation? a narrative review of antimicrobials in stem cell transplantation

INTRODUCTION

Hematopoietic Stem Cell Transplantation (HSCT) is a life-saving procedure for multiple types of hematological cancer, autoimmune diseases, and genetic-linked metabolic diseases in humans. Recipients of HSCT transplant are at high risk of microbial infections that significantly correlate with the presence of graft-versus-host disease (GVHD) and the degree of immunosuppression. Infection in HSCT patients is a leading cause of life-threatening complications and mortality.

AREAS COVERED

This review covers issues pertinent to infection in the HSCT patient, including bacterial and viral infection; strategies to reduce GVHD; infection patterns; resistance and treatment options; adverse drug reactions to antimicrobials, problems of antimicrobial resistance; perturbation of the microbiome; the role of prebiotics, probiotics, and antimicrobial peptides. We highlight potential strategies to minimize the use of antimicrobials.

EXPERT OPINION

Measures to control infection and its transmission remain significant HSCT management policy and planning issues. Transplant centers need to consider carefully prophylactic use of antimicrobials for neutropenic patients. The judicious use of appropriate antimicrobials remains a crucial part of the treatment protocol. However, antimicrobials' adverse effects cause microbiome diversity and dysbiosis and have been shown to increase morbidity and mortality.

Steroid-refractory acute graft-versus-host disease graded III-IV in pediatric patients. A mono-institutional experience with a long-term follow-up

aGvHD remains a major obstacle to successful HSCT. We report our experience on steroid-refractory aGvHD III and IV from 1989 to 2017. Ninety patients with aGvHD III or IV were stratified according to the HSCT year: 1989-1998, 1999-2007, and 2008-2017 and to aGvHD extension (GvHD III vs IV) and finally the probability of OS, RI, and TRM was calculated accordingly. aGvHD III patients had a substantial improvement over time: day 100 OS raised from 64% (95% CI 39-89) in the first cohort to 100% in the latest (P = .022), and it was mainly due to a reduction of TRM (it was 28% [95% CI 12-65] in the first cohort to 0% in the latest (P = .01). The aGvHD IV patients did not present a significant improvement. Day 100 OS was 42% (95% CI 16-68) in the first group and 54% (95% CI 25-83) in the year 2008-2017 (P = NS), and the day-100 TRM was very similar (it was 57% [95% CI 36-90] in the first cohort and 45% [95% CI 23-89] in the latest (P = NS). We report significant improvements in OS and TRM in patients diagnosed with grade III aGvHD. Patients with the most severe aGvHD appear to have no or fewer benefits on long-term outcomes.

Antigen-Specific Immunoadsorption With the Glycosorb® ABO Immunoadsorption System as a Novel Treatment Modality in Pure Red Cell Aplasia Following Major and Bidirectional ABO-Incompatible Allogeneic Hematopoietic Stem Cell Transplantation

Pure red cell aplasia (PRCA) after ABO-incompatible allogeneic hematopoietic stem cell transplantation (HSCT) is caused by persisting host-derived isohemagglutinins directed against donor red blood cell (RBC) antigens. ABO antigen-specific immunoadsorption (ABO-IA) with Glycosorb®, commonly used for desensitization therapy in ABO-incompatible living donor renal transplantation, specifically eliminates circulating isohemagglutinins and might represent a novel treatment option for post-HSCT PRCA. In this prospective observational (n = 3) and retrospective (n = 3) analysis of six adult HSCT-recipients with PRCA, ABO-IA was initiated at 159 (range: 104–186) days following HSCT. The median treatment frequency was 4.5 (range: 3.9–5.5) sessions/week. ABO-IA-treatment led to a continuous decrease in isohemagglutinin titers. Reticulocytes increased to ≥30 G/L after 17.5 (range: 4–37) immunoadsorption sessions over 28.5 (range: 6–49) days and continued to rise after that. By the end of the 3-month follow-up period after discontinuation of ABO-IA, all patients showed a sustained remission of PRCA and were independent of erythropoietin-stimulating agents and transfusions. No case of infection or graft-versus-host disease was observed. After a median follow-up of 22.03 (range: 6.08–149.00) months after ABO-IA-treatment, all patients were alive and showed a stable RBC engraftment of the donor blood group. Our data provide the first evidence for ABO-IA as an effective treatment for post-HSCT PRCA.

Salp15, a Multifunctional Protein From Tick Saliva With Potential Pharmaceutical Effects

Ixodes ticks are the main vectors for a number of zoonotic diseases, including Lyme disease. Ticks secrete saliva directly into a mammalian host while feeding on the host's blood. This action serves to modulate host immunity and coagulation, thus allowing ticks to attach and feed upon their host. One of the most extensively studied components of tick saliva is Salp15. Research has shown that this protein binds specifically to CD4 molecules on the surface of T lymphocytes, interferes with TCR-mediated signaling transduction, inhibits CD4+ T cell activation and proliferation, and impedes the secretion of interleukin 2 (IL-2). Salp15 also binds specifically to dendritic cell dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) to up-regulate the expression of CD73 in regulatory T cells. Collectively, these findings render this salivary protein a potential candidate for a range of therapeutic applications. Here, we discuss our current understanding of Salp15 and the mechanisms that might be used to treat disease.

Clinical trajectories, healthcare resource use, and costs of long-term hematopoietic stem cell transplantation survivors: a latent class analysis

PURPOSE

To identify patterns of healthcare utilization in allogeneic and autologous hematopoietic stem cell transplantation (HSCT) recipients and evaluate factors associated with high-need and high-cost post-transplantation care.

METHODS

Latent class analysis of a retrospective cohort of long-term allogeneic (n = 436) and autologous (n = 888) HSCT survivors within the Truven MarketScan database (2009-2014). We assessed factors associated with the latent classes by comparing post-transplantation healthcare utilization including inpatient admissions and length of stay, emergency room visits, specialist visits, and primary care provider visits.

RESULTS

Four utilization classes were identified in allogeneic and autologous HSCT recipients: (i) outpatient specialist care dominant (51.8% and 57.3%), (ii) outpatient primary care dominant (10.3% and 25.7%), (iii) outpatient/inpatient balanced (20.6% and 13.5%), and (iv) inpatient dominant (17.2% and 3.5%). Mean monthly healthcare expenditures in the inpatient dominant utilization class were $41,097 and $25,556 for allogeneic and autologous survivors, respectively, which were two to five times higher compared with other classes during the 2-year post-transplantation period. Factors associated with the high utilization class were transfusion (OR = 1.87, 95% CI 1.06-3.30) and 100-day post-transplant graft-versus-host-disease (OR = 1.76, 95% CI 1.05-2.94) in allogeneic HSCT; higher baseline Charlson comorbidity index (OR = 1.45, 95% CI 1.19-1.76) in autologous HSCT.

CONCLUSION

Based on distinct patterns of healthcare utilization following HSCT, we identified factors associated with higher resource utilization and greater healthcare related expenditures.

IMPLICATIONS FOR CANCER SURVIVORS

Earlier identification of high-cost and high-need HSCT long-term survivors could pave the way for clinicians to offer more continuous engagement in survivorship care delivery.

Incidence and Outcomes of Bacterial Bloodstream Infections during Acute Graft-versus-Host Disease Involving the Gastrointestinal Tract after Hematopoietic Cell Transplantation

Despite the association of acute graft-versus-host disease (aGVHD) and bacterial bloodstream infections (BSIs) in hematopoietic cell transplant (HCT) recipients, relatively little is known about BSIs, specifically during gastrointestinal (GI) tract aGVHD (aGHVD-GI). The purpose of this study was to evaluate the incidence, risk factors, and mortality of BSIs complicating aGVHD-GI. This was a retrospective review of adult HCT recipients with grades I to IV aGVHD-GI between January 2009 and October 2017 at Oregon Health and Sciences University. BSIs occurring within 30 days of onset of aGVHD-GI were included. BSIs were categorized as "clinical" or "surveillance" based on chart review. A subgroup analysis of patients with grade IV aGVHD-GI examined potential BSI risk factors and cumulative survival at 30 and 45 days after onset of aGVHD-GI. Included were 229 patients. There were 45 unique BSIs in 39 patients (17%): 31 clinical (68.9%) and 14 surveillance (32.1%). The median time from aGVHD-GI onset to BSI was 18.5 days. BSIs were significantly more common during grade IV aGVHD-GI compared with grades I, II, or III. Fifty-two organisms were isolated during BSIs: 23 (44.2%) gram-positive and 29 (55.8%) gram-negative. Sixteen BSIs (36%) occurred during antibiotic exposure, and those were more likely to be caused by multidrug-resistant organisms. Prior BSI occurring between the time of HCT and onset of aGVHD-GI and receipt of etanercept for steroid-refractory aGVHD-GI were independently associated with BSI. Eight patients, all with grade IV aGVHD, representing 30.8% of patients with BSI in this subgroup, experienced infection-associated mortality. Cumulative survival at days 30 and 45 after onset of grade IV aGVHD-GI was similar among patients with and without BSI. BSI is a common complication of grade IV aGVHD-GI, resulting in significant infection-associated mortality. Interventions targeting those at highest risk may be warranted.

Early CD8+-recovery independently predicts low probability of disease relapse but also associates with severe GVHD after allogeneic HSCT

In this single-center study we retrospectively evaluated the impact of early reconstitution of different lymphocyte subsets on patient outcomes after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We found that CD8+ T-cell counts exceeding 50x10(6)/l as early as on day 28 post-transplantation correlated significantly with decreased relapse risk, with three-year relapse rates of 17.0% and 55.6% (P = 0.002), but were also associated with severe acute and chronic GVHD. Incidence of grade III-IV acute GVHD was 30.5% for those with early CD8+ T-cell recovery compared to 2.1% for those with lower CD8+ T-cell counts on day 28 post-transplant (HR = 20.24, P = 0.004). Early CD8+ T-cell reconstitution did not, however, affect the overall survival. Multivariate analysis showed that slow CD8+ T-cell reconstitution was strongly associated with increased risk of relapse (HR = 3.44, P = 0.026). A weaker correlation was found between CD4+ reconstitution and relapse-risk, but there was no such association with CD19+ B-cells or NK-cells. In conclusion, the early CD8+ T-cell recovery on day 28 post-transplant is associated with the lower risk of relapse but also predicts the impending severe GVHD, and thus could be useful in guiding timely treatment decisions.

Comparison of Different Conditioning Regimens of Haploidentical Hematopoietic Stem Cell Transplant in Patients With Acute Myeloid Leukemia

OBJECTIVES

We evaluated the safety and efficacy of 2 conditioning regimens (busulfan/fludarabine vs modified busulfan/cyclophosphamide) in patients with acute myeloid leukemia undergoing haploidentical hematopoietic stem cell transplant.

MATERAILS AND METHODS

Twenty patients with primary acute myeloid leukemia had been randomized into busulfan/fludarabine and modified busulfan/cyclophosphamide groups. We retrospectively compared hematopoietic engraftment, regimen-related toxicity, graft-versus-host disease, transplant-related mortality, leukemia-free survival, and overall survival between the groups.

RESULTS

All patients achieved engraftment with 100% donor chimerism. The median times for the neutrophil and platelet engraftment in the busulfan/fludarabine and modified busulfan/cyclophosphamide groups were 14.1 versus 14.3 days and 12.7 versus 12.2 days, respectively. Significantly lower incidences of pretreatment toxicity, blood transfusion, and virus activation were observed in the busulfan/fludarabine group. Acute grade 1 graft-versus-host-disease developed in all patients, which was successfully controlled with methylprednisolone. There were no significant differences in engraftment, graft-versus-host disease, leukemia-free survival, and overall survival between groups. Both of these conditioning regimens achieved stable engraftment. Regimen-related toxicity in the busulfan/fludarabine group was well tolerated compared with that in the modified busulfan/cyclophosphamide group, without an increase in relapse rate.

CONCLUSIONS

Our results demonstrated that myeloablative busulfan/fludarabine might be a highly effective and low-toxicity alternative for patients with acute myeloid leukemia.

New and emerging therapies for acute and chronic graft versus host disease

Graft versus host disease (GVHD) remains a major cause of morbidity and mortality following allogeneic hematopoietic stem-cell transplantation (HSCT). Despite the use of prophylactic GVHD regimens, a significant proportion of transplant recipients will develop acute or chronic GVHD following HSCT. Corticosteroids are standard first-line therapy, but are only effective in roughly half of all cases with ~50% of patients going on to develop steroid-refractory disease, which increases the risk of nonrelapse mortality. While progress has been made with improvements in survival outcomes over time, corticosteroids are associated with significant toxicities, and many currently available salvage therapies are associated with increased immunosuppression, infectious complications, and potential loss of the graft versus leukemia (GVL) effect. Thus, there is an unmet need for development of newer treatment strategies for both acute and chronic GVHD to improve long-term post-transplant outcomes and quality of life for HSCT recipients. Here, we provide a concise review of major emerging therapies currently being studied in the treatment of acute and chronic GVHD.

Surgical treatment of intestinal complications of graft versus host disease in the pediatric population: Case series and review of literature

BACKGROUND/PURPOSE

Intestinal complications of acute graft-versus-host disease (aGVHD) include hemorrhage and perforation in the short-term, and stricture with bowel obstruction in the long-term. As medical management of severe aGVHD has improved, more patients are surviving even advanced stages of intestinal aGVHD. This review summarizes the available pediatric literature on surgical treatment of complications of intestinal GVHD.

METHODS

A systematic review was performed using PubMed, Cochrane, Embase, and Scopus databases. Any publication that addressed surgical treatment of acute and chronic intestinal GVHD in the pediatric population was reviewed in detail. Furthermore, we included information on 5 additional patients from the institutions of this review's authors, which had not been previously published.

RESULTS

We identified 8 studies, comprising 13 patients. Surgical interventions were undertaken for a variety of intestinal GVHD complications, including small bowel obstruction owing to stricture (n=8), enterocutaneous fistulae (n=2), gastrointestinal hemorrhage/perforation (n=1 each), and esophageal stricture (n=1). Among eight patients with bowel obstruction as an indication, pathology revealed ulceration with fibrosis in all but one; 3 had signs of persistent GVHD. Surgical mortality was reported in 4 patients (31%) at an average of 6weeks postoperatively. The median overall follow-up time was 20months (IQR, 2-21).

CONCLUSIONS

Although intestinal aGVHD management is almost exclusively medical, a small subset of patients develops complications of intestinal GVHD that require surgical intervention. With expanding indications for stem cell transplantation as well as improved survival after previously fatal bouts of intestinal aGVHD, it is likely that surgical intervention will become more common in these complicated patients.

SYSTEMATIC REVIEW

Level of Evidence: Level IV.

Mesenchymal Stromal Cells: What Is the Mechanism in Acute Graft-Versus-Host Disease?

After more than a decade of preclinical and clinical development, therapeutic infusion of mesenchymal stromal cells is now a leading investigational strategy for the treatment of acute graft-versus-host disease (GVHD). While their clinical use continues to expand, it is still unknown which of their immunomodulatory properties contributes most to their therapeutic activity. Herein we describe the proposed mechanisms, focusing on the inhibitory activity of mesenchymal stromal cells (MSCs) at immunologic checkpoints. A deeper understanding of the mechanism of action will allow us to design more effective treatment strategies.

Improved survival after acute graft-versus-host disease diagnosis in the modern era

A cute graft-versus-host disease remains a major threat to a successful outcome after allogeneic hematopoietic cell transplantation. While improvements in treatment and supportive care have occurred, it is unknown whether these advances have resulted in improved outcome specifically among those diagnosed with acute graft-versus-host disease. We examined outcome following diagnosis of grade II-IV acute graft-versus-host disease according to time period, and explored effects according to original graft-versus-host disease prophylaxis regimen and maximum overall grade of acute graft-versus-host disease. Between 1999 and 2012, 2,905 patients with acute myeloid leukemia (56%), acute lymphoblastic leukemia (30%) or myelodysplastic syndromes (14%) received a sibling (24%) or unrelated donor (76%) blood (66%) or marrow (34%) transplant and developed grade II-IV acute graft-versus-host disease (n=497 for 1999–2001, n=962 for 2002–2005, n=1,446 for 2006–2010). The median (range) follow-up was 144 (4–174), 97 (4–147) and 60 (8–99) months for 1999–2001, 2002–2005, and 2006–2010, respectively. Among the cohort with grade II-IV acute graft-versus-host disease, there was a decrease in the proportion of grade III-IV disease over time with 56%, 47%, and 37% for 1999–2001, 2002–2005, and 2006–2012, respectively (P<0.001). Considering the total study population, univariate analysis demonstrated significant improvements in overall survival and treatment-related mortality over time, and deaths from organ failure and infection declined. On multivariate analysis, significant improvements in overall survival (P=0.003) and treatment-related mortality (P=0.008) were only noted among those originally treated with tacrolimus-based graft-versus-host disease prophylaxis, and these effects were most apparent among those with overall grade II acute graft-versus-host disease. In conclusion, survival has improved over time for tacrolimus-treated transplant recipients with acute graft-versus-host disease.