Several international recommendations address the assessment of graft-versus-host disease (GvHD) after hematopoietic cell transplantation (HCT). This position statement by GvHD experts from the European Society for Blood and Marrow Transplantation (EBMT), the National Institutes of Health (NIH) and the Center for International Blood and Marrow Transplant Research (CIBMTR) reviews the existing guidelines for both acute and chronic GvHD, addresses potential confusions that arise in daily practice and proposes consensus definitions for many key terms. We provide a historical perspective on the currently available guidelines and recommend the Mount Sinai Acute GvHD International Consortium (MAGIC) criteria for acute GvHD and the NIH 2014 criteria for chronic GvHD as the most comprehensive and detailed criteria available. This statement also offers practical guidance for the implementation of these recommendations and a set of consensus definitions for commonly used GvHD terms in order to facilitate future clinical and translational research. To assist the dissemination of these recommendations, a web-application based on this position statement is available ( https://www.uzleuven.be/egvhd ). We believe that adherence to a common set of GvHD assessment criteria is vitally important to improve the quality of data, compare results of retrospective studies and prospective clinical trials, and make therapeutic recommendations based on quality evidence.

Numbers of Hematopoietic cell transplantation (HCT) in Europe and collaborating countries continues to rise with 48,512 HCT in 43,581 patients, comprising of 19,798 (41%) allogeneic and 28,714 (59%) autologous, reported by 700 centers in 51 countries during 2019. Main indications were myeloid malignancies 10,764 (25%), lymphoid malignancies 27,895 (64%), and nonmalignant disorders 3173 (7%). A marked growth in CAR-T cellular therapies from 151 in 2017 to 1134 patients in 2019 is observed. This year’s analyses focus on changes over 30 years. Since the first survey in 1990 where 143 centers reported 4234 HCT, the number has increased to 700 centers and 48,512 HCT. Transplants were reported in 20 countries in 1990, and 51, 30 years later. More than 800,000 HCT in 715,000 patients were reported overall. Next to the massive expansion of HCT technology, most notable developments include the success of unrelated donor and haploidentical HCT, an increase followed by decrease in the number of cord blood transplants, use of reduced intensity HCT in older patients, and the phenomenal rise in cellular therapy. This annual report of the European Society for Blood and Marrow Transplantation (EBMT) reflects current activity and highlights important trends vital for health care planning.

For over two decades, the EBMT has updated recommendations on indications for haematopoietic cell transplantation (HCT) practice based on clinical and scientific developments in the field. This is the eighth special EBMT report on the indications for HCT for haematological diseases, solid tumours and immune disorders. Our aim is to provide general guidance on HCT indications according to prevailing clinical practice in EBMT countries and centres. In order to inform patient decisions, these recommendations must be considered in conjunction with the risk of the disease, risk of HCT procedure and non-transplant strategies, including evolving cellular therapies. HCT techniques are constantly evolving and we make no specific recommendations, but encourage harmonisation of practice, where possible, to ensure experience across indications can be meaningfully aggregated via registry outputs. We also recommend working according to JACIE accreditation standards to maintain quality in clinical and laboratory components of practice, including benchmarking of survival outcomes. Since the last edition, the COVID-19 pandemic has affected clinical decision making and activity across indications. Although the full impact of the pandemic is yet to be determined, we recommend that decision making across indications is delivered with ongoing reference to EBMT and national COVID-19 guidance, in accordance with current local conditions.

Information on incidence, and factors associated with mortality is a prerequisite to improve outcome after hematopoietic stem cell transplantation (HSCT). Therefore, 55′668 deaths in 114′491 patients with HSCT (83.7% allogeneic) for leukemia were investigated in a landmark analysis for causes of death at day 30 (very early), day 100 (early), at 1 year (intermediate) and at 5 years (late). Mortality from all causes decreased from cohort 1 (1980–2001) to cohort 2 (2002–2015) in all post-transplant phases after autologous HSCT. After allogeneic HSCT, mortality from infections, GVHD, and toxicity decreased up to 1 year, increased at 5 years; deaths from relapse increased in all post-transplant phases. Infections of unknown origin were the main cause of infectious deaths. Lethal bacterial and fungal infections decreased from cohort 1 to cohort 2, not unknown or mixed infections. Infectious deaths were associated with patient-, disease-, donor type, stem cell source, center, and country- related factors. Their impact varied over the post-transplant phases. Transplant centres have successfully managed to reduce death after HSCT in the early and intermediate post-transplant phases, and have identified risk factors. Late post-transplant care could be improved by focus on groups at risk and better identification of infections of “unknown origin”.

Patients with blood disorders colonized with antibiotic-resistant bacteria (ARB) are prone to systemic infections that are difficult to treat. Reintroduction of commensal bacteria in a murine model of enterococcal colonization of the gut can lead to eradication of enterococci. We hypothesized that fecal microbiota transplantation (FMT) could be used to eradicate ARB in humans. Participants colonized with ARB were treated with intraduodenal FMT according to a prospective protocol (NCT02461199). The primary endpoint was complete ARB decolonization at 1 month after FMT. Secondary endpoints included safety assessment and partial ARB decolonization. Microbiome sequencing was performed to investigate the influence of microbial composition of the transplanted material on the outcome of FMT. Twenty-five FMTs were performed in 20 participants (including 40% who had neutropenia) who were colonized by a median of 2 (range, 1–4) strains of ARB. The primary endpoint was reached in 15/25 (60%) of the FMTs and more frequently in cases in which there was no periprocedural use of antibiotics (79% vs 36%, P < .05). Among participants, 15/20 (75%) experienced complete ARB decolonization. There were no severe adverse events, and partial ARB decolonization was observed in 20/25 (80%) of the FMTs. The microbiota composition analysis revealed higher abundance of Barnesiella spp., Bacteroides, and Butyricimonas and greater bacterial richness in the fecal material, resulting in eradication of Klebsiella pneumoniae compared with nonresponders. FMT in patients with blood disorders is safe and promotes eradication of ARB from the gastrointestinal tract. NCT02461199.

We performed a study to find out how advances in modern medicine have improved the mortality risk of allogeneic stem cell transplantation. We analyzed major transplantation outcome parameters in adult patients on the European Society for Blood and Marrow Transplantation (EBMT) registry who had hematologic malignancies and had received transplants from matched sibling donors. We performed multivariate analyses using the Cox proportional-hazards model including known risk factors for nonrelapse mortality and a matched-pairs analysis. We identified 38 800 patients who fulfilled the inclusion criteria. Considerable changes in patient characteristics have occurred in the past decades, such as older age, different underlying diseases, and a higher proportion of patients with advanced disease. Major reasons for transplantation-related death in the 1980s were infectious complications and graft-versus-host disease. Nonrelapse mortality, measured at 1 year after transplantation, has decreased over time: 29.7% from 1980 through 1989, 24.4% from 1990 through 1999, 14.8% from 2000 through 2009, and 12.2% from 2010 through 2016. On multivariate analysis, the year of transplantation was associated with reduced nonrelapse mortality (P < .0001; hazard ratio [HR] [95% confidence interval (CI)], 0.8 [0.79-0.82], for 5-year intervals) and decreased overall mortality (P < .0001; HR [95% CI], 0.87 [0.86-0.88]. In the matched-pairs analysis of 3718 patients in each group, nonrelapse mortality at 1 year was 24.4% in the 1990s and 9.5% from 2013 through 2016 (P < .0001; HR [95% CI], 0.39 [0.34-0.43]). Transplantation-related mortality has decreased significantly in the past 40 years. These favorable data facilitate evidence-based treatment decisions on transplantation indications in the context of the availability of novel immunotherapies.