Chronic liver graft-versus-host disease in allogeneic hematopoietic stem cell transplantation recipients during tapering or after stopping calcineurin inhibitors

Chronic graft-versus-host disease (cGVHD) of the liver is often observed in allogeneic hematopoietic stem cell transplantation (allo-HSCT) during tapering or after stopping calcineurin inhibitors (CI). We conducted a retrospective analysis of 242 allo-HSCT recipients whose CI dose was reduced to less than 40 mg of cyclosporin A or 0.4 mg of tacrolimus to clarify the clinical characteristics of liver GVHD in patients on low-dose CI. Sixty patients (25%) developed clinically suspected liver cGVHD while on low-dose CI. Multivariate analysis showed that donor age ≥ 40 years [hazard ratio (HR) 2.20], myeloablative conditioning (HR 2.19), female donor to male recipient (HR 2.53) and recipient seropositivity for herpes simplex virus (HR 2.52) were significant risk factors for liver cGVHD during low-dose CI period. Peak aspartate aminotransferase and alanine aminotransferase levels were higher in patients with liver GVHD during low-dose CI period than in other periods. Twenty-seven patients were initially treated with resumption of CI or a CI dose increase and 21 responded. Among the 18 patients treated with corticosteroids, total bilirubin was a risk factor for failure of corticosteroid therapy. The results of this study clarified the clinical characteristics of liver GVHD in patients on low-dose CIs.

Development of acoustically isolated extracellular plasma vesicles for biomarker discovery in allogeneic hematopoietic stem cell transplantation

Background

Infection and graft-versus-host disease (GvHD) are the major causes for mortality and morbidity of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Plasma-derived extracellular vesicles (EVs) contain disease-related proteins, DNAs and RNAs, and have recently been suggested as potential biomarker candidates for transplantation complications. However, EV isolation from small plasma volumes in clinical biomarker studies using conventional methods is challenging. We therefore investigated if EVs isolated by novel automated acoustic trapping could be developed as potential biomarkers for allo-HSCT complications by performing a clinical proof-of-principle study.

Results

Plasma samples were collected from twenty consecutive patients with high-risk/relapsed hematologic malignancies undergoing allo-HSCT before transplantation and post-transplant up to 12 weeks. EVs were isolated from small plasma sample volumes (150 μl) by an automated, acoustofluidic-based particle trapping device, which utilizes a local λ/2 ultrasonic standing wave in a borosilicate glass capillary to capture plasma EVs among pre-seeded polystyrene microbeads through sound scatter interactions. We found that EVs could be reliably isolated from all plasma samples (n = 173) and that EV numbers increased more than 2-fold in the majority of patients after transplantation. Also, sufficient quantities of RNA for downstream microRNA (miRNA) analysis were obtained from all samples and EV miRNA profiles were found to differ from whole plasma profiles. As a proof of principle, expression of platelet-specific miR-142-3p in EVs was shown to correlate with platelet count kinetics after transplantation as expected. Importantly, we identified plasma EV miRNAs that were consistently positively correlated with infection and GvHD, respectively, as well as miRNAs that were consistently negatively correlated with these complications.

Conclusions

This study demonstrates that acoustic enrichment of EVs in a clinical biomarker study setting is feasible and that downstream analysis of acoustically-enriched EVs presents a promising tool for biomarker development in allo-HSCT. Certainly, these findings warrant further exploration in larger studies, which will have significant implications not only for biomarker studies in transplantation but also for the broad field of EV-based biomarker discovery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40364-020-00259-4.

[Intestinal microbiota and allogeneic stem cell transplantation]

Allogeneic hematopoïetic stem cell transplantation is one of the most efficient curative treatment for acute leukemia. But it is also a heavy process with an important risk of complications, particularly infection and graft versus host disease. Increasing data in literature show that an alteration of the intestinal microbiota of allogeneic stem cell recipients is associated with these complications. Indeed, treatments used during conditioning regimen lead to an impaired microbiota, which cannot fulfill its protective functions anymore. To limit this microbiota impairment, we could restore a healthy microbiota by a fecal microbiota transplantation, which has already shown its efficiency in the treatment of Clostridium difficile infection. The aim of this review is to describe the intestinal microbiota, the link between microbiota and complications of allogeneic stem cells transplantation, and the recent published data on fecal microbiota transplantation in this field.

Allogeneic Hematopoietic Stem Cell Transplantation for GATA2 Deficiency Using a Busulfan-Based Regimen

Allogeneic hematopoietic stem cell transplantation (HSCT) reverses the bone marrow failure syndrome due to GATA2 deficiency. The intensity of conditioning required to achieve reliable engraftment and prevent relapse remains unclear. Here, we describe the results of a prospective study of HSCT in 22 patients with GATA2 deficiency using a busulfan-based conditioning regimen. The study included 2 matched related donor (MRD) recipients, 13 matched unrelated donor (URD) recipients, and 7 haploidentical related donor (HRD) recipients. MRD and URD recipients received 4 days of busulfan and 4 days of fludarabine. HRD recipients received low-dose cyclophosphamide for 2 days, fludarabine for 5 days, 2 to 3 days of busulfan depending on cytogenetics, and 200 cGy total body irradiation. MRD and URD recipients received tacrolimus and short-course methotrexate for graft-versus-host disease (GVHD) prophylaxis. HRD recipients received high-dose post-transplant cyclophosphamide (PTCy) followed by tacrolimus and mycophenolate mofetil. At a median follow-up of 24 months (range, 9 to 50), 19 of 22 patients were alive with reversal of the disease phenotype and correction of the myelodysplastic syndrome, including eradication of cytogenetic abnormalities. Three patients died: 1 from refractory acute myelogenous leukemia, 1 from GVHD, and 1 from sepsis. There was a 26% incidence of grades III to IV acute GVHD in the MRD and URD groups and no grades III to IV acute GVHD in the HRD cohort. Similarly, there was a 46% incidence of chronic GVHD in the MRD and URD cohorts, whereas only 28% of HRD recipients developed chronic GVHD. Despite excellent overall disease-free survival (86%), GVHD remains a limitation using standard prophylaxis for GVHD. We are currently extending the use of PTCy to the MRD and URD cohorts to reduce GVHD.

Histologic analysis has a prognostical value in colorectal biopsies assessed for suspicion of graft-versus-host disease

Gastrointestinal (GI) graft-versus-host-disease (GVHD) is a common and severe complication of allogeneic hematopoietic stem cell transplantation, but clinical and histological features are unspecific. The aim of this study was to correlate the histological GI GVHD grade with the clinical outcomes. In a retrospective study of 112 patients with clinically suspected GI GVHD, colonic biopsies were reviewed by three pathologists without knowledge of the corresponding clinical data and classified in four scores, according to the NIH Consensus Project recommendations: no GVHD, possible, probable, and unequivocal GVHD. At the end of the study, the histological and clinical data were confronted with the following results: clinical diagnosis of GI GVHD was established for 70 patients (62.5%) and histological scores correlated well with the clinical diagnosis (p < 0.001) and particularly with the prognosis (p < 0.05).When severe lesions were observed, the 1 year overall survival declined to 9%. None of the features reported in the literature to support GVHD diagnosis, eosinophil count, endocrine cells aggregate, immunohistochemical analysis (cytomegalovirus, CD123, chromogranin), did not help us for diagnosis. So routine histopathology alone without immunohistochemistry is a strong and reproducible tool to diagnose GI GVHD with the help of clinical and biological information, and most importantly, histological grading proved to be a powerful prognostic value.

Cytomegalovirus Infection in Pediatric Hematopoietic Stem Cell Transplantation: Risk Factors for Primary Infection and Cases of Recurrent and Late Infection at a Single Center

Cytomegalovirus (CMV) infection is a significant source of morbidity and mortality in allogeneic stem cell transplantation (SCT). We identified a cohort of 91 pediatric SCT patients at risk (defined as either donor and/or recipient seropositivity) for CMV infection at our institution. We retrospectively categorized at-risk SCT recipients as those who (1) were at risk of CMV infection in the post-SCT period, (2) had documented CMV infection before SCT, (3) experienced recurrence of post-SCT CMV viremia, or (4) experienced late post-SCT CMV viremia; categories were not mutually exclusive. We analyzed the impact of SCT-related factors on incidence of CMV infection and outcome, and we described the outcome of each of these cohorts. In univariate analysis, recipient CMV seropositivity, use of umbilical cord blood graft, and acute graft-versus-host disease (GVHD) predicted post-SCT CMV viremia, and the effects of acute GVHD (odds ratio, 4.018; 95% confidence interval, 1.032 to 15.643) and CMV seropositivity (odds ratio, 16.525; 95% confidence interval, 2.041 to 133.803) were confirmed in multivariate analysis. Patients with recurrence of post-SCT CMV viremia had a 50% all-cause mortality rate, compared with 12% in all 91 patients. Patients with pre-SCT CMV infection had a high incidence of post-SCT CMV infection but could successfully undergo SCT with antiviral prophylaxis and pre-emptive CMV treatment. All patients with late CMV infection had prior GVHD. Theses findings identify risk factors for post-SCT CMV infection and provide novel descriptions of childhood SCT recipients with pre-SCT, recurrent, and late CMV infection, which may contribute to risk stratification strategies for CMV at-risk patients in pediatric allogeneic SCT.