UNASSIGNED: Chronic graft-versus-host disease (cGvHD) is a serious late complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT).
UNASSIGNED: This multicenter analysis determined the cumulative incidence (CI) of cGvHD and late acute GvHD (laGvHD) and its impact on transplantation-related mortality (TRM), relapse (R), and overall survival (OS) in 317 patients [296 adults, 21 pediatrics (<12 years of age)] who underwent their first allo-HSCT in 2017.
UNASSIGNED: The CI of laGvHD was 10.5% in adults and 4.8% in pediatrics, and the CI of cGvHD was 43.0% in all adult transplant patients and 50.2% in the adult at-risk cohort at the study end. The onset of cGvHD was de novo in 42.0% of patients, quiescent in 52.1%, and progressive in 5.9%. In adults, prophylactic use of antithymocyte globulin or posttransplant cyclophosphamide was associated with a significantly lower incidence of cGvHD (28.7%) vs. standard prophylaxis with calcineurin inhibitors (30.6%) and methotrexate/mycophenolate mofetil (58.4%) (all p < 0.01). TRM was significantly higher in patients with aGvHD (31.8%) vs. cGvHD (12.6%) and no GvHD (6.3%) (all p = 0.0001). OS in the adult at-risk cohort was significantly higher in patients with cGvHD (78.9%) vs. without (66.2%; p = 0.0022; HR 0.48) due to a significantly lower relapse rate (cGvHD: 14.5%; without cGvHD: 27.2%; p = 0.00016, HR 0.41). OS was also significantly higher in patients with mild (80.0%) and moderate (79.2%) cGvHD vs. without cGvHD (66.2%), excluding severe cGvHD (72.7%) (all p = 0.0214).
UNASSIGNED: The negative impact of severe cGvHD on OS suggests a focus on prevention of severe forms is warranted to improve survival and quality of life.

Chronic graft-versus-host disease (cGVHD) is a long-term complication of allogeneic hematopoietic stem cell transplantation. The clinical importance of long-term corticosteroid dependency in steroid-responsive cGVHD is undetermined. We retrospectively reviewed the data of 120 consecutive patients who received systemic steroid therapy for cGVHD between January 2007 and December 2018 at three institutions. Among patients with steroid-responsive cGVHD, those who successfully tapered off corticosteroids within 1 year were defined as the early withdrawal group (EW-cGVHD) and others were defined as the dependent group (Dp-cGVHD). Twenty-six patients were classified as EW-cGVHD and 55 as Dp-cGVHD. The proportion of men was significantly higher and performance status was significantly better in EW-cGVHD. The 5-year overall survival and cGVHD recurrence-free survival rates were significantly higher in EW-cGVHD than Dp-cGVHD (96% vs. 68%, p = 0.017 and 84% vs. 41%, p = 0.002, respectively). While the relapse-free survival rate did not differ significantly (84% vs. 65%, p = 0.15), the proportion of patients requiring readmission, mainly due to cGVHD recurrence or infection, was significantly increased in Dp-cGVHD (38% vs. 84%, p < 0.001). In summary, steroid dependency in cGVHD for more than 1 year was significantly associated with poor transplant outcomes.

Belumosudil is a selective Rho-associated protein kinase 2 inhibitor. Inhibition of Rho-associated protein kinase 2 has emerged as a promising treatment for chronic graft-versus-host disease by restoring immune homeostasis and reducing fibrosis. In vitro assessments have suggested that metabolism of belumosudil is primarily dependent on cytochrome P450 (CYP) 3A4 activity and that the solubility of belumosudil is pH dependent. As such, this 2-part clinical drug-drug interaction study was conducted to assess the effect of itraconazole (a strong CYP3A4 inhibitor), rifampicin (a strong CYP3A4 inducer), rabeprazole, and omeprazole (both proton pump inhibitors) on the pharmacokinetics of belumosudil. No clinically relevant change in belumosudil exposure was observed following a 200-mg single oral dose of belumosudil with itraconazole; however, exposure of main metabolite, KD025m2, was decreased. Consistent with the proposed metabolic pathway of belumosudil, the strong CYP3A4 inducer rifampicin significantly decreased exposure of belumosudil and KD025m2 and increased KD025m1 exposure. When a 200-mg single oral dose of belumosudil was coadministered with both rabeprazole and omeprazole, parent and metabolite exposures were largely reduced, suggesting that belumosudil dosage should be increased when given with PPIs. Administration of belumosudil with and without perpetrator drugs was safe, and no notable adverse events were reported.

Chronic graft-versus-host disease (cGvHD) is an immune mediated late complication of allogeneic hematopoietic stem cell transplantation (alloHSCT). Discovery of adequate biomarkers could identify high-risk patients and provide an effective pre-emptive intervention or early modification of therapeutic strategy, thus reducing prevalence and severity of the disease among long-term survivors of alloHSCT. Inflammation, endothelial injury, and endothelial dysfunction are involved in cGvHD development. Altered levels of acute phase reactants have shown a strong correlation with the activity of several immune mediated disorders and are routinely used in clinical practice. Since elevated von Willebrand factor (VWF) and factor VIII (FVIII) levels have been described as acute phase reactants that may indicate endothelial dysfunction and inflammation in different settings, including chronic autoimmune diseases, they could serve as potential candidate biomarkers of cGvHD. In this review we focused on reported data regarding VWF and FVIII as well as other markers of inflammation and endothelial dysfunction, evaluating their potential role in cGvHD.

Prognostic, diagnostic or predictive biomarkers are urgently needed for assessment of chronic graft-versus-host disease (cGvHD), a major risk for patients undergoing allogeneic hematopoietic stem cell transplantation. The main goal of this review generated within the COST Action EUROGRAFT \"Integrated European Network on Chronic Graft Versus Host Disease\" was to identify potential novel biomarkers for cGvHD besides the widely accepted molecular and cellular biomarkers. Thus, the focus was on cellular biomarkers, alloantibodies, glycomics, endothelial derived particles, extracellular vesicles, microbiome, epigenetic and neurologic changes in cGvHD patients. Both host-reactive antibodies in general, and particularly alloantibodies have been associated with cGvHD and require further consideration. Glycans attached to IgG modulate its activity and represent a promising predictive and/or stratification biomarker for cGVHD. Furthermore, epigenetic changes such as microRNAs and DNA methylation represent potential biomarkers for monitoring cGvHD patients and novel targets for developing new treatment approaches. Finally, the microbiome likely affects the pathophysiology of cGvHD; bacterial strains as well as microbial metabolites could display potential biomarkers for dysbiosis and risk for the development of cGvHD. In summary, although there are no validated biomarkers currently available for clinical use to better inform on the diagnosis, prognosis or prediction of outcome for cGvHD, many novel sources of potential markers have shown promise and warrant further investigation using well characterized, multi-center patient cohorts.

Graft-versus-host disease (GVHD) is a common complication of hematopoietic stem cell transplant, which is known to be mediated by cytotoxic T-cell effectors and dysregulated inflammatory cytokines. Similarly, the lung injury observed in severe COVID-19 cases appears to be related to a massive production of pro-inflammatory cytokines. The selective JAK1/2 inhibitor ruxolitinib has shown promising results in the context of GVHD, and different trials are currently underway in patients with severe COVID-19; nevertheless, no clinical observation of safety or efficacy of treatment with ruxolitinib in this context has been published yet. We describe a first case of severe COVID-19 developed after hematopoietic stem cell transplantation in a patient with a concomitant chronic GVHD (cGVHD), in which a treatment with ruxolitinib was administered with good tolerance and positive outcome.

In addition to malignant diseases, hematopoietic stem cell transplantation (HSCT) is also a vital option as a curative therapy for non-malignant diseases, such as immunodeficiency, and other hematological disorders. Not only for malignant diseases, but for non-malignant diseases, cytotoxic therapy of conditioning regimens are associated with high risks of adverse effects; however, clinical details regarding the long term outcomes of cytotoxic therapy for non-malignant diseases are not documented yet. To clarify the endocrinological consequences of pediatric HSCT for non-malignant disease patients, we conducted a retrospective analysis. From 1983 to 2014, 75 patients that underwent HSCT for non-malignant diseases were selected for this study. Of these, 23 patients (19 men, 4 women) were continuously followed up in our institute, with regular health check-ups for late effects. Based on a multiple linear regression analysis, the glucocorticoid treatment duration for chronic graft-versus-host disease (cGVHD) and the conditioning regimen were found to be independent predictors of growth retardation. All four female patients developed hypogonadism, and required hormone replacement therapy. The conditioning regimen for the four female patients with hypogonadism was based on the use of alkylating agents, and two female patients were treated with a reduced-intensity conditioning (RIC) regimen. Our study revealed that even the RIC regimen was toxic for the gonads in female patients, and that the survivors of both non-malignant and malignant diseases should be followed up carefully after pediatric HSCT.

Allogeneic hematopoietic stem cell transplantation (alloHCT) is the definitive therapy for numerous otherwise incurable hematologic malignancies and non-malignant diseases. The genetic disparity between donor and recipient both underpins therapeutic effects and confers donor immune system-mediated damage in the recipient, called graft-versus-host disease (GVHD). Chronic GVHD (cGVHD) is a major cause of late post-transplant morbidity and mortality. B cells have a substantiated role in cGVHD pathogenesis, as first demonstrated by clinical response to the anti-CD20 monoclonal antibody, rituximab. Initiation of CD20 blockade is met at times with limited therapeutic success that has been associated with altered peripheral B cell homeostasis and excess B Cell Activating Factor of the TNF family (BAFF). Increased BAFF to B cell ratios are associated with the presence of circulating, constitutively activated B cells in patients with cGVHD. These cGVHD patient B cells have increased survival capacity and signal through both BAFF-associated and B Cell Receptor (BCR) signaling pathways. Proximal BCR signaling molecules, Syk and BTK, appear to be hyper-activated in cGVHD B cells and can be targeted with small molecule inhibitors. Murine studies have confirmed roles for Syk and BTK in development of cGVHD. Emerging evidence has prompted investigation of several small molecule inhibitors in an attempt to restore B cell homeostasis and potentially target rare, pathologic B cell populations.

Mesenchymal stromal cells (MSCs) are a promising therapy for preventing chronic Graft-Versus-Host Disease (cGVHD) due to their potent immunomodulatory properties. However, the safety concerns regarding the use of MSCs remain unsolved, and conflicting effects are observed due to the heterogeneity of MSCs. Recently, exosomes were shown to mediate the paracrine effects of MSCs, making it a potential candidate for cell-free therapies. The aim of this study is to investigate the efficacy and safety of MSCs-derived exosomes (MSCs-exo) in an established cGVHD mouse model.
Bone marrow (BM)-derived MSCs were cultured, and the supernatants of these cultures were collected to prepare exosomes using ultracentrifugation. Exosomes from human dermal fibroblasts (Fib-exo) were used as a negative control. The cGVHD model was established, and tail vein injections of MSCs-exo or Fib-exo were administered once per week for 6 weeks. The symptoms and signs of cGVHD were monitored, and histopathological changes were detected by hematoxylin and eosin and Masson staining. The effects of MSCs-exo on Th17, Th1, and Treg were evaluated by flow cytometry, qPCR, and Luminex. In addition, human peripheral blood mononuclear cells (PBMCs) were stimulated and treated with MSCs-exo in vitro. IL-17-expressing Th17 and IL-10-expressing Treg were evaluated by flow cytometry, qPCR, and ELISA.
We found that MSCs-exo effectively prolonged the survival of cGVHD mice and diminished the clinical and pathological scores of cGVHD. Fibrosis in the skin, lung, and liver was significantly ameliorated by MSCs-exo application. In MSCs-exo treated mice, activation of CD4+ T cells and their infiltration into the lung were reduced. Of note, MSCs-exo exhibited potent immunomodulatory effects via the inhibition of IL-17-expressing pathogenic T cells and induction of IL-10-expressing regulatory cells during cGVHD. The expressions of Th17 cell-relevant transcription factors and pro-inflammatory cytokines was markedly reduced after MSCs-exo treatment. In vitro, MSCs-exo blocked Th17 differentiation and improved the Treg phenotype in PBMCs obtained from healthy donors and patients with active cGVHD, further indicating the regulatory effect of MSCs-exo on GVHD effector T cells.
Our data suggested that MSCs-exo could improve the survival and ameliorate the pathologic damage of cGVHD by suppressing Th17 cells and inducing Treg. This finding provides a novel alternative approach for the treatment of cGVHD.

Chronic graft-versus-host disease (cGVHD) manifests with features characteristic of autoimmune disease with organs attacked by pathogenic Th17 cells. However, the mechanism of Th17 cells generation in the setting of cGVHD is still unclear. Here we defined C5a/C5aR-IL-17Aaxis as a novel signaling that required in the pathologies of cGVHD. We firstly found a positive link between complement activation and the Th17 cells in patients with cGVHD. C5a, a critical component of complements, promoted the generation of Th17 cells in vitro and inhibition of the receptor for C5a (C5aR) reduced the Th17-bias response. Of note, C5aR blockade by PMX53 could suppress the generation of IL-17A-expressing Th17 cells and retard the onset and progression of cGVHD in vivo. Overall, our results provide new mechanistic insights that activation of C5a-C5aR signaling was required for IL-17A-induced immune responses in cGVHD and define novel molecular targets for developing effective therapeutics for cGVHD.