Oral and gut microbiome alterations in oral chronic graft-versus-host disease: results from Close Assessment and Testing for Chronic GVHD (CATCH study).

PURPOSE: Whether and how the oral microbiome and its changes in allogeneic hematopoietic cell transplantation (alloHCT) recipients may contribute to oral chronic graft-versus-host disease (cGVHD) pathogenesis is unknown. In addition, while the oral and colonic microbiota are distinct in healthy adults, whether oral microbes may ectopically colonize the gut in alloHCT patients is unknown. EXPERIMENTAL DESIGN: To address these knowledge gaps, longitudinal oral and fecal samples were collected prospectively in the multicenter CATCH Study (Close Assessment and Testing for Chronic GVHD; NCT04188912). Through shotgun metagenomic sequencing of the samples collected at baseline, oral cGVHD onset, first post-cGVHD onset visit, and 1-year post-HCT timepoints in patients with oral cGVHD (cases; N = 29) or without any cGVHD (controls; N = 51), we examined whether (i) oral and/or gut microbiomes and their longitudinal trajectories differ between cases and controls, and (ii) oral and gut microbiomes overlap in alloHCT recipients, especially those developing cGVHD. RESULTS: A total of 195 samples were analyzed. The onset of oral cGVHD was characterized by an expansion of Streptococcus salivarius and Veillonella parvula in the oral microbiome. High levels of oral/gut microbiota overlap were observed, particularly in patients with oral cGVHD, suggesting ectopic colonization of the gut by oral bacteria. CONCLUSIONS: The unusual coalescence of two distant niches in these patients may have short- or long-term consequences for the host, a novel avenue for future research. In addition, this study suggests a contribution of the oral microbiome to oral cGVHD pathogenesis.

Study protocol: Close Assessment and Testing for Chronic Graft-vs.-Host disease (CATCH).

Chronic graft-versus-host disease (GVHD) is an immune-mediated disorder that causes significant late morbidity and mortality following allogeneic hematopoietic cell transplantation. The "Close Assessment and Testing for Chronic GVHD (CATCH)" study is a multi-center Chronic GVHD Consortium prospective, longitudinal cohort study designed to enroll patients before hematopoietic cell transplantation and follow them closely to capture the development of chronic GVHD and to identify clinical and biologic biomarkers of chronic GVHD onset. Data are collected pre-transplant and every two months through one-year post-transplant with chart review thereafter. Evaluations include clinician assessment of chronic GVHD and its manifestations, patient-reported outcomes, multiple biospecimens (blood, saliva, tears, buccal mucosa and fecal samples, biopsies of skin and mouth), laboratory testing, and medical record abstraction. This report describes the rationale, design, and methods of the CATCH study, and invites collaboration with other investigators to leverage this resource. trial registration: This study is registered at www.clinicaltrials.gov as NCT04188912.

High-dose alemtuzumab and cyclosporine vs tacrolimus, methotrexate, and sirolimus for chronic graft-versus-host disease prevention.

ABSTRACT: Chronic graft-versus-host disease (cGVHD) remains a significant problem for patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Although in vivo lymphodepletion for cGVHD prophylaxis has been explored in the myeloablative setting, its effects after reduced-intensity conditioning (RIC) are not well described. Patients (N = 83) with hematologic malignancies underwent targeted lymphodepletion chemotherapy followed by a RIC allo-HSCT using peripheral blood stem cells from unrelated donors. Patients were randomized to 2 GVHD prophylaxis arms: alemtuzumab and cyclosporine (AC; n = 44) or tacrolimus, methotrexate, and sirolimus (TMS; n = 39), with the primary end point of cumulative incidence of severe cGVHD. The incidence of severe cGVHD was lower with AC vs TMS prophylaxis at 1- and 5-years (0% vs 10.3% and 4.5% vs 28.5%; overall, P = .0002), as well as any grade (P = .003) and moderate-severe (P < .0001) cGVHD. AC was associated with higher rates of grade 3 to 4 infections (P = .02) and relapse (52% vs 21%; P = .003) with no difference in 5-year GVHD-free-, relapse-free-, or overall survival. AC severely depleted naïve T-cell reconstitution, resulting in reduced T-cell receptor repertoire diversity, smaller populations of CD4Treg and CD8Tscm, but a higher ratio of Treg to naïve T-cells at 6 months. In summary, an alemtuzumab-based regimen successfully reduced the rate and severity of cGVHD after RIC allo-HSCT and resulted in a distinct immunomodulatory profile, which may have reduced cGVHD incidence and severity. However, increased infections and relapse resulted in a lack of survival benefit after long-term follow-up. This trial was registered at www.ClinicalTrials.gov as #NCT00520130.

Identification of Fibroinflammatory and Fibrotic Transcriptomic Subsets of Human Cutaneous Sclerotic Chronic Graft-Versus-Host Disease.

Cutaneous sclerotic chronic graft-versus-host disease (cGVHD) is a common and highly morbid complication of allogeneic hematopoietic stem cell transplantation. Our goals were to identify signals active in the skin of patients with sclerotic cGVHD in an effort to better understand how to treat this manifestation and to explore the heterogeneity of the disease. We identified genes that are significantly upregulated in the skin of patients with sclerotic cGVHD (n = 17) compared with those in the skin of patients who underwent allogeneic hematopoietic stem cell transplantation without cutaneous cGVHD (n = 9) by bulk RNA sequencing. Sclerotic cGVHD was most associated with T helper 1, phagocytic, and fibrotic pathways. In addition, different transcriptomic groups of affected patients were discovered: those with fibrotic and inflammatory/T helper 1 gene expression (the fibroinflammatory group) and those with predominantly fibrotic/TGFß-associated expression (the fibrotic group). Further study will help elucidate whether these gene expression findings can be used to tailor treatment decisions. Multiple proteins encoded by highly induced genes in the skin (SFRP4, SERPINE2, COMP) were also highly induced in the plasma of patients with sclerotic cGVHD (n = 16) compared with those in plasma of control patients who underwent allogeneic hematopoietic stem cell transplantation without sclerotic cGVHD (n = 17), suggesting these TGFß and Wnt pathway mediators as candidate blood biomarkers of the disease.

Heightened TLR7 signaling primes BCR-activated B cells in chronic graft-versus-host disease for effector functions.

ABSTRACT: Chronic graft-versus-host disease (cGVHD) is a debilitating, autoimmune-like syndrome that can occur after allogeneic hematopoietic stem cell transplantation. Constitutively activated B cells contribute to ongoing alloreactivity and autoreactivity in patients with cGVHD. Excessive tissue damage that occurs after transplantation exposes B cells to nucleic acids in the extracellular environment. Recognition of endogenous nucleic acids within B cells can promote pathogenic B-cell activation. Therefore, we hypothesized that cGVHD B cells aberrantly signal through RNA and DNA sensors such as Toll-like receptor 7 (TLR7) and TLR9. We found that B cells from patients and mice with cGVHD had higher expression of TLR7 than non-cGVHD B cells. Using ex vivo assays, we found that B cells from patients with cGVHD also demonstrated increased interleukin-6 production after TLR7 stimulation with R848. Low-dose B-cell receptor (BCR) stimulation augmented B-cell responses to TLR7 activation. TLR7 hyperresponsiveness in cGVHD B cells correlated with increased expression and activation of the downstream transcription factor interferon regulatory factor 5. Because RNA-containing immune complexes can activate B cells through TLR7, we used a protein microarray to identify RNA-containing antigen targets of potential pathological relevance in cGVHD. We found that many of the unique targets of active cGVHD immunoglobulin G (IgG) were nucleic acid-binding proteins. This unbiased assay identified the autoantigen and known cGVHD target Ro-52, and we found that RNA was required for IgG binding to Ro-52. Herein, we find that BCR-activated B cells have aberrant TLR7 signaling responses that promote potential effector responses in cGVHD.

Development and psychometric testing of a pediatric chronic graft-versus-host disease symptom scale: protocol for a two-phase, mixed methods study.

Background: Chronic graft-versus-host disease (cGVHD) is a debilitating late complication of hematopoietic stem cell transplantation. It is often accompanied by extensive symptom burden. No validated cGVHD patient-reported outcome (PRO) measure exists to evaluate cGVHD symptom bother in children and adolescents younger than 18 years. This paper presents the study protocol for a multi-center, two-phase protocol to develop a psychometrically valid pediatric cGVHD Symptom Scale (PCSS) and a companion caregiver-proxy measure to capture the symptom burden experienced by children with cGVHD. In the first phase of the study, our aim is to evaluate the comprehension, clarity and ease of response of the PCSS through cognitive interviewing and to iteratively refine the measure to optimize content validity. In the second phase of the study, we will quantitatively examine the measurement properties of the PCSS in children and their caregiver-proxies. Methods and analysis: Eligible participants are children/adolescents ages 5-17 with cGVHD who are receiving systemic immunosuppressive treatment or have recently tapered to discontinuation. In the first phase, we are enrolling 60 child and caregiver-proxy dyads in three child age strata (5-7, 8-12, and 13-17 years old). Semi-scripted cognitive debriefing interviews are conducted to assess comprehension, clarity, and ease of response of each PCSS item with the child alone, and then jointly with the caregiver-proxy to explore discordant ratings. In phase two, an age-stratified cohort of 120 child-caregiver dyads will be enrolled to evaluate test-retest reliability, construct validity, and responsiveness. Anchors for known-groups validity include the PedsQL module and clinical variables, including cGVHD clinician-rated severity scores. In participants ages 13-17, we will also compare responses on the PCSS with those from the Lee cGVHD Symptom Scale, to gauge the youngest age at which adolescent respondents can comprehend this adult measure. Discussion: This study will yield a well-validated, counterpart measure to the Lee cGVHD Symptom Scale for use in children with cGVHD and their caregiver-proxies. This new patient-reported outcome measure can be integrated into clinical trials and care delivery for pediatric transplant survivors to improve the precision and accuracy with which their cGVHD symptom experience is captured. Clinical trial registration: www.ClinicalTrials.gov, NCT04044365.