Consensus diagnostic histopathological criteria for acute gastrointestinal graft versus host disease improve interobserver reproducibility

[Recto-colic graft-versus-host disease (GVH). Diagnostic and prognostic criteria in a cohort of patients from Amiens university hospital]

INTRODUCTION

Recto-colic graft-versus-host disease (GVHD) is a frequent and serious complication of hematopoietic stem cell allogeneic transplantation, which is sometimes difficult to diagnose. The aim of our study was to identify histological diagnostic and prognostic criteria for recto-colic GVH.

MATERIAL AND METHOD

Patients allografted at Amiens university hospital from 2012 to 2017 were retrieved. Those who had a recto-colic biopsy were included and divided into two groups (final diagnosis of GVH and non-GVH), then biopsies were reviewed by 2 pathologists.

RESULTS

One hundred and nineteen patients were included. Sixty-seven were allocated to the GVH group and 52 to the non-GVH group. In the GVH group, we observed a significantly greater number of apoptotic bodies (AB) on standard HES staining and with the anti-Caspase 3 immunohistochemistry, cryptolytic AB abscesses, atrophy, regenerative glands and glands lined with eosinophilic cells (P<0.001). Anti-Caspase 3 immunohistochemistry revealed more AB than standard HES staining (P<0.005). But to differentiate GVH cases from non-GVH cases, we obtained a threshold value of 3.5 AB per 10 contiguous crypts on standard HE staining and with the anti-Caspase 3 immunohistochemistry. From 4 AB per 10 contiguous crypts, on HES staining and anti-Caspase 3 immunostaining, the diagnosis of GVH became consistent. No non-GVH case had more than 6 AB per 10 contiguous crypts. GVH patients with more than 8 AB per 10 contiguous crypts had a worse prognosis (P<0.001).

CONCLUSION

We confirm the value of AB and their counting in the diagnosis of GVH, with a diagnostic threshold of 4 AB and a prognostic threshold of 8 AB. Glands lined with eosinophilic cells could be an additional diagnostic criterion in favor of GVH to be confirmed by further studies.

Is Contrast-Enhanced Ultrasonography a New, Reliable Tool for Early-Graft-versus-Host Disease Diagnosis?

Acute gastrointestinal graft-versus-host disease (GI aGVHD) is a significant and life-threatening complication in patients undergoing allogeneic stem cell transplantation (allo-SCT). Early diagnosis of GI aGVHD is crucial for improving patient outcomes, but it remains a challenge due to the condition's nonspecific symptoms and the reliance on invasive diagnostic methods, such as biopsies and endoscopic procedures. In recent years, interest in non-invasive diagnostic techniques for graft-versus-host disease has increased, with contrast-enhanced ultrasound (CEUS) being one of them. For this reason, we aimed to examine the potential of ultrasound as a non-invasive, safe, and cost-effective alternative for the early detection and monitoring of GI aGVHD in this review. Our narrative review aims to describe the use of multimodal US that includes conventional US (B-mode and Doppler US) and advanced ultrasound techniques such as CEUS and CRTE for the non-invasive diagnosis of GI GVHD. We browsed several databases, including PubMed, Scopus, Web of Science, and Google Scholar. The search spanned 2000 to the present, focusing on articles written in English that reviewed the use of these imaging techniques in the context of GI GVHD. Following our research, we noticed that CEUS offers several advantages, including the real-time visualization of the gastrointestinal wall, assessment of blood flow, and detailed microvascular analysis-all achieved without the use of ionizing radiation. This feature makes CEUS an appealing option for repeated assessments, which are often necessary in monitoring the progression of GI aGVHD. When used in conjunction with conventional gastrointestinal ultrasound (GIUS), CEUS provides a more comprehensive view of the structural and functional changes occurring in the GI tract, potentially enhancing diagnostic accuracy and allowing for earlier intervention. In comparison to traditional diagnostic methods like tissue biopsy or CT scans, CEUS is less invasive, quicker to perform, and better tolerated by patients, especially those in fragile health following allo-SCT. Its non-invasive nature and ability to provide immediate imaging results make it a valuable tool for clinicians, particularly in settings where minimizing patient discomfort and risk is paramount. However, despite these advantages, there are still gaps in the literature regarding CEUS's full diagnostic accuracy for GI aGVHD. Further research, including larger clinical trials and comparative studies, is needed to validate CEUS's role in routine clinical practice and to establish standardized protocols for its use. Nonetheless, CEUS shows considerable potential to transform the diagnostic approach to GI aGVHD by improving early detection, reducing the need for invasive procedures, and ultimately enhancing treatment outcomes for affected patients.

Reproducibility of Rejection Grading in Uterus Transplantation: A Multicenter Study

Background

Diagnosis of rejection after uterus transplantation is based on histopathological examination of ectocervical biopsies. Inflammation at the stromal-epithelial interface is the backbone of the histopathological classification proposed by our group in 2017. However, the reproducibility of this grading scheme has not been tested, and it is unclear whether it covers the full morphological spectrum of rejection.

Methods

We present a multicenter study in which 5 pathologists from 4 uterus transplantation centers performed 2 rounds of grading on 145 and 48 cervical biopsies, respectively. Three of the centers provided biopsies. Additionally, the presence of perivascular stromal inflammation was recorded. During discussions after the first round, further histological lesions (venous endothelial inflammation and apoptosis) were identified for closer evaluation and added to the panel of lesions to score in the second round. All participants completed a questionnaire to explore current practices in handling and reporting uterus transplant biopsies.

Results

Cervical biopsies were commonly performed in all centers to monitor rejection. Intraobserver reproducibility of rejection grading (performed by 1 rater) was excellent, whereas interobserver reproducibility was moderate and did not improve in the second round. Reproducibility of perivascular stromal inflammation was moderate but unsatisfactory for venous endothelial inflammation and apoptosis. All lesions were more frequent in, but not restricted to, biopsies with rejection patterns.

Conclusions

Grading of rejection in cervical biopsies is reproducible and applicable to biopsies from different centers. Diagnosis of rejection may be improved by adding further histological lesions to the grading system; however, lesions require rigorous consensus definition.

Unique Reduced-Intensity Conditioning Haploidentical Peripheral Blood Stem Cell Transplantation Protocol for Patients with Hematologic Malignancy

Reduced-intensity conditioning (RIC) haploidentical (haplo-) hematopoietic stem cell transplantation (HSCT) requires more hematopoietic progenitor and stem cells (HPSCs) to promote engraftment and immune reconstitution and needs a stronger graft-versus-leukemia effect. Peripheral blood stem cells (PBSCs) offer advantages over bone marrow; however, the use of higher-dose non-T cell-depleted (non-TCD) in vitro PBSCs may increase the occurrence of severe graft-versus-host disease (GVHD). This prospective, single-arm clinical study was performed to investigate using high-dose non-TCD in vitro PBSCs as the graft source, using fludarabine/Ara-C/busulfan (FAB) as the conditioning regimen, using rabbit antithymocyte globulin to remove T cells in vivo, and enhancing GVHD prophylaxis with an IL-2 receptor antagonist in RIC-haplo-HSCT in patients with hematologic malignancies age 50 to 70 years or <50 years with comorbidities (Hematopoietic Cell Transplantation Comorbidity Index score ≥2) classified as intermediate to high risk. The primary endpoint was day 100 acute GVHD (aGVHD). A total of 47 patients were enrolled; the median age was 52 years (range, 30 to 68 years), the median duration of follow-up was 34 months (range, 2 to 99 months), and the medium-infused doses of mononuclear cells, CD34⁺ cells, and CD3⁺ cells were 15.93 × 10⁸/kg, 8.68 × 10⁶/kg, and 5.57 × 10⁸/kg, respectively. The cumulative incidence of grade II-IV aGVHD at day 100 was 30.3% (95% confidence interval [CI], 15.9% to 44.8%), and that of grade III-IV aGVHD was 10.2% (95% CI, .6% to 19.8%). The 2-year cumulative incidence of chronic GVHD (cGVHD) was 34.9% (95% CI, 19.0% to 50.8%). The 2-year cumulative incidences of localized and extensive cGVHD were 26.1% (95% CI, 11.80% to 40.40%) and 8.7% (95% CI, 3.26% to 20.65%), respectively. The 2-year cumulative incidence of relapse was 17.3% (95% CI, 5.1% to 29.5%), the 2-year overall survival rate was 71.2% (95% CI, 57.9% to 84.5%), and the 2-year disease-free survival rate was 66.2% (95% CI, 52.1% to 80.3%). The incidence of aGVHD was not high, and the overall efficacy was good. This study demonstrates that this unique RIC-haplo-PBSC transplantation protocol was effective in treating hematologic malignancies. Nonetheless, larger prospective multicenter clinical trials and experimental studies should be performed to further confirm our findings.

Histological diagnosis of acute graft-versus-host disease in different sites of the upper gastrointestinal tract with correlation to endoscopic findings

Graft-versus-host disease (GvHD) involving the intestine is a threat to patients after allogeneic hematopoietic stem cell transplantation (alloHSCT). We evaluated biopsies from different sites of the upper gastrointestinal tract (GIT) of 97 patients after alloHSCT. Forty-six patients with clinical symptoms consistent with upper GI GvHD revealed histological features of GvHD in the esophagus, stomach, and/or duodenum. Biopsies of the duodenum and esophagus were significantly more sensitive for signs of GvHD than those of the gastric antrum or corpus. The histological features of GvHD were significantly correlated with the endoscopic findings of ulcers, erosion, atrophy, and white plaques; however, the sensitivity and specificity of the latter were low. In univariate analysis, overall mortality was significantly associated with histological GvHD signs in all four sites. Nonrelapse mortality was associated with histologic GvHD features in the antrum only. Regarding GvHD diagnosis, biopsies of the upper gastrointestinal tract should include the duodenum and/or esophagus.

The clinical impact of donor against recipient HLA one way mismatch on the occurrence of graft versus host disease in liver transplantation

Graft versus host disease (GVHD) after liver transplantation (LT) is a rare, fatal disease. This study aimed to evaluate the risk factors of GVHD after LT including the human leukocyte antigen (HLA) donor-recipient relationship after LT. LT recipients, who underwent HLA typing together with donors, were included in the study. The donor against recipient (D → R) one-way mismatch of HLA loci was evaluated. HLA relationships, along with basic characteristics, were analyzed as variable factors of GVHD, graft survival, and patient survival. A total of 994 living donor LT (LDLT) and 393 deceased donor LT (DDLT) patients were included. Nine patients had suffered GVHD, four LDLT with D → R one-way at three loci, one LDLT without D → R one-way at three loci, and four DDLT without D → R one-way at three loci. Four (57.1%) of seven LDLT patients, with D → R one-way mismatch at three loci, developed GVHD. D → R one-way mismatch at three loci was related to high GVHD incidence (HR 787, p < 0.001, multivariate). D → R one-way mismatch at three loci was related to graft failure and patient death (HR 9.90, p = 0.020 and HR 12.8, p < 0.001, respectively, multivariate). Only one GVHD without D → R one-way mismatch at three loci, survived despite receiving multiple modalities including tumor necrosis factor-alpha inhibitors. D → R one-way mismatch at three loci was significantly related to GVHD incidence after LT.

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.

Plasma cells are essentially absent in the luminal gastrointestinal tract of patients with "complete" 22q11.2 deletion syndrome (DiGeorge syndrome)

Gastrointestinal symptoms are commonly reported in patients with 22q11.2 deletion syndrome or DiGeorge syndrome (DGS) in addition to the dominant cardiac manifestations and immunodeficiency. But literature providing specific morphologic details of the gastrointestinal tract pathology is very limited. Here, we provide the first comprehensive morphologic description of the luminal gastrointestinal tract changes in patients with DGS. Cytogenetically confirmed DGS patients were identified, clinical and laboratory data were reviewed to determine the severity of immunodeficiency, and patients were stratified into mildly immunocompromised, that is, partial DiGeorge anomaly or severely immunosuppressed, that is, complete DiGeorge anomaly groups. Gastrointestinal tract biopsies from these patients were retrospectively reviewed and compared with those from controls without the history of DGS. Patients with immunosuppressed DGS showed a near complete absence of plasma cells in the stomach, duodenum, and colon lamina propria by hematoxylin and eosin evaluation. Immunohistochemistry for CD138 used to highlight plasma cells confirmed this finding. The notable absence of plasma cells adds to the existing knowledge of the pathophysiology underlying DGS and expands the differential diagnostic considerations for this finding, which has been previously described in common variable immunodeficiency. It also provides a useful morphologic marker observable by the readily accessible light microscopy. Second, patients with DGS showed a mild increase in epithelial cell apoptosis in their colon. This finding is significant because of its overlap with morphologic features of gastrointestinal graft versus host disease as thymus transplantation is being used as a treatment option for patients with complete DGS.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: IV. The 2020 Highly morbid forms report

Chronic graft-versus-host disease (GVHD) can be associated with significant morbidity, in part because of nonreversible fibrosis, which impacts physical functioning (eye, skin, lung manifestations) and mortality (lung, gastrointestinal manifestations). Progress in preventing severe morbidity and mortality associated with chronic GVHD is limited by a complex and incompletely understood disease biology and a lack of prognostic biomarkers. Likewise, treatment advances for highly morbid manifestations remain hindered by the absence of effective organ-specific approaches targeting "irreversible" fibrotic sequelae and difficulties in conducting clinical trials in a heterogeneous disease with small patient numbers. The purpose of this document is to identify current gaps, to outline a roadmap of research goals for highly morbid forms of chronic GVHD including advanced skin sclerosis, fasciitis, lung, ocular and gastrointestinal involvement, and to propose strategies for effective trial design. The working group made the following recommendations: (1) Phenotype chronic GVHD clinically and biologically in future cohorts, to describe the incidence, prognostic factors, mechanisms of organ damage, and clinical evolution of highly morbid conditions including long-term effects in children; (2) Conduct longitudinal multicenter studies with common definitions and research sample collections; (3) Develop new approaches for early identification and treatment of highly morbid forms of chronic GVHD, especially biologically targeted treatments, with a special focus on fibrotic changes; and (4) Establish primary endpoints for clinical trials addressing each highly morbid manifestation in relationship to the time point of intervention (early versus late). Alternative endpoints, such as lack of progression and improvement in physical functioning or quality of life, may be suitable for clinical trials in patients with highly morbid manifestations. Finally, new approaches for objective response assessment and exploration of novel trial designs for small populations are required.

An investigation of the diagnostic, predictive, and prognostic impacts of three colonic biopsy grading systems for acute graft versus host disease

Acute graft versus host disease (aGvHD) is an important, life-threatening complication after allogeneic hematopoietic stem cell transplantation (alloHSCT). To investigate the value of multiple simultaneous colon biopsies in improving diagnostic accuracy in patients with aGvHD, we retrospectively analyzed 157 patients after alloHSCT. The biopsies were evaluated individually using three established histological grading systems (Lerner, Sale, and Melson). The maximum, minimum, median, and mean histological aGvHD grades were calculated for each patient, and the results were correlated with the Glucksberg grade of clinical manifestation of GvHD, steroid therapy status, and outcome. We found that multiple colon biopsies enhanced diagnostic sensitivity. Moreover, higher histological grades correlated with steroid therapy initiation and refractoriness; the latter particularly occurred when advanced damage was present in all samples and healthy colon mucosa was reduced or absent. On multivariate analysis, the minimal Lerner and Glucksberg grades for intestinal aGvHD were significantly associated with steroid treatment failure. Ninety-nine patients died. The median survival was 285 days after the biopsies were taken. Fifteen patients died from relapse of their underling disorder and 84 from other causes, mostly infection (53 patients) and GvHD (14 patients). Multivariate analysis revealed a significant association between none-relapse mortality and the mean Lerner grade, minimum Melson grade, Glucksberg organ stage, and platelet counts. Thus, we found the Lerner system to be superior to the other grading methods in most instances and histologic evaluation of multiple simultaneously obtained biopsies from the colon to result in a higher diagnostic yield, which helps plan systemic steroid treatment while predicting treatment response and outcome.

Intestinal goblet cells protect against GVHD after allogeneic stem cell transplantation via Lypd8

Graft-versus-host disease (GVHD) and infection are major obstacles to successful allogeneic hematopoietic stem cell transplantation (HSCT). Intestinal goblet cells form the mucus layers, which spatially segregate gut microbiota from host tissues. Although it is well known that goblet cell loss is one of the histologic features of GVHD, effects of their loss in pathophysiology of GVHD remain to be elucidated. In mouse models of allogeneic HSCT, goblet cells in the colon were significantly reduced, resulting in disruption of the inner mucus layer of the colon and increased bacterial translocation into colonic mucosa. Pretransplant administration of interleukin-25 (IL-25), a growth factor for goblet cells, protected goblet cells against GVHD, prevented bacterial translocation, reduced plasma concentrations of interferon-γ (IFN-γ) and IL-6, and ameliorated GVHD. The protective role of IL-25 was dependent on Lypd8, an antimicrobial molecule produced by enterocytes in the colon that suppresses motility of flagellated bacteria. In clinical colon biopsies, low numbers of goblet cells were significantly associated with severe intestinal GVHD, increased transplant-related mortality, and poor survival after HSCT. Goblet cell loss is associated with poor transplant outcome, and administration of IL-25 represents an adjunct therapeutic strategy for GVHD by protecting goblet cells.

Evaluation of crypt apoptotic bodies and apoptotic indices in pediatric celiac disease by routine staining and H2AX immunostaining

Celiac disease (CD) is an immune-mediated disorder with premature apoptosis occurring along the entire crypt-villous axis. H2AX is the end product of the intrinsic apoptotic pathway. This is the first study to assess apoptotic body counts (ABC) by H&E and apoptotic indices (AI) by immunohistochemistry (IHC) in pediatric CD. The aim of the current study was to evaluate ABC in pediatric patients with CD prior to and following institution of a gluten free diet (GFD). Sixty-three pediatric endoscopic duodenal samples were assessed and divided into three groups. A total of 21 samples from treatment naïve CD patients, 21 from the same patients after instituting a GFD, and 21 from non-celiac patients as a control group. Histopathological evaluation of ABC by H&E, and immunohistochemistry assessment of apoptotic indices (AI) by H2AX antibody were performed. The mean maximum ABC and AI were significantly higher in treatment naïve CD than in GFD and control samples. These values were also significantly higher in treatment naïve Marsh 3C (flat) than in Marsh 1, 2, 3A, and 3B (non-flat) CD cases. GFD samples with persistent flat lesions had significantly higher ABC and AI than GFD non-flat cases. ROC analysis of the mean maximum ABC and AI of treatment naïve CD cases had a statistically significant predictive potential for persistent villous atrophy at a cut-off level ⩾6.61 (P = 0.008) and ⩾105.4 (P = 0.003), respectively. Histopathological evaluation of crypt apoptotic bodies could provide predictive potential for continued villous atrophy following GFD.

Retinoic acid-responsive CD8 effector T cells are selectively increased in IL-23-rich tissue in gastrointestinal GVHD

Gastrointestinal (GI) graft-versus-host disease (GVHD) is a major barrier in allogeneic hematopoietic stem cell transplantation (allo-HSCT). The metabolite retinoic acid (RA) potentiates GI-GVHD in mice via alloreactive T cells expressing the RA receptor-α (RARα), but the role of RA-responsive cells in human GI-GVHD remains undefined. Therefore, we used conventional and novel sequential immunostaining and flow cytometry to scrutinize RA-responsive T cells in tissues and blood of patients who had received allo-HSCT and to characterize the impact of RA on human T-cell alloresponses. Expression of RARα by human mononuclear cells was increased after exposure to RA. RARαhi mononuclear cells were increased in GI-GVHD tissue, contained more cellular RA-binding proteins, localized with tissue damage, and correlated with GVHD severity and mortality. By using a targeted candidate protein approach, we predicted the phenotype of RA-responsive T cells in the context of increased microenvironmental interleukin-23 (IL-23). Sequential immunostaining confirmed the presence of a population of RARαhi CD8 T cells with the predicted phenotype that coexpressed the effector T-cell transcription factor T-bet and the IL-23-specific receptor (IL-23R). These cells were increased in GI- but not skin-GVHD tissues and were also selectively expanded in the blood of patients with GI-GVHD. Finally, functional approaches demonstrated that RA predominantly increased alloreactive GI-tropic RARαhi CD8 effector T cells, including cells with the phenotype identified in vivo. IL-23-rich conditions potentiated this effect by selectively increasing β7 integrin expression on CD8 effector T cells and reducing CD4 T cells with a regulatory cell phenotype. In summary, we have identified a population of RA-responsive effector T cells with a distinctive phenotype that is selectively expanded in human GI-GVHD and that represents a potential new therapeutic target.

Parametric Imaging of Contrast-Enhanced Ultrasound (CEUS) for the Evaluation of Acute Gastrointestinal Graft-Versus-Host Disease

In recent years contrast-enhanced ultrasound (CEUS) has been an emerging diagnostic modality for the detection of acute gastrointestinal (GI) graft-versus-host disease (GvHD) in patients after allogeneic stem cell transplantation. However, broad clinical usage has been partially limited by its high dependence on the expertise of an experienced examiner. Thus, the aim of this study was to facilitate detection of acute GI GvHD by implementing false color-coded parametric imaging of CEUS. As such, two inexperienced examiners with basic knowledge in abdominal and vascular ultrasound analyzed parametric images obtained from patients with clinical suspicion for acute GvHD in a blinded fashion. As diagnostic gold standard, histopathological GvHD severity score on intestinal biopsies obtained from lower GI tract endoscopy was performed. The evaluation of parametric images by the two inexperienced ultrasound examiners in patients with histological confirmation of acute GI GvHD was successful in 17 out of 19 patients (89%) as opposed to analysis of combined B-mode ultrasound, strain elastography, and CEUS by an experienced examiner, which was successful in 18 out of 19 of the patients (95%). Therefore, CEUS with parametric imaging of the intestine was technically feasible and has the potential to become a valuable diagnostic tool for rapid and widely accessible detection of acute GvHD in clinical practice.

Diagnostic disagreement between clinical standard histopathological- and retrospective assessment of histopathology-based gastrointestinal graft-versus-host disease in children

BACKGROUND

No previous paediatric study has evaluated the frequency of diagnostic disagreement between clinical standard histopathological assessment (CSHA) and retrospective, independent, histopathological assessment (RIHA) of gastrointestinal Graft-Versus-Host Disease (GI-GVHD) METHODS: In a retrospective cohort study, based on gastrointestinal biopsies collected from allogeneic HSCT-treated children (<18 years) with symptom-based GI-GVHD, we evaluated; disagreement of histopathology-based GI-GVHD diagnosis in CSHA vs RIHA, and potential clinical consequences of differences between the assessments. The CSHA-based diagnoses were retrieved from histopathology reports. The RIHA was performed by one pathologist, blinded to the CSHA outcomes and based on the minimal criteria for histopathology-based GI-GVHD diagnosis by the NIH 2014.

RESULTS

Seventy children with 92 endoscopic occasions (including 22 re-endoscopies) were enrolled. GI-GVHD was observed in 73% (67/92) of the endoscopies in the RIHA and in 54% (50/92) in the CSHA (P = .014). The RIHA confirmed 94% (47/50) with GI-GVHD and 52% (22/42) with non-GI-GVHD diagnoses, established in the CSHA. Disagreement, that is endoscopic occasions with GI-GVHD solely detected in RIHA or detection of GI-GVHD in CSHA but not in RIHA, was observed in 20/42 (48%) and 3/50 (6%), respectively (McNemar's test, P = .0008). The risk of a subsequent re-endoscopy was higher in endoscopic occasions with GI-GVHD detected in RIHA but not in CSHA vs if non-GI-GVHD were detected in both readings (P = .005).

CONCLUSION

Our results suggest that in children with symptom-based GI-GVHD without histopathological confirmation in CSHA, a second, NIH 2014 based histopathological assessment should be considered before performing a re-endoscopy.

Clinical relevance of endoscopy with histopathological assessment in children with suspected gastrointestinal graft-versus-host disease

Endoscopy with histopathological assessment is an established practice to confirm gastrointestinal graft-versus-host disease (GI-GVHD). However, the clinical relevance of this approach in children is incompletely evaluated. In a retrospective cohort study, we investigated the frequency of treatment changes in response to histopathological findings in all children (<18 years) in Sweden who underwent endoscopy for suspected GI-GVHD (2000-2013) after receiving hematopoietic stem cell transplantation. Sixty-eight children with ninety-one endoscopic occasions were enrolled. At the time of endoscopy, anti-GI-GVHD treatment was ongoing in 71% (65/91). In 18% (12/65) with ongoing treatment, no histopathological evidence of GI-GVHD or another cause to justify anti-GI-GVHD treatment was found. In 48% (44/91), endoscopy with histopathological assessment led to changes in the treatment regimen. Re-endoscopy was more frequent among those with treatment changes, versus unchanged treatment, 39% (17/44) and 13% (6/47), respectively (P = .007). Histopathological findings generating treatment changes were as follows: GI-GVHD in 68% (30/44), normal histology in 25% (11/44), and an alternative diagnosis in 7% (3/44). In conclusion, this study supports that endoscopy with histopathological assessment should be considered in all children with suspected GI-GVHD.

How many serial sections are needed to detect apoptosis in endoscopic biopsies with gastrointestinal graft versus host disease?

Aims

The hallmark histological feature of acute gastrointestinal graft versus host disease (GI GVHD) is epithelial apoptosis. This is the first formal evaluation of how many serial sections are required to consistently detect apoptotic bodies in endoscopic biopsies from various GI locations in patients with clinically validated GI GVHD.

Methods, results and conclusions

Assessment of 1008 serial sections showed that apoptotic bodies are uniformly distributed among such sections of gastric, duodenal and colorectal biopsies from these patients. Assessment of 59 further biopsies showed that assessing 12 serial sections should suffice to detect GVHD in gastric, duodenal and colorectal biopsies using thresholds of one apoptotic body per biopsy fragment or one apoptotic body per 4 mm2. Assessing 12 serial sections should also suffice to detect GVHD in duodenal and colorectal biopsies using the threshold of 6 apoptotic bodies per 10 contiguous crypts, but it remains uncertain whether this assessment and threshold can be applied to gastric biopsies.

Safety considerations with current and emerging antiviral therapies for cytomegalovirus infection in transplantation

Introduction: Human cytomegalovirus (HCMV) is a major contributor of morbidity and mortality, and its management is essential for the successful outcome of solid organ and hematopoietic stem cell transplantation. Areas covered: This review discusses the safety profiles of currently available and emerging antiviral drugs and the other strategies for HCMV prevention and treatment after transplantation. Expert opinion: Strategies for management of HCMV rely largely on the use of antiviral agents that inhibit viral DNA polymerase (ganciclovir/valganciclovir, foscarnet, and cidofovir/brincidofovir) and viral terminase complex (letermovir), with different types and degrees of adverse effects. An investigational agent, maribavir, exerts its anti-CMV effect through UL97 inhibition, and its safety profile is under clinical evaluation. In choosing the antiviral medication to use, it is important to consider these safety profiles in addition to overall efficacy. In addition to antiviral drugs, reduction of immunosuppression is often generally needed in the management of HCMV infection, but with a potential risk of allograft rejection or graft-versus-host disease. The use of HCMV-specific or non-specific intravenous immunoglobulins remains debated, while adoptive HCMV-specific T cell therapy remains investigational, and associated with unique set of adverse effects.

An association between crypt apoptotic bodies and mucosal flattening in celiac disease patients exposed to dietary gluten

BACKGROUND

Celiac disease (CD) is characterized histologically by inflammation and villous atrophy. Villous atrophy is thought to result from a disruption of epithelial cellular proliferation and death. Epithelial cells in intestinal mucosa normally proliferate in the crypts and migrate towards the lumen, eventually dying. Apoptotic bodies in crypts are usually abnormal and are associated with certain disease states. The presence of crypt apoptosis in celiac disease has not been thoroughly examined by routine histologic assessment of crypt apoptotic body count (ABC).

METHODS

We quantified the ABC in duodenal biopsies from celiac patients before and after initiation of a gluten-free diet (GFD). We examined twenty-three duodenal biopsies from adult patients with celiac disease at diagnosis and following GFD and determined the maximum ABC in 10 consecutive crypts. Fourteen biopsies from heartburn patients served as controls.

RESULTS

Mean duration between paired biopsies was 2.9 (0.5-8.5) years. Mean maximum ABC in active celiac disease was 5.44 per crypt and decreased to 2.60 with GFD (p = <.0001). The mean maximum ABC in controls was 1.79, lower than both active celiac disease and GFD (p = <.0001 and p = .019 respectively). Flat lesions with total villous atrophy (mean: 6.44) showed a higher ABC compared to non-flat lesions (mean: 4.87); p = .04.

CONCLUSIONS

Crypt ABC is markedly elevated in active celiac disease and decreases significantly with GFD, however it does not achieve normalcy. Total villous atrophy is associated with a higher ABC than all other lesions. Crypt apoptosis is likely a significant contributor to villous atrophy in celiac disease and can be appreciated by routine histologic examination.

Current approach to early gastrointestinal and liver complications of hematopoietic stem cell transplantation

The gastrointestinal (GI) system is one of the most commonly affected sites during a hematopoietic stem cell transplantation (HSCT) due to toxicities of preparative regimens, the accompanying immunodeficiency, and organ damage caused by graft versus host disease. In this review, we focus on early GI and liver complications following autologous (auto-) and allogeneic (allo-) HSCT and clarify both the risk factors and therapeutic strategies. Early GI and liver complications associated with HSCT remain challenging issues. Despite the improvements in this field during the last decade, treatments for these complications still place a significant burden on both patients and the physicians treating these patients. GI and liver complications remain some of the causes of mortality associated with HSCT. For practicing hematologists, oncologists, and gastroenterologists in this field, the awareness and early diagnosis of the GI complications remain important factors to obtain optimal outcomes in this patient population.

Site specific diagnostic yield of endoscopic biopsies in Gastrointestinal Graft-versus-Host Disease: A tertiary care Center experience

BACKGROUND

Gastrointestinal (GI) graft versus host disease (GVHD) occurs in up to 40% of patients undergoing allogenic hematopoietic stem cell transplantation (HSCT). However, the optimal endoscopic approach is still unclear and the area of the GI tract with the highest diagnostic yield is still a topic of debate.

OBJECTIVE

We compared the diagnostic yield of different anatomic site biopsies in the diagnosis of GI GVHD and assessed the correlation of endoscopic findings with histopathology.

METHODS

All cases of biopsy proven GI GVHD were obtained from pathology database AUBMC between 1/1/2005 and 31/8/2017. We retrospectively analyzed the demographical, clinical and endoscopic data.

RESULTS

Nineteen patients were diagnosed with GI GVHD over 17.6 years. The most common presenting symptom was severe diarrhea (18 patients, 94.7%). Combining upper endoscopy and sigmoidoscopy with biopsies had the highest diagnostic yield of 90% in diagnosing GI GVHD compared to 63.6%, 78.6% and 77.8% for upper endoscopy, sigmoidoscopy and colonoscopy respectively. In macroscopically normal mucosa, the recto-sigmoid and duodenal biopsies had the highest diagnostic yield (75%). As for the macroscopically abnormal mucosa, the highest yield was for the recto-sigmoid biopsies (100%) in lower endoscopy and duodenal biopsies in the upper endoscopy (60%).

CONCLUSION

In a patient suspected to have GI GVHD, the best endoscopic approach is the combination of upper endoscopy and flexible sigmoidoscopy with biopsies of normal as well as abnormal mucosa. It should be emphasized that normal mucosa be biopsied especially in the duodenum and recto-sigmoid for a better diagnostic yield.

Non-invasive diagnosis of acute intestinal graft-versus-host disease by a new scoring system using ultrasound morphology, compound elastography, and contrast-enhanced ultrasound

Acute gastrointestinal (GI) graft-versus-host disease (GvHD) is a life-threating complication in patients after allogeneic stem cell transplantation (ASCT). In 60 sonographic analyses, a novel scoring system for non-invasive diagnosis of severe GI GvHD was developed. The score comprised morphological and vascular changes using B-mode and color-coded Doppler sonography, changes of mural stiffness using compound elastography, and dynamic microvascularisation using contrast-enhanced ultrasound (CEUS). Furthermore, inflammatory parameters such as CRP, Calprotectin, and regenerating islet-derived protein 3α (Reg3α) were obtained. ROC curve analysis of our novel GvHD sum score revealed an area under the curve of 1.0 (95% CI: 0.99-1.00) in diagnosing GI GvHD and 0.88 (95% CI: 0.79-0.96) for severe GI GvHD. A sum score above 5 correlated with GI GvHD with a sensitivity of 97.6% (41/42) and a specificity of 94.4% (17/18) and score values above 10 with severe GI GvHD with a sensitivity of 91.7% (11/12) and specificity of 79.2% (38/48). The additional use of inflammatory parameters did not improve the predictive power. CEUS is a promising, non-invasive tool for the diagnosis of acute GI GvHD. Together with further descriptive parameters for inflammatory processes, it gains significant diagnostic accuracy in identifying patients with severe stages of acute intestinal GvHD.

A Randomized, Double-Blind, Placebo-Controlled Phase 3 Trial of Oral Brincidofovir for Cytomegalovirus Prophylaxis in Allogeneic Hematopoietic Cell Transplantation

Cytomegalovirus (CMV) infection is a common complication of allogeneic hematopoietic cell transplantation (HCT). In this trial, we randomized adult CMV-seropositive HCT recipients without CMV viremia at screening 2:1 to receive brincidofovir or placebo until week 14 post-HCT. Randomization was stratified by center and risk of CMV infection. Patients were assessed weekly through week 15 and every third week thereafter through week 24 post-HCT. Patients who developed clinically significant CMV infection (CS-CMVi; CMV viremia requiring preemptive therapy or CMV disease) discontinued the study drug and began anti-CMV treatment. The primary endpoint was the proportion of patients with CS-CMVi through week 24 post-HCT; patients who discontinued the trial or with missing data were imputed as primary endpoint events. Between August 2013 and June 2015, 452 patients were randomized at a median of 15 days after HCT and received study drug. The proportion of patients who developed CS-CMVi or were imputed as having a primary endpoint event through week 24 was similar between brincidofovir-treated patients and placebo recipients (155 of 303 [51.2%] versus 78 of 149 [52.3%]; odds ratio, .95 [95% confidence interval, .64 to 1.41]; P = .805); fewer brincidofovir recipients developed CMV viremia through week 14 compared with placebo recipients (41.6%; P < .001). Serious adverse events were more frequent among brincidofovir recipients (57.1% versus 37.6%), driven by acute graft-versus-host disease (32.3% versus 6.0%) and diarrhea (6.9% versus 2.7%). Week 24 all-cause mortality was 15.5% among brincidofovir recipients and 10.1% among placebo recipients. Brincidofovir did not reduce CS-CMVi by week 24 post-HCT and was associated with gastrointestinal toxicity.

Inflammatory and infectious manifestations of immunodeficiency in the gastrointestinal tract

Immune compromise may result from genetic abnormalities, HIV/AIDS, or consequences of therapy for neoplastic and autoimmune diseases. Many immunocompromised patients develop severe gastrointestinal symptoms, particularly diarrhea, accompanied by non-specific or mild endoscopic abnormalities; mucosal biopsy with pathologic interpretation has a major role in the diagnosis and management of these patients. Immunocompromised individuals are at risk for all the diseases that affect those with a healthy immune system, but they are also prone to other illnesses that rarely affect immunocompetent patients. This review discusses the gastrointestinal manifestations of primary and acquired immunodeficiency, chemotherapy-related injury, and infections that show a predilection for immunocompromised patients. Key histologic features and relevant differential diagnoses are emphasized.

Use of the National Institutes of Health Consensus Guidelines Improves the Diagnostic Sensitivity of Gastrointestinal Graft-Versus-Host Disease

CONTEXT

- Graft-versus-host disease of the gastrointestinal tract is a common complication of hematopoietic stem cell transplant associated with significant morbidity and mortality. Accurate diagnosis can be difficult and is a truly clinicopathologic endeavor.

OBJECTIVES

- To assess the diagnostic sensitivity of gastrointestinal graft-versus-host disease using the 2015 National Institutes of Health (NIH) histology consensus guidelines and to analyze histologic findings that support the guidelines.

DESIGN

- Patients with allogeneic hematopoietic stem cell transplants were identified via a retrospective search of our electronic medical records from January 1, 2005, to January 1, 2011. Endoscopies with available histology were reviewed by 2 pathologists using the 2015 NIH guidelines. The clinical diagnosis was used as the gold standard. A nontransplant set of endoscopic biopsies was used as a control.

RESULTS

- Of the 250 total endoscopies, 217 (87%) had a clinical diagnosis of gastrointestinal graft-versus-host disease. Use of the NIH consensus guidelines showed a sensitivity of 86% and a specificity of 65%. Thirty-seven of 58 (64%) cases with an initial false-negative histopathologic diagnosis were diagnosed as graft-versus-host disease on our review.

CONCLUSIONS

- Use of the NIH histology consensus guidelines results in a high sensitivity and specificity, thereby decreasing false-negatives. Additionally, use of the NIH guidelines aids in creating uniformity and diagnostic clarity. Correlation with clinical and laboratory findings is critical in evaluating the differential diagnosis and to avoid false-positives. As expected, increased apoptosis with decreased inflammation was associated with a pathologic diagnosis of graft-versus-host disease and supports the NIH guidelines.

Graft versus Host Disease: From Basic Pathogenic Principles to DNA Damage Response and Cellular Senescence

Graft versus host disease (GVHD), a severe immunogenic complication of allogeneic hematopoietic stem cell transplantation (HSCT), represents the most frequent cause of transplant-related mortality (TRM). Despite a huge progress in HSCT techniques and posttransplant care, GVHD remains a significant obstacle in successful HSCT outcome. This review presents a complex summary of GVHD pathogenesis with focus on references considering basic biological processes such as DNA damage response and cellular senescence.

The association of histologic grade with acute graft-versus-host disease response and outcomes

Consensus criteria are routinely used to clinically grade acute graft-versus-host disease (GVHD). A histologic grading system for acute GVHD is available, but there are limited data on its correlation with clinical grade and hematopoietic cell transplantation (HCT) outcomes. Among 503 patients who underwent allogeneic HCT from 2005 to 2013, we identified 300 biopsy episodes of the skin and gastrointestinal (GI) tract in 231 patients. Histologic grade was correlated with clinical grade of GVHD, day 28 treatment response, and outcome. Both skin (R = 0.32) and GI (R = 0.61) histologic grade correlated with clinical grade (P < 0.001). On multivariable analysis, histologic grade (HR 0.87, P = 0.011) and clinical grade (HR 0.86, P = 0.008) were significantly associated with day 28-treatment response. A histologic grade lower than its associated clinical grade predicted for better response (HR 1.26, P = 0.027), while a histologic grade higher than associated clinical grade had no correlation with response (P = 0.89). Both clinical and histologic GVHD grade were significant predictors of non-relapse mortality (HR 1.47, P = 0.04 and HR 1.67, P = 0.002, respectively) and all-cause mortality (HR 1.57, P = 0.001 and HR 1.29, P = 0.046, respectively). Histologic GVHD grade thus is correlated with clinical grading and treatment response, and may play a role in further predicting severity and treatment response of acute GVHD.

Graft-versus-Host Disease of the Gut: A Histologic Activity Grading System and Validation

The pathologic interpretation of gut biopsies in hematopoietic cell transplant recipients to assess graft-versus-host disease (GVHD) is well accepted and supplements clinical and endoscopic findings. However, the histologic activity grading of GVHD is controversial, with attempts to predict prognosis or response to treatment largely unsuccessful. GVHD is being diagnosed earlier in its course, raising the possibility that the pathologic grading system can be profitably modified. We developed a histologic activity grading system designed to replace the commonly used modified Lerner grading systems. Our system stratifies the low-level Lerner grade I category into 4 activity grade categories, based on the average frequency of apoptotic cells. The results are expressed as ordinal categories: GVHD of minimal, mild, moderate, severe histologic activity, or severe histologic activity with destruction (activity grades 1 to 5). In a retrospective study, we studied 87 consecutive cases with 201 post-transplantation specimens (median, 48 days; range, 18 to 1479 days) of stomach, duodenum, and colorectum, which had been activity graded at the time of the original diagnosis. Most of the biopsies diagnosed as GVHD were low grade-minimal (11%) or mild (71%) histologic activity. We hypothesized that the higher activity grades would be associated with more therapeutic intervention. The odds of increased therapy in the combined all-site specimens were increased as activity grade increased (odds ratio, 2.9 [95% confidence interval {CI}, 1.9 to 4.5]; P = < .0001). Thus, our grading system was validated. To investigate whether the activity grade was associated with therapy within the formerly undivided Lerner grade I category, the analysis was restricted to these 174 all-site specimens. The validation result was similar (odds ratio, 3.1 [95% CI, 1.3 to 7.2]; P = .009). This result interestingly suggests that there is useful information hidden in the Lerner grade I category, which could potentially guide immediately actionable treatment decisions. This histologic activity grade system has been in use at our institution for over 2 years with good acceptance.