Biomarkers in Graft-Versus-Host Disease: from Prediction and Diagnosis to Insights into Complex Graft/Host Interactions

Unlocking protein-based biomarker potential for graft-versus-host disease following allogenic hematopoietic stem cell transplants

Despite the numerous advantages of allogeneic hematopoietic stem cell transplants (allo-HSCT), there exists a notable association with risks, particularly during the preconditioning period and predominantly post-intervention, exemplified by the occurrence of graft-versus-host disease (GVHD). Risk stratification prior to symptom manifestation, along with precise diagnosis and prognosis, relies heavily on clinical features. A critical imperative is the development of tools capable of early identification and effective management of patients undergoing allo-HSCT. A promising avenue in this pursuit is the utilization of proteomics-based biomarkers obtained from non-invasive biospecimens. This review comprehensively outlines the application of proteomics and proteomics-based biomarkers in GVHD patients. It delves into both single protein markers and protein panels, offering insights into their relevance in acute and chronic GVHD. Furthermore, the review provides a detailed examination of the site-specific involvement of GVHD. In summary, this article explores the potential of proteomics as a tool for timely and accurate intervention in the context of GVHD following allo-HSCT.

Umbilical Cord Blood Cell Clearance Post-Infusion in Immune-Competent Children with Cerebral Palsy

Umbilical cord blood cells have therapeutic potential for neurological disorders, through a paracrine mechanism of action. A greater understanding of the safety and immunological effects of allogeneic donor cord blood cells in the context of a healthy recipient immune system, such as in cerebral palsy, is needed. This study aimed to determine how quickly donor cord blood cells were cleared from the circulation in children with cerebral palsy who received a single intravenous infusion of 12/12 human leucocyte antigen (HLA)-matched sibling cord blood cells. Twelve participants with cerebral palsy aged 2-12 years received cord blood cell infusions as part of a phase I trial of umbilical blood infusion for cerebral palsy. Digital droplet PCR analysis of DNA copy number variants specific to donor and recipient was used to assess donor DNA clearance at five timepoints post-infusion, a surrogate measure of cell clearance. Donor cells were cleared by 3 months post-infusion in 11/12 participants. When detected, donor DNA was at a fraction of 0.01-0.31% of total DNA with no signs of graft-versus-host disease in any participant. The donor DNA clearance times provided by this study have important implications for understanding the safety of allogeneic cord blood cell infusion for cerebral palsy and translational tissue engineering or regenerative medicine research in other disorders.

Activated CD4 + T lymphocyte is a potential biomarker for acute graft-vs.-host disease after hematopoietic stem cell transplantation in children with transfusion-dependent β-thalassemia

BACKGROUND

Acute graft-vs.-host disease (aGVHD) is still one of the most common and life-threatening complications of allogeneic hematopoietic stem cell transplantation (HSCT). Whether or not the level of activated T lymphocytes rises before the onset of aGVHD is unknown. We explored the possibility of T lymphocytes as biomarkers for early prediction of aGVHD in children with transfusion-dependent β-thalassemia (TDTβ).

METHODS

We retrospectively analyzed the characteristics of T lymphocyte subsets before and 14 days after HSCT in children with TDTβ who developed aGVHD. Data from 95 children (Age ≤ 14 years) who underwent allogeneic HSCT from January 2020 to December 2021 were collected. Patients were divided into non-aGVHD group (n = 55) and aGVHD group (n = 40), and aGVHD group was divided into two subgroups: grade I aGVHD (n = 16) and grade II-IV aGVHD (n = 24). Receiver operating characteristic curve (ROC) analysis was performed to predict aGVHD.

RESULTS

Before preconditioning in non-aGVHD and aGVHD groups, there was no significant difference in all lymphocyte subsets and ratio of CD4 + /CD8 + T cells. On day 14 post-transplantation in non-aGVHD and aGVHD groups, the absolute concentrations per μl blood of T cells, CD4 + T cells, CD8 + T cells, activated CD4 + T cell and NK cells, were 69.73 (14.70, 137.77) and 140.36 (65.06, 293.42), 10.00 (2.35, 23.59) and 35.91 (12.41, 68.71), 37.25 (5.82, 84.36) and 89.99 (35.83, 180.81), 0.52 (0.17, 2.20) and 4.08 (0.91, 11.12), 43.86 (15.00, 91.31) and 26.35 (15.19, 49.39), respectively. On day + 14 (14 days post-transplantation), the differences in all cell subsets and the ratio of CD4 + /CD8 + T cells were not statistically significant between grade I aGVHD and grade II-IV aGVHD subgroups. The absolute concentrations of CD8 + T cells in grade I aGVHD were significantly higher than in grade II-IV aGVHD [128.21 (61.11, 258.91) vs. 60.81 (21.59, 176.38), P = 0.057]. AUC of NK cells, CD8 + T cells, T cells, CD4 + T cells, and CD4 + CD25 + T cells were 0.6275, 0.6839, 0.7068, 0.7241, and 0.7589, and cut-off values were 73.75 (97.50, 34.55), 146.90 (37.50, 94.55), 187.30 (45.00, 90.91), 18.95 (70.00, 72.73), and 3.24 (52.50, 87.27), respectively. The AUC of the combined CD4 + CD25 + T cells and CD8 + T cells, CD4 + CD25 + T cells and T cells, CD4 + CD25 + T cells and CD4 + T cells, CD4 + CD25 + T cells and NK cells, respectively, were 0.7500, 0.7598, 0.7750, and 0.8050.

CONCLUSION

Our findings demonstrate that level of activated CD4 + T cells on day + 14 (post-HSCT) is a valuable biomarker for predicting aGVHD in children with TDTβ and CD8 + T cells could likely be a biomarker for severe aGVHD.

Association of Pre-Transplant Angiopoietin-2 Index with the Risk of Acute Graft versus Host Disease After Hematopoietic Stem Cell Transplantation

Objective:

Angiogenic factors (AFs) released under endothelial stress are reflective of tissue healing, while some may also contribute to tissue damage/inflammation. We investigated whether alterations in the pre-transplant levels of AFs were associated with the risk of acute graft-versus-host disease (aGvHD).

Materials and Methods:

The pre-conditioning plasma levels of angiopoietin-2 (Ang2), endoglin, and follistatin were measured for 37 patients together with inflammatory markers. The index values defined were evaluated to better identify the alterations.

Results:

The patients had higher pre-conditioning levels of Ang2, endoglin, and follistatin compared to controls. The patients with aGvHD had higher Ang2 index and lower albumin index scores in comparison to those without aGvHD. Multivariate analysis revealed that the pre-transplant Ang2 index was an independent risk factor for aGvHD development.

Conclusion:

Pre-transplant evaluation of plasma Ang2 levels along with inflammatory status even before conditioning is associated with endothelial vulnerability. The pre-transplant Ang2 index could be a promising candidate to estimate the risk of aGvHD.

Biomarkers for acute and chronic graft versus host disease: state of the art

INTRODUCTION

Despite significant advances in treatment and prevention, graft-versus-host disease (GVHD) still represents the main cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Thus, considerable research efforts have been made to find and validate reliable biomarkers for diagnosis, prognosis, and risk stratification of GVHD.

AREAS COVERED

In this review the most recent evidences on different types of biomarkers studied for GVHD, such as genetic, plasmatic, cellular markers, and those associated with microbiome, were summarized. A comprehensive search of peer-review literature was performed in PubMed including meta-analysis, preclinical and clinical trials, using the terms: cellular and plasma biomarkers, graft-versus-host disease, cytokines, and allogeneic hematopoietic stem cell transplantation.

EXPERT OPINION

In the near future, several validated biomarkers will be available to help clinicians in the diagnosis of GVHD, the identification of patients at high risk of GVHD development and in patients' stratification according to its severity. Then, immunosuppressive treatment could be tailored to each patient's real needs. However, more efforts are needed to achieve this goal. Although most of the proposed biomarkers currently lack validation with large-scale clinical data, their study led to improved knowledge of the biological basis of GVHD, and ultimately to implementation of GHVD treatment.

Clostridioides difficile Infection and Risk of Acute Graft-versus-Host Disease among Allogeneic Hematopoietic Stem Cell Transplantation Recipients

Clostridioides difficile infection (CDI) is a major cause of infectious diarrhea among allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. The relationship between CDI and acute graft-versus-host disease (aGVHD) has been a topic of interest, as these 2 conditions may influence each other. We studied the temporal relationship of CDI to aGVHD in the first 100 days post-transplantation in a large cohort of allo-HSCT recipients. We performed a retrospective cohort study of adult patients undergoing their first allo-HSCT at our tertiary care medical center between January 1, 2010, and December 31, 2016. Patients were followed for CDI diagnosis, development of aGVHD, and vital status up to day +100 post-transplantation. Descriptive statistics and multivariate Cox models with CDI as a time-varying covariate and aGVHD and high-grade aGVHD as outcomes were used for data analyses. A total of 656 allo-HSCT recipients were included in the analysis. Of these, 419 (64%) developed aGVHD, and 111 (17%) were diagnosed with CDI within the first 100 days post-transplantation. CDI developed before the onset of aGVHD in 72 of the 84 allo-HSCT recipients (85%) with both CDI and aGVHD. Fidaxomicin was used in the treatment of 57 of the 111 CDI cases (50%), whereas vancomycin was used in 52 (47%). Most of the CDI cases (88%) were diagnosed in the peritransplantation period (between day -10 and day +10). The median time to the development of CDI and aGVHD was 3.5 days (range, -7 to 95 days) and 33 days (range, 9 to 98 days) post-transplantation, respectively. Using multivariate Cox model, the following predictors were significantly associated with the development of aGVHD: CDI (adjusted hazard ratio [aHR], 1.52; 95% confidence interval [CI], 1.17 to 1.97; P = .0018), transplantation from a matched related donor (MRD) compared with a matched unrelated donor (aHR, 0.68; 95% CI, 0.54 to 0.85; P = .0003), and myeloablative versus nonmyeloablative conditioning (aHR, 2.45; 95% CI, 1.80 to 3.34; P < .0001), adjusting for age, sex, race, underlying disease, cytomegalovirus CMV serostatus, transplant source, and receipt of antithymocyte globulin (ATG). There was no association between CDI and high-grade aGVHD after adjustment for age, underlying disease, transplant type, intensity of conditioning, and receipt of ATG (aHR, 1.59; 95% CI, 0.95 to 2.66; P = .0755). CDI after allo-HSCT is associated with increased risk of GVHD when no CDI prophylaxis was used. Further studies examining CDI preventive measures, including prophylaxis, as well as the preservation or reconstitution of the gastrointestinal microbiome in the setting of HSCT are warranted.

Treatment and unmet needs in steroid-refractory acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) is a common complication of allogeneic hematopoietic stem cell transplantation (alloHCT) and is a major cause of morbidity and mortality. Systemic steroid therapy is the first-line treatment for aGVHD, although about half of patients will become refractory to treatment. As the number of patients undergoing alloHCT increases, developing safe and effective treatments for aGVHD will become increasingly important, especially for those whose disease becomes refractory to systemic steroid therapy. This paper reviews current treatment options for patients with steroid-refractory aGVHD and discusses data from recently published clinical studies to outline emerging therapeutic strategies.

Real-time, personalized medicine through wearable sensors and dynamic predictive modeling: a new paradigm for clinical medicine

Accurately predicting the onset and course of a disease in an individual is a major unmet challenge in medicine due to the complex and dynamic nature of disease progression. Continuous data from wearable technologies and biomarker data with a fine time resolution provide a unique opportunity to learn more about disease evolution and to usher in a new era of personalized and real-time medicine. Herein, we propose the potential of real-time, continuously measured physiological data as a noninvasive biomarker approach for detecting disease transitions, using allogeneic hematopoietic stem cell transplant (HCT) patient care as an example. Additionally, we review a recent computational technique, the landscape dynamic network biomarker method, that uses biomarker data to identify transition states in disease progression and explore how to use it with both biomarker and physiological data for earlier detection of graft-versus-host disease specifically. Throughout, we argue that increased collaboration across multiple fields is essential to realizing the full potential of wearable and biomarker data in a new paradigm of personalized and real-time medicine.

Application of latent class analysis in diagnosis of graft-versus-host disease by serum markers after allogeneic haematopoietic stem cell transplantation

Graft-versus-host disease (GVHD) is one of the major causes of morbidity and mortality in 25–70% of patients. The gold standard (GS) test to confirm the diagnosis of GVHD has some limitations. The current study was conducted to evaluate the accuracy of three serum markers in diagnosing GVHD without a GS. 94 patients who were hospitalized for allogeneic transplantation were studied. Mean levels from day of haematopoietic stem cell transplantation (HSCT) to discharge of serum uric acid (UA), lactate dehydrogenase (LDH), and creatinine (Cr) were measured for all participants. We adapted a Bayesian latent class analysis to modelling the results of each marker and combination of markers. The Sensitivity, Specificity, and area under receiver operating characteristic curve (AUC) for LDH were as 51%, 81%, and 0.70, respectively. For UA, the Sensitivity, Specificity, and AUC were 54%, 75%, and 0.71, respectively. The estimated Sensitivity, Specificity, and AUC of Cr were 72%, 94%, and 0.86, respectively. Adjusting for covariates, the combined Sensitivity, Specificity, and AUC of the optimal marker combination were 76%, 83%, and 0.94, respectively. To conclude, our findings suggested that Cr had the strongest diagnosis power for GVHD. Moreover, the classification accuracy of the three-marker combination outperforms the other combinations.

A panel of 4 biomarkers for the early diagnosis and therapeutic efficacy of aGVHD

BACKGROUNDCytokine biomarkers have already been used to predict acute graft-versus-host disease (aGVHD) onset, nonrelapse mortality, and overall survival in human and mouse models, but the consistency of the consequences between patients and mice has not been evaluated. Furthermore, no study about any biomarker or biomarker panel for aGVHD grading or steroid sensitivity of aGVHD patients simultaneously has been reported.METHODSHere we established an aGVHD mouse model and explored the relation between aGVHD onset and variations of some cytokines. Based on the results and latest progress, we selected 16 cytokines and compared their serum variations in aGVHD patients and non-aGVHD patients after allogeneic hematopoietic stem cell transplantation. Using protein microarray, we explored the relation between the cytokine levels and aGVHD-related events (onset, grading, and steroid sensitivity).RESULTSThe increase of chemokine levels in murine aGVHD was very consistent with that of patients. We found obviously higher levels of IL-2, IL-4, Elafin, sST2, TLR4, and TNF-α, and lower levels of TGF-β in both aGVHD mouse models and aGVHD patients. In addition, patients with severe aGVHD showed increased IL-6, TLR4, TNF receptor 1 (TNFR1), and Elafin and decreased TGF-β. TLR4 and TNFR1 were significantly increased in steroid-refractory aGVHD patients compared with steroid-effective patients (P < 0.05).CONCLUSIONA combination of TLR4, TNFR1, TGF-β, and Elafin could be a new 4-biomarker panel to assist aGVHD diagnosis, grading, and evaluation of steroid sensitivity for clinical aGVHD patients.TRIAL REGISTRATIONChiCTR1900022292 "Clinical Research of Umbilical Cord-Derived Mesenchymal Stromal Cells in the Prophylaxis of Graft-Versus-Host Disease After HLA-Haploidentical Stem-Cell Transplantation."FUNDINGNational Key Research Program, National Natural Science Foundation of China, Chongqing Social Career and People's Livelihood Security Science and Technology Innovation Project, Fundamental and Frontier Research Program of Chongqing, and Foundation of Xinqiao Hospital.

MicroRNAs as Potential Diagnostic, Prognostic, and Predictive Biomarkers for Acute Graft-versus-Host Disease

Successful treatment of various hematologic diseases with allogeneic hematopoietic stem cell transplantation is often limited due to the occurrence of acute graft-versus-host disease (aGVHD). So far, there are no approved molecular biomarkers for the diagnosis and prediction of aGVHD at the clinical level due to our incomplete understanding of the molecular biology of the disease. Various studies have been conducted on animal models and humans to investigate the role of microRNAs in aGVHD pathogenesis to implicate them as biomarkers and therapeutic targets. Because of their high stability, tissue specificity, ease of measurement, low cost, and simplicity, they are excellent targets for biomarkers. In this review, we focused on microRNA expression profiling studies that were performed recently in both animal models and human cases of aGVHD to identify diagnostic and predictive biomarkers for this disease. The expression pattern of microRNAs can be specific to cells and tissues. Because aGVHD affects several organs, microRNA signatures in target tissues may help to understand the molecular pathology of the disease. Identification of organ-specific microRNAs in aGVHD can be promising to categorize patients for organ-specific therapies. Thus, microRNAs can be used as noninvasive diagnostic tests in clinic to improve prophylaxis, predict incidence and severity, and reduce morbidity.

Why is a 3-year NRM following allogeneic transplantation still stuck at approximately 20%?

Whether and when to recommend an allogeneic stem cell transplant (SCT) for a patient with leukemia is a treatment decision that rests on determining whether the transplant or non-transplant option carries the greatest probability of 3-5-year survival. While SCT confers a greater possibility of leukemia cure, the decision to transplant has to be made in the light of the high chance of treatment-related mortality (TRM) that follows the allograft. Here we identify that current estimates of a 20% 3-year TRM hold largely true for a variety of leukemias, diverse types of conditioning regimen, and varied donor-recipient compatibility across a wide age-range. While there is a wide spectrum of causes of death in the first few months after SCT, they usually stem from a limited set of immediate post-transplant complications, including those induced by the conditioning regimen, post-transplant endovascular damage, gut dysbiosis, graft-versus-host disease, and immunodeficiency causing viral reactivation. As we better understand and improve preventative treatments for these initiating events there is a real expectation that TRM will continue to fall to levels well below 10% within the next decade.