Biomarkers for posttransplantation outcomes. Blood. 2018;131:2193-2204. [PMID: 29622549 DOI: 10.1182/blood-2018-02-791509]

Investigation of biomarkers to predict outcomes in allogeneic hematopoietic stem cell transplantation

BACKGROUND

Various biomarkers have been developed and evaluated to predict the prognosis and complications of allogeneic hematopoietic cell transplantation (HCT). Most previous studies conducted on different biomarkers evaluated single effects such as those associated with inflammation, immunology, iron metabolism, and nutrition, and only a few studies have comprehensively analyzed markers.

OBJECTIVE

The study aimed to survey comprehensive multiple markers prior to HCT and extract those that significantly predict the outcomes.

STUDY DESIGN

A prospective multicenter observational study was performed. (UMIN000013506) Patients undergoing HCT for hematologic diseases were consecutively enrolled. Besides the usual clinical biomarkers, serum samples for extra-clinical biomarkers were collected and cryopreserved before starting the conditioning regimen. A total of 32 candidate biomarkers were selected, 23 from hematology, biochemistry, immunology, nutrition, and iron metabolism, and 9 from composite markers. Based on the area under the curve (AUC) values for survival, promising biomarkers was extracted. Internal validation for these markers was applied based on bootstrap methods. Setting the cut-off values for them, log-rank test was applied and outcomes including overall survival (OS), relapse, and non-relapse mortality (NRM) were evaluated using multivariate analyses. Furthermore, detailed analysis including transplant-related complications and external validation were conducted focusing on C-reactive protein (CRP) to platelet (Plt) ratio.

RESULTS

A total of 152 patients with hematologic malignancies were enrolled from April 2014 to March 2017. CRP, soluble interleukin-2 receptor (IL2R), CRP to albumin (Alb) ratio, CRP to Plt ratio, Plt to IL2R ratio, and IL2R to Alb ratio were identified as promising markers. Internal validation successfully confirmed their reliability of AUC and multivariate analysis demonstrated the statistical significance between the higher and the lower markers. Above all, a higher CRP to Plt ratio was significantly associated with a lower OS (hazard ratio [HR] 2.77; 95% confidence interval [CI] 1.30-5.91; P = 0.008) and higher non-relapse mortality rates (HR 2.79; 95%CI 1.14-6.80; P = 0.024) at 180 days. Furthermore, univariate analysis showed that a higher CRP to Plt ratio was significantly associated with a higher incidence of sinusoidal obstructive syndrome (P < 0.001) and bloodstream infection (P = 0.027). An external validation test confirmed the significance of the CRP to Plt ratio for these outcomes.

CONCLUSION

The multicenter prospective observational study successfully identified significant biomarkers in patients with hematologic malignancies who received HCT. In particular, CRP to Plt ratio was identified as a novel and useful biomarker for predicting transplant outcomes. Further investigations are needed to validate the novel markers, analysis of the pathophysiology, and application to treatment settings other than HCT.

Galectin-3 predicts acute GvHD and overall mortality post reduced intensity allo-HCT: a BMT-CTN biorepository study

Identifying plasma biomarkers early after allo-HCT may become crucial to prevent and treat severe aGvHD. We utilized samples from 203 allo-HCT patients selected from the Blood & Marrow Transplant Clinical Trials Network (BMT CTN) to identify new biomarker models to predict aGvHD and overall mortality. Two new biomarkers (Gal-3 and LAG-3), and previously identified biomarkers (ST2/IL33R, IL6, Reg3A, PD-1, TIM-3, TNFR1) were screened. Increased Gal-3 levels measured at Day +7 post-transplant predicted the development of aGvHD (grade 2-4) in the total population [AUC: 0.602; P = 0.045] while higher Day +14 levels predicted overall mortality due to toxicity among patients receiving reduced intensity conditioning [P = 0.028] but not myeloablative conditioning. Elevated LAG-3 levels (Day +21) were associated with less severe aGvHD [159.1 ng/mL vs 222.0 ng/mL; P = 0.046]. We developed a model utilizing Gal-3, LAG-3, and PD-1 levels at Days +14 and +21 with an improved performance to predict aGvHD and overall non-relapse mortality. We confirmed four informative biomarkers (Reg3A, ST2, TIM-3, and TNFR1) predict severe aGvHD at day +14 and day +21 (grade 3-4). In conclusion, the combination of Gal-3 alone or in combination with LAG-3, and PD-1 is a new informative model to predict aGvHD development and overall non-relapse mortality after allo-HCT.

Toward Precision Medicine: Exploring the Landscape of Biomarkers in Acute Kidney Injury

Acute kidney injury (AKI) remains a complex challenge with diverse underlying pathological mechanisms and etiologies. Current detection methods predominantly rely on serum creatinine, which exhibits substantial limitations in specificity and poses the issue of late-stage detection of kidney injury. In this review, we propose an up-to-date and comprehensive summary of advancements that identified novel biomarker candidates in blood and urine and ideal criteria for AKI biomarkers such as renal injury specificity, mechanistic insight, prognostic capacity, and affordability. Recently identified biomarkers not only indicate injury location but also offer valuable insights into a range of pathological processes, encompassing reduced glomerular filtration rate, tubular function, inflammation, and adaptive response to injury. The clinical applications of AKI biomarkers are becoming extensive and serving as relevant tools in distinguishing acute tubular necrosis from other acute renal conditions. Also, these biomarkers can offer significant insights into the risk of progression to chronic kidney disease CKD and in the context of kidney transplantation. Integration of these biomarkers into clinical practice has the potential to improve early diagnosis of AKI and revolutionize the design of clinical trials, offering valuable endpoints for therapeutic interventions and enhancing patient care and outcomes.

Early inflammatory markers as prognostic indicators following allogeneic stem cell transplantation

Allogeneic stem cell transplantation is used widely in the treatment of hematopoietic malignancy although graft versus host disease and relapse remain major complications. We measured the serum protein expression of 92 inflammation-related markers from 49 patients at Day 0 (D0) and 154 patients at Day 14 (D14) following transplantation and related values to subsequent clinical outcomes. Low levels of 7 proteins at D0 were linked to GvHD whilst high levels of 7 proteins were associated with relapse. The concentration of 38 proteins increased over 14 days and higher inflammatory response at D14 was strongly correlated with patient age. A marked increment in protein concentration during this period associated with GvHD but reduced risk of disease relapse, indicating a link with alloreactive immunity. In contrast, patients who demonstrated low dynamic elevation of inflammatory markers during the first 14 days were at increased risk of subsequent disease relapse. Multivariate time-to-event analysis revealed that high CCL23 at D14 was associative of AGvHD, CXCL10 with reduced rate of relapse, and high PD-L1 with reduced overall survival. This work identifies a dynamic pattern of inflammatory biomarkers in the very early post-transplantation period and reveals early protein markers that may help to guide patient management.

The level of Tim-3+CD8+ T cells can serve as a potential marker for evaluating the severity of acute graft-versus-host disease after haplo-PBSCT

Early and accurate diagnosis of acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation is crucial for the prognosis of patients. This study identified a potential biomarker for the severity of aGVHD after human leukocyte antigen (HLA)-haploidentical peripheral blood hematopoietic stem cell transplantation (haplo-PBSCT). We included 20 healthy subjects and 57 patients who underwent haplo-PBSCT. Of these patients, 22 developed aGVHD after haplo-PBSCT. The results showed that patients with aGVHD had significantly increased levels of Tim-3+/Perforin+/Granzyme B+CD8+ T cells, but significantly decreased Galectin-9. The differences in Galectin-9 and Tim-3+/Granzyme B+CD8+ T cells between grade I-II aGVHD and III-IV aGVHD were also significant. In vitro, the apoptosis of CD8+ T cells from aGVHD patients was significantly increased after Tim-3/Galectin-9 pathway activation, which decreased Granzyme B secretion. As revealed by univariate analysis, the level of Tim-3+CD8+ T cells was a risk factor for severe aGVHD. ROC analysis demonstrated that high levels of Tim-3+CD8+ T cells had a significant diagnostic value for severe aGVHD, with an area under the curve of 0.854 and cut-off value of 14.155%. In conclusion, the binding of Tim-3 with exogenous Galectin-9 can promote apoptosis of CD8+ T cells and affect the secretion of Granzyme B. Tim-3+CD8+ T cells have the potential to serve as immunological markers for assessing the severity of aGVHD after haplo-PBSCT and identifying patients at a higher risk for severe aGVHD.

EASIX score predicts inferior survival after allogeneic hematopoietic cell transplantation

The Endothelial Activation and Stress Index (EASIX) is a prognostic tool that uses common clinical laboratory values and has been shown to predict non-relapse mortality (NRM) and overall survival (OS) at the onset of acute graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). We hypothesized that EASIX calculated at different time points pre- and post- HCT may predict NRM and OS, and that EASIX calculated at onset of GVHD may predict response to steroids. We evaluated the EASIX score pre- and post-HCT in 152 patients with lymphoid malignancies undergoing unmodified reduced intensity conditioning (RIC) alloHCT with uniform GVHD prophylaxis. In multivariate analysis, EASIX calculated pre-HCT was significantly associated with higher NRM (HR = 1.64, p = 0.009) and lower OS (HR = 1.33, p = 0.046). Furthermore, EASIX calculated at day 30 and at day 100 was associated with increased NRM (HR = 1.65, p < 0.001; and HR = 1.65, p < 0.001) and decreased OS (HR = 1.27, p = 0.018; and HR = 1.49, p < 0.001), independent of HCT-CI, disease and conditioning regimen. Our study shows that high EASIX scores at various time points pre- and post-HCT are significantly associated with poorer overall outcomes. EASIX provides an independent and easily accessible tool to predict outcomes that can be complementary to other measures of risk stratification for patients undergoing HCT.

Inflammatory CD4/CD8 double-positive human T cells arise from reactive CD8 T cells and are sufficient to mediate GVHD pathology

An important paradigm in allogeneic hematopoietic cell transplantations (allo-HCTs) is the prevention of graft-versus-host disease (GVHD) while preserving the graft-versus-leukemia (GVL) activity of donor T cells. From an observational clinical study of adult allo-HCT recipients, we identified a CD4+/CD8+ double-positive T cell (DPT) population, not present in starting grafts, whose presence was predictive of ≥ grade 2 GVHD. Using an established xenogeneic transplant model, we reveal that the DPT population develops from antigen-stimulated CD8 T cells, which become transcriptionally, metabolically, and phenotypically distinct from single-positive CD4 and CD8 T cells. Isolated DPTs were sufficient to mediate xeno-GVHD pathology when retransplanted into naïve mice but provided no survival benefit when mice were challenged with a human B-ALL cell line. Overall, this study reveals human DPTs as a T cell population directly involved with GVHD pathology.

Low Plasma Levels of Hyaluronic Acid Might Rule Out Sinusoidal Obstruction Syndrome after Hematopoietic Stem Cell Transplantation

Background

Sinusoidal obstructive syndrome (SOS) is a potentially fatal complication secondary to hematopoietic stem cell transplant (HSCT) conditioning. Endothelial damage plasma biomarkers such as plasminogen activator inhibitor-1 (PAI-1), hyaluronic acid (HA), and vascular adhesion molecule-1 (VCAM1) represent potential diagnostic tools for SOS.

Methods

We prospectively collected serial citrated blood samples (baseline, day 0, day 7, and day 14) in all adult patients undergoing HSCT at La Paz Hospital, Madrid. Samples were later analyzed by ELISA (enzyme-linked immunosorbent assay) for HA, VCAM1, and PAI-1 concentrations.

Results

During sixteen months, we prospectively recruited 47 patients. Seven patients (14%) were diagnosed with SOS according to the EBMT criteria for SOS/VOD diagnosis and received treatment with defibrotide. Our study showed a statistically significant elevation of HA on day 7 in SOS patients, preceding clinical SOS diagnosis, with a sensitivity of 100%. Furthermore, we observed a significant increase of HA and VCAM1 levels on day 14. Regarding risk factors, we observed a statistically significant association between SOS diagnosis and the fact that patients received 3 or more previous lines of treatment before HSCT.

Conclusions

The early significant increase in HA levels observed opens the door to a noninvasive peripheral blood test which could have the potential to improve diagnosis and facilitate prophylactic and therapeutic management of SOS before clinical/histological damage is established.

Leukemia inhibitory factor protects against graft-versus-host disease while preserving graft-versus-leukemia activity

Graft-versus-host disease (GVHD) remains a major complication after allogeneic hematopoietic stem cell transplantation, a widely used therapy for hematologic malignancies and blood disorders. Here, we report an unexpected role of cytokine leukemia inhibitory factor (LIF) in protecting against GVHD development. Administrating recombinant LIF protein (rLIF) protects mice from GVHD-induced tissue damage and lethality without compromising the graft-versus-leukemia activity, which is crucial to prevent tumor relapse. We found that rLIF decreases the infiltration and activation of donor immune cells and protects intestinal stem cells to ameliorate GVHD. Mechanistically, rLIF downregulates IL-12-p40 expression in recipient dendritic cells after irradiation through activating STAT1 signaling, which results in decreased major histocompatibility complex II levels on intestinal epithelial cells and decreased donor T-cell activation and infiltration. This study reveals a previously unidentified protective role of LIF for GVHD-induced tissue pathology and provides a potential effective therapeutic strategy to limit tissue pathology without compromising antileukemic efficacy.

Longitudinal proteomics study of serum changes after allogeneic HSCT reveals potential markers of metabolic complications related to aGvHD

Even though hematopoietic stem cell transplantation (HSCT) allows successful treatment for many malignant and non-malignant disorders, its curative potential remains limited by severe side effects, including infections and other transplant-related complications such as graft-versus-host disease (GvHD). This study examined changes in serum proteome via high-performance two-dimensional gel electrophoresis (2-DE) during HSCT to search for diagnostic biomarkers for post-HSCT complications. Longitudinal proteomic analysis revealed proteins related to metabolic complications and hemolytic anemia. Retinol-binding protein 4 (RBP4), a reliable marker of insulin resistance, was identified, and is possibly associated with the onset mechanism of acute graft-versus-host disease (aGvHD) and/or skin GvHD. Although the cause of insulin resistance is not fully understood, it is thought to be associated with adipocytes inflammation induced by RBP4, iron overload and hemolytic anemia after HSCT, as observed in this study. The present study has demonstrated that insulin resistance and metabolic complications could be immediate complications after transplantation and are associated with aGvHD. The biomarkers revealed in this study are promising tools to be used for improving the early diagnosis of HSCT-associated complications, especially aGvHD, possibly even before clinical manifestations.

Impact of serum insulin-like growth factor-1 on HSCT outcome in pediatric cancer patients

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is associated with severe medical complications and variable outcome depending on the recipient's disease stage and health condition. Biomarkers predicting outcome may have therapeutic relevance in pediatric cancer care. Insulin like growth factor 1 (IGF 1) is a mitogenic and anabolic peptide hormone that is expressed in almost all tissues. This hormone is the major growth factor in childhood. As IGF 1 is decreased in conditions that cause catabolic metabolism, it may reflect the degree of physical robustness of the patient and serve as predictive biomarker for transplant outcome.

OBJECTIVES AND STUDY DESIGN

We evaluated the impact of pre-transplant serum-IGF 1 on both survival and adverse events in 587 pediatric cancer patients, who underwent autologous or allogeneic HSCT between 1987 and 2014 at the University Children's Hospital Tübingen, Germany. Survival probabilities of the entire cohort and of defined subgroups according to pre-transplant serum-IGF-1 were estimated using the Kaplan-Meier method.

RESULTS

Mean pre-transplant IGF 1 (n = 498) was low: -1.67 SDS (SD, 1.54). Completeness of follow-up three and ten years post HSCT was 96 % and 83 %, respectively. The ten-year overall survival was 44.8 % (95 % confidence interval [CI], 40.6-48.9). With decreasing IGF-1 SDS, there was a significant increase of transplant-related mortality (p = 0.027), sinusoidal obstruction syndrome (quartiles 4 to 1: 3; 1; 12; 12%; p < 0.001) and thrombotic microangiopathy (quartiles 4 to 1: 0: 0: 2; 5%; p = 0.004). IGF 1 decile 1 showed a significantly poorer outcome (p=0.042) with lower median (12 versus 68 months) and ten-year overall survival (37 % versus 52 %) when compared to decile 2-10.

CONCLUSIONS

This retrospective study suggests pre-transplant serum-IGF 1 as a predictor of survival and selected vascular adverse events that may have diagnostic and therapeutic relevance in pediatric cancer care.

Increased risk of nonrelapse mortality post T-cell-replete haploidentical stem cell transplantation in patients with recurrence of acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) causes significant morbidity and mortality. While most studies focus on classic or late aGVHD, some patients with previous aGVHD achieve complete remission and later develop another episode of aGVHD. Data on recurrence of aGVHD (RaGVHD) are lacking. This study aimed to identify the incidence, risk factors, and impacts of RaGVHD after T-cell-replete haploidentical hematopoietic cell transplantation (haplo-HCT) without posttransplantation cyclophosphamide. We evaluated patients with RaGVHD after haplo-HCT between 2017 and 2019 and compared their outcomes to those of patients with no aGVHD and those of patients with one episode of de novo aGVHD. Of 199 patients included in the analysis, 45 experienced 50 cases of RaGVHD with a 1-year cumulative incidence of 19.0% (95% CI: 14.5-24.6). Grade III-IV aGVHD was more common in RaGVHD than in previous aGVHD (22.2% vs 4.4%, p = 0.01). Female donor to male recipient was strongly associated with RaGVHD (HR: 2.5, p = 0.009). The most common death in patients with RaGVHD was GVHD-related, which was different from controls who mostly died from relapse (p =0.008). RaGVHD was an independent risk factor for chronic GVHD (HR: 2.6, p = 0.006) and nonrelapse mortality (HR: 2.4, p = 0.019) and a significant predictor of lower GVHD relapse-free survival (HR: 1.9, p = 0.020) and cGVHD relapse-free survival (HR: 2.1, p = 0.007). In conclusion, clinical manifestations and negative impacts of RaGVHD needs to be recognized independently. This article is protected by copyright. All rights reserved.

Persistent Musculoskeletal Deficits in Pediatric, Adolescent and Young Adult Survivors of Allogeneic Hematopoietic Stem-Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a common therapy for pediatric hematologic malignancies. With improved supportive care, addressing treatment-related late effects is at the forefront of survivor long-term health and quality of life. We previously demonstrated that alloHSCT survivors had increased adiposity, decreased lean mass, and lower bone density and strength, 7 years (median) from alloHSCT compared to their healthy peers. Yet it is unknown whether these deficits persist. Our longitudinal study characterized changes in muscle and bone over a period of 3.4 (range, 2.0 to 4.9) years in 47 childhood alloHSCT survivors, age 5-26 years at baseline (34% female). Tibia cortical bone geometry and volumetric density and lower leg muscle cross-sectional area (MCSA) were assessed via peripheral quantitative computed tomography (pQCT). Anthropometric and pQCT measurements were converted to age, sex, and ancestry-specific standard deviation scores, adjusted for leg length. Muscle-specific force was assessed as strength relative to MCSA adjusted for leg length (strength Z-score). Measurements were compared to a healthy reference cohort (n = 921), age 5-30 years (52% female). At baseline and follow-up, alloHSCT survivors demonstrated lower height Z-scores, weight Z-scores, and leg length Z-scores compared to the healthy reference cohort. Deficits in MCSA, trabecular volumetric bone density, and cortical bone size and estimated strength (section modulus) were evident in survivors (all p < 0.05). Between the two study time points, anthropometric, muscle, and bone Z-scores did not change significantly in alloHSCT survivors. Approximately 15% and 17% of alloHSCT survivors had MCSA and section modulus Z-score < -2.0, at baseline and follow-up, respectively. Furthermore, those with a history of total body irradiation compared to those without demonstrated lower MCSA at follow-up. The persistent muscle and bone deficits in pediatric alloHSCT survivors support the need for strategies to improve bone and muscle health in this at-risk population. © 2022 American Society for Bone and Mineral Research (ASBMR).

Salivary ZG16B expression loss follows exocrine gland dysfunction related to oral chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) targets include the oral mucosa and salivary glands after allogeneic hematopoietic stem cell transplant (HSCT). Without incisional biopsy, no diagnostic test exists to confirm oral cGVHD. Consequently, therapy is often withheld until severe manifestations develop. This proteomic study examined saliva and human salivary gland for a biomarker profile at first onset of oral cGVHD prior to initiation of topical steroid therapy. Whole saliva collected at onset of biopsy-proven oral GVHD was assessed using liquid chromatography-coupled tandem mass spectrometry with identification of 569 proteins, of which 77 significantly changed in abundance. ZG16B, a secretory lectin protein, was reduced 2-fold in oral cGVHD saliva (p <0.05), and significantly decreased in salivary gland secretory cells affected by cGVHD. Single-cell RNA-seq analysis of healthy MSG localized ZG16B expression to two discrete acinar cell populations. Reduced ZG16B expression may indicate specific cGVHD activity and possibly general salivary gland dysfunction.

Secreted osteopontin from CD4+ T cells limits acute graft-versus-host disease

Osteopontin (OPN) has been considered a potential biomarker of graft-versus-host disease (GVHD). However, the function of OPN in GVHD is still elusive. Using a mouse model of acute GVHD (aGVHD), we report that OPN generated by CD4+ T cells is sufficient to exert a beneficial effect in controlling aGVHD through limiting gastrointestinal pathology, a major target organ of aGVHD. CD4+ T cell-derived OPN works on CD44 expressed in intestinal epithelial cells (IECs) and abates cell death of IECs. OPN also modulates gut microbiota with enhanced health-associated commensal bacteria Akkermansia. Importantly, we use our in vivo mouse mutant model to specifically express OPN isoforms and demonstrate that secreted OPN (sOPN), not intracellular OPN (iOPN), is solely responsible for the protective role of OPN. This study demonstrates that sOPN generated by CD4+ T cells is potent enough to limit aGVHD.

Exploring the Mechanism of Action of Canmei Formula Against Colorectal Adenoma Through Multi-Omics Technique

Background: Canmei formula (CMF) is a traditional Chinese medicine compound with definite effect on the prevention and treatment of colorectal adenoma (CRA). CMF can prevent the transformation of intestinal inflammation to cancer. This study explored the mechanism of action of CMF in anti-CRA using multi-omics techniques.

Method: The mice were randomly divided into four groups: blank group (Control), high-fat diet (HFD) + AOM/DSS colorectal adenoma model (ADH) groups, Canmei formula treatment group (ADH-CMF) and sulfasalazine treatment group (Sul). Except for the blank group, ADH model was established in the other three groups by intraperitoneal injection with AOM reagent, and then mice were given 2.5% DSS in free drinking water and high-fat diet. The mice in the blank group and ADH groups were intragastrically perfused with normal saline, and the mice in the other two groups were treated with corresponding drugs for 20 weeks. During this period, the changes of physical signs of mice in each group were observed. The differentially expressed genes and proteins in the Control group, ADH group and ADH-CMF group were detected by RNA-seq transcriptome sequencing and Tandem Mass Tags (TMT) quantitative proteomics. After the combined analysis and verification, the key targets were analyzed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Moreover, the changes of intestinal flora in mice of the three groups were examined.

Results: A total of 2,548 differential genes were obtained by transcriptomics analysis, and 45 differential proteins were obtained by proteomics analysis. The results of proteomics data and experimental verification showed that CMF mainly affected the Phospholysine Phosphohistidine Inorganic Pyrophosphate Phosphatase (LHPP) target. GO analysis showed that the targets of CMF were involved in the biological processes such as cellular process, metabolic process and biological regulation. KEGG analysis showed that those genes were involved in oxidative phosphorylation, cell senescence, and metabolic pathways. Studies have shown that LHPP overexpression impeded colorectal cancer cell growth and proliferation in vitro, and was associated with a change in PI3K/AKT activity. The results of 16S DNA high-throughput sequencing showed that CMF could effectively regulate the abundance of Bifidobacterium, Candidatus_Saccharimonas and Erysipelatoclostridium in the intestinal flora at the genus level.

Conclusion: CMF regulates LHPP via the PI3K/AKT signaling pathway. CMF affects the abundance of specific intestinal flora and can regulate the disorder of intestinal flora to achieve the role of prevention and treatment of CRA.

Early Myeloid Derived Suppressor Cells (eMDSCs) Are Associated With High Donor Myeloid Chimerism Following Haploidentical HSCT for Sickle Cell Disease

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is a widely available curative option for patients with sickle cell disease (SCD). Our original non-myeloablative haplo-HSCT trial employing post-transplant (PT) cyclophosphamide had a low incidence of GVHD but had high rejection rates. Here, we aimed to evaluate immune reconstitution following haplo-HSCT and identify cytokines and cells associated with graft rejection/engraftment. 50 cytokines and 10 immune cell subsets were screened using multiplex-ELISA and flow cytometry, respectively, at baseline and PT-Days 30, 60, 100, and 180. We observed the most significant differences in cytokine levels between the engrafted and rejected groups at PT-Day 60, corresponding with clinical findings of secondary graft rejection. Of the 44 cytokines evaluated, plasma concentrations of 19 cytokines were different between the two groups at PT-Day 60. Factor analysis suggested two independent factors. The first factor (IL-17A, IL-10, IL-7, G-CSF, IL-2, MIP-1a, VEGF, and TGFb1 contributed significantly) was strongly associated with engraftment with OR = 2.7 (95%CI of 1.4 to 5.4), whereas the second factor (GROa and IL-18 contributed significantly) was not significantly associated with engraftment. Sufficient donor myeloid chimerism (DMC) is critical for the success of HSCT; here, we evaluated immune cells among high (H) DMC (DMC≥20%) and low (L) DMC (DMC<20%) groups along with engrafted and rejected groups. We found that early myeloid-derived suppressor cell (eMDSC) frequencies were elevated in engrafted patients and patients with HDMC at PT-Day 30 (P< 0.04 & P< 0.003, respectively). 9 of 20 patients were evaluated for the source of eMDSCs. The HDMC group had high mixed chimeric eMDSCs as compared to the LDMC group (P< 0.00001). We found a positive correlation between the frequencies of eMDSCs and Tregs at PT-Day 100 (r=0.72, P <0.0007); eMDSCs at BSL and Tregs at PT-Day 100 (r=0.63, P <0.004). Of 10 immune regulatory cells and 50 cytokines, we observed mixed chimeric eMDSCs and IL-17A, IL-10, IL-7, G-CSF, IL-2, MIP-1a, VEGF, TGFb1 as potential hits which could serve as prognostic markers in predicting allograft outcome towards engraftment following haploidentical HSCT employing post-transplant cyclophosphamide. The current findings need to be replicated and further explored in a larger cohort.

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.

Pre-and Post-Transplant Serum Lactate Dehydrogenase Levels as a Predictive Marker for Patient Survival and Engraftment in Allogeneic Hematopoietic Stem Cell Transplant Recipients

Background

The discovery of biomarkers to predict the development of complications associated with hematopoietic stem cell transplantation (HSCT) offers a potential avenue for the early identification and treatment of these life-threatening consequences. Serum lactate dehydrogenase (sLDH) has been identified as a potential biomarker for determining the outcome of allogenic HSCT (allo-HSCT).

Methods

A retrospective study was performed using data collected from 204 allo-HSCT recipient patients to examine the predictive value of sLDH levels pre- and post-allo-HSCT on patient survival, graft-versus-host-disease (GVHD) incidence, and time to platelet/white blood cells (WBC) engraftment.

Results

Our findings show that neither pre- (p= 0.61) nor post-transplantation (p= 0.55) sLDH levels were associated with GVHD incidence. However, elevated sLDH levels pre- and post-transplantation (≥ 386 and ≥ 409 IU/mL, respectively) were found to be adverse risk factors for patient survival (p= 0.16, p= 0.20, respectively). Furthermore, a median sLDH level ≥ 400 IU/mL from day +5 to day +15 post-transplantation had a significant positive association with enhanced time to platelet and white blood cell (WBC) engraftment, compared to patients with sLDH levels < 400 IU/mL (p< 0.001).

Conclusion

Our data suggests that high sLDH levels pre- and post-allo-HSCT could be considered a predictor of poor patient survival. Furthermore, high levels of sLDH days 5-15 post-allo-HSCT could be associated with improved time to platelet and WBC engraftment; however, this appears to come at the cost of increased mortality risk.

Biomarkers of graft-vs-host disease: Understanding and applications for the future

Hematopoietic stem cell transplantation (HSCT) is widely performed as a treatment for malignant blood disorders, such as leukemia. To achieve good clinical outcomes in HSCT, it is necessary to minimize the unfavorable effects of acute graft-vs-host disease (GVHD) and induce the more tolerable, chronic form of the disease. For better management of GVHD, sensitive and specific biomarkers that predict the severity and prognosis of the disease have been intensively investigated using proteomics, transcriptomics, genomics, cytomics, and tandem mass spectrometry methods. Here, I will briefly review the current understanding of GVHD biomarkers and future prospects.

GVHD Pathogenesis, Prevention and Treatment: Lessons From Humanized Mouse Transplant Models

Graft-vs-host disease (GVHD) is the most common cause of non-relapse mortality following allogeneic hematopoietic stem cell transplantation (HSCT) despite advances in conditioning regimens, HLA genotyping and immune suppression. While murine studies have yielded important insights into the cellular responses of GVHD, differences between murine and human biology has hindered the translation of novel therapies into the clinic. Recently, the field has expanded the ability to investigate primary human T cell responses through the transplantation of human T cells into immunodeficient mice. These xenogeneic HSCT models benefit from the human T cell receptors, CD4 and CD8 proteins having cross-reactivity to murine MHC in addition to several cytokines and co-stimulatory proteins. This has allowed for the direct assessment of key factors in GVHD pathogenesis to be investigated prior to entering clinical trials. In this review, we will summarize the current state of clinical GVHD research and discuss how xenogeneic HSCT models will aid in advancing the current pipeline of novel GVHD prophylaxis therapies into the clinic.

Preventive and Therapeutic Effects of a Novel JAK Inhibitor SHR0302 in Acute Graft-Versus-Host Disease

Acute graft-versus-host disease (aGVHD) is one of the most common complications of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Janus kinase (JAK) inhibitors are considered as reliable and promising agents for patients with aGVHD. The prophylactic and therapeutic effects of SHR0302, a novel JAK inhibitor, were evaluated in aGVHD mouse models. The overall survival (OS), progression-free survival (PFS), bodyweight of mice, GVHD scores were observed and recorded. The bone marrow and spleen samples of diseased model mice or peripheral blood of patients were analyzed. SHR0302 could prevent and reverse aGVHD in mouse models with preserving graft-versus-tumor effect. Functionally, SHR0302 improved the OS and PFS, restored bodyweight, reduced GVHD scores, and reduced immune cells infiltrated in target tissues. SHR0302 treatment also enhanced the hematopoietic reconstruction compared to the control group. Mechanistically, our results suggested that SHR0302 could inhibit the activation of T cells and modulate the differentiation of helper T (Th) cells by reducing Th1 and increasing regulatory T (Treg) cells. In addition, SHR0302 decreased the expression of chemokine receptor CXCR3 on donor T cells and the secretion of cytokines or chemokines including interleukin (IL)-6, interferon γ (IFN-γ), tumor necrosis factor α (TNF-α), CXCL10, etc. thereby destroying the IFN-γ/CXCR3/CXCL10 axis which promotes the progression of GVHD. Besides, SHR0302 decreased the phosphorylation of JAK and its downstream STATs, AKT and ERK1/2, which ultimately regulated the activation, proliferation, and differentiation of lymphocytes. Experiments on primary cells from aGVHD patients also confirmed the results. In summary, our results indicated that JAK inhibitor SHR0302 might be used as a novel agent for patients with aGVHD.

Artificial Intelligence and Precision Medicine: A Perspective

This article aims to present how the advanced solutions of artificial intelligence and precision medicine work together to refine medical management. Multi-omics seems the most suitable approach for biological analysis of data on precision medicine and artificial intelligence. We searched PubMed and Google Scholar databases to collect pertinent articles appearing up to 5 March 2021. Genetics, oncology, radiology, and the recent coronavirus disease (COVID-19) pandemic were chosen as representative fields addressing the cross-compliance of artificial intelligence (AI) and precision medicine based on the highest number of articles, topicality, and interconnectedness of the issue. Overall, we identified and perused 1572 articles. AI is a breakthrough that takes part in shaping the Fourth Industrial Revolution in medicine and health care, changing the long-time accepted diagnostic and treatment regimens and approaches. AI-based link prediction models may be outstandingly helpful in the literature search for drug repurposing or finding new therapeutical modalities in rapidly erupting wide-scale diseases such as the recent COVID-19.

Posttransplantation Cyclophosphamide- and Sirolimus-Based Graft-Versus-Host-Disease Prophylaxis in Allogeneic Stem Cell Transplant

Post-transplantation cyclophosphamide (PTCy) has emerged as a promising graft-versus-host-disease (GVHD) prophylaxis in the setting of allogeneic hematopoietic stem cell transplantation (HSCT) from haploidentical donors and more recently in matched donor transplants. Herein, we describe our real-life experience on 249 adult patients undergoing allogeneic HSCT, from HLA-matched related (MRD), HLA-matched unrelated (MUD), or mismatched related donors (MMRD). Patients received unmanipulated peripheral blood stem cells (PBSCs), using a GVHD prophylaxis with PTCy and sirolimus. Mycophenolate mofetil was added in MUD or MMRD. In the HLA-matched donor group (MRD, n = 48, MUD, n = 50), the cumulative incidence of grades II-IV and III-IV acute GvHD was 23% and 9% at 100 days, respectively. The cumulative incidence of chronic GvHD was 25% at 2 years, severe only for 5% of the patients. The cumulative incidences of relapse and transplant-related mortality (TRM) were 31% and 9% at 2 years, respectively. The 2-year overall survival (OS) was 72% and progression-free survival (PFS) 60%; the composite endpoint of GvHD/relapse-free survival (GRFS) was 52% at 2 years. In the haploidentical donor group (n = 151), we documented a cumulative incidence of grades II-IV and III-IV acute GVHD of 35% and 20% at 100 days, respectively, and a cumulative incidence of chronic GvHD of 39% at 2 years. We observed severe chronic GVHD in 15% of the patients. The cumulative incidence of relapse and TRM was 32% and 25% at 2 years, respectively. The 2-year OS was 48%, whereas PFS was 43%; GRFS was 28% at 2 years. However, more patients in the haploidentical group presented high/very high disease risk index (DRI) and higher HCT-comorbidity index. In patients classified in the low-intermediate DRI, 2-year GRFS was 53% in MRD, 65% in MUD, and 46% in haploidentical HSCT (P = .33). Sirolimus-PTCy platform deserves further investigation as an alternative to calcineurin-inhibitor-based GVHD prophylaxis for all donor sources. In patients presenting a low-intermediate DRI, this strategy translates in relevant survival independently from the transplant source.

Immunopathology and biology-based treatment of steroid-refractory graft-versus-host disease

Acute graft-versus-host disease (GVHD) is 1 of the major life-threating complications after allogeneic cell transplantation. Although steroids remain first-line treatment, roughly one-half of patients will develop steroid-refractory GVHD (SR-GVHD), which portends an extremely poor prognosis. Many agents that have shown encouraging response rates in early phase 1/2 trials for prevention and treatment have been unsuccessful in demonstrating a survival advantage when applied in the setting of SR-GVHD. The discovery of novel treatments has been further complicated by the absence of clinically informative animal models that address what may reflect a distinct pathophysiology. Nonetheless, the combined knowledge of established bone marrow transplantation models and recent human trials in SR-GVHD patients are beginning to illuminate novel mechanisms for inhibiting T-cell signaling and promoting tissue tolerance that provide an increased understanding of the underlying biology of SR-GVHD. Here, we discuss recent findings of newly appreciated cellular and molecular mechanisms and provide novel translational opportunities for advancing the effectiveness of treatment in SR-GVHD.

Analysis of HLA haplotype and clinical factors during hematopoietic stem cell transplantation

BACKGROUND

The human leukocyte antigen (HLA) haplotype of the recipient in hematopoietic stem cell transplantation (HSCT) is a key factor in its success or failure. We analyzed the relationship between HLA haplotype frequency and associated clinical factors in HSCT patients.

METHODS

Patients who underwent allogeneic HSCT between 2000 and 2019 at our institution were enrolled in this study. The HSCT composition was 77 bone marrow transplantations (BMT), 38 peripheral blood stem cell transplantations (PBSCT), and 36 cord blood transplantations (CBT). Patients were classified into three groups according to their donor HLA haplotype frequency in the Japan Population: group A, top 1-10 haplotypes; group B, top 11-100 haplotypes; and group C, haplotype 101-. We then compared various items including clinical biomarkers with the HLA haplotype frequency.

RESULTS

A significant negative correlation was identified between older persons and length of survival. There are also significant correlations between survival and levels of immunoglobulin G, D-dimer, and C-reactive protein, as well as the platelet-large cell ratio before transplantation. A total of 96, 30, and 25 patients were classified into groups A, B, and C, respectively. The HSCT match rate was significantly higher in group A patients than in those of groups B and C. In contrast, the death rate, D-dimer level, and length of time for engraftment were significantly higher in group B and C patients than in those of group A.

CONCLUSION

An assessment of transplant-related complications is important in improving the performance of HSCT. The present data suggest that a special therapeutic strategy is necessary for HSCT using low-frequency HLA haplotypes.

The role of microbiota in allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is commonly performed to treat a variety of benign and malignant hematological diseases. Acute graft-versus-host disease (GVHD) is a major life-threatening complication that often occurs following allo-HSCT. Recently, improvements in methods to characterize the microbiota have led to a greater appreciation for how frequently and profoundly an alteration in microbial composition, or dysbiosis, can occur in allo-HSCT recipients to better decipher the complex interplay between microbiota and allo-HSCT outcomes.

AREAS COVERED

This article reviews the current knowledge of the microbiota's impact on allo-HSCT outcomes, including effects of microbiota-derived metabolites, and crosstalk between commensals and the allogeneic immune response. This article also summarizes the effects of HSCT and transplant-related procedures on microbiota, and recent developments in interventional strategies.

EXPERT OPINION

A growing body of literature indicates that the composition of the intestinal microbiota can function as a predictive biomarker for the risk and severity of acute GVHD, as well as overall survival, in patients undergoing allo-HSCT. Mechanisms underpinning these associations, however, are not well understood, and clinical strategies that modulate the microbiome to improve outcomes have yet to be fully developed. There is an unmet need to determine mechanisms to improve the efficacy of allo-HSCT.

Phase II Trial of Costimulation Blockade With Abatacept for Prevention of Acute GVHD

PURPOSE

Severe (grade 3-4) acute graft-versus-host disease (AGVHD) is a major cause of death after unrelated-donor (URD) hematopoietic cell transplant (HCT), resulting in particularly high mortality after HLA-mismatched transplantation. There are no approved agents for AGVHD prevention, underscoring the critical unmet need for novel therapeutics. ABA2 was a phase II trial to rigorously assess safety, efficacy, and immunologic effects of adding T-cell costimulation blockade with abatacept to calcineurin inhibitor (CNI)/methotrexate (MTX)-based GVHD prophylaxis, to test whether abatacept could decrease AGVHD.

METHODS

ABA2 enrolled adults and children with hematologic malignancies under two strata: a randomized, double-blind, placebo-controlled stratum (8/8-HLA-matched URD), comparing CNI/MTX plus abatacept with CNI/MTX plus placebo, and a single-arm stratum (7/8-HLA-mismatched URD) comparing CNI/MTX plus abatacept versus CNI/MTX CIBMTR controls. The primary end point was day +100 grade 3-4 AGVHD, with day +180 severe-AGVHD-free-survival (SGFS) a key secondary end point. Sample sizes were calculated using a higher type-1 error (0.2) as recommended for phase II trials, and were based on predicting that abatacept would reduce grade 3-4 AGVHD from 20% to 10% (8/8s) and 30% to 10% (7/8s). ABA2 enrolled 142 recipients (8/8s, median follow-up = 716 days) and 43 recipients (7/8s, median follow-up = 708 days).

RESULTS

In 8/8s, grade 3-4 AGVHD was 6.8% (abatacept) versus 14.8% (placebo) (P = .13, hazard ratio = 0.45). SGFS was 93.2% (CNI/MTX plus abatacept) versus 82% (CNI/MTX plus placebo, P = .05). In the smaller 7/8 cohort, grade 3-4 AGVHD was 2.3% (CNI/MTX plus abatacept, intention-to-treat population), which compared favorably with a nonrandomized matched cohort of CNI/MTX (30.2%, P < .001), and the SGFS was better (97.7% v 58.7%, P < .001). Immunologic analysis revealed control of T-cell activation in abatacept-treated patients.

CONCLUSION

Adding abatacept to URD HCT was safe, reduced AGVHD, and improved SGFS. These results suggest that abatacept may substantially improve AGVHD-related transplant outcomes, with a particularly beneficial impact on HLA-mismatched HCT.

Low content of clonogenic progenitors on day+18 is associated with acute graft-versus-host disease and predicts transplant-related mortality

A marrow reaction associated with acute-graft-versus-host disease (a-GVHD) has been demonstrated in experimental models; its existence in human transplantation is controversial. The aim of the present study was to investigate whether clonogenic marrow precursors are an early marker for a-GVHD and transplant-related mortality (TRM). We prospectively studied 133 patients for colony-forming units-granulocyte-monocyte (CFU-GM) at day +18/+19 posttransplantation. CFU-GM frequency below the 25th percentile was predictive of an acute GVHD score I°-IV° when evaluated in multivariate logistic regression analysis (odds ratio = 13.551, 95% confidence interval [CI]: 1.583-116.031, p = 0.01). In the group with a clonogenic frequency below the 25th percentile, the cumulative incidence of GVHD grades II-IV was significantly more frequent with respect to the group with a frequency greater than the 25th percentile, 86% versus 54% (Gray test: p = 0.02). In multivariate Cox proportional analysis, a CFU-GM frequency below the 25th percentile at day +18 was associated with reduced overall survival (OS) (hazard ratio = 1.778, 95% CI: 1.022-3.093, p = 0.04). Patients with a frequency of CFU-GM greater than the 25th percentile had increased TRM with respect to patients with a clonogenic cell frequency greater than the 25th percentile (33.5% vs. 13.0%, p = 0.01). Patients were divided based on median content of viable CD34+ cells, and measurement of viable CD34+ cells was predictive for OS (p = 0.005) and TRM (p = 0.003). A weak correlation was observed between CFU-GM frequency in marrow at day +18 and levels of IL-2 receptor (IL-2R) in plasma (r = -0.226, p = 0.03). We conclude that marrow progenitor cell counts, on day +18 may be a useful marker for identifying patients at risk for severe a-GVHD, TRM, and inferior survival.

Post-transplant ferritin level predicts outcomes after allogeneic hematopoietic stem cell transplant, independent from pre-transplant ferritin level

Allogeneic hematopoietic stem cell transplantation (HCT) is associated with significant morbidity and mortality. Elevated pre-transplant ferritin level (ferritin^Pre-HCT) is reported to be associated with increased mortality following HCT. The present study attempted to determine whether post-transplant ferritin level (ferritin^Post-HCT) is associated with outcomes post-HCT, especially in the subgroups which developed acute or chronic graft-versus-host disease (GVHD). Out of 229 patients with serum ferritin level measured post-HCT, median ferritin^Post-HCT was 2178 ng/mL. Patients were stratified into low- or high-risk groups using recursive partitioning, based on ferritin^Post-HCT (≤ 3169 vs > 3169 ng/mL) and ferritin^Pre-HCT (≤ 669 vs > 669 ng/mL). Compared to the low ferritin^Post-HCT group, the high ferritin^Post-HCT group had lower 3-year overall survival (OS) (40.0% vs 66.7%, p < 0.001) and higher non-relapse mortality (NRM) (48.6% vs 17.8%, p < 0.001), but no difference in relapse (10.5% vs 19.7%, p = 0.079). Multivariate analysis confirmed ferritin^Post-HCT as an independent prognostic factor for OS (p = 0.001, HR = 2.323) and NRM (p < 0.001, HR = 3.905). However, ferritin^Pre-HCT did not stratify well for OS or NRM. Ferritin^Post-HCT was also found to be an independent prognostic marker for OS and NRM in the subgroups which developed GVHD. In our cohort, high ferritin^Post-HCT levels were significantly associated with decreased OS and increased NRM independent of ferritin^Pre-HCT or GVHD. Additional studies including larger sample sizes and prospective investigation are warranted to clarify the prognostic significance and pathophysiology of pre- and post-transplant hyperferritinemia.

Prognostic plasma biomarkers of early complications and graft-versus-host disease in patients undergoing allogeneic hematopoietic stem cell transplantation

Early complications post hematopoietic stem cell transplantation (HSCT) such as sinusoidal obstruction syndrome (SOS) and graft versus host disease (GVHD) can be life threatening. Although several biomarkers have been identified to correlate with these complications and their response to treatment, these are yet to be used in clinical practice. Here, we evaluated circulating endothelial cells (CECs) (n = 26) and plasma biomarkers (ST2, REG3α, VCAM1, ICAM1, TIM3) (N = 210) at early time points, to determine their association with early complications post-HSCT. Elevated CEC counts at the end of conditioning was associated with GVHD, indicating endothelial damage during HSCT. Plasma levels of REG3α, VCAM1, ICAM1, and TIM3 on day 14 (D14) and D14 ICAM1 and D28 ST2 were significantly higher in patients with SOS and aGVHD, respectively. Upon sub-group analysis, D28 ST2, D14/D28 REG3α, and D14ICAM1 levels were significantly higher in patients with gastrointestinal GVHD, while D28ST2 was higher in those with skin/liver GVHD. High ST2 levels on D28 was significantly associated with non-relapse mortality (NRM) and overall survival. Our results suggest that elevated ST2 levels on D28 could predict the likelihood of developing aGVHD and could influence NRM and OS.

Photodepletion with 2-Se-Cl prevents lethal graft-versus-host disease while preserving antitumor immunity

Acute graft-versus-host-disease (GVHD), limits the use of hematopoietic cell transplant (HCT) to treat a variety of malignancies. Any new therapeutic approach must satisfy three requirements: 1) Prevent GVHD, 2) Maintain anti-pathogen immunity, and 3) Maintain anti-tumor immunity. In prior studies we have shown that the selective photosensitizer 2-Se-Cl eliminates highly alloreactive lymphocytes from the graft prior to HCT preventing GVHD and that antiviral immune responses were preserved following incubation with 2-Se-Cl. In this report, we investigated whether 2-Se-Cl treatment preserves antitumor immunity, and then used high dimensional flow cytometry to identify the determinants of successful immune reconstitution. Donor C57BL/6 splenocytes were cocultured for 4 days with irradiated BALB/c splenocytes and then exposed to 2-Se-Cl. Photodepletion (PD)-treated splenocytes were then infused into lethally irradiated BALB/c mice inoculated with A20 leukemia/lymphoma cells. Recipient mice that received PD-treated splenocytes survived > 100 days without evidence of GVHD or leukemia. In contrast, mice that did not receive PD-treated cells at time of HCT died of leukemia progression. Multiparameter flow cytometry of cytokines and surface markers on peripheral blood samples 15 days after HCT demonstrated unique patterns of immune reconstitution. We found that before clinical disease onset GVHD was marked by functionally exhausted T cells, while tumor clearance and long-term survival were associated with an expansion of polyfunctional T cells, monocytes, and DCs early after transplantation. Taken together these results demonstrate that 2-Se-Cl photodepletion is a new treatment that can facilitate HCT by preventing GVHD while preserving antiviral and anti-tumor immunity.

Identification of Candidate Biomarkers for Transplant Rejection from Transcriptome Data: A Systematic Review

BACKGROUND

Traditional methods for rejection control in transplanted patients are considered invasive, risky, and prone to sampling errors. Using molecular biomarkers as an alternative protocol to biopsies, for monitoring rejection may help to mitigate some of these problems, increasing the survival rates and well-being of patients. Recent advances in omics technologies provide an opportunity for screening new molecular biomarkers to identify those with clinical utility.

OBJECTIVE

This systematic literature review (SLR) aimed to summarize existing evidence derived from large-scale expression profiling regarding differentially expressed mRNA and miRNA in graft rejection, highlighting potential molecular biomarkers in transplantation.

METHODS

The study was conducted following PRISMA methodology and the BiSLR guide for performing SLR in bioinformatics. PubMed, ScienceDirect, and EMBASE were searched for publications from January 2001 to January 2018, and studies (i) aiming at the identification of transplant rejection biomarkers, (ii) including human subjects, and (iii) applying methodologies for differential expression analysis from large-scale expression profiling were considered eligible. Differential expression patterns reported for genes and miRNAs in rejection were summarized from both cross-organ and organ-specific perspectives, and pathways enrichment analysis was performed for candidate biomarkers to interrogate their functional role in transplant rejection.

RESULTS

A total of 821 references were collected, resulting in 604 studies after removal of duplicates. After application of inclusion and exclusion criteria, 33 studies were included in our analysis. Among the 1517 genes and 174 miRNAs identifed, CXCL9, CXCL10, STAT1, hsa-miR-142-3p, and hsa-miR-155 appeared to be particularly promising as biomarkers in transplantation, with an increased expression associated with transplant rejection in multiple organs. In addition, hsa-miR-28-5p was consistently decreased in samples taken from rejected organs.

CONCLUSION

Despite the need for further research to fill existing knowledge gaps, transcriptomic technologies have a relevant role in the discovery of accurate biomarkers for transplant rejection diagnostics. Studies have reported consistent evidence of differential expression associated with transplant rejection, although issues such as experimental heterogeneity hinder a more systematic characterization of observed molecular changes. Special attention has been giving to large-scale mRNA expression profiling in rejection, whereas there is still room for improvements in the characterization of miRnome in this condition.

PROSPERO REGISTRATION NUMBER

CRD42018083321.

Assessment of ST2 for risk of death following graft-versus-host disease in pediatric and adult age groups

Assessment of prognostic biomarkers of nonrelapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT) in the pediatric age group is lacking. To address this need, we conducted a prospective cohort study with 415 patients at 6 centers: 170 were children age 10 years or younger and 245 were patients older than age 10 years (both children and adults were accrued from 2013 to 2018). The following 4 plasma biomarkers were assessed pre-HCT and at days +7, +14, and +21 post-HCT: stimulation-2 (ST2), tumor necrosis factor receptor 1 (TNFR1), regenerating islet-derived protein 3α (REG3α), and interleukin-6 (IL-6). We performed landmark analyses for NRM, dichotomizing the cohort at age 10 years or younger and using each biomarker median as a cutoff for high- and low-risk groups. Post-HCT biomarker analysis showed that ST2 (>26 ng/mL), TNFR1 (>3441 pg/mL), and REG3α (>25 ng/mL) are associated with NRM in children age 10 years or younger (ST2: hazard ratio [HR], 9.13; 95% confidence interval [CI], 2.74-30.38; P = .0003; TNFR1: HR, 4.29; 95% CI, 1.48-12.48; P = .0073; REG3α: HR, 7.28; 95% CI, 2.05-25.93; P = .0022); and in children and adults older than age 10 years (ST2: HR, 2.60; 95% CI, 1.15-5.86; P = .021; TNFR1: HR, 2.09; 95% CI, 0.96-4.58; P = .06; and REG3α: HR, 2.57; 95% CI, 1.19-5.55; P = .016). When pre-HCT biomarkers were included, only ST2 remained significant in both cohorts. After adjustment for significant covariates (race/ethnicity, malignant disease, graft, and graft-versus-host-disease prophylaxis), ST2 remained associated with NRM only in recipients age 10 years or younger (HR, 4.82; 95% CI, 1.89-14.66; P = .0056). Assays of ST2, TNFR1, and REG3α in the first 3 weeks after HCT have prognostic value for NRM in both children and adults. The presence of ST2 before HCT is a prognostic biomarker for NRM in children age 10 years or younger allowing for additional stratification. This trial was registered at www.clinicaltrials.gov as #NCT02194439.

Biomarkers for Allogeneic HCT Outcomes

Allogeneic hematopoietic cell transplantation (HCT) remains the only curative therapy for many hematological malignant and non-malignant disorders. However, key obstacles to the success of HCT include graft-versus-host disease (GVHD) and disease relapse due to absence of graft-versus-tumor (GVT) effect. Over the last decade, advances in "omics" technologies and systems biology analysis, have allowed for the discovery and validation of blood biomarkers that can be used as diagnostic test and prognostic test (that risk-stratify patients before disease occurrence) for acute and chronic GVHD and recently GVT. There are also predictive biomarkers that categorize patients based on their likely to respond to therapy. Newer mathematical analysis such as machine learning is able to identify different predictors of GVHD using clinical characteristics pre-transplant and possibly in the future combined with other biomarkers. Biomarkers are not only useful to identify patients with higher risk of disease progression, but also help guide treatment decisions and/or provide a basis for specific therapeutic interventions. This review summarizes biomarkers definition, omics technologies, acute, chronic GVHD and GVT biomarkers currently used in clinic or with potential as targets for existing or new drugs focusing on novel published work.

Clinical characteristics and cytokine biomarkers in patients with chronic graft-vs-host disease persisting seven or more years after diagnosis

Chronic graft-versus-host disease (cGVHD) is the leading late complication after allogeneic hematopoietic stem cell transplantation (HSCT). Many patients receive multiple lines of systemic therapy until cGVHD resolves, but about 15% remain on systemic treatment for more than 7 years after cGVHD diagnosis. This study describes the clinical and biological factors of patients who present with cGVHD persisting for ≥7 years (persistent cGVHD). Patients with persistent cGVHD (n = 38) and those with cGVHD for <1 year (early cGVHD) (n = 83) were enrolled in a prospective cross-sectional natural history study. Patients in the persistent cGVHD group were a median of 10.2 years from cGVHD diagnosis (range 7-27 years). Fifty-eight percent of persistent cGVHD patients (22/38) were receiving systemic immunosuppression, compared to 88% (73/83) in the early cGVHD group. In multivariable analysis, bone marrow (BM) stem cell source, presence of ENA autoantibodies, higher NIH lung score, higher platelet counts, and higher IgA levels were significantly associated with persistent cGVHD. A high sensitivity panel of serum biomarkers including seven cytokines diagnostic for cGVHD was analyzed and showed significantly lower levels of BAFF and CXCL10 in patients with persistent cGVHD. In conclusion, standardly accepted clinical measures of disease severity may not accurately reflect disease activity in patients with persistent cGVHD. However, many patients with persistent cGVHD are still receiving systemic immunosuppression despite lacking evidence of disease activity. Development of reliable clinical biomarkers of cGVHD activity may help guide future systemic treatments.

Preliminary Results of a Combined Score Based on sIL2-Rα and TIM-3 Levels Assayed Early After Hematopoietic Transplantation

Assays of cytokines in the plasma at the onset of graft-vs. -host disease (GVHD) can predict disease severity and treatment-related mortality (TRM); however, the optimal time during which cytokines should be tested and the specific panel of cytokines with the highest predictive ability remain unknown. We chose a predefined time point, 18 days after hematopoietic stem cell transplantation (HSCT), to measure the levels of six cytokines in the plasma: soluble interleukin-2 receptor alpha (sIL2-Rα), T-cell immunoglobulin domain and mucin domain-3 (TIM-3), suppression of tumorigenicity-2 (ST-2), intercellular adhesion molecule (ICAM-1), interferon-gamma (IFN-γ), and interleukin-6 (IL-6). The study included 95 patients, who underwent allogeneic hematopoietic transplantation at our institution. Plasma levels of sIL2-Rα and TIM-3, measured as continuous data, had predictive value for overall survival (sIL2-Rα, p = 0.002; TIM-3, p = 0.0007), while TRM could be predicted by sIL2-Rα (p = 0.0005), IFN-gamma (p = 0.01), and IL-6 (p = 0.0001). No cytokine was associated with the risk of relapse. Patients were categorized into groups, according to cytokine thresholds determined by receiver operating characteristic curve analysis (sIL2-Rα ≤ or > 8,100 pg/ml; TIM-3 ≤ or > 950 pg/ml) and multivariate analysis was conducted. High levels of both TIM-3 and sIL2-Rα were significant predictors of poor survival [TIM-3 > 950 pg/ml: hazard ratio (HR) = 6.214 (95% CI 1.939–19.910), p = 0.002 and sIL2-Rα > 8.100 pg/ml: HR = 2.644 (95% CI 1.308–5.347), p = 0.006]. Using these cutoff thresholds, we constructed a composite scoring system that could distinguish three different groups of patients with varying rates of TRM: high risk, 41.7%; intermediate risk, 10.8%; and low risk, 7.1% (Gray's test: p = 0.001). If confirmed in a validation cohort, this composite scoring system could be used to guide the modulation of post-transplant immune suppressive therapy.

Diagnostic and Prognostic Biomarkers for Graft-Versus-Host Disease After Allogeneic Hematopoietic Stem Cell Transplantation

PROBLEM IDENTIFICATION

A lack of testing options for the diagnosis and prognosis of chronic graft-versus-host disease (cGVHD) is a barrier to clinical management. Studies that have investigated the role of blood proteins as diagnostic and prognostic biomarkers for cGVHD were reviewed.

LITERATURE SEARCH

PubMed and Scopus databases were searched for articles published from January 1, 2000, to May 31, 2019. 660 articles were retrieved.

DATA EVALUATION

The authors appraised seven articles based on the inclusion and exclusion criteria to summarize identified blood protein biomarkers for cGVHD.

SYNTHESIS

Several blood proteins were identified as potential diagnostic and prognostic biomarkers. Most of these proteins are thought to be key contributors in cGVHD pathogenesis and, therefore, could be ideal biomarkers to guide clinical management.

IMPLICATIONS FOR PRACTICE

These biomarkers could aid providers in diagnosing cGVHD, identifying patients at high risk for development of cGVHD, and initiating preemptive therapy.

Extracorporeal Photopheresis (ECP) and the Potential of Novel Biomarkers in Optimizing Management of Acute and Chronic Graft vs. Host Disease (GvHD)

As the use of hematopoietic stem cell transplantation (HSCT) has become a more widespread and effective treatment for hematological malignant and non-malignant conditions, the need to minimize the harmful effects of graft- vs.-host disease (GvHD) has become more important in achieving good outcomes. With diagnosis of GvHD reliant on its clinical manifestations, research into biomarkers for the diagnosis, progression, and even for the prediction of disease, is imperative to combating the high levels of morbidity and mortality post-HSCT. Despite the development of novel treatment approaches to GvHD, corticosteroids remain the standard first-line treatment, with immunosuppressant therapies as second-line options. These strategies however have significant limitations and associated complications. Extracorporeal Photopheresis (ECP) has shown to be effective and safe in treating patients with symptomatic GvHD. ECP has been shown to have varied effects on multiple parts of the immune system and does not appear to increase the risk of relapse or infection in the post HSCT setting. Even so, ECP can be logistically more complex to organize and requires patients to be sufficiently stable. This review aims to summarize the potential role of biomarkers to help guide individualized treatment decisions in patients with acute and chronic GvHD. In relation to ECP, robust biomarkers of GvHD will be highly useful in informing patient selection, intensity and duration of the ECP schedule, monitoring of response and other treatment decisions alongside the concurrent administration of other GvHD therapies. Further research is warranted to establish how GvHD biomarkers are best incorporated into ECP treatment pathways with the goal of tailoring ECP to the needs of individual patients and maximizing benefit.

Biomarkers in acute graft-versus-host disease: new insights

Hematopoietic cell transplantation (HCT) is a potentially curative therapy for hematologic malignancies that relies on the graft-versus-leukemia (GVL) effect to eradicate malignant cells. GVL is tightly linked to graft-versus-host disease (GVHD) however, in which donor T cells damage healthy host tissues. Acute GVHD occurs in nearly 50% of patients receiving HCT, and damages the skin, liver, and gastrointestinal (GI) tract. The organ stages are totaled in an overall grade (I-IV), and severe (grade III/IV) GVHD has a high mortality rate (50-70%). In the past decade, serum biomarkers have emerged as an additional potential measurement of acute GVHD severity. The discovery and validation of GVHD biomarkers is a principal objective of the Mount Sinai Acute GVHD International Consortium (MAGIC), a group of 25 HCT centers conducting GVHD research. MAGIC has validated an algorithm that combines two GI biomarkers (ST2 and REG3α) into a single value that estimates the probability of 6 month nonrelapse mortality (NRM) for individual patients, known as the MAGIC algorithm probability (MAP). The MAP reflects GI crypt damage and serves as a 'liquid biopsy' of the lower GI tract; it also predicts response to treatment and maximum GVHD severity and is now commercially available and widely used among scores of centers in clinical practice. The MAP is the focus of this review, with consideration of the categorization of types of biomarkers as defined by the United States National Institutes of Health (NIH) and Food and Drug Administration (FDA).

Increased Mac-2 binding protein glycan isomer in patients at risk for late nonrelapse mortality after HSCT

Macrophages play a crucial role in the pathogenesis of chronic graft-versus-host disease (cGVHD). We hypothesized that galectin-3, Mac-2 binding protein (M2BP), or Wisteria floribunda agglutinin (WFA)+-M2BP, called M2BP glycan isomer (M2BPGi), might contribute to macrophage activation, and fibrosis would be associated with cGVHD and nonrelapse mortality (NRM) in hematopoietic stem cell transplant (HSCT) recipients. Patients who underwent their first allogeneic HSCT and survived for >180 days without relapse were included. The predictive potential of the 3 markers for NRM was assessed using the discovery cohort (n = 55) and validation cohort 1 (n = 55). When we used the threshold determined by a receiver operating characteristics curve analysis in the discovery cohort, only M2BPGi at day +180 was significantly associated with a higher NRM in the discovery cohort (15.0% vs 0.0% at 5 years, P = .001) and in validation cohort 1 (34.0% vs 8.4% at 5 years, P = .014). This result was confirmed in validation cohort 2 (n = 50). M2BPGi was not increased in healthy individuals or in patients who received autologous HSCT. In the entire cohort (N = 110), M2BPGi was significantly related to liver cGVHD but not to other organ involvement. In multivariate analyses, M2BPGi was an independent risk factor for NRM. In immunofluorescence staining of autopsy cases, WFA+-M2BP-positive macrophages were found only in the liver sections with cGVHD. In conclusion, M2BPGi could be a promising predictor of late NRM after HSCT and was associated with liver involvement.

Drugs as a Frequent Cause of Acute Rash in Patients after CD34+-Selected Peripheral Blood Stem Cell Transplantation

Although histopathological differences have been reported between acute graft-versus-host disease (aGVHD) rash and non-aGVHD rash in CD34+-selected peripheral blood stem cell transplantation (PBSCT) recipients, skin biopsy alone is usually insufficient to determine rash etiology. As such, distinguishing inflammatory non-aGVHD rashes, such as drug eruptions, from cutaneous aGVHD after CD34+-selected PBSCT remains challenging and relies on clinical presentation. This study aimed to identify etiologies of skin rash in the first year after CD34+-selected PBSCT and to assess whether laboratory serologic markers, transplant characteristics, and rash morphology and symptomatology aid in differentiation of cutaneous aGVHD rash versus non-aGVHD rash. We conducted a retrospective study of 243 adult patients who underwent CD34+-selected PBSCT at Memorial Sloan Kettering Cancer Center between 2008 and 2011. Among this cohort of transplant recipients, only 43 patients (17.7%) developed cutaneous aGVHD. A total of 152 patients (63%) were identified with rash within 1 year after PBSCT. The proportion of patients who experienced peripheral eosinophilia was not different between those with an aGVHD versus non-aGVHD rash (P ≥ .90), nor when stratified by CD34+ selection method (Isolex, P = .70; CliniMACS, P≥ .90). The proportion of patients with pruritus was also not different between those with an aGVHD rash versus non-aGVHD rash (P= .20), or when stratified by CD34+ selection modality (Isolex, P = .20; CliniMACS, P = .50). The most common cause of non-aGVHD rash among those with a clear etiology was drug (39% of Isolex; 26% of CliniMACS). Single drug culprits were identified in 51% of drug rashes. The most commonly reported offending agents included antibiotics, keratinocyte growth factor, chemotherapy, and recombinant glycosylated human IL-7.

Role of interferon-γ in immune-mediated graft failure after allogeneic hematopoietic stem cell transplantation

Pathophysiology of graft failure (GF) occurring after allogeneic hematopoietic stem cell transplantation (HSCT) still remains elusive. We measured serum levels of several different cytokines/chemokines in 15 children experiencing GF, comparing their values with those of 15 controls who had sustained donor cell engraftment. Already at day +3 after transplantation, patients developing GF had serum levels of interferon (IFN)-γ and CXCL9 (a chemokine specifically induced by IFNγ) significantly higher than those of controls (8859±7502 vs. 0 pg/mL, P=0.03, and 1514.0±773 vs. 233.6±50.1 pg/mlL, P=0.0006, respectively). The role played by IFNγ in HSCT-related GF was further supported by the observation that a rat anti-mouse IFNγ-neutralizing monoclonal antibody promotes donor cell engraftment in Ifngr1-/-mice receiving an allograft. In comparison to controls, analysis of bone marrow-infiltrating T lymphocytes in patients experiencing GF documented a predominance of effector memory CD8+ cells, which showed markers of activation (overexpression of CD95 and downregulation of CD127) and exhaustion (CD57, CD279, CD223 and CD366). Finally, we obtained successful donor engraftment in 2 out of 3 children with primary hemophagocytic lymphohistiocytosis who, after experiencing GF, were re-transplanted from the same HLA-haploidentical donor under the compassionate use coverage of emapalumab, an anti-IFNγ monoclonal antibody recently approved by the US Food and Drug Administration for treatment of patients with primary hemophagocytic lymphohistiocytosis. Altogether, these results suggest that the IFNγ pathway plays a major role in GF occurring after HSCT. Increased serum levels of IFNγ and CXCL9 represent potential biomarkers useful for early diagnosis of GF and provide the rationale for exploring the therapeutic/preventive role of targeted neutralization of IFNγ.

ST2 and REG3α as Predictive Biomarkers After Haploidentical Stem Cell Transplantation Using Post-transplantation High-Dose Cyclophosphamide

Allogenic hematopoietic stem cell transplantation (allo-HSCT) is a curative procedure for several hematological malignancies. Haploidentical HSCT (haplo-HSCT) using high-dose post-transplantation cyclophosphamide (PTCy) makes transplantation possible for patients with no HLA-matched sibling donor. However, this treatment can cause complications, mainly infection, graft-vs.-host disease (GVHD), and conditioning-related toxicity. In recent years, different biomarkers in the form of tissue-specific proteins have been investigated; these may help us to predict complications of allo-HSCT. In this study we explored two such biomarkers, suppression of tumorigenicity 2 (ST2) and regenerating islet-derived 3α (REG3α), in the largest series reported of T cell–replete haplo-HSCT with PTCy. Plasma samples drawn from 87 patients at days +15 and +30 were analyzed. ST2 and REG3α levels at day +15 were not associated with post-transplant complications. ST2 levels at day +30 were higher in patients with grade II-IV acute GVHD, mainly those who received reduced intensity conditioning (RIC; median 2,503 vs. 1,830 ng/ml; p = 0.04). Of note, patients with higher plasma ST2 levels at day +30 also presented a higher incidence of non-relapse mortality (HR, 7.9; p = 0.004) and lower 2-year overall survival (25 vs. 44 months; p = 0.02) than patients with lower levels. Patients with REG3α levels higher than 1,989 pg/ml at day +30 presented a higher incidence of acute gastrointestinal GVHD in the whole cohort (HR, 8.37; p = 0.003) and in the RIC cohort (HR 6.59; p = 0.01). These data suggest that measurement of ST2 and REG3α might be useful for the prognosis and prediction of complications in patients undergoing haplo-HSCT with PTCy.

EASIX and mortality after allogeneic stem cell transplantation

Allogeneic stem cell transplantation (alloSCT) is an effective immunotherapy in patients with hematological malignancies. Endothelial dysfunction was linked to major complications after alloSCT. We asked the question if the "Endothelial Activation and Stress Index" (EASIX; [(creatinine × LDH) ÷ thrombocytes]) can predict mortality after alloSCT. We performed a retrospective cohort analysis in five alloSCT centers in the USA and Germany. EASIX was assessed prior to conditioning (EASIX-pre) and correlated with mortality in 755 patients of a training cohort in multivariable models. The predictive model established in the training cohort was validated in 1267 adult allo-recipients. Increasing EASIX-pre predicted lower overall survival (OS) after alloSCT, and successful model validation was achieved for the validation cohort. We found that EASIX-pre predicts OS irrespective of established scores. Moreover, EASIX-pre was also a significant prognostic factor for transplant-associated microangiopathy. Finally, EASIX-pre correlated with biomarkers of endothelial homeostasis such as CXCL8, interleukin-18, and insulin-like-growth-factor-1 serum levels. This study establishes EASIX-pre based on a standard laboratory biomarker panel as a predictor of individual risk of mortality after alloSCT independently from established clinical criteria.