B-cell activating factor (BAFF) plasma level at the time of chronic GvHD diagnosis is a potential predictor of non-relapse mortality

Biological markers for risk stratification of chronic GvHD (cGvHD) could improve the care of patients undergoing allogeneic hematopoietic stem cell transplantation. Increased plasma levels of B-cell activating factor (BAFF), chemokine (C-X-C motif) ligand 9 (CXCL9) and elafin have been associated with the diagnosis, but not with outcome in patients with cGvHD. We evaluated the association between levels of these soluble proteins, measured by ELISA at the time of cGvHD diagnosis and before the initiation of therapy, with non-relapse-mortality (NRM). Based on the log-transformed values, factor levels were divided into tertiles defined respectively as low, intermediate, and high levels. On univariable analysis, BAFF levels were significantly associated with NRM, whereas CXCL9 and elafin levels were not. Both low (⩽2.3 ng/mL, hazard ratio (HR)=5.8, P=0.03) and high (>5.7 ng/mL, HR=5.4, P=0.03) BAFF levels were associated with a significantly higher NRM compared with intermediate BAFF level. The significant effect of high or low BAFF levels persisted in multivariable analysis. A subset of cGvHD patients had persistently low BAFF levels. In conclusion, our data show that BAFF levels at the time of cGvHD diagnosis are associated with NRM, and also are potentially useful for risk stratification. These results warrant confirmation in larger studies

Granzyme A-producing T helper cells are critical for acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) can occur after hematopoietic cell transplant in patients undergoing treatment for hematological malignancies or inborn errors. Although CD4+ T helper (Th) cells play a major role in aGVHD, the mechanisms by which they contribute, particularly within the intestines, have remained elusive. We have identified a potentially novel subset of Th cells that accumulated in the intestines and produced the serine protease granzyme A (GrA). GrA+ Th cells were distinct from other Th lineages and exhibited a noncytolytic phenotype. In vitro, GrA+ Th cells differentiated in the presence of IL-4, IL-6, and IL-21 and were transcriptionally unique from cells cultured with either IL-4 or the IL-6/IL-21 combination alone. In vivo, both STAT3 and STAT6 were required for GrA+ Th cell differentiation and played roles in maintenance of the lineage identity. Importantly, GrA+ Th cells promoted aGVHD-associated morbidity and mortality and contributed to crypt destruction within intestines but were not required for the beneficial graft-versus-leukemia effect. Our data indicate that GrA+ Th cells represent a distinct Th subset and are critical mediators of aGVHD

Donor Killer Immunoglobulin Receptor Gene Content and Ligand Matching and Outcomes of Pediatric Patients with Juvenile Myelomonocytic Leukemia Following Unrelated Donor Transplantation

Natural killer (NK) cell determinants predict relapse-free survival after allogeneic hematopoietic cell transplantation (HCT) for acute myelogenous leukemia, and previous studies have shown a beneficial graft-versus-leukemia effect in patients with juvenile myelomonocytic leukemia (JMML). However, whether NK cell determinants predict protection against relapse for JMML patients undergoing HCT is unknown. Therefore, we investigated NK cell-related donor and recipient immunogenetics as determinants of HCT outcomes in patients with JMML. Patients with JMML (age 0 to 3 (HR, 0.52; 95% CI, 0.29 to 0.95; P = .032), centromeric A/B score (HR, 0.57; 95% CI, 033 to 0.98; P = .041), and telomeric A/B score (HR, 0.58; 95% CI, 0.34 to 1.00; P = .048). To our knowledge, this is the first study analyzing the association of NK cell determinants and outcomes in JMML HCT recipients. This study identifies potential benefits of donor KIR-B genotypes in reducing aGVHD. Our findings warrant further study of the role of NK cells in enhancing the graft-versus-leukemia effect via recognition of JMML blasts

Loss of epigenetic regulator TET2 and oncogenic KIT regulate myeloid cell transformation via PI3K pathway

Mutations in KIT and TET2 are associated with myeloid malignancies. We show that loss of TET2-induced PI3K activation and -increased proliferation is rescued by targeting the p110α/δ subunits of PI3K. RNA-Seq revealed a hyperactive c-Myc signature in Tet2-/- cells, which is normalized by inhibiting PI3K signaling. Loss of TET2 impairs the maturation of myeloid lineage-derived mast cells by dysregulating the expression of Mitf and Cebpa, which is restored by low-dose ascorbic acid and 5-azacytidine. Utilizing a mouse model in which the loss of TET2 precedes the expression of oncogenic Kit, similar to the human disease, results in the development of a non-mast cell lineage neoplasm (AHNMD), which is responsive to PI3K inhibition. Thus, therapeutic approaches involving hypomethylating agents, ascorbic acid, and isoform-specific PI3K inhibitors are likely to be useful for treating patients with TET2 and KIT mutations

Neonatal hyperoxia promotes asthma-like features through IL-33–dependent ILC2 responses

Background Premature infants often require oxygen supplementation and, therefore, are exposed to oxidative stress. Following oxygen exposure, preterm infants frequently develop chronic lung disease and have a significantly increased risk of asthma. Objective We sought to identify the underlying mechanisms by which neonatal hyperoxia promotes asthma development. Methods Mice were exposed to neonatal hyperoxia followed by a period of room air recovery. A group of mice was also intranasally exposed to house dust mite antigen. Assessments were performed at various time points for evaluation of airway hyperresponsiveness, eosinophilia, mucus production, inflammatory gene expression, and TH and group 2 innate lymphoid cell (ILC2) responses. Sera from term- and preterm-born infants were also collected and levels of IL-33 and type 2 cytokines were measured. Results Neonatal hyperoxia induced asthma-like features including airway hyperresponsiveness, mucus hyperplasia, airway eosinophilia, and type 2 pulmonary inflammation. In addition, neonatal hyperoxia promoted allergic TH responses to house dust mite exposure. Elevated IL-33 levels and ILC2 responses were observed in the lungs most likely due to oxidative stress caused by neonatal hyperoxia. IL-33 receptor signaling and ILC2s were vital for the induction of asthma-like features following neonatal hyperoxia. Serum IL-33 levels correlated significantly with serum levels of IL-5 and IL-13 but not IL-4 in preterm infants. Conclusions These data demonstrate that an axis involving IL-33 and ILC2s is important for the development of asthma-like features following neonatal hyperoxia and suggest therapeutic potential for targeting IL-33, ILC2s, and oxidative stress to prevent and/or treat asthma development related to prematurity

Biomarkers for Diagnosis and Prognosis of Sinusoidal Obstruction Syndrome after Hematopoietic Cell Transplantation.

Reliable, non-invasive methods for diagnosing and prognosing sinusoidal obstruction syndrome (SOS) early after hematopoietic cell transplantation (HCT) are needed. We used a quantitative mass spectrometry-based proteomics approach to identify candidate biomarkers of SOS by comparing plasma pooled from 20 patients with and 20 patients without SOS. Of 494 proteins quantified, we selected six proteins [L-Ficolin, vascular-cell-adhesion-molecule-1 (VCAM1), tissue-inhibitor of metalloproteinase-1, von Willebrand factor, intercellular-adhesion-molecule-1, and CD97] based on a differential heavy/light isotope ratio of at least 2 fold, information from the literature, and immunoassay availability. Next, we evaluated the diagnostic potential of these six proteins and five selected from the literature [suppression of tumorigenicity-2 (ST2), angiopoietin-2 (ANG2), hyaluronic acid (HA), thrombomodulin, and plasminogen activator inhibitor-1] in samples from 80 patients. The results demonstrate that together ST2, ANG2

Proteomic characterization reveals that MMP-3 correlates with bronchiolitis obliterans syndrome following allogeneic hematopoietic cell and lung transplantation

Improved diagnostic methods are needed for bronchiolitis obliterans syndrome (BOS), a serious complication after allogeneic hematopoietic cell transplantation (HCT) and lung transplantation. For proteins candidate discovery, we compared plasma pools from HCT transplantation recipients with: BOS at onset (n=12), pulmonary infection (n=16), chronic graft-versus-host disease without pulmonary involvement (n=15), and no chronic complications post-HCT (n=15). Pools were labeled with different tags [isobaric Tags for Relative and Absolute Quantification (iTRAQ)], and two software tools identified differentially expressed proteins (≥1.5-fold change). Candidate proteins were further selected using a six-step computational biology approach. The diagnostic value of the lead candidate, matrix metalloproteinase-3 (MMP-3), was evaluated by ELISA in plasma of a verification cohort (n=112) with and without BOS following HCT (n=76) or lung transplantation (n=36). MMP-3 plasma concentrations differed significantly between patients with and without BOS (AUC=0.77). Thus, MMP-3 represents a potential non-invasive blood test for diagnosis of BOS

Impact of Previously Unrecognized HLA Mismatches Using Ultrahigh Resolution Typing in Unrelated Donor Hematopoietic Cell Transplantation

PURPOSE: Ultrahigh resolution (UHR) HLA matching is reported to result in better outcomes following unrelated donor hematopoietic cell transplantation, improving survival and reducing post-transplant complications. However, most studies included relatively small numbers of patients. Here we report the findings from a large, multicenter validation study. METHODS: UHR HLA typing was available on 5,140 conventionally 10 out of 10 HLA-matched patients with malignant disease transplanted between 2008 and 2017. RESULTS: After UHR HLA typing, 82% of pairs remained 10 out of 10 UHR-matched; 12.3% of patients were 12 out of 12 UHR HLA-matched. Compared with 12 out of 12 UHR-matched patients, probabilities of grade 2-4 acute graft-versus-host disease (aGVHD) were significantly increased with UHR mismatches (overall P = .0019) and in those patients who were HLA-DPB1 T-cell epitope permissively mismatched or nonpermissively mismatched (overall P = .0011). In the T-cell-depleted subset, the degree of UHR HLA mismatch was only associated with increased transplant-related mortality (TRM) (overall P = .0068). In the T-cell-replete subset, UHR HLA matching was associated with a lower probability of aGVHD (overall P = .0020); 12 out of 12 UHR matching was associated with reduced TRM risk when compared with HLA-DPB1 T-cell epitope permissively mismatched patients, whereas nonpermissive mismatching resulted in a greater risk (overall P = .0003). CONCLUSION: This study did not confirm that UHR 12 out of 12 HLA matching increases the probability of overall survival but does demonstrate that aGVHD risk, and in certain settings TRM, is lowest in UHR HLA-matched pairs and thus warrants consideration when multiple 10 out of 10 HLA-matched donors of equivalent age are available

Specific Class I HLA Supertypes but Not HLA Zygosity or Expression Are Associated with Outcomes following HLA-Matched Allogeneic Hematopoietic Cell Transplant: HLA Supertypes Impact Allogeneic HCT Outcomes

Maximizing the probability of antigen presentation to T cells through diversity in HLAs can enhance immune responsiveness and translate into improved clinical outcomes, as evidenced by the association of heterozygosity and supertypes at HLA class I loci with improved survival in patients with advanced solid tumors treated with immune checkpoint inhibitors. We investigated the impact of HLA heterozygosity, supertypes, and surface expression on outcomes in adult and pediatric patients with acute myeloid leukemia (AML), myelodysplastic syndrome, acute lymphoblastic leukemia, and non-Hodgkin lymphoma who underwent 8/8 HLA-matched, T cell replete, unrelated, allogeneic hematopoietic cell transplant (HCT) from 2000 to 2015 using patient data reported to the Center for International Blood and Marrow Transplant Research. HLA class I heterozygosity and HLA expression were not associated with overall survival, relapse, transplant-related mortality (TRM), disease-free survival (DFS), and acute graft-versus-host disease following HCT. The HLA-B62 supertype was associated with decreased TRM in the entire patient cohort (hazard ratio [HR], 0.79; 95% CI, 0.69 to 0.90; P = .00053). The HLA-B27 supertype was associated with worse DFS in patients with AML (HR = 1.21; 95% CI, 1.10 to 1.32; P = .00005). These findings suggest that the survival benefit of HLA heterozygosity seen in solid tumor patients receiving immune checkpoint inhibitors does not extend to patients undergoing allogeneic HCT. Certain HLA supertypes, however, are associated with TRM and DFS, suggesting that similarities in peptide presentation between supertype members play a role in these outcomes. Beyond implications for prognosis following HCT, these findings support the further investigation of these HLA supertypes and the specific immune peptides important for transplant outcomes

Biomarkers in chronic graft-versus-host disease: quo vadis?

Biomarkers are increasingly used for diagnosis and treatment of transplant-related complications including the first biomarker-driven interventional trials of acute graft-versus-host disease (GvHD). In contrast, the development of biomarkers of chronic GvHD (cGvHD) has lagged behind due to a broader variety of manifestations, overlap with acute GvHD, a greater variation in time to onset and maximum severity, and lack of sufficient patient numbers within prospective trials. An international workshop organized by a North-American and European consortium was held in Marseille in March 2017 with the goal to discuss strategies for future biomarker development to guide cGvHD therapy. As a result of this meeting, two areas were prioritized: the development of prognostic biomarkers for subsequent onset of moderate/severe cGvHD, and in parallel, the development of qualified clinical-grade assays for biomarker quantification. The most promising prognostic serum biomarkers are CXCL9, ST2, matrix metalloproteinase-3, osteopontin, CXCL10, CXCL11, and CD163. Urine-proteomics and cellular subsets (CD4+ T-cell subsets, NK cell subsets, and CD19+CD21low B cells) represent additional potential prognostic biomarkers of cGvHD. A joint effort is required to verify the results of numerous exploratory trials before any of the potential candidates is ready for validation and subsequent clinical application