Prognostic values of increased B7 family proteins in haploidentical hematopoietic stem cell transplantation patients with aGVHD

B7 immune checkpoint family members as putative therapeutics in autoimmune disease: An updated overview

Autoimmune diseases, especially among young people in the US, are one of the leading causes of morbidity and death. The immune responses are the fundamental pathogenicity of autoimmune disorders. The equilibrium between stimulatory and inhibitory signals is critical for the stimulation, migration, survival, and T cell-related immune responses. The B7 family can substantially regulate T cell-mediated immune responses. Nevertheless, recent breakthroughs in immune checkpoint blockade in cancer immunotherapy have facilitated autoimmune diseases, especially among the prone populations. In the current study, we tried to concisely review the role of the B7 family in regulating immune reactions and the influence of immune checkpoint inhibitors on autoimmunity development.

The clinical outcomes of B-cell Acute Lymphoblastic Leukemia Patients Treated with Haploidentical Stem Cells Combined with Umbilical Cord Blood Transplantation

BACKGROUND

Clinical outcomes of the transplantation strategy combined with a haploidentical stem cell graft and an unrelated umbilical cord blood unit (haplo-cord HSCT) for the treatment of B-cell acute lymphoblastic leukemia (B-ALL) remain unclear.

OBJECTIVE

To explore the clinical outcomes of haplo-cord HSCT in B-ALL patients.

STUDY DESIGN

A total of 112 B-ALL patients who received haplo-cord HSCT and 64 patients who received haploidentical hematopoietic stem cell transplantation (haplo-HSCT) in our center from 2010 to 2020 were retrospectively included in this study, and clinical outcomes and prognostic factors were further analyzed.

RESULTS

A total of 94.6% (106/112) of the haplo-cord patients achieved complete haploidentical chimerism, while 5.4% (6/112) of patients had mixed cord blood chimerism. No differences were observed in neutrophil and platelet recovery or the incidences of GVHD, CMV/EBV viremia, bloodstream infection or hemorrhagic cystitis between the haplo-cord HSCT and haplo-HSCT groups. Compared to haplo-HSCT group, the haplo-cord HSCT group had a higher absolute number of CD3⁺ cells (P=0.029) and a lower ratio of CD3⁺CD4⁺ /CD3⁺CD8⁺ cells (P=0.049) at 1 month after transplantation. Moreover, Haplo-cord HSCT patients showed lower minimal residual disease (MRD) levels at 1 month (P=0.020) and 100 days (P=0.038) after transplantation and better 3-year prognoses than the haplo-HSCT group (OS: P=0.016; DFS: P=0.041; cumulative incidence of relapse (CIR): P=0.016). The CIRs in patients with adverse genomic features (P=0.040) or flow cytometry-based minimal residual disease (FCM-MRD)≥1 × 10^-4 (P=0.033) were improved by haplo-cord HSCT. By multivariate analysis, we found that haplo-cord HSCT could independently improve the 3-year OS, DFS and CIR of B-ALL patients (OS: P=0.029; DFS: P=0.024; CIR: P=0.024). Additionally, allo-HSCT at CR1 was an independent parameter associated with 3-year OS for B-ALL patients (P=0.014). FCM-MRD≥1 × 10^-4 pre-HSCT could independently predict unfavorable 3-year DFS and CIR (DFS: P=0.020; CIR: P=0.036) in B-ALL patients.

CONCLUSION

Haplo-cord HSCT could independently improve survival in B-ALL patients.

The clinical outcomes and genomic landscapes of acute lymphoblastic leukemia patients with E2A-PBX1: A 10-year retrospective study

The clinical outcomes and genomic features of E2A-PBX1 (TCF3-PBX1)-positive B-cell acute lymphoblastic leukemia (B-ALL) patients remain unclear. A total of 137 patients carrying E2A-PBX1 among 3164 B-ALL patients between 2009 and 2019 were retrospectively analyzed. The 5-year overall survival (OS) and disease-free survival (DFS) rates of the whole cohort were 68.6% and 61.0%, respectively. Age [DFS, p = 0.037; cumulative incidence of relapse (CIR), p = 0.005] and the level of minimal residual disease (MRD) after induction chemotherapy (OS, p = 0.020; DFS, p = 0.002; CIR, p = 0.006) were independent risk factors. In adolescents/adults, allogeneic hematopoietic stem cell transplantation (allo-HSCT) at first complete remission (CR1) significantly improved the 5-year prognosis (OS, p < 0.001; DFS, p < 0.001; CIR, p < 0.001). Haploidentical HSCT decreased the CIR compared with human leukocyte antigen-matched HSCT in adolescents/adults (p = 0.017). Mutations in PBX1, PAX5, CTCF and SETD2, amplification of AKT3, and deletion of CDKN2A/B were common in the total cohort, while transcriptome differences were found in the cell cycle, nerve growth factor (NGF) signaling pathway and transcriptional regulation by TP53 between adolescents/adults and children. Patients with multiple subclones at diagnosis tended to have unfavorable 3-year prognoses (DFS, p = 0.010; CIR, p = 0.021). Leukemia clones with DNA repair gene mutations showed aggressive and treatment-refractory phenotypes in this subtype of ALL. Our study indicated that age, the level of MRD and DNA repair gene mutations were associated with E2A-PBX1-positive B-ALL outcomes. Allo-HSCT, especially haploidentical HSCT, could improve the prognosis of adolescent/adult patients.

Removal of CD276+ cells from haploidentical memory T-cell grafts significantly lowers the risk of GVHD

Detrimental graft-versus-host disease (GVHD) still remains a major cause of death in hematopoietic stem cell transplantation (HSCT). The recently explored depletion of naive cells from mobilized grafts (CD45RA depletion) has shown considerable promise, yet is unable to eliminate the incidence of GVHD. Analysis of CD45RA-depleted haploidentical mixed lymphocytes culture (haplo-MLC) revealed insufficient suppression of alloresponses in the CD4⁺ compartment and identified CD276 as a marker for alloreactive memory Th1 T cells. Conclusively, depleting CD276⁺ cells from CD45RA-depleted haplo-MLC significantly attenuated alloreactivity to recipient cells while increasing antiviral reactivity and maintaining anti-third party reactivity in vitro. To evaluate these findings in vivo, bulk, CD45RA-depleted, or CD45RA/CD276-depleted CD4⁺ T cells from HLA-DR4^negative healthy humans were transplanted into NSG-Ab°DR4 mice, a sensitive human allo-GVHD model. Compellingly, CD45RA/CD276-depleted grafts from HLA-DR4^negative donors or in vivo depletion of CD276⁺ cells after transplant of HLA-DR4^negative memory CD4 T cells significantly delay the onset of GVHD symptoms and significantly alleviate its severity in NSG-Ab°DR4 mice. The clinical courses correlated with diminished Th1-cytokine secretion and downregulated CXCR6 expression of engrafted peripheral T cells. Collectively, mismatched HLA-mediated GVHD can be controlled by depleting recipient-specific CD276⁺ alloreacting T cells from the graft, highlighting its application in haplo-HSCT.

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

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