Best Practice & Research Clinical Haematology最新文献

Advances in hematopoietic cell transplantation have expanded the use of alternative donors such as haploidentical family donors or mismatched unrelated donors. However, donor-specific HLA antibodies (DSA) have been recognized as a significant risk factor of primary graft failure after HLA incompatible transplantation. Therefore, screening for HLA antibodies and taking DSA into consideration in the process of donor search play an increasingly important role in donor selection. If an HLA compatible donor is not available, desensitization may enable a successful transplantation. In this review, we describe the currently most widely used methods for HLA antibody detections including their pitfalls. In addition, we summarize the results of the studies on the impact of preformed DSA on transplant outcomes and their treatment options. Many more and larger studies are needed to clarify laboratory issues as well as immunological and clinical aspects in the management of DSA.

Mismatching at the HLA-DPB1 locus occurs frequently in hematopoietic cell transplantation with unrelated donors. Despite this, HLA-DPB1 allelic mismatches have traditionally not been considered in patient-donor matching. A T-cell epitope (TCE) model for the functional assessment of permissive mismatches at this locus has nevertheless been adopted in clinical practice. While initially based on a hierarchical immunogenicity elucidated from allorecognition by T-cell clones isolated from a patient, newer developments in the understanding of this model's biological basis, including a central role for immunopeptidome divergence between mismatched allotypes, have prompted changes in the assignment of permissiveness, providing the opportunity for a more granular evaluation of graft-versus-host disease and relapse risks according to the nature and directionality of permissive mismatches. How these advances impact the assessment of permissiveness at HLA-DPB1 and potentially the intelligent selection of donors according to the main clinical goal for different patients is the subject of the present review.

The degree of HLA compatibility between a patient and donor has formed the basis of donor selection since the development of allogeneic hematopoietic cell transplantation over 50 years ago and has advanced understanding of the basic immunobiology of HLA. New evidence supports a role for germline variation in the patient and the donor that do not require HLA matching for their effects to have clinical consequences. The discovery of novel non-coding polymorphisms, structural features of HLA molecules, and expression provide new models for donor selection and inspire the development of tools for clinical translation. Pairwise effects of HLA ligand/donor NK receptors may play an important role in transplant outcomes and showcase the value of understanding the role played by each constituent of the NK pathway in modulating donor responses to target antigens.

Due to their intrinsic ability to eliminate malignant cells, natural killer (NK) cells emerge as a promising immunotherapy for cancer. While clinical studies have affirmed the safety of NK cell infusions and combination therapies have demonstrated encouraging outcomes in hematological malignancies, the efficacy of NK cell immunotherapeutic interventions remains heterogeneous across patient cohorts. Moreover, the implementation of NK cell immunotherapy in solid tumors presents notable challenges. Interfering with key NK cell inhibitory signaling pathways by targeting inhibitory killer cell immunoglobulin-like receptors (KIRs) and CD94/NK group 2 member A (NKG2A), holds promise for unleashing the full potential of NK cell-based immunotherapy. In this review, we provide an overview of the current approaches for interfering with inhibitory KIR and NKG2A signaling, exploring a selection of the multitude of combination strategies available. We discuss the significance of maintaining the delicate balance between achieving optimal suppression of NK cell inhibition and ensuring effective activation of anti-tumor effector function, while preserving the favorable safety profiles. The consideration of strategies to modulate inhibitory signaling pathways associated with KIR and NKG2A presents promising avenues for enhancing the efficacy of NK cell immunotherapy.