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Ohm B, Jungraithmayr W. B Cell Immunity in Lung Transplant Rejection - Effector Mechanisms and Therapeutic Implications. Front Immunol 2022; 13:845867. [PMID: 35320934 PMCID: PMC8934882 DOI: 10.3389/fimmu.2022.845867] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/10/2022] [Indexed: 12/14/2022] Open
Abstract
Allograft rejection remains the major hurdle in lung transplantation despite modern immunosuppressive treatment. As part of the alloreactive process, B cells are increasingly recognized as modulators of alloimmunity and initiators of a donor-specific humoral response. In chronically rejected lung allografts, B cells contribute to the formation of tertiary lymphoid structures and promote local alloimmune responses. However, B cells are functionally heterogeneous and some B cell subsets may promote alloimmune tolerance. In this review, we describe the current understanding of B-cell-dependent mechanisms in pulmonary allograft rejection and highlight promising future strategies that employ B cell-targeted therapies.
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Affiliation(s)
- Birte Ohm
- Department of Thoracic Surgery, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Wolfgang Jungraithmayr
- Department of Thoracic Surgery, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Thoracic Surgery, University Hospital Zurich, Zurich, Switzerland
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Abstract
Antibody mediated rejection (ABMR) in the kidney can show a wide range of clinical presentations and histopathologic patterns. The Banff 2019 classification currently recognizes four diagnostic categories: 1. Active ABMR, 2. Chronic active ABMR, 3. Chronic (inactive) ABMR, and 4. C4d staining without evidence of rejection. This categorization is limited in that it does not adequately represent the spectrum of antibody associated injury in allograft, it is based on biopsy findings without incorporating clinical features (e.g., time post-transplant, de novo versus preformed DSA, protocol versus indication biopsy, complement inhibitor drugs), the scoring is not adequately reproducible, and the terminology is confusing. These limitations are particularly relevant in patients undergoing desensitization or positive crossmatch kidney transplantation. In this article, I discuss Banff criteria for these ABMR categories, with a focus on patients with pre-transplant DSA, and offer a framework for considering the continuum of allograft injury associated with donor specific antibody in these patients.
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Affiliation(s)
- Lynn D Cornell
- Division of Anatomic Pathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
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Nguyen LS, Salem JE, Bories MC, Coutance G, Amour J, Bougle A, Suberbielle C, Kheav VD, Carmagnat M, Rouvier P, Kirsch M, Varnous S, Leprince P, Saheb S. Impact of Sex in the Efficacy of Perioperative Desensitization Procedures in Heart Transplantation: A Retrospective Cohort Study. Front Immunol 2021; 12:659303. [PMID: 34305891 PMCID: PMC8292826 DOI: 10.3389/fimmu.2021.659303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/18/2021] [Indexed: 11/13/2022] Open
Abstract
Background Sensitized patients, i.e. recipients with preformed donor-specific HLA antibodies (pfDSA), are at high-risk of developing antibody-mediated rejections (AMR) and dying after heart transplantation (HTx). Perioperative desensitization procedures are associated with better outcomes but can cause sensitization, which may influence their efficacy. Methods In sensitized patients (pfDSA>1000 mean immunofluorescence (MFI) units), we assessed the effect of perioperative desensitization by comparing treated patients to a historical control cohort. Multivariable survival analyses were performed on the time to main outcome, a composite of death and biopsy-proven AMR with 5-year follow-up. Results The study included 68 patients: 31 control and 37 treated patients. There was no difference in preoperative variables between the two groups, including cumulative pfDSA [4026 (1788;8725) vs 4560 (3162;13392) MFI units, p=0.28]. The cause of sensitization was pregnancy in 24/68, 35.3%, transfusion in 61/68, 89.7%, and previous HTx in 4/68, 5.9% patients. Multivariable analysis yielded significant protective association between desensitization and events (adjusted (adj.) hazard ratio (HR)=0.44 (95% confidence interval (95CI)=0.25-0.79), p=0.006) and deleterious association between cumulative pfDSA and events [per 1000-MFI increase, adj.HR=1.028 (1.002-1.053), p=0.031]. There was a sex-difference in the efficacy of desensitization: in men (n=35), the benefit was significant [unadj.HR=0.33 (95CI=0.14-0.78); p=0.01], but not in women (n=33) [unadj.HR=0.52 (0.23-1.17), p=0.11]. In terms of the number of patients treated, in men, 2.1 of patients that were treated prevented 1 event, while in women, 3.1 required treatment to prevent 1 event. Conclusion Perioperative desensitization was associated with fewer AMR and deaths after HTx, and efficacy was more pronounced in men than women.
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Affiliation(s)
- Lee S Nguyen
- Sorbonne Université, Department of Cardiothoracic Surgery, AP.HP.6 Pitie-Salpetriere, Paris, France.,CMC Ambroise Paré, Research and Innovation, RICAP, Neuilly-sur-Seine, France.,Sorbonne Université, Clinical Investigations Center, AP.HP.6, INSERM, Paris, France
| | - Joe-Elie Salem
- Sorbonne Université, Clinical Investigations Center, AP.HP.6, INSERM, Paris, France
| | - Marie-Cécile Bories
- Sorbonne Université, Department of Cardiothoracic Surgery, AP.HP.6 Pitie-Salpetriere, Paris, France
| | - Guillaume Coutance
- Sorbonne Université, Department of Cardiothoracic Surgery, AP.HP.6 Pitie-Salpetriere, Paris, France
| | - Julien Amour
- Jacques Cartier Private Hospital, Department of Cardiothoracic Surgery, Massy, France
| | - Adrien Bougle
- Sorbonne Université, Department of Anesthesiology, AP.HP.6 Pitie-Salpetriere, Paris, France
| | | | | | | | - Philippe Rouvier
- Sorbonne Université, Department of Anatomopathology, AP.HP.6 Pitie-Salpetriere, Paris, France
| | - Matthias Kirsch
- Department of Cardiovascular Surgery, University Hospital, Lausanne, Switzerland
| | - Shaida Varnous
- Sorbonne Université, Department of Cardiothoracic Surgery, AP.HP.6 Pitie-Salpetriere, Paris, France
| | - Pascal Leprince
- Sorbonne Université, Department of Cardiothoracic Surgery, AP.HP.6 Pitie-Salpetriere, Paris, France
| | - Samir Saheb
- Sorbonne Université, service d'hémobiologie, AP.HP.6 Pitie-Salpetriere, Paris, France
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Abstract
The current immunosuppressive protocols used in transplant recipients have improved short-term outcomes, but long-term allograft failure remains an important clinical problem. Greater understanding of the immunologic mechanisms that cause allograft failure are needed, as well as new treatment strategies for protecting transplanted organs. The complement cascade is an important part of the innate immune system. Studies have shown that complement activation contributes to allograft injury in several clinical settings, including ischemia/reperfusion injury and antibody mediated rejection. Furthermore, the complement system plays critical roles in modulating the responses of T cells and B cells to antigens. Therapeutic complement inhibitors, therefore, may be effective for protecting transplanted organs from several causes of inflammatory injury. Although several anti-complement drugs have shown promise in selected patients, the role of these drugs in transplantation medicine requires further study.
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Affiliation(s)
- Monica Grafals
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States
| | - Joshua M Thurman
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, United States
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Tatapudi VS, Montgomery RA. Therapeutic Modulation of the Complement System in Kidney Transplantation: Clinical Indications and Emerging Drug Leads. Front Immunol 2019; 10:2306. [PMID: 31632397 PMCID: PMC6779821 DOI: 10.3389/fimmu.2019.02306] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/12/2019] [Indexed: 12/20/2022] Open
Abstract
The complement system is integral to innate immunity, and it is an essential deterrent against infections. The complement apparatus comprises of >30 fluid-phase and surface-bound elements that also engage with the adaptive immune system, clear harmful immune complexes, and orchestrates several salutary physiological processes. An imbalance in the complement system's tightly regulated machinery and the consequent unrestrained complement activation underpins the pathogenesis of a wide array of inflammatory, autoimmune, neoplastic and degenerative disorders. Antibody-mediated rejection is a leading cause of graft failure in kidney transplantation. Complement-induced inflammation and endothelial injury have emerged as the primary mechanisms in the pathogenesis of this form of rejection. Researchers in the field of transplantation are now trying to define the role and efficacy of complement targeting agents in the prevention and treatment of rejection and other complement related conditions that lead to graft injury. Here, we detail the current clinical indications for complement therapeutics and the scope of existing and emerging therapies that target the complement system, focusing on kidney transplantation.
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