Management of an ABO-incompatible lung transplant

Intentional Lung Transplantation Due to ABO Incompatibility: A Case Report

We present a case of a 16-year-old adolescent female with blood group O+ who was diagnosed with cystic fibrosis (CF). The patient had to be hospitalized due to septic shock and respiratory failure, and extracorporeal membrane oxygenation and mechanical ventilation were applied. Faced with high urgency, she was promptly enlisted for a lung transplant, ultimately receiving a blood group A1 deceased donor lung through rescue allocation. Bilateral incompatible lung transplantation, with parental consent, was successfully performed. The postoperative course was favorable, marked by the administration of rabbit anti-thymocyte globulin, plasmapheresis, and immunosuppression (mycophenolate, steroids, and tacrolimus) as per the prescribed protocol. Notably, the patient experienced a smooth recovery without infectious complications or humoral rejection. This case highlights the viability of lung transplantation in cases of ABO incompatibility, particularly for patients in urgent need on the transplant waiting list.

The first successful case of ABO-incompatible living-donor lobar lung transplantation following desensitization therapy

ABO-incompatible (ABO-I) living-donor lobar lung transplantation (LDLLT) was successfully performed in a 14-year-old girl who suffered from bronchiolitis obliterans due to graft-versus-host disease following hematopoietic stem cell transplantation. In the ABO-I LDLLT procedure, the blood type O patient received a right lower lobe donated from her blood type B father and a left lower lobe donated from her blood type O mother. Desensitization therapy, using rituximab, immunosuppressants, and plasmapheresis, was implemented for 3 weeks prior to transplantation to reduce the production of anti-B antibodies in the recipient and prevent acute antibody-mediated rejection after ABO-I LDLLT.

Expanding Donor Options for Lung Transplant: Extended Criteria, Donation After Circulatory Death, ABO Incompatibility, and Evolution of Ex Vivo Lung Perfusion

Only using brain-dead donors with standard criteria, the existing donor shortage has never improved in lung transplantation. Currently, clinical efforts have sought the means to use cohorts of untapped donors, such as extended criteria donors, donation after circulatory death, and donors that are ABO blood group incompatible, and establish the evidence for their potential contribution to the lung transplant needs. Also, technical maturation for using those lungs may eliminate immediate concerns about the early posttransplant course, such as primary graft dysfunction or hyperacute rejection. In addition, recent clinical and preclinical advances in ex vivo lung perfusion techniques have allowed the safer use of lungs from high-risk donors and graft modification to match grafts to recipients and may improve posttransplant outcomes. This review summarizes recent trends and accomplishments and future applications for expanding the donor pool in lung transplantation.

Review 1: Lung transplant-from donor selection to graft preparation

For various end-stage lung diseases, lung transplantation remains one of the only viable treatment options. While the demand for lung transplantation has steadily risen over the last few decades, the availability of donor grafts is limited, which have resulted in progressively longer waiting lists. In the early years of lung transplantation, only the 'ideal' donor grafts are considered for transplantation. Due to the donor shortages, there is ongoing discussion about the safe use of 'suboptimal' grafts to expand the donor pool. In this review, we will discuss the considerations around donor selection, donor-recipient matching, graft preparation and graft optimisation.

Current State of Pediatric Lung Transplantation

Cardiothoracic transplantation has significantly impacted the lives of pediatric patients with advanced cardiopulmonary failure. The current state of lung transplantation in children as well as its ongoing and future challenges are discussed.

Molecular deciphering of the ABO system as a basis for novel diagnostics and therapeutics in ABO incompatible transplantation

In recent years ABO incompatible kidney transplantation (KTx) has become a more or less clinical routine procedure with graft and patient survival similar to those of ABO compatible transplants. Antigen-specific immunoadsorption (IA) for anti-A and anti-B antibody removal constitutes in many centers an important part of the treatment protocol. ABO antibody titration by hemagglutination is guiding the treatment; both if the recipient can be transplanted as well as in cases of suspected rejections if antibody removal should be performed. Despite the overall success of ABO incompatible KTx, there is still room for improvements and an extension of the technology to include other solid organs. Based on an increased understanding of the structural complexity and tissue distribution of ABH antigens and the fine epitope specificity of the ABO antibody repertoire, improved IA matrices and ABO antibody diagnostics should be developed. Furthermore, understanding the molecular mechanisms behind accommodation of ABO incompatible renal allografts could make it possible to induce long-term allograft acceptance also in human leukocyte antigen (HLA) sensitized recipients and, perhaps, also make clinical xenotransplantation possible.

Lessons and insights from ABO-incompatible lung transplantation

With ABO blood group incompatibility (ABOi) between donor and recipient becoming a part of mainstream living-donor renal transplantation, the applicability of ABOi to other areas of transplantation is being reconsidered. Here we present a case of inadvertent ABOi lung retransplantation managed successfully with initial plasmapheresis, antithymocyte globulin and intravenous immunoglobulin; and subsequently with oral cyclophosphamide and sirolimus in addition to tacrolimus and prednisolone. Interestingly, in the setting of solid levels of tacrolimus and sirolimus, the patient developed a fatal thrombotic microangiopathy of uncertain origin subsequent to the cessation of cyclophosphamide at 9 years posttransplant. It is apparent that ABOi lung transplantation can result in surprisingly successful long-term outcomes. Low pretransplant antibody titers likely aid this and, in pediatric neonatal or infant cases, this may not be uncommon. We must proceed cautiously as there are significant risks. Understanding the monitoring, prevention and treatment of lung transplant antibody-mediated rejection, while avoiding the long-term complications of overimmunosuppression, will be the keys to the success of future cases.

ABO-incompatible lung transplantation in an infant

Waitlist mortality continues to be a limiting factor for all solid-organ transplant programs. Strategies that could improve this situation should be considered. We report the first ABO-incompatible lung transplantation in an infant. The recipient infant was ABO blood group A1 and the donor group B. The recipient was diagnosed with surfactant protein B deficiency, which is a fatal condition and lung transplantation is the only definitive therapy. At 32 days of age, a bilateral lung transplantation from a donation after cardiac death (DCD) donor was performed. Intraoperative plasma exchange was the only preparatory procedure performed. No further interventions were required as the recipient isohemagglutinins were negative before transplant and have remained negative to date. At 6 months posttransplant, the recipient is at home, thriving, with normal development. This outcome suggests that ABO-incompatible lung transplantation is feasible in infants, providing another option to offer life-saving lung transplantation in this age range.

Rituximab-associated infections

After more than 10 years of use, rituximab has proven to be remarkably safe. However, accumulated evidence now suggests that under some circumstances it may significantly increase the risk of infections. This risk is difficult to quantify because of confounding factors (namely, concomitant use of immunosuppressive or chemotherapeutic agents and underlying conditions), as well as under-reporting. Increased number of infections has been documented in patients treated with maintenance rituximab for low-grade lymphoma and in patients with concomitant severe immunodeficiency, whether caused by human immunodeficiency virus (HIV) infection or immunosuppressive agents like fludarabine. From the practical standpoint, the most important infection is hepatitis B reactivation, which may be delayed and result in fulminant liver failure and death. Special care should be placed on screening for hepatitis B virus (HBV) and preemptive antiviral treatment. Some investigators have reported an increase in Pneumocystis pneumonia. Finally, there is increasing evidence of a possible association with progressive multifocal leukoencephalopathy (PML), a lethal encephalitis caused by the polyomavirus JC. This review enumerates the described infectious complications, summarizes the possible underlying mechanisms of the increased risk, and makes recommendations regarding prevention, diagnosis and management.

Usefulness of serum IgG4 in the diagnosis and follow up of autoimmune pancreatitis: A systematic literature review and meta-analysis

High circulating serum immunoglobulin G4 (IgG4) levels have been proposed as a marker of autoimmune pancreatitis (AIP). The aim of the present study was to review the data existing in the English literature on the usefulness of the IgG4 serum levels in the diagnosis and follow up of patients with AIP. A total of 159 patients with AIP and 1099 controls were described in seven selected papers reporting the usefulness of serum IgG4 in diagnosing AIP. In total, 304 controls had pancreatic cancer, 96 had autoimmune diseases, and the remaining 699 had other conditions. The summary receiver-operating characteristic curve analysis was carried out by means of Meta-DiSc open-access software. Serum IgG4 showed good accuracy in distinguishing between AIP and the overall controls, pancreatic cancer and other autoimmune diseases (area under the curve [+/- SE]: 0.920 +/- 0.073, 0.914 +/- 0.191, and 0.949 +/- 0.024, respectively). The studies analyzed showed significantly heterogeneous specificity values in each of the three analyses performed. The analysis of the four studies comparing AIP and pancreatic cancers also showed significantly heterogeneous values of sensitivities and odds ratios. Regarding the usefulness of IgG4 as a marker of efficacy of steroid treatment, a decrease in the serum concentrations of IgG4 was found in the four available studies. The serum IgG4 subclass is a good marker of AIP, and its determination should be included in the diagnostic workup of this disease. However, the heterogeneity of the studies published until now means that more studies are necessary in order to better evaluate the true accuracy of IgG4 in discriminating AIP versus other autoimmune diseases.

Intentional ABO-incompatible lung transplantation

We report on a case of intentional blood group incompatible lung transplantation. A blood group O cystic fibrosis patient was mechanically ventilated and put on interventional lung assist for severe respiratory decompensation. Since timely allocation of a blood group O donor lung was impossible, an AB deceased donor lung rescue allocation was accepted and the transplant performed using a pre-, peri- and postoperative antibody depletion protocol including plasmapheresis, ivIg administration, rituximab and immunoadsorption. Nine months after the transplant the patient is at home and well.

Successful Management of Antibody-Mediated Cardiac Allograft Rejection With Combined Immunoadsorption and Anti-CD20 Monoclonal Antibody Treatment: Case Report and Literature Review

Chronic rejection is still the major limitation of long-term outcome of heart transplant recipients. Several recent studies demonstrated that a not negligible proportion of chronic allograft rejection episodes are not only mediated by T-cell response but also triggered by pre-transplant and de novo post-transplant donor-specific alloantibodies. This points at a fundamental role of humoral immune response mechanisms that contribute to early and late graft failure. This type of rejection is an unsolved problem solid organ transplantation because current immunosuppressive regimens are generally intended to interfere in T-cell signalling pathways. Various options for the removal of circulating alloantibodies and the prevention of alloantibody formation by B-cell depletion have been described. Nevertheless, effective standardized schemes for the treatment of antibody-mediated graft rejection have to be defined. We present a heart transplant recipient with sustained antibody-mediated graft rejection who was successfully managed with a combination treatment consisting of 3 cycles of immunoadsorption and a single-dose administration of the anti-CD20 monoclonal antibody rituximab.

Tolerance in Heart Transplantation: The Holy Grail, or an Attainable Goal?

The father of cardiac transplantation, Norman Shumway, famously predicted that tolerance was the future of the field, and always would be. Although his prediction remains true to date, significant progress has been made toward this goal, the "Holy Grail" for transplant clinicians. Current efforts are fueled by disappointing long-term outcomes associated with chronic immunosuppression, and the promise that partial or complete tolerance will impact long-term results favorably. This article provides a clinical definition of tolerance primarily based on lessons learned from animal heart allograft models. It reviews several promising strategies for inducing tolerance and detecting its presence through the use of biomarkers in peripheral blood or the graft, and outlines a possible path toward making this vision a clinical reality.

Influence of Blood Group on Mortality and Waiting Time Before Heart Transplantation in the United Kingdom: Implications for Equity of Access

BACKGROUND

We examined waiting time for adult heart transplantation in the UK and sought to determine whether recipients with particular ABO blood groups were disadvantaged.

METHODS

Data were obtained from the National Transplant Database. Registration outcome data were analyzed for 622 new, non-urgent, adult, heart-only registrations from April 1, 1999 to March 31, 2003. Unadjusted waiting times of the 618 first registrations were summarized using Kaplan-Meier estimates.

RESULTS

Death rates were relatively low, with no significant difference in the proportions of patients among the different blood groups who died while waiting. A smaller proportion of blood group O patients were transplanted at 1 year after registration, with a significant difference in waiting time to transplant between blood groups (p < 0.0001). Blood group A and AB patients were generally transplanted sooner than O and B patients, with median waiting times of 81 days (95% CI: 67 to 114) and 76 days (95% CI: 52 to 178) vs 214 days (95% CI: 162 to 308) and 174 days (95% CI: 78 to 249), respectively.

CONCLUSIONS

Although no particular blood group was disadvantaged in terms of mortality on the heart transplant list, blood group O and B patients waited significantly longer for transplantation. The difference was at least partly due to a large proportion of blood group O hearts being used for non-O patients. To address this imbalance, the UK Transplant Cardiothoracic Advisory Group (CTAG) changed the allocation protocol, so that "out-of-zone" offers of blood group O donors for non-urgent patients are now restricted to O and B recipients.

ABO-histo blood group incompatibility in hematopoietic stem cell and solid organ transplantation

In contrast to solid organ transplantation (SOT), ABO-histo blood group incompatibility is of minor importance for hematopoietic stem cell transplantation (HSCT). Patients receiving ABO-incompatible HSCT are at an increased risk for immune-mediated hematological complications including immediate and delayed hemolysis, late red blood cell engraftment and pure red cell aplasia, but seem not to have a worse overall survival or increased transplant-related mortality. This review gives an overview of the immunological mechanisms leading to complications associated with ABO-incompatible HSCT and describes approaches to prevent them. The current organ shortage in SOT stimulates the exploration of new strategies to expand the donor pool including ABO-incompatible SOT and xenotransplantation. Here, we discuss the hypothesis that ABO-incompatible transplantation may be viewed as a human in vivo model for the humoral immune mechanisms of antigen-mismatched transplantation. ABO-incompatible HSCT and SOT provide excellent possibilities to analyze graft accommodation and transplantation tolerance. Understanding the underlying mechanisms of graft survival in ABO-incompatible transplantation may facilitate new strategies to overcome the immunological barriers in SOT and xenotransplantation.

Lung Transplantation: Current Status and Challenges

The lung is an anatomically complex vital organ whose normal physiology depends on actively regulated ventilation and perfusion, and maintenance of a delicate blood-air barrier over a huge surface area in direct contact with a potentially hostile environment. Despite significant progress over the past 25 years, both short- and long-term outcomes remain significantly inferior for lung recipients relative to other "solid" organs. This review summarizes the current status of lung transplantation so as to frame the principle challenges currently facing end-stage lung-failure patients and the practitioners who care for them.

ABO histo-blood group system-incompatible allografting

Most of the 29 blood group systems known today are not restricted to erythroid tissues hence their more recent identification as histo-blood group systems. Beyond the uncontested importance of the HLA system in human allograft survival, some of the histo-blood group systems might increasingly become recognised to play a role in graft-host interaction and peritransplant transfusion therapy. At least the ABO histo-blood group system has drawn a lot of interest since both, elective ABO-mismatch with living kidney donor/recipient pairs and infant heart recipients have been described as radical, but effective treatments of end-stage organ dysfunction. More recently, at least in part successful efforts to overcome unintentional ABO-mismatched lung and heart grafts spark interest in more precisely avoiding hyperacute transplant rejection due to complement-activating anti-A/B antibodies of the recipients. Such options as to prepare the recipient with plasma exchange and following him up with polyspecific intravenous immunoglobulins, monoclonal antibodies and targeted immunosuppression using mycophenolate, rabbit antithymocyte globulin and anti-CD20 antibody rituximab are bound to efficiently remove anti-A/B antibodies and apparently inhibit their resynthesis. The present contribution overviews recently acquired knowledge on the ABO histo blood group system and the role it plays in solid organ transplantation leant against a patient observed at our institution.