Successful ABO-Incompatible Renal Transplantation: Blood Group A1B Donor Into A2B Recipient With Anti-A1 Isoagglutinins

Blood Type A1 Mismatch Does Not Affect Heart Transplant Outcomes at One Year

There are subtypes within blood type A, termed non-A1, that have reduced expression of A antigen on cell surfaces. This can result in the development of anti-A1 antibodies. There is limited information regarding the impact of this in heart transplant (HTx) recipients. We conducted a single-center cohort study of 142 Type A HTx recipients in which we compared outcomes of a match group (an A1/O heart into an A1 recipient or a non-A1/O heart into a non-A1 recipient) with a mismatch group (an A1 heart into a non-A1 recipient or a non-A1 heart into an A1 recipient). At one year post-transplant, there were no differences between the groups in survival, freedom from non-fatal major adverse cardiovascular events, freedom from any treated rejection, or freedom from cardiac allograft vasculopathy. There was an increased hospital length of stay in the mismatch group (13.5 vs. 17.1 days, p = 0.04). Our study showed that A1 mismatch was not associated with worse outcomes at one year post-HTx.

Temporal Change in Blood Group after Bone Marrow Transplant: A Case of Successful ABO-Incompatible Deceased Donor Transplant

ABO-incompatible kidney transplantation has been successfully utilised in a deceased donor and living donor kidney transplantation to improve organ utilisation and decrease waiting times. We describe a case of a successful, unanticipated ABO-incompatible donation after cardiac death (DCD) kidney transplant in a patient who had a previous ABOi haematopoietic stem cell transplant (HSCT) and had reverted to his original blood group B, after matching as a blood group A recipient with a blood group A donor. The recipient was unsensitized with a cPRA which was 0% and no donor-specific antibodies and zero HLA mismatch. An urgent anti-A titre was 1 : 2. Given the low antibody titres, we proceeded to transplantation. The patient developed delayed graft function and required dialysis on postoperative day 1 and day 2. The creatinine fell spontaneously on day 5, with progressively increased urine output and stable graft function on discharge at day 6. Anti-A titres were 1 : 1 on serial postoperative measurements. There were no rejection episodes, and the patient has a functioning graft at 16 months posttransplant. We describe a rare case in which the blood group can change after stem cell transplant and should be checked. We also demonstrate that a DCD ABOi transplant in the context of low anti-A titres for a patient with previous ABOi stem cell transplant can be performed successfully with standard immunosuppression.

Non-Human Leukocyte Antigen Antibody-Mediated Lung Transplant Rejection: The Other Anti-A

Background

Acute rejection of lung allografts is an important contributor to morbidity and mortality in the transplant patient population, resulting in the dysfunction and destruction of the graft by the host's immune system via cellular or antibody-mediated mechanisms. Acute cellular rejection (ACR) is more common and better characterized than antibody-mediated rejection, which to date lacks any widely agreed upon, standardized set of diagnostic criteria. We present a case of AMR attributable to a rare phenomenon, non-human leukocyte antigen (HLA) antibodies.

Case Report

A 50-year-old male underwent an uneventful single lung transplant for pulmonary sarcoidosis. Donor and recipient blood type was A positive. No pretransplant donor-specific antibodies were identified. Flow cytometric crossmatch was negative. The postoperative course was significant for a single-unit transfusion of packed red blood cells on postoperative day (POD) 1 and persistent asymptomatic Serratia marcescens in bronchial washes despite ongoing levofloxacin treatment. A surveillance biopsy (POD 34) showed no evidence of rejection. One week later (on POD 41), the patient presented with fever, shortness of breath, and imaging abnormalities of the grafted lung. Inpatient antibiotic escalation to cefepime, ertapenem, and meropenem resolved the positive cultures and fever, but the patient's respiratory function continued to decline, requiring intubation and extracorporeal membrane oxygenation. High-dose steroids and therapeutic plasma exchanges were initiated for suspected acute rejection. During the workup, a newly developed anti-A1 red blood cell antibody was identified. Despite supportive efforts, the patient died on POD 55, 14 days after symptomatic presentation.

Conclusion

This case highlights the clinical significance of AMR in lung allografts, as well as the need to investigate both HLA and non-HLA antibody sources in pulmonary transplant rejection refractory to treatment.

The influence of HK2 blood group antigen on human B cell activation for ABOi-KT conditions

Background

It is well known that ABO blood group system incompatible kidney transplantation (ABOi-KT) is an effective strategy for end-stage renal disease. The main barrier for ABOi-KT is how to keep host B cell activation and blood group antibody titer in low levels. Moreover, the mechanism of B cell activation induced by blood group antigen was unclear in ABOi-KT.

Results

In this study, HK2 cells were identified to express blood group B antigen when cocultured with lymphocytes of blood group A. Optical microscope observation demonstrated that HK2 cells in coculture group gradually decreased. Furthermore, flow cytometer assay identified that T cell phenotypes (CD3⁺, CD3⁺CD4⁺ and CD3⁺CD8⁺) had no significant change and B cell phenotypes (CD19⁺ and CD138⁺) were all significantly enhanced (3.07 and 3.02 folds) at day 4. In addition, immunoturbidimetry analysis demonstrated that blood group B antibody was significantly increased to 2.35 fold at day 4, IgG was significantly increased to 3.60 and 2.81 folds at days 4 and 8 respectively, while IgM had no significant change at the measured time points.

Conclusions

Taken together, B cells were activated and secreted blood group B antibody after treatment with HK2 expressing blood group B antigen. The results of this study maybe useful for further determination of the mechanism of B cell activation after ABO incompatible kidney endothelial cells stimulation.

Electronic supplementary material

The online version of this article (10.1186/s12865-017-0233-9) contains supplementary material, which is available to authorized users.