ABO incompatible kidney transplantations without splenectomy, using antigen-specific immunoadsorption and rituximab

Novel Flow Cytometry Method Detecting Complement C1q Bound to Blood Type A/B IgG Antibody for Preventing Severe Antibody-Mediated Rejection in ABO-Incompatible Kidney Transplantation

We aimed to develop a novel method for measuring the complement-binding ability of anti-blood type antibodies (ab-Abs), the flow cytometry method for the complement C1q test (FCM-C1q) for detecting antibody-mediated rejection (AMR) caused by ab-Abs in ABO-incompatible kidney transplantation (ABOI-KTx). FCM-C1q distribution was surveyed in 44 healthy participants and 43 dialysis patients (Cohort A). The relationship between AMR and FCM-C1q levels was examined along with ab-Ab titers by the flow cytometry method for the IgG test (FCM-IgG) in 62 ABOI-KTx patients (Cohort B). FCM-IgG and C1q levels were significantly higher in type O participants than in A/B participants in Cohort A. There were minimal differences in the distribution of FCM-IgG and C1q between dialysis and healthy participants. Sixteen cases were suspected of acute rejections (ARs) in Cohort B, of whom nine had AR clinically. One patient with severe AMR was highly suspected of hyperacute rejection along with another patient with severe AMR. Their postoperative FCM-C1q and FCM-IgG levels were elevated. Another two patients showed high FCM-IgG and C1q levels before KTx, and these levels remained low after KTx with no or mild rejection. In conclusion, our results suggest that a high positivity rate for FCM-C1q may predict moderate to severe AMR caused by ab-Abs and poor prognosis in ABOI-KTx.

Non-antigen-specific Immunoadsorption Is a Risk Factor for Severe Postoperative Infections in ABO-Incompatible Kidney Transplant Recipients

ABO-incompatible (ABOi) living kidney transplantation (KTx) is an established procedure to address the demand for kidney transplants with outcomes comparable to ABO-compatible KTx. Desensitization involves the use of immunoadsorption (IA) to eliminate preformed antibodies against the allograft. This monocentric retrospective study compares single-use antigen-selective Glycosorb® ABO columns to reusable non-antigen-specific Immunosorba® immunoglobulin adsorption columns regarding postoperative infectious complications and outcome. It includes all 138 ABOi KTx performed at Freiburg Transplant Center from 2004-2020. We compare 81 patients desensitized using antigen-specific columns (sIA) to 57 patients who received IA using non-antigen-specific columns (nsIA). We describe distribution of infections, mortality and allograft survival in both groups and use Cox proportional hazards regression to test for the association of IA type with severe infections. Desensitization with nsIA tripled the risk of severe postoperative infections (adjusted HR 3.08, 95% CI: 1.3-8.1) compared to sIA. nsIA was associated with significantly more recurring (21.4% vs. 6.2%) and severe infections (28.6% vs. 8.6%), mostly in the form of urosepsis. A significantly higher proportion of patients with sIA suffered from allograft rejection (29.6% vs. 14.0%). However, allograft survival was comparable. nsIA is associated with a two-fold risk of developing a severe postoperative infection after ABOi KTx.

Therapeutic apheresis in renal transplantation: An update

Therapeutic apheresis (TA) plays a significant role in various aspects of renal transplantation. It has been a necessary preconditioning component in ABO incompatible kidney transplants and an important modality in the removal of anti-human leukocyte antigen (HLA) antibodies both in the context of desensitization protocols that have been developed to allow highly sensitized kidney transplant candidates to be successfully transplanted and as treatment of antibody mediated rejection episodes post transplantation. In addition, TA has been used with various results for the management of recurrent focal segmental glomerulosclerosis. The purpose of this review is to examine the evidence supporting the application of TA as an adjunctive therapeutic option to immunosuppressive agents in protocols both before and after kidney transplantation.

WITHDRAWN:Therapeutic apheresis in renal transplantation: An update

The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.transci.2023.103844 of original article. The duplicate article has therefore been withdrawn. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal

An atypical case of refractory passenger lymphocyte syndrome after renal transplantation

BACKGROUND

Passenger lymphocyte syndrome (PLS) causes immune-mediated hemolysis in solid and bone marrow transplant recipients. Donor-derived antibodies against the recipient erythrocyte drive the pathogenesis. It is a rare entity in kidney transplantation, and most of the cases are self-limited.

CASE PRESENTATION

A 36-year-old woman presented with fatigue 13 days after living donor renal transplantation. The operation was uneventful, and she was discharged with normal graft functions on the 11th day of transplantation Findings were consistent with cold agglutinin disease at her admission. However, the cold agglutinin test was negative. Eventually, she was diagnosed with PLS. Refractory intravascular hemolysis and frank hemoglobinuria were also present in the patient. Hemolysis was resistant to steroids, intravenous immunoglobulin (IVIG), and Rituximab. Because of life-threatening anemia related to refractory PLS, mycophenolate and tacrolimus were interrupted. However, hemolysis persisted. Following that, immunoadsorption (IA) treatment was obtained. Unfortunately, graft loss occurred due to rejection despite the resolution of PLS after IA.

CONCLUSION

PLS is a rare and usually self-limited entity. Our case was an atypical refractory PLS that resembled cold agglutinin disease. Also, frank hemoglobinuria was observed related to severe intravascular hemolysis. These features have not been described before in PLS, to the best of our knowledge. Additionally, IA treatment had never been reported in the literature for PLS, as far as we know. Treatment and management could be a challenge in refractory PLS. Rituximab, IVIG, and extracorporeal treatments could be beneficial. It should be borne in mind that refractory PLS can cause graft and patient loss.

Unconventional Strategies for Solid Organ Transplantation and Special Transplantation Scenarios

Solid organ transplantation is the only long-term therapeutic option for patients with end-organ failure but cadaveric and living donor transplant pools are unable to meet the demand for organ transplantation. Newer techniques, innovative strategies and altruistic donors can help bridge this wide gap between the number of organ donors and recipients. Domino liver transplantation, paired organ donation, and ABO incompatible transplants are some of the ways to ensure increased transplant organ availability. Split liver transplantation and ex vivo liver resection and auto transplantation are considered surgically challenging but are being done at tertiary transplant centers.

Updated management for antibody-mediated rejection: opportunity to prolong kidney allograft survival

PURPOSE OF REVIEW

Antibody-mediated rejection (ABMR) is an important barrier to achieve long-term kidney allograft survival. Human leukocyte antibody (HLA)-incompatibility and ABO-incompatibility are the two main mechanisms of ABMR. Nevertheless, the advances in managing ABMR have changed the paradigm for kidney transplantation. This review aimed to emphasize the HLA-incompatibility and ABO-incompatibility kidney transplant and update the management of ABMR.

RECENT FINDINGS

HLA-incompatibility kidney transplantation is a strong risk factor for ABMR. Donor-specific antibody (DSA) is a surrogate biomarker that prevents long-term allograft survival. The standard treatment for ABMR has unfavorable results. New drugs that target the B cell are a promising approach to treat ABMR. In the past, ABO-incompatibility kidney donor was an absolute contraindication but now, it is widely accepted as an alternative organ resource. The advancement of ABO antibody removal and B-cell depletion therapy has been successfully developed. ABO isoagglutination remains the main biomarker for monitoring ABMR during the transplantation process. C4d staining without inflammation of the kidney allograft is the marker for the accommodation process.

SUMMARY

With the shortage of organ donors, transplant experts have expanded the organ resources and learned how to overcome the immunological barriers by using novel biomarkers and developing new treatments that support long-term graft survival.

Recommendations for living donor kidney transplantation

This Guide for Living Donor Kidney Transplantation (LDKT) has been prepared with the sponsorship of the Spanish Society of Nephrology (SEN), the Spanish Transplant Society (SET), and the Spanish National Transplant Organization (ONT). It updates evidence to offer the best chronic renal failure treatment when a potential living donor is available. The core aim of this Guide is to supply clinicians who evaluate living donors and transplant recipients with the best decision-making tools, to optimise their outcomes. Moreover, the role of living donors in the current KT context should recover the level of importance it had until recently. To this end the new forms of incompatible HLA and/or ABO donation, as well as the paired donation which is possible in several hospitals with experience in LDKT, offer additional ways to treat renal patients with an incompatible donor. Good results in terms of patient and graft survival have expanded the range of circumstances under which living renal donors are accepted. Older donors are now accepted, as are others with factors that affect the decision, such as a borderline clinical history or alterations, which when evaluated may lead to an additional number of transplantations. This Guide does not forget that LDKT may lead to risk for the donor. Pre-donation evaluation has to centre on the problems which may arise over the short or long-term, and these have to be described to the potential donor so that they are able take them into account. Experience over recent years has led to progress in risk analysis, to protect donors' health. This aspect always has to be taken into account by LDKT programmes when evaluating potential donors. Finally, this Guide has been designed to aid decision-making, with recommendations and suggestions when uncertainties arise in pre-donation studies. Its overarching aim is to ensure that informed consent is based on high quality studies and information supplied to donors and recipients, offering the strongest possible guarantees.

Transplant outcomes of 100 cases of living-donor ABO-incompatible kidney transplantation

BACKGROUND

Although ABO-incompatible (ABOi) kidney transplantation (KT) has been performed successfully, a standard preconditioning regimen has not been established. Based on the initial antidonor ABO antibody titers, an individualized preconditioning regimen is developed, and this study explored the efficacy and safety of the regimen.

METHODS

From September 1, 2014, to September 1, 2020, we performed 1668 consecutive living-donor KTs, including 100 ABOi and 1568 ABO-compatible (ABOc) KTs. ABOi KT recipients (KTRs) with a lower antibody titer (≤1:8) were administered oral immunosuppressive drugs (OIs) before KT, while patients with a medium titer (1:16) received OIs plus antibody-removal therapy (plasma exchange/double-filtration plasmapheresis), patients with a higher titer (≥1:32) were in addition received rituximab (Rit). Competing risk analyses were conducted to estimate the cumulative incidence of infection, acute rejection (AR), graft loss, and patient death.

RESULTS

After propensity score analyses, 100 ABOi KTRs and 200 matched ABOc KTRs were selected. There were no significant differences in graft and patient survival between the ABOi and ABOc groups (P  = 0.787, P  = 0.386, respectively). After using the individualized preconditioning regimen, ABOi KTRs showed a similar cumulative incidence of AR (10.0% υs . 10.5%, P  = 0.346). Among the ABOi KTRs, the Rit-free group had a similar cumulative incidence of AR ( P  = 0.714) compared to that of the Rit-treated group. Multivariate competing risk analyses revealed that a Rit-free regimen reduced the risk of infection (HR: 0.31; 95% CI: 0.12-0.78, P  = 0.013). Notably, antibody titer rebound was more common in ABOi KTRs receiving a Rit-free preconditioning regimen ( P  = 0.013) than those receiving Rit. ABOi KTRs with antibody titer rebound had a 2.72-fold risk of AR (HR: 2.72, 95% CI: 1.01-7.31, P  = 0.048). ABOi KTRs had similar serum creatinine and estimated glomerular filtration rate compared to those of ABOc KTRs after the first year.

CONCLUSIONS

An individualized preconditioning regimen can achieve comparable graft and patient survival rates in ABOi KT with ABOc KT. Rit-free preconditioning effectively prevented AR without increasing the risk of infectious events in those with lower initial titers; however, antibody titer rebound should be monitored.

Excellent outcome following emergency deceased donor ABO-incompatible liver transplantation using rituximab and antigen specific immunoadsorption

BACKGROUND

The acceptance of ABO-incompatible (ABOi) liver grafts will expand the donor pool for a patient in urgent need for a liver transplantation (LT). Here we report our results with emergency ABOi DD (deceased donor) LT using rituximab and antigen specific immunoadsorption.

PATIENTS AND METHODS

2009 to 2019 we performed 20 ABOi DD LTs (adults n = 17, children n = 3) for patients in urgent need for a LT. Immunosuppression consisted of rituximab (n = 20) and basiliximab (n = 15) or anti-thymocyte globuline (n = 4), intravenous immunoglobulin (IVIG; n = 6), tacrolimus, prednisolone and mycophenolate mofetil. Fifteen patients were treated with IA (n = 14) or both IA and plasmapheresis (PP; n = 1) pre-transplant and 18 patients were treated with IA (n = 15) or both IA and PP (n = 3) post-transplant. The median pre-transplant MELD- score was 40 (range 18-40). Patient and graft survival and complications were compared to a 1:4 case matched control group of ABO-identical or compatible (ABOid/c) DDLT.

RESULTS

The 1-, 3- and 5-year patient and graft survival rates were 85, 85 and 78% for the ABOi recipients and not significantly different compared to ABOid/c controls. Only one ABOi patient developed antibody-mediated rejection.

CONCLUSION

Patient and graft survival after emergency ABOi DDLT using rituximab and immunoadorption was equal to ABOid/DDLT. ABOi DD LT was a successful approach to expand the donor pool for patients in urgent need for a liver graft.

Establishment of a Hyperacute Rejection Model of ABO-Incompatible Renal Transplantation in Nonhuman Primates

The establishment of a hyperacute rejection (HAR) model of ABO-incompatible kidney transplantation (ABOi-KTx) in nonhuman primates is of great significance for the study of the relevant clinical pathophysiological processes and related interventions in ABOi-KTx. In this study, blood group B cynomolgus monkeys were presensitized with synthetic blood group A-antigen conjugated to keyhole limpet hemocyanin (A-KLH) to boost circulating anti-A antibody levels. The serum anti-A antibody levels were measured by flow cytometry using type A human reagent red blood cells (RBCs) or monkey primary renal tubular epithelial cells (RTECs) as target cells. ABOi-KTx was performed in type B monkeys using type A monkeys as donors. After 14 days of A-KLH sensitization, 12 of 16 (75%) type B monkeys had significantly elevated anti-A antibody levels. We found that in order to avoid irregular results in the detection of blood group antibodies by flow cytometry, it was more effective to use RTECs rather than RBCs as target cells. In the absence of presensitization, ABOi-KTx in three monkeys with relatively high levels of natural anti-A antibodies did not produce HAR. However, when four Type B monkeys with significantly increased anti-A antibodies after presensitization were randomly selected as recipients for ABOi-KTx, the allografts in all four monkeys developed HAR with typical pathologic characteristics. Thus, we have successfully established a monkey model of HAR in ABOi-KTx via blood group antigen presensitization, which will be helpful for the further study of rejection, accommodation, and clinical intervention in ABOi-KTx.

ABO(H) and Lewis blood group substances and disease treatment

Since the early 20th century, scientists have determined that blood group antigens can be inherited. With more and more studies have been devoted to finding the relationship between blood groups and diseases, the relationship of ABO(H) and Lewis blood groups and the development of human diseases have been summarised. In addition, many studies have shown that blood group substances, such as blood group antigen or related antibody, play an important role in disease prevention and treatment. This review focuses on the advances of ABO(H), Lewis blood group substances in the treatment of diseases, which has important significance for the development of novel therapeutic methods.

ABO incompatibility in renal transplantation

ABO blood group incompatibility (ABO-I) was historically considered an absolute contraindication to kidney transplantation due to the significant risk of acute antibody-mediated rejection and early graft loss. Nevertheless, the urge to minimize the gap between the candidates’ number on the waitlist for kidney transplants and the available kidney donors encourage investigation into finding ways to use organs from ABO-I kidney donors, especially in the era of using more potent immunosuppression therapies. This review aims to discuss a general overview of ABO-I kidney transplantation and the different protocols adopted by some transplant centers to meaningfully overcome this barrier.

Effect of Donor and Recipient ABH-Secretor Status on ABO-Incompatible Living Donor Kidney Transplantation

Introduction

ABO blood group antigens within grafts are continuously exposed to anti-A/B antibodies in the serum of recipients after ABO-incompatible (ABOi) kidney transplantation and are instrumental in antibody-mediated rejection. Some individuals secrete soluble blood group antigens into body fluids. In this study, we investigated the effect of donor and recipient secretor status on the outcomes of ABOi kidney transplantation.

Methods

Data of a total of 32 patients with ABOi living donor kidney transplantation were retrospectively collected between 2014 and 2020 in West China Hospital. The genotype and phenotype of both donors and recipients were examined and evaluated with post-transplantation anti-A/B titer changes, graft function, and rejection.

Results

Of the 32 recipients and 32 donors, 23 (71.9%) recipients and 27 (84.4%) donors had secretor genotypes, whereas 9 (28.1%) recipients and 5 (15.6%) donors did not. Anti-A/B titers after ABOi kidney transplantation were not significantly influenced by the secretor status of either donors or recipients. The post-transplantation serum creatinine (Scr) levels and estimated glomerular filtration rate (eGFR) was better in weak- or non-secretor recipients at day 30 (Scr P = 0.047, eGFR P = 0.008), day 90 (Scr P = 0.010, eGFR P = 0.005), and month 9 (eGFR P = 0.008), and recipients from secretor donors had a lower incidence of graft rejection in the first year after ABOi transplantation (P = 0.004).

Conclusions

A weak secretor status phenotype was found in both genotypes, i.e., individuals who secreted soluble antigens as well as those who did not. The recipient ABH-secretor status may have an influence on early posttransplant renal function, and the donor ABH-secretor status might affect the incidence of graft rejection.

Impact of kidney transplantation on the risk of retinal vein occlusion in end-stage renal disease

It has been known that retinal vein occlusion (RVO) is associated with chronic kidney disease, especially end-stage renal disease (ESRD). However, little is known about the effect of kidney transplantation (KT) on RVO incidence in ESRD patients. This study aimed to compare the incidence of RVO in KT recipients (n = 10,498), matched ESRD patients (n = 10,498), and healthy controls (HCs, n = 10,498), using a long-term population-based cohort. The incidence of RVO was 2.74, 5.68, and 1.02 per 1000 patient-years, for the KT group, the ESRD group, and the HCs group, respectively. Adjusted hazard ratios for RVO development compared to the HCs group, were 1.53 and 3.21, in the KT group and the ESRD group, respectively. In the KT group, multivariable regression analysis indicated that an age over 50, a Charlson Comorbidity Index score over 4, and a history of desensitization therapy were associated with an increased risk of RVO. In summary, KT recipients have a lower risk for development of RVO than ESRD patients treated with dialysis. However, the risk is still higher compared to healthy people who have normal kidney functions.

A Safe Anti-A2 Titer for a Successful A2 Incompatible Kidney Transplantation: A Single-center Experience and Review of the Literature

Background.

Kidney allocation system allows blood type B candidates accept kidneys from A2/A2B donors. There is no mandate by UNOS on which the anti-A2 level is acceptable. We aimed to investigate the safety of kidney transplant in blood group B patients with anti-A2 titers ≤16.

Methods.

We performed 41 A2-incompatible kidney transplants in blood group B recipients between May 2015 and September 2019. Clinical outcomes were compared with a control group of 75 blood group B recipients who received blood group compatible kidney transplantation at the same period.

Results.

Of the 41 recipients, 85% were male, 48% African American, with a median age of 53 (20–73) y. Thirty-eight (93%) were deceased-donor and 3 (7%) were living-donor kidney transplant recipients. Pretransplant anti-A2 IgG titers were 2 in 16, 4 in 9, 8 in 6, and 16 in 5 and too weak to titer in 5 recipients. Eight patients had pretransplant donor-specific antibodies. During a median follow-up of 32.6 mo (6–57.3) patient and graft survival were 100% and 92% in the A2-incompatible kidney transplant group, and 91% and 92% in the blood group compatible group, respectively. Twelve A2-incompatible recipients underwent a 21 clinically indicated kidney biopsies at a median 28 d (6–390) after transplantation. None of the patients developed acute antibody-mediated rejection and 2 patients (5%) had acute T-cell–mediated rejection. Interestingly, peritubular capillary C4d positivity was seen in 7 biopsies which did not have any findings of acute rejection or microvascular inflammation but not in any of the rejection-free biopsies in the control group. C4d positivity was persistent in 5 of those patients who had follow-up biopsies.

Conclusions.

A2-incompatible transplantation is safe in patients with anti-A2 titers ≤16 with excellent short-term kidney allograft outcomes. C4d positivity is frequent in allograft biopsies without acute rejection.

Use of immunoadsorption columns in ABO-incompatible renal transplantation: A prospective study at a tertiary care center in India

Background

We present our experience of ABO-incompatible renal transplant using immunoadsorption (IA) columns. We have compared efficacy of two commercially available columns.

Methods

This single-center prospective study was conducted at Army Hospital Research and Referral, Delhi. All consecutive ABO-incompatible renal transplants from January 2014 to February 2018 were analyzed. Of 30 patients who underwent transplantations, 28 underwent antibody depletion with immunoadsorption columns. Of them, 14 cases were in the "Glycosorb group," while 14 in the "Adsopak group."

Results

The donors in the Adsopak group were older than those in the Glycosorb group (p < 0.05). Both groups had spousal donors in majority. The cutoff for the antibody titer was 1:8. The median titer in the Adsopak group was 128 (range, 1:4 to 1:2048), while that in the Glycosorb group was 24 (range, 1:8 to 1:128). All patients in the Glycosorb group had baseline titers ≤1:128, while 13 patients in the Adsopak group had baseline titers ≤1:512. Nil titer was achievable with Glycosorb® (50%,7/14) but not with Adsopak® (P < 0.01). Around 4 sessions were required for the Glycosorb group, while around 8 sessions were required for the Adsopak group before transplantation (p < 0.001). The Glycosorb group was advantageous in terms of graft failure because no rejection was noticed in these patients in their follow-up period. Three patients in the Adsopak group developed rejection (two had mixed rejection, and one had antibody-mediated rejection). Four patients died of sepsis (three in the Glycosorb and one in the Adsopak group). Lower baseline serum creatinine level was achieved in the Glycosorb group.

Conclusions

Results of ABO-incompatible renal transplantation were satisfactory, and the use of immunoadsorption columns could effectively deplete antibody titers. Glycosorb columns were more efficient than Adsopak columns. Graft survival was better with Glycosorb. Posttransplant infections were a major cause of mortality.

Immunoadsorption Column Reuse

Introduction:

Selective immunoadsorption (IA) is a technique to remove preformed Anti-ABO antibodies in ABO-incompatible renal transplants (ABOiRT). Since the cost of a single IA column is high and single use rarely achieves the target anti-ABO titers, its use is not widely spread. We studied the safety and efficacy of the reuse of IA columns in ABOiRT.

Methods:

Single-center, retrospective analysis of all patients who underwent ABOiRT with IA column reuse from January 2016 to July 2018. The column was reused after sterilization with ethylene oxide and flushed with normal saline before use. Target titers (IgG) were 1:4 preoperatively. Baseline IgG titers, plasma volume processed in each session, postoperative titer rebound were recorded. The primary outcome was IgG titer reduction after each use and adverse reaction during the IA column reuse. Patients were followed up until 1 year.

Results:

16 patients underwent ABOiRT using IA columns. Baseline IgG titer ranged from 1:32 to 1:512. Reuse of IA column was done 23 times and underwent 2^nd reuse for 9 times. The average plasma volume treated was 22 L. Efficacy of the IA column in log titer reduction of anti-ABO titer was 4 logs after the first use, 3 logs after 1^st reuse, and 1.5 logs after 2^nd reuse. 12 (75%) patients successfully reached the target IgG titer of ≤1:4 solely with column reuse. One patient received a single session of plasma exchange before transplantation. Postoperatively, one patient received one session of plasma exchange due to a rebound in anti-ABO antibodies. No serious side effects were noted during the reuse.

Conclusion:

IA column reuse up to two times showed efficacy in the successful reduction of antibody titers. Column reuse was not associated with any significant side effects.

The First North American Experience Using Glycosorb Immunoadsorption Columns for Blood Group-Incompatible Kidney Transplantation

Background:

Blood group incompatibility (ABOi) is the most common barrier to living donor kidney transplantation. Options for such recipients include kidney paired donation (KPD) or desensitization methodology to reduce blood antibody response.

Objective:

The objective of this study is to report on the first North America experience in ABOi living donor kidney transplantation using Glycosorb ABO immunoadsorption columns.

Design:

Retrospective observational cohort study.

Setting:

Renal transplant program at St. Michael’s Hospital, Unity Health Toronto, University of Toronto.

Patients:

Twenty-six ABOi living donor transplants from August 2011 through February 2020 were undertaken at our center.

Measurements:

Renal allograft and patient survival postdesensitization for ABOi living donor transplants and isohemagglutinin titer reduction.

Methods:

Preoperative immunosuppressive regimen consisted of a single dose of Rituximab 375 mg/m² IV on day −28; tacrolimus, mycophenolic acid, and prednisone to start on day −7. Immunoadsorption treatments with Glycosorb A or B columns were performed on day −7 through day −1 based on anti-A or anti-B titers on Spectra Optia Apheresis System. Immunosuppression included basiliximab, solumedrol followed by oral prednisone, once-daily tacrolimus, and mycophenolic acid. The mean follow-up was 53 months (3-96 months).

Results:

A total of 26 individuals underwent an attempt at desensitization of whom 24 patients underwent immediate transplant. One patient had a rebound in titers and subsequently was transplanted from a blood group compatible living donor. A second patient had an unrelated medical issue and desensitization was discontinued. Five-year patient survival was 96% and death censored allograft survival was 92%. Posttransplant anti-A or anti-B titers were monitored daily for the first 7 days posttransplant and every 2 days from days 7 to 14. There were no acute rejections seen in this cohort of transplant recipients.

Limitations:

As our protocol was first initiated as proof of concept, a few recipients had low initial isohemagglutinin titers. This may have contributed to improved clinical outcomes.

Conclusions:

ABO column immunoadsorption with specific columns is a safe and effective method for ABOi living donor kidney transplantation, and an option when KPD is less than ideal.

Trial not registered as this was a retrospective cohort review.

ABO-incompatible living kidney transplantation

ABO-incompatible living kidney transplantation is nowadays a routine procedure to expand living donor pool. The past decades have seen the evolution of desensitization protocol and immunosuppression regimen. Despite increased bleeding events, infectious complications, and rejection episodes reported in some studies, favorable graft and patient survival rate are now achieved, regardless of various protocols among transplant centers. Several issues such as the usage of rituximab and standardization of blood group antibody titration remain to be settled. The deposition of C4d is no longer the histopathologic hallmark of antibody-mediated rejection, which have inspired innovative strategies of peripheral molecular screening and the improvement of histological diagnosis of AMR (antibody-mediated rejection). The better understanding of the underlying mechanism might facilitate the distinction and therapeutic schemes of AMR.

Current protocols and outcomes of ABO-incompatible kidney transplantation

One of the principal obstacles in transplantation from living donors is that approximately 30% are immunologically incompatible because of the presence in the recipient of antibodies directed against the human leukocyte antigen system of the donor or because of the incompatibility of the ABO system. The aim of this review is to describe the more recent data from the literature on the different protocols used and the clinical outcomes of ABO-incompatible kidney transplantation. Two different strategies are used to overcome these barriers: desensitization of the recipient to remove the antibodies and to prevent their rebound after transplantation and the exchange of organs between two or more pairs. The largest part of this review is dedicated to describing the techniques of desensitization. Even if the first reports of successful renal transplantation between ABO-incompatible pairs have been published by 1980, the number of ABO-incompatible transplants increased substantially in this century because of our improved knowledge of the immune system and the availability of new drugs. Rituximab has substantially replaced splenectomy. The technique of apheresis has improved and more recently a tailored desensitization proved to be the more efficient strategy avoiding an excess of immunosuppression with the related side effects. Recent reports document outcomes for such transplantation similar to the outcomes of standard transplantation.

Outcome of ABO Blood Type-Incompatible Living-Related Donor Kidney Transplantation Under a Contemporary Immunosuppression Strategy in Japan

BACKGROUND

Because of the serious donor shortage in Japan, there is an increasing need for ABO blood type-incompatible kidney transplantation (ABOi-KT) in living-related donor kidney transplantation. We evaluated the outcomes of ABOi-KT performed at our hospitals using a contemporary immunosuppression strategy with low-dose rituximab.

PATIENTS AND METHODS

Between June 2006 and April 2019, 107 patients underwent living-related donor kidney transplantation at our hospitals. The patients were divided into ABO-compatible (ABOc) and ABOi groups. The basic immunosuppression regimen differed between the 2 groups in the use of low-dose rituximab and therapeutic apheresis in the ABOi group. We compared graft survival, patient survival, rejection, viral infection, and posttransplant renal function between the 2 groups.

RESULTS

Of 107 recipients, 37 (35%) underwent ABOi-KT. The 5-year graft survival rates in the ABOc and ABOi group were 91% and 100%, respectively. The Kaplan-Meier analyses showed no difference in graft survival (P = .168) or patient survival (P = .873) between the groups. Biopsy-proven rejection in the ABOc and ABOi groups was observed in 13 (19%) and 7 (19%) patients, respectively (P = .965), and viral infection was observed in 21 (30%) and 10 (27%) patients (P = .747), respectively. Renal function by estimated glomerular filtration rate from 1 week to 5 years after transplantation was similar in both groups.

CONCLUSIONS

The outcomes of ABOi-KT with low-dose rituximab were comparable with those of ABOc-KT at our hospitals. ABOi-KT with proper immunosuppression may be an option to help resolve the severe donor shortage in Japan.

ABO-incompatible pediatric kidney transplantation without antibody removal

BACKGROUND

Because of the severe shortage of suitable deceased donors, ABO-incompatible living donor kidney transplantation (ABOi LDKT) is performed even in pediatric recipients in Japan. We performed pediatric ABOi LDKT using rituximab without anti-A/B antibody removal.

METHODS

Thirteen pediatric recipients (mean age 7.4, range 3.4-15.7, four females) whose baseline anti-A/B IgG titers were ≤ × 64 underwent ABOi LDKT without antibody removal and splenectomy between July 2013 and April 2017 at Toho University. Mycophenolate mofetil (MMF) was initiated on day - 10. Rituximab (100 mg) was administered twice. Basiliximab and triple maintenance immunosuppression (calcineurin inhibitor, MMF, and steroids) were administered. Protocol biopsy was performed at 3 months and 1 year after transplantation. We retrospectively compared the clinical outcomes between these recipients and 37 children (mean age 9.0, range 2.6-18.9, 15 female) who underwent ABO-compatible (ABOc) LDKT during the same period.

RESULTS

The mean follow-up periods of ABOi and ABOc groups were 31.9 ± 13.5 and 28.8 ± 14.4 months, respectively. In the ABOi group, no clinical acute rejection (AR) was noted and subclinical AR was observed in four patients without evidence of acute antibody-mediated rejection. In the ABOc group, clinical and subclinical AR developed in 3 and 10 patients, respectively. No significant difference was identified for the mean eGFR between the ABOi and ABOc groups (98.3 ± 48.8 vs. 86.9 ± 39.4, P = 0.452 at 3 months; 78.2 ± 21.2 vs. 79.7 ± 21.3, at 1 year, P = 0.830). Death-censored graft survival at follow-up was 100% in the ABOi group and 94.6% in the ABOc group. Patient survival during the follow-up period in both the groups was 100%. Late-onset neutropenia (LON) requiring granulocyte colony-stimulating factor occurred more frequently in the ABOi group than in the ABOc group (4 vs. 0 patients) (P < 0.001).

CONCLUSIONS

Pre- and post-transplantation antibody removal is not a prerequisite for successful pediatric ABOi LDKT, at least in patients with a low anti-A/B IgG antibody titer. However, LON caused by rituximab should be monitored.

Molecular Patterns Discriminate Accommodation and Subclinical Antibody-mediated Rejection in Kidney Transplantation

BACKGROUND

Accommodation in ABO-incompatible (ABOi) transplantation and subclinical antibody-mediated rejection in HLA-incompatible (HLAi) transplantation share several morphological similarities. Because the clinical long-term outcomes differ, we hypothesized different molecular processes involved in ABOi transplantation and subclinical antibody-mediated rejection.

METHODS

Using Illumina Human HT-12 v4 Expression BeadChips, the whole transcriptome was evaluated based on 3-month protocol C4d+ biopsies in otherwise stable ABOi and HLAi kidney grafts, as well as in C4d-negative HLA-compatible grafts exhibiting normal histological findings. Top differently regulated genes were further validated using real-time quantitative polymerase chain reaction in another patient cohort and complement regulatory proteins by immunohistochemistry.

RESULTS

In the case of genes involved in immune response-related biological processes, ABOi and HLAi cohorts had similar transcriptomic profiles to C4d-negative controls. The majority of deregulated genes in the ABOi and HLAi groups consisted of metallothioneins and epithelial transporter genes. Increased expression of epithelial transporters (SLC4A1, SLC4A9, SLC17A3, SLC12A3, and SLC30A2) and class 1 metallothioneins (MT1F, MT1G, and MT1X) in HLAi transplantation was validated by real-time quantitative polymerase chain reaction. In comparison to controls, both incompatible cohorts were characterized by the upregulation of intrarenal complement regulatory genes. CD46 and CD59 transcripts were increased in the ABOi cohort, whereas CD46 solely in HLAi group, and CD59 protein expression was similar in both incompatible groups.

CONCLUSIONS

Several epithelial transporters and metallothioneins discriminate subclinical antibody-mediated rejection in HLAi transplantation from accommodation in ABOi transplantation, which suggest different involved downstream mechanisms and increased risk of injury in HLAi settings. Metallothioneins with their antioxidative properties may help to attenuate the inflammation response induced by donor-specific anti-HLA antibody binding.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Single fixed low-dose rituximab as induction therapy suppresses de novo donor-specific anti-HLA antibody production in ABO compatible living kidney transplant recipients

This study was conducted to evaluate de novo donor-specific anti-human leukocyte antigen (HLA) antibody (dnDSA) production leading to antibody-mediated rejection (ABMR) after rituximab induction in non-sensitized ABO-compatible living kidney transplantation (ABO-CLKTx). During 2008-2015, 318 ABO-CLKTx were performed at the Department of Surgery III at Tokyo Women's Medical University Hospital. To reduce confounding factors, we adopted a propensity score analysis, which was applied with adjustment for age, gender, duration of pretransplant dialysis, HLA mismatch count, preformed DSA, non-insulin-dependent diabetes mellitus, immunosuppressive treatment, and estimated glomerular filtration rate (eGFR) on postoperative day 7. Using a propensity score matching model (1:1, 115 pairs), we analyzed the long-term outcomes of 230 ABO-CLKTx recipients retrospectively. Recipients were classified into a rituximab-treated (RTX-KTx, N = 115) group and a control group not treated with rituximab (C-KTx, N = 115). During five years, adverse events, survival rates for grafts and patients, and incidence of biopsy-proven acute rejection (BPAR) and dnDSA production for the two groups were monitored and compared. All recipients in the RTX-KTx group received rituximab induction on preoperative day 4 at a single fixed low dose of 100 mg; the CD19+ B cells were eliminated completely before surgery. Of those recipients, 13 (11.3%) developed BPAR; 1 (0.8%) experienced graft loss. By contrast, of C-KTx group recipients, 25 (21.7%) developed BPAR; 3 (2.6%) experienced graft loss. The RTX-KTx group exhibited a significantly lower incidence of BPAR (P = .041) and dnDSA production (13.9% in the RTX-KTx group vs. 26.9% in the C-RTx group, P = .005). Furthermore, lower incidence of CMV infection was detected in the RTX-KTx group than in the C-KTx group (13.9% in the RTX-KTx group vs. 27.0% in the C-KTx group, P = .014). No significant difference was found between groups for several other factors: renal function (P = .384), graft and patient survival (P = .458 and P = .119, respectively), and the respective incidences of BK virus infection (P = .722) and leukopenia (P = .207). During five-year follow-up, single fixed low-dose rituximab therapy is sufficient for ensuring safety, reducing rejection, and suppressing dnDSA production for immunological low-risk non-sensitized ABO-CLKTx.

Latest insights on ABO-incompatible living-donor renal transplantation

This review summarizes the latest insights on ABO‐incompatible living‐donor renal transplantation. Desensitization protocols and clinical outcomes were investigated, and a comparison was made with kidney‐paired donation, which is not permitted in Japan for ethical reasons. Although renal transplantation is greatly beneficial for most patients with end‐stage kidney disease, many of these patients must remain on dialysis therapy for extended periods due to the scarcity of organs from deceased donors. ABO blood type incompatibility was once believed to be a contraindication to renal transplantation due to the increased risk for antibody‐mediated rejection and early graft loss attributable to isoagglutinins. Recently, pretransplant desensitization strategies, such as removal of isoagglutinins and antibody‐producing cells, have achieved successful outcomes, although it remains unclear whether graft survival and patient morbidity are equivalent to those for ABO‐compatible renal transplantation. The present review suggested that ABO‐incompatible living‐donor renal transplantation might be a favorable radical renal replacement therapy for patients with end‐stage kidney disease.

Association Between Peripheral Blood CD19-Positive Rate and Antibody-Mediated Rejection Following Rituximab Administration in Kidney Transplant Recipients

Background.

Rituximab is used widely for desensitization in ABO-incompatible and donor-specific antibody-positive kidney transplantation. However, data about the effects of individual differences in rituximab-induced B-cell suppression on antibody-mediated rejection (AMR) remain unknown. We aimed to assess the association between CD19-positive rate and AMR following rituximab administration after kidney transplantation.

Methods.

Overall, 42 patients who underwent rituximab therapy for pretransplant desensitization in ABO-incompatible (n = 33) and donor-specific antibody-positive (n = 15) kidney transplantation were observed retrospectively. To predict AMR incidence, the peripheral blood CD19-positive rate was determined and classified into short- and long-acting groups. AMR incidence, allograft function, complications, and rituximab dose were compared.

Results.

Eight patients (19%) had AMR within 39.2 months after transplantation. The CD19-positive rate cutoff value to predict AMR incidence was 4.4%, 6.4%, and 7.7% at 6, 12, and 18 months after transplantation, respectively. When comparing the short- and long-acting groups stratified according to the CD19-positive rate cutoff value, AMR incidence was significantly higher in the short-acting group than in the long-acting group at 6 (71.4% vs 8.6%), 12 (70.0% vs 3.1%), and 18 (58.3% vs 3.3%) months after transplantation. The CD19-positive rate for all patients with AMR exceeded the cutoff value 6, 12, or 18 months. Conversely, serum creatinine level, tacrolimus trough-level, cytomegalovirus antigenemia-positive rate, neutropenia incidence rate, and total dose of rituximab before transplantation showed no significant differences between the 2 groups.

Conclusions.

The risk of AMR was higher in patients with short-term B-cell suppression following rituximab administration. Additional rituximab administration after transplantation may prevent AMR in patients with a CD19-positive rate higher than the cutoff value.

Therapeutic Plasma Exchange Practices in Intensive Care Unit

OBJECTIVE

To observe the indications, practices and outcome of therapeutic plasma exchange (TPE) in a tertiary care ICU.

MATERIALS AND METHODS

The study involves retrospective analysis of 56 patients who underwent TPE between May 2011 and August 2013. Data relating to demographics, diagnosis, category of indication, number of sessions, volume and type of replacement solutions were collected.

RESULTS

Category I indications were 50%, with a mean of 3.32 sessions per patient. Per session volume exchanged was 9775.1 ± 11812.9 mL and replacement volume was 7414 ± 6993.03 mL. Fresh frozen plasma (FFP), crystalloids, cryopoorplasma and PRBC constituted 62.9%, 22%, 9.9% and 5.3% of volume replacement, respectively. TPE was terminated in three patients for Transfusion Associated Acute Lung Injury (TRALI), hypotension and cardiac arrest respectively. Clinical improvement was noted in 82% of patients and overall mortality rate was 12.5%.

CONCLUSION

TPE is feasible and well tolerated in ICU with favorable disease resolution and outcome. Common indications included sickle cell and myasthenia crisis and blood products were the most commonly used for volume replacement.

HOW TO CITE THIS ARTICLE

Ranganathan L, Menon R, Ramakrishnan N, Venkatraman R, Ramachandran P. Therapeutic Plasma Exchange Practices in Intensive Care Unit. Indian J Crit Care Med 2019;23(7):336-338.

Therapeutic Immunoadsorption and Conventional Plasma Exchange in ABO-incompatible Renal Transplant: An Exculpatory Evidence

Aim

The objective of this study was to compare the efficacy of immunoadsorption (IA) with conventional therapeutic plasma-exchange (cTPE) in ABO-incompatible (ABOi) renal transplant.

Methods

Data of patients from July 2015 to June 2017 (category-I, number of patients (N) = 11; IA±cTPE) on the average length of stay (ALOS), number of cTPE/IA, antibody-titers (AT), creatinine, patient and graft survival at one year were compared retrospectively with patients in period from February 2012 to June 2015 (category-II, N = 29; cTPE only). AT of patients not decreasing to less than one fold after two cTPE were shifted for IA. For patients undergoing IA, real-time AT was done and IA stopped after target titer (TT <1:8) was achieved. Post-transplant cTPE was done if, titers rebounded to ≥1:8. Intravenous immunoglobulin (IVIG) was given after every cTPE/IA. Cost comparisons were made.

Results

In category-I, seven patients (63.63%) were shifted to IA from cTPE. The mean cTPE procedures in category I and II are 3.5 ± 2.4 and 4.8 ± 2.5, respectively (p = 0.206). The mean IA procedures in category-I are 1.6 ± 0.5. The number of patients requiring post-operative TPE was less in category-I than category-II, i.e., N = 5, 45.5% vs N = 20, 69%, respectively (p = 0.171). The expense of IA in category-I vs cTPE in category-II was statistically not significant (p = 0.422) but had significant lesser ALOS (p = 0.044). Expenses, when a patient undergoes both cTPE and IA (category-I), are significantly higher to category-II (p = 0.003). The two groups were comparable in AT, creatinine value, graft and patient survival rates at one year.

Conclusion

Contrary to the general judgment of IA being expensive than cTPE, this study shows equivalent expenditures with comparable therapeutic outcomes.

Clinical outcomes after ABO-incompatible renal transplantation: a systematic review and meta-analysis

BACKGROUND

ABO-incompatible renal transplantation (ABOi-rTx) is increasingly used to overcome organ shortage. Evidence about its non-inferiority in comparison with ABO-compatible renal transplantation (ABOc-rTx) needs to be analysed at early and late timepoints. We aimed to investigate differences in outcome after ABOi-rTX and ABOc-rTX.

METHODS

We did a systematic review and meta-analysis of observational studies published up until Dec 31, 2017, that reported outcome data (≥1 year of follow-up) after ABOi-rTx and included an ABO-compatible control group, by searching the Cochrane Central Register of Controlled Trials (CENTRAL), Embase Ovid, MEDLINE Ovid, and PubMed. Trials on recipients of ABOi-rTx were assessed, if an ABO-compatible control group was included and if outcome data on at least graft or recipient survival with 1 year or more of follow-up were available. Exclusion criteria included case reports, editorials, reviews and letters, animal studies, meeting papers, studies unable to extract data, non-renal solid organ and bone-marrow transplant studies, and deceased donor ABOc-rTx. Data were extracted from published reports. Primary endpoints were all-cause mortality and graft survival at 1, 3, 5, and more than 8 years after transplantation. In the meta-analysis, we used a fixed-effects model if the I² value was 0, and both a fixed-effects and random-effects model if I² was more than 0. This study is registered with PROSPERO, number CRD42018094550.

FINDINGS

1264 studies were screened and 40 studies including 49 patient groups were identified. 65 063 patients were eligible for analysis, 7098 of whom had undergone ABOi-rTx. Compared with ABOc-rTx, ABOi-rTx was associated with significantly higher 1-year mortality (odds ratio [OR] 2·17 [95% CI 1·63-2·90], p<0·0001; I²=37%), 3 years (OR 1·89 [1·46-2·45], p<0·0001; I²=29%), and 5 years (OR 1·47 [1·08-2·00], p=0·010; I²=68%) following transplantation. Death-censored graft survival was lower with ABOi-rTx than with ABOc-rTx at 1 year (OR 2·52 [1·80-3·54], p<0·0001; I²=61%) and 3 years (OR 1·59 [1·15-2·18], p=0·0040; I²=58%) only. Graft losses were equivalent to that of ABOc-rTx after 5 years and patient survival after 8 years. No publication bias was detected and the results were robust to trial sequential analysis until 5 years after transplantation; thereafter, data became futile or inconclusive.

INTERPRETATION

Despite progress in desensitisation protocols and optimisation of ABOi-rTx procedures, excess mortality and loss of kidney grafts was found compared with ABOc-rTx within the first 3 years after transplantation. Only long-term outcomes after 5 years yielded equivalent survival rates and organ function. Awareness of the increased risks of infection, organ rejection, and bleeding could improve care of patients and promote efforts towards paired kidney exchange programmes.

FUNDING

None.

ABO-Incompatible Liver Transplantation - A Review of the Historical Background and Results

ABO-incompatible liver transplantation (ABOi LT) using conventional immunosuppression has been considered a contraindication due to the high risk for antibody-mediated complications potentially resulting in graft loss. However, organ shortage has led to the development of anti-A/B antibody reducing immunosuppressive protocols which have made the outcome after living donor (LD) ABOi LT equivalent to that achieved with LD ABO-compatible (ABOc). The experience of deceased donor (DD) ABOi LT is however still limited. In this article, we discuss the historical background and the results after ABOi LT, in the setting of both LD and DD transplantation. We also discuss the remaining hurdles and future strategies in the breaching of the ABO barrier for LT.

Current protocols and outcomes of ABO-incompatible kidney transplantation based on a single-center experience

ABO-incompatible living kidney transplantation (ABO-ILKT) is an effective option for increasing living kidney transplant opportunities. ABO-ILKT has been conducted in our institution since 1989 to widen the indication for living kidney transplantation. ABO-ILKT is considered to require extra treatment, and it has increased risks compared with ABO-compatible living kidney transplantation (ABO-CLKT). In the past two decades, some protocols have removed anti-blood-type antibodies to prevent the production of antibodies. Additionally, we have made considerable changes to our ABO-ILKT protocol as new immunosuppressive agents have been developed. Consequently, increased immunosuppression and immunological understanding have helped shape recent desensitization protocols. Herein, we review the history, therapeutic strategy, pathology, and future directions of ABO-ILKT. Our standard immunosuppressive regimen and desensitization protocol for ABO-ILKT recipients consist of low doses of tacrolimus (TAC), mycophenolate mofetil (MMF), and rituximab; several sessions of double filtration plasmapheresis; and basiliximab induction. We do not use thymoglobulin induction, intravenous immunoglobulin, or prophylactic post-transplant plasmapheresis. Recently, ABO-ILKT has been recognized as a useful alternative therapy for end-stage kidney disease with ABO-incompatibility, and its outcome is comparable to that of ABO-CLKT.

Resultados de la inmnuadsorción en el trasplante ABOi y el rechazo humoral en una unidad de hemodiáilsis hospitalaria

INTRODUCCIÓN El tratamiento con inmunoadsorción no selectiva fue introducido en nuestra unidad de hemodiálisis hospitalaria con el objetivo de permitir la desensibilización previa a un trasplante renal con incompatibilidad de grupo sanguíneo y el tratamiento del rechazo mediado por anticuerpos. OBJETIVO Analizar los resultados de la técnica de inmunoadsorción no selectiva, en una unidad de hemodiálisis hospitalaria. MATERIAL Y MÉTODOS Estudio retrospectivo, descriptivo, de los primeros 18 pacientes tratados en nuestro centro con inmunoadsorción no selectiva (años 2012-2017) en las indicaciones de acondicionamiento del trasplante ABOi y tratamiento del rechazo humoral. RESULTADOS Durante un periodo de 5 años se analizaron un total de 128 sesiones de inmunoadsorción no selectiva. El 38,9% (n=7) de los casos para desensibilización previa al trasplante renal con incompatibilidad de grupo sanguíneo y el 61,1% (n=11) restante para el tratamiento del rechazo mediado por anticuerpos. En el primer caso, realizaron una media de 8±0,6 sesiones de inmunoadsorción previas al trasplante renal y el 57,1% se complementaron 2 sesiones posteriores. El tratamiento concomitante fue el protocolizado con Rituximab e inmunoglobulinas, requiriendo el 57,1% la realización de recambios plasmáticos. En el segundo caso, realizaron una media de 5,9±2 sesiones de inmunoadsorción. El tratamiento concomitante fue el mismo y el 27,3% realizaron recambios plasmáticos. CONCLUSIONES El trasplante renal de donante vivo ABOi tras la desensibilización fue posible en el 100% de los pacientes. El 72,7% de los pacientes tratados para el rechazo mediado por anticuerpos mantienen actualmente la funcionalidad del injerto.

Three Severe Cases of Viral Infections with Post-Kidney Transplantation Successfully Confirmed by Polymerase Chain Reaction and Flow Cytometry

Viral infections in patients with post-kidney transplantation are often difficult to diagnose as well as treat. We herein report three cases with severe viral infections after kidney transplantation. All their causative pathogens could be detected promptly by polymerase chain reaction and flow cytometry during the early stages of infection. These examinations would also be of great use to monitor therapeutic responses and disease activity. It is indeed true that no specific treatment is available for most of the viral infections, but we should be aware that some infections, such as Epstein-Barr virus infection, can be treatable with prompt and specific treatment, such as rituximab.

Anti-CD20 Blocker Rituximab in Kidney Transplantation

Rituximab is a chimeric anti-CD20 monoclonal protein used in various clinical scenarios in kidney transplant recipients. However, its evidence-based use there remains limited due to lack of controlled studies, limited sample size, short follow-up and poorly defined endpoints. Rituximab is indicated for CD20+ posttransplant lymphoproliferative disorder. It may be beneficial for treating recurrent membranous nephropathy and recurrent allograft antineutrophilic cytoplasmic antibody vasculitis and possibly for recurrent focal segmental glomerulosclerosis. Rituximab, in combination with IVIg/plasmapheresis, appears to decrease antibody level and increase the odds of transplantation in sensitized recipients. The role of Rituximab in ABOi transplant remains unclear, as similar outcomes are achieved without its use. Rituximab is not efficacious in antibody-mediated rejection/chronic antibody-mediated rejection. Strict randomized control trials are necessary to elucidate its true role in these settings.

Similar Microvascular Inflammation and Tubulointerstitial Injury in ABO-Incompatible and Matched ABO-Compatible Kidney Allografts

ABO-incompatible (ABOi) kidney transplantation represents a viable tool to increase the donor pool for kidney transplantation, however, increased alloimmune response has been debated. The early outcomes of 25 low-risk ABOi kidney transplant recipients were compared with thoroughly matched 50 ABO-compatible (ABOc) ones. The matching process was based on gender and age of recipients and immunologic parameters, such as panel reactive antibodies, number of human leukocyte antigen mismatches, and transplantation era. Three-month protocol kidney graft biopsy Banff scores and 1-year clinical outcomes were compared. Apart from C4d positivity, no statistically significant differences were found regarding the Banff scores between the two groups. Similarly, microvascular inflammation and tubulointerstitial injury revealed no differences either. The eGFR at 3 months and 1 year was similar in both groups. In conclusion, blood group incompatibility yields no additional microvascular and tubulointerstitial graft injury if desensitization protocol was applied to low-risk kidney transplant recipients.

Safety and Efficacy of Induction Therapy With Thymoglobulin in AB0-Incompatible Kidney Transplantation

INTRODUCTION

Data suggest an additional role of T cells in antibody-mediated rejections. In 2001 a protocol for AB0-incompatible kidney transplantation based on B-cell-depleting anti-CD20 antibody rituximab, antigen-specific blood group IgG immunoadsorption, intravenous immunoglobulins, and triple immunosuppression was introduced in Europe, which used induction therapy with the use of interleukin-2 receptor antibody (IL2-RA) basiliximab. We used thymoglobulin in AB0-incompatible patients as induction in the face of high immunologic risk.

METHODS

We retrospectively evaluated a cohort of 9 AB0i living donation (LD) recipients from 2011 to 2014. Desensitization included blood group-specific immunoadsorption. Eighteen AB0-compatible LD recipients receiving induction therapy with thymoglobulin served as control subjects. Another control group consisted of 18 AB0-compatible LD recipients receiving basiliximab. Follow-up was 24 months. We captured graft function by estimating glomerular filtration rate (eGFR by Modification of Diet in Renal Disease formula), rejection episodes, and bacterial and viral infections.

RESULTS

All patients experienced immediate graft function. No significant or clinical differences were observed regarding graft function, rejection rates, or infections between the groups, although there seemed to be slightly higher cytomegalovirus infection rates due to preemptive therapy strategy.

CONCLUSIONS

Thymoglobulin appears to be similar in safety and efficacy to IL-2-antagonists in AB0i kidney transplantation.