Double filtration plasmapheresis in antibody-incompatible kidney transplantation

The effects of double-filtration plasmapheresis on coagulation profiles and the risk of bleeding

BACKGROUND/PURPOSE

Double-filtration plasmapheresis (DFPP) can be used to remove circulating pathogenic molecules. By reclaiming filtered albumin, DFPP reduces the need for albumin and plasma replacement. Large proteins, such as fibrinogen, are removed. Our institution adopts a DFPP treatment protocol consisting of active surveillance of coagulation profiles and prophylactic supplementation of blood products containing fibrinogen. This study aims to investigate the effects of consecutive DFPP treatments on serial coagulation profiles and the risk of bleeding under this protocol.

METHODS

Serial laboratory data and bleeding events at a single tertiary medical center were prospectively collected. Prophylactic transfusion of cryoprecipitate or fresh frozen plasma (FFP) was instituted if significant coagulopathy or a clinically evident bleeding event was observed.

RESULTS

After the first treatment session, plasma fibrinogen levels decreased from 332 ± 106 mg/dL to 96 ± 44 mg/dL in the 37 study patients. In the following sessions, plasma fibrinogen levels were maintained at around 100 mg/dL under prophylactic transfusion. No major bleeding events were recorded, but five (14%) patients experienced minor bleeding.

CONCLUSION

DFPP treatment might be performed safely along with active monitoring of coagulation profiles and prophylactic transfusion of cryoprecipitate or FFP.

Success rate and safety of living donor kidney transplantation in ABO blood group incompatible relatives: A systematic review and meta-analysis

BACKGROUND

Kidney transplantation is considered an ideal treatment for end-stage renal disease (ESRD) because it provides a longer and better quality of life than dialysis. ABO-incompatible (ABO-I) kidney transplantation relies on two principles: (i) removal of antibodies from a blood group; and (ii) inhibition of reappearance of blood group antibodies by intensifying the induction and maintenance of immunosuppression. This systematic review aimed to analyze the success and safety of ABO-I live-donor kidney transplantation.

METHODS

Databases, including Google Scholar, PubMed, Embase, Web of Science, and Medline were searched. Search duration was from the database establishment to December 2022. A thorough search was performed for relevant studies investigating the success and safety of ABO-I live-donor kidney transplantation. Two investigators independently extracted literature information and assessed the quality of the included studies. Heterogeneity test was performed using Cochrane's Q and chi-squared tests. All statistical analyses were performed using R software (version 4.2.1).

RESULTS

The search for relevant literature in the five electronic databases yielded 1238 articles. Of the 1238 articles, only 15 were included. Meta-analysis of outcomes from five studies showed a survival rate of 0.93 (95% confidence interval [CI]: 0.88 to 0.97, P < 0.001) after ≥3 years, while outcomes from 12 studies revealed a short-term patient survival rate of 0.94 (95% CI: 0.92 to 0.96, P = 0.75). In contrast, long- and short-term graft survival rates were 0.89 (95% CI: 0.75 to 0.96, P < 0.001) and 0.94 (95% CI: 0.90 to 0.97, P < 0.001), respectively. Incidence rates of infectious, surgical, and medical complications were 0.31 (95% CI: 0.22 to 0.41, P < 0.001), 0.12 (95% CI: 0.05 to 0.25, P < 0.001), and 0.38 (95% CI: 0.17 to 0.66, P < 0.001), respectively.

CONCLUSION

Good long- and short-term patient outcomes and graft survival rates were observed after ABO-I kidney transplantation. Similarly, the safety of performing kidney transplantations from living donors with ABO-I blood groups was established by the results of the current meta-analysis. Therefore, ABO-I live-donor kidney transplantations should be encouraged to reduce the time recipients spend on waiting lists and supplement the existing paired-exchange donor program.

Advancement in preoperative desensitization therapy for ABO incompatible kidney transplantation recipients

ABO incompatibility has long been considered an absolute contraindication for kidney transplantation. However, with the increasing number of patients with ESRD in recent years, ABO-incompatible kidney transplantation (ABOi-KT) has expanded the types of donors by crossing the blood group barrier through preoperative desensitization therapy. At present, the desensitization protocols consist of removal of preexisting ABO blood group antibody titers and prevention of ABO blood group antibody return. Studies have suggested similar patient and graft survival among ABOi-KT and ABOc-KT recipients. In this review, we will summarize the effective desensitization regimens of ABOi-KT, aiming to explore effective ways to improve the success rate and the long-term survival rate of ABOi-KT recipients.

Optimal Immunosuppression Strategy in the Sensitized Kidney Transplant Recipient

Patients with previous sensitization events against anti-human leukocyte antigens (HLA) often have circulating anti-HLA antibodies. Following organ transplantation, sensitized patients have higher rates of antibody-mediated rejection (AMR) compared to those who are non-sensitized. More stringent donor matching is required for these patients, which results in a reduced donor pool and increased time on the waitlist. Current approaches for sensitized patients focus on reducing preformed antibodies that preclude transplantation; however, this type of desensitization does not modulate the primed immune response in sensitized patients. Thus, an optimized maintenance immunosuppressive regimen is necessary for highly sensitized patients, which may be distinct from non-sensitized patients. In this review, we will discuss the currently available therapeutic options for induction, maintenance, and adjuvant immunosuppression for sensitized patients.

Regional Citrate Anticoagulation during Double-Filtration Plasmapheresis in Kidney Transplant Recipients: A Single-Center Retrospective Cohort Study

INTRODUCTION

Double-filtration plasmapheresis (DFPP) may be used for immunomodulation in kidney transplant (KTx). While DFPP reduces plasma product exposure, risk of circuit clotting merits adequate anticoagulation. Regional citrate anticoagulation (RCA) avoids the risks of systemic anticoagulation, but a protocol for RCA-DFPP is not previously widely described.

METHODS

We conducted a single-center retrospective cohort study involving adult (≥21 years old) KTx recipients who underwent RCA-DFPP from 2018 to 2020 to investigate efficacy and safety for an RCA protocol during DFPP in KTx recipients.

RESULTS

Fifty-one (85%) of 60 RCA-DFPP sessions in 17 patients completed without circuit clotting. Circuit clotting was associated with high post-filter ionized calcium (28 vs. 3.7%, odds ratio 10.1, 95% CI 1.1-89.4, p = 0.037). Hypo- and hypercalcemia developed in 5 (8.3%) and 8 (13.3%) sessions, respectively, but no adverse effects were noted despite severe hypocalcemia in one. There was no significant change in pre- and post-RCA-DFPP sodium, bicarbonate, albumin, and platelet levels. With regards DFPP procedure, prolongation of prothrombin time (PT) and activated partial thromboplastin time (aPTT) was observed following 38 (64.4%) and 12 (20.3%) sessions, respectively. Severely prolonged (>1.5 × upper limit normal) PT and aPTT were recorded in 2 sessions each. Expectedly, hypofibrinogenemia developed after 31 (51.7%) sessions: including 4 (6.7%) severe hypofibrinogenemia (<0.5 g/L). Two patients developed bleeding requiring blood product transfusion. The median total volume of fluids administered per session was 1.495 (1.373-1.612) L; post-RCA-DFPP significant weight gain of 0.5 (0-1.25) kg was noted. Diuretic was commenced or dose increased following 20 (33.3%) sessions for fluid balance management.

DISCUSSION/CONCLUSION

Protocol-based RCA for DFPP is feasible and safe in KTx recipients. However, DFPP-related coagulopathy can develop consequent to treatment; caution should be exercised for patients with bleeding risk. Close monitoring and management of the patients' electrolytes, especially hypocalcemia and hypomagnesemia, and fluid status is recommended.

Emerging New Approaches in Desensitization: Targeted Therapies for HLA Sensitization

There is an urgent need for therapeutic interventions for desensitization and antibody-mediated rejection (AMR) in sensitized patients with preformed or de novo donor-specific HLA antibodies (DSA). The risk of AMR and allograft loss in sensitized patients is increased due to preformed DSA detected at time of transplant or the reactivation of HLA memory after transplantation, causing acute and chronic AMR. Alternatively, de novo DSA that develops post-transplant due to inadequate immunosuppression and again may lead to acute and chronic AMR or even allograft loss. Circulating antibody, the final product of the humoral immune response, has been the primary target of desensitization and AMR treatment. However, in many cases these protocols fail to achieve efficient removal of all DSA and long-term outcomes of patients with persistent DSA are far worse when compared to non-sensitized patients. We believe that targeting multiple components of humoral immunity will lead to improved outcomes for such patients. In this review, we will briefly discuss conventional desensitization methods targeting antibody or B cell removal and then present a mechanistically designed desensitization regimen targeting plasma cells and the humoral response.

Apheresis Efficacy and Tolerance in the Setting of HLA-Incompatible Kidney Transplantation

Nearly 18% of patients on a waiting list for kidney transplantation (KT) are highly sensitized, which make access to KT more difficult. We assessed the efficacy and tolerance of different techniques (plasma exchanges [PE], double-filtration plasmapheresis [DFPP], and immunoadsorption [IA]) to remove donor specific antibodies (DSA) in the setting of HLA-incompatible (HLAi) KT. All patients that underwent apheresis for HLAi KT within a single center were included. Intra-session and inter-session Mean Fluorescence Intensity (MFI) decrease in DSA, clinical and biological tolerances were assessed. A total of 881 sessions were performed for 45 patients: 107 DFPP, 54 PE, 720 IA. The procedures led to HLAi KT in 39 patients (87%) after 29 (15–51) days. A higher volume of treated plasma was associated with a greater decrease of inter-session class I and II DSA (p = 0.04, p = 0.02). IA, PE, and a lower maximal DSA MFI were associated with a greater decrease in intra-session class II DSA (p < 0.01). Safety was good: severe adverse events occurred in 17 sessions (1.9%), more frequently with DFPP (6.5%) p < 0.01. Hypotension occurred in 154 sessions (17.5%), more frequently with DFPP (p < 0.01). Apheresis is well tolerated (IA and PE > DFPP) and effective at removing HLA antibodies and allows HLAi KT for sensitized patients.

Plasma volume treated with double filtration plasmapheresis and outcomes of acute antibody-mediated rejection in kidney transplant recipients: A retrospective cohort study

A retrospective cohort study was conducted to evaluate the association between the plasma volume treated by double filtration plasmapheresis and allograft outcomes for the treatment of acute antibody-mediated rejection in kidney transplant recipients. Patients were divided into two groups: group 1, plasma volume treated between 1 and <1.3 total plasma volume and group 2, plasma volume treated ≥1.3 total plasma volume. Primary outcome was ≥50% reduction of serum creatinine rising from baseline value at 1 month. A total of 32 courses (146 sessions) of double filtration plasmapheresis were performed; 17 and 15 courses in group 1 and group 2, respectively. Primary outcome occurred in 41% of group 1 and 40% of group 2 (adjusted risk ratio 1.15 [95%CI, 0.48-2.76]). Graft loss at 1 year did not differ between the two groups (adjusted hazard ratio 0.65 [95%CI, 0.23-1.87]). Infection tendency seemed to be higher in group 2 (40% vs 18%, P = .243).

[How to implement a complete apheresis program within a hemodialysis unit]

Many apheresis techniques can be performed in a blood-bank facility or a hemodialysis (HD) facility. However, it makes sense to perform apheresis in a hemodialysis facility as apheresis involves extra-corporeal circuits and because HD can be performed at the same time as apheresis (tandem procedure). Apheresis techniques comprise therapeutic plasma exchange, double-filtration plasmapheresis, and its derivative (rheopheresis and LDL-apheresis), and immunoadsorption (specific and semi-specific). We have setup an apheresis platform in our hospital that fulfills health recommendations. This process has involved financial investment and significant human resources, and has enabled us to network with different specialties (neurology, hematology, vascular medicine). We have setup protocols according to the type of pathology to be treated by apheresis, and to monitor clinical and biological data for each apheresis session. The main side effects of apheresis are a fall in blood pressure when a session is initiated, an increase in fluid overload, hypocalcemia, and the loss of some essential plasmatic factors. However, these side-effects are easily identified and can be properly managed in real time. Within two-years, we have performed 1845 apheresis sessions (134 patients). Of these, 66 received apheresis before and/or after kidney transplantation for ABO and/or HLA incompatibility (desensitization), for humoral rejection, or in the setting of relapsing focal-segmental glomerulosclerosis. Our patients' outcomes have been similar to those reported in the literature. The other 68 patients had various conditions. Because our program is now well-established, we are currently forming a specialist center to train physicians and nurses in the various apheresis techniques/procedures.

The impact of therapeutic plasma exchange and double filtration plasmapheresis on hemostasis in renal transplant recipients

Aim. To investigate the impact of double filtration plasmapheresis (DFPP) and therapeutic plasma exchange (TPE) on hemostasis in renal transplant recipients. Materials and methods. 54 renal transplant patients with an acute humoral rejection were treated with therapeutic apheresis methods: 24 patients with DFPP and 30 patients with TPE. In all patients was performed 3-4 session. We analyzed international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen concentration and platelet count just before and after each session, and after the course of all procedures. After TPE plasma replacement was performed with an equivalent volume of a fresh frozen plasma. After DFPP was performed 10-20% albumin solution. Results and discussion. After each DFPP session was occurred an increased INR and aPTT. After course of all DFPP procedures fibrinogen level decreased by 46%. It was associated with increase of APTT and INR by 35% and 32% respectively. Mainly it was associated with dose of the procedures (volume of plasma perfusion), but not with the plasma separator type. One patient noted hemorrhagic complication. After each TPE session level of fibrinogen concentration, INR and aPPT remained in the normal range, but there was a moderate reduction in platelet count, more pronounced than during DFPP. Hemorrhagic complications were not. Conclusion. Double cascade plasmapheresis and therapeutic plasma exchange generate preconditions for hemorrhagic complications such as increased aPTT and INR, reduce fibrinogen concentration. However, bleeding complications are rare. At the same time, during high volume DFPP should be careful when initially level of fibrinogen is low. In this case fibrinogen concentration should be controlled after the procedure for timely replenishment of its deficit.

Clinical analysis of single filtration plasmapheresis using continuous renal replacement therapy machines in kidney transplantation

BACKGROUND

Plasmapheresis has become an essential element of kidney transplantation (KT). In the present study, we report clinical outcomes of filtration plasmapheresis using continuous renal replacement therapy machines with a single filter for the first time in Korea.

METHODS

We retrospectively analyzed six patients who underwent filtration plasmapheresis for KT in our center; plasmapheresis was performed using the Plasmaflex (Baxter^®) with a TPE 2000 filter set (Baxter^®) in our hemodialysis unit. Five percent albumin was used as the replacement fluid, and intravenous immunoglobulin G was administered after each plasmapheresis session. The target preoperative ABO isoagglutinin titer was less than 1:8.

RESULTS

Filtration plasmapheresis was performed in four patients for ABO-incompatible KT, one for antibody-mediated rejection after KT, and the last one for positive T cell crossmatch. Altogether, 46 sessions of plasmapheresis were performed. ABO isoagglutinin titers successfully declined to or below the target level in all patients, and all patients successfully received KT with no significant antibody titer rebound. Acute antibody-mediated rejection and positive T cell crossmatch were well treated with filtration plasmapheresis, and no patient required fresh frozen plasma infusion for coagulopathy. There were one episode of hypotension and three of hypocalcemia. No patients experienced bleeding, infection, or allergic reaction.

CONCLUSION

Filtration plasmapheresis was effective and safe. Although our result is from a single center, our protocol appears to be promising.

Role of therapeutic plasmapheresis in ANCA-associated vasculitis

Plasma exchange, or plasmapheresis, is a treatment method that developed over a period of two decades and involves the removal and replacement of a patient's circulating plasma. The aim of treatment is to remove disease-associated molecules and therefore interrupt disease progression. This article summarizes the developmental history of this treatment and then looks in more detail at data on the use of plasma exchange in treating antineutrophil antibody (ANCA)-associated vasculitis. The eight randomized trials and the Cochrane Systematic Review on treating renal vasculitis are summarized to show that plasma exchange may be effective in this disease, specifically in reducing the development of end-stage kidney disease (ESKD) by approximately 40%. The plasma exchange and glucocorticoid dosing in the treatment of anti-neutrophil cytoplasm antibody associated vasculitis (PEXIVAS) study is a currently enrolling study aiming to answer some of the outstanding questions relating to the use of this treatment in ANCA-associated vasculitis.

Current progress in ABO-incompatible kidney transplantation

ABO-incompatible kidney transplantation (ABOi KT) was introduced to expand the donor pool and minimize shortage of kidneys for transplantation. Because improved outcomes of ABOi KT were reported in Japan in the early 2000s, the number of ABOi KTs has been increasing worldwide. In addition, a better understanding of immune pathogenesis and subsequent aggressive immunosuppression has helped to make effective desensitization protocols. Current strategies of ABOi KT consist of pretransplant antibody removal using plasmapheresis or immunoadsorption to prevent hyperacute rejection and potent maintenance immunosuppression, such as tacrolimus and mycophenolate mofetil, to inhibit antibody-mediated rejection. Recent outcomes of ABOi KT are comparable with ABO-compatible KT. However, there are still many problems to be resolved. Very high anti-ABO antibody producers are difficult to desensitize. In addition, ABOi KT is associated with an increased risk of infection and possibly malignancy due to aggressive immunosuppression. Optimization of desensitization and patient-tailored immunosuppression protocols are needed to achieve better outcomes of ABOi KT. This review provides an overview of the history, immune mechanism, immunosuppressive protocol, outcomes, current obstacles, and future perspectives in ABOi KT.

Antibody-incompatible kidney transplantation in 2015 and beyond

Rejection caused by donor-specific antibodies (principally ABO and HLA antibodies) has become one of the major barriers to successful long-term transplantation. This review focuses on clinical outcomes in antibody-incompatible transplantation, the current state of the science underpinning clinical observations, and how these may be translated into further novel therapies. The clinical outcomes for allografts facing donor-specific antibodies are at present determined largely by the use of agents developed in the 20th century for the treatment of T-lymphocyte-mediated cellular rejection, such as interleukin-2 agents and anti-thymocyte globulin. These treatments are partially effective, because acute antibody-mediated rejection is mediated to a considerable extent by T lymphocytes. However these treatments are essentially ineffective in chronic antibody-mediated rejection. Future therapies for the prevention and treatment of antibody-mediated rejection are likely to fall into the categories of those that reduce antibody production, extracorporeal antibody removal and disruption of the effector arms of antibody-mediated tissue damage.

Innate functions of immunoglobulin M lessen liver gene transfer with helper-dependent adenovirus

The immune system poses obstacles to viral vectors, even in the first administration to preimmunized hosts. We have observed that the livers of B cell-deficient mice were more effectively transduced by a helper-dependent adenovirus serotype-5 (HDA) vector than those of WT mice. This effect was T-cell independent as shown in athymic mice. Passive transfer of the serum from adenovirus-naïve WT to Rag1KO mice resulted in a reduction in gene transfer that was traced to IgM purified from serum of adenovirus-naïve mice. To ascribe the gene transfer inhibition activity to either adenoviral antigen-specific or antigen-unspecific functions of IgM, we used a monoclonal IgM antibody of unrelated specificity. Both the polyclonal and the irrelevant monoclonal IgM inhibited gene transfer by the HDA vector to either cultured hepatocellular carcinoma cells or to the liver of mice in vivo. Adsorption of polyclonal or monoclonal IgMs to viral capsids was revealed by ELISAs on adenovirus-coated plates. These observations indicate the existence of an inborn IgM mechanism deployed against a prevalent virus to reduce early post-infection viremia. In conclusion, innate IgM binding to adenovirus serotype-5 capsids restrains gene-transfer and offers a mechanism to be targeted for optimization of vector dosage in gene therapy with HDA vectors.

Reduced functional measure of cardiovascular reserve predicts admission to critical care unit following kidney transplantation

BACKGROUND

There is currently no effective preoperative assessment for patients undergoing kidney transplantation that is able to identify those at high perioperative risk requiring admission to critical care unit (CCU). We sought to determine if functional measures of cardiovascular reserve, in particular the anaerobic threshold (VO₂AT) could identify these patients.

METHODS

Adult patients were assessed within 4 weeks prior to kidney transplantation in a University hospital with a 37-bed CCU, between April 2010 and June 2012. Cardiopulmonary exercise testing (CPET), echocardiography and arterial applanation tonometry were performed.

RESULTS

There were 70 participants (age 41.7±14.5 years, 60% male, 91.4% living donor kidney recipients, 23.4% were desensitized). 14 patients (20%) required escalation of care from the ward to CCU following transplantation. Reduced anaerobic threshold (VO₂AT) was the most significant predictor, independently (OR = 0.43; 95% CI 0.27-0.68; p<0.001) and in the multivariate logistic regression analysis (adjusted OR = 0.26; 95% CI 0.12-0.59; p = 0.001). The area under the receiver-operating-characteristic curve was 0.93, based on a risk prediction model that incorporated VO₂AT, body mass index and desensitization status. Neither echocardiographic nor measures of aortic compliance were significantly associated with CCU admission.

CONCLUSIONS

To our knowledge, this is the first prospective observational study to demonstrate the usefulness of CPET as a preoperative risk stratification tool for patients undergoing kidney transplantation. The study suggests that VO₂AT has the potential to predict perioperative morbidity in kidney transplant recipients.

ABO-incompatible kidney transplantation

PURPOSE OF REVIEW

A dramatic shortage of available organs around the world encouraged attempts to cross previously forbidden immunological boundaries in kidney transplantation. This review focuses on the recent results of ABO-incompatible kidney transplantation.

RECENT FINDINGS

The outcome of ABO-incompatible kidney transplantation in terms of patient and graft survival is comparable to ABO-compatible transplantation for adult and pediatric recipients. Splenectomy has been replaced by the B-cell-depleting agent rituximab to avoid isoagglutinin titer rebound, prevent antibody-mediated rejection, and improve graft survival. However, the risk for infections may be increased and warrants caution. Corticosteroids remain a necessary component of any ABO-incompatible protocol; early as well as late steroid withdrawal may bear an enhanced risk for acute rejection and should only be performed with careful follow-up including protocol biopsies. The few studies that have long-term outcomes using protocol biopsies have characterized a state of accommodation by up-regulation of complement inhibitors, down-regulation of A/B antigens, and establishment of endothelial chimerism over time.

SUMMARY

The experience accumulated around the world indicates that ABO-incompatible kidney transplantation is well tolerated and effective in adults and in children, and it represents an important step forward in expanding the living donor pool. Further understanding of ABO-incompatible graft accommodation may have broader implication also for human leukocyte antigen-sensitized allograft recipients.

Incompatible kidney transplantation: a brief overview of the past, present and future

Live kidney donor transplantation across immunological barriers, either blood group or positive crossmatch [ABO- and human leucocyte antigens (HLA)-incompatible kidney transplantation, respectively], is now practised widely across many transplant centres. This provides transplantation opportunities to patients that hitherto would have been deemed contra-indicated and would subsequently have waited indefinitely for a suitably matched kidney. Protocols have evolved with time as experience has grown and now a variety of desensitization strategies are currently practised to overcome such immunological barriers. In addition, desensitization protocols are complemented by kidney paired donation exchange schemes and therefore incompatible patients now have strategies to either confront or bypass immunological barriers, respectively. As the field expands it is clear that non-transplant clinicians will be exposed to incompatible kidney transplant recipients outside of experienced centres. It is therefore timely to review the evolution of practice that have led to current desensitization modalities, contrast protocols and outcomes of current regimens and speculate on future direction of incompatible kidney transplantation.

Rapid resolution of severe sustained low blood pressure in haemodialysis patients after successful renal transplantation

BACKGROUND

Low blood pressure occurring in the absence of volume depletion, anti-hypertensive medication, heart failure or cortisol deficiency occurs in ~5-10% of haemodialysis patients, and can result in serious complications. The pathophysiology of this syndrome is poorly understood.

METHODS

We describe eight cases with dialysis-associated hypotension who underwent renal transplantation. Four patients were severely hypotensive with a systolic blood pressure (SBP) <100 mmHg before and during dialysis, and four had a SBP usually <100 mmHg during dialysis, but usually >100 mmHg between sessions. All had donor-specific human leukocyte antigen antibodies. Six patients underwent pre-transplant plasmapheresis, which was curtailed in two because of further falls in blood pressure. Two patients experienced clotting of their arteriovenous fistula. In one patient cryofiltration was used, which was tolerated without severe falls in the BP. The remaining patient, who had hypotension-associated retinal vein thrombosis before transplant, was supported with an epinephrine infusion and did not receive plasmapheresis.

RESULTS

Post-transplant, the first patient did not receive pressor therapy and died from bowel ischaemia. The other seven patients were supported with inotropes on critical care. The administration of steroids did not reverse hypotension. The mean pre-treatment SBP was 96 mmHg (range 71-110, SEM 5.0). After inotropes were withdrawn and graft function was established, the mean SBP was 127 mmHg (range 113-149, SEM 4.9) (P < 0.01).

CONCLUSIONS

Renal transplantation was performed successfully and safely in patients when pressor therapy was used to treat severe dialysis-associated hypotension and, moreover, the blood pressure normalized rapidly after graft function was established.

ABO Incompatible Kidney Transplantation-Current Status and Uncertainties

In the past, ABO blood group incompatibility was considered an absolute contraindication for kidney transplantation. Progress in defined desensitization practice and immunologic understanding has allowed increasingly successful ABO incompatible transplantation during recent years. This paper focused on the history, disserted outcomes, desensitization modalities and protocols, posttransplant immunologic surveillance, and antibody-mediated rejection in transplantation with an ABO incompatible kidney allograft. The mechanism underlying accommodation and antibody-mediated injury was also described.

Human leukocyte antigen antibody-incompatible renal transplantation: excellent medium-term outcomes with negative cytotoxic crossmatch

BACKGROUND

Human leukocyte antigen (HLA) antibody-incompatible renal transplantation has been increasingly performed since 2000 but with few data on the medium-term outcomes.

METHODS

Between 2003 and 2011, 84 patients received renal transplants with a pretreatment donor-specific antibody (DSA) level of more than 500 in a microbead assay. Seventeen patients had positive complement-dependent cytotoxic (CDC) crossmatch (XM), 44 had negative CDC XM and positive flow cytometric XM, and 23 had DSA detectable by microbead only. We also reviewed 28 patients with HLA antibodies but no DSA at transplant. DSAs were removed with plasmapheresis pretransplant, and patients did not routinely receive antithymocyte globulin posttransplant.

RESULTS

Mean follow-up posttransplantation was 39.6 (range 2-91) months. Patient survival after the first year was 93.8%. Death-censored graft survival at 1, 3, and 5 years was 97.5%, 94.2%, and 80.4%, respectively, in all DSA+ve patients, worse at 5 years in the CDC+ve than in the CDC-ve/DSA+ve group at 45.6% and 88.6%, respectively (P<0.03). Five-year graft survival in the DSA-ve group was 82.1%. Rejection occurred in 53.1% of DSA+ve patients in the first year compared with 22% in the DSA-ve patients (P<0.003).

CONCLUSIONS

HLA antibody-incompatible renal transplantation had a high success rate if the CDC XM was negative. Further work is required to predict which CDC+ve XM grafts will be successful and to treat slowly progressive graft damage because of DSA in the first few years after transplantation.