What's new--what's hot in clinical science: American Transplant Congress 2004.
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The American Transplant Congress 2004, held in Boston last May, was the biggest conference in the history of the event, with over 4000 attendees. A wide variety of clinical topics were presented and discussed, all advancing the field of solid organ transplantation. This manuscript will attempt to summarize the presentations at the meeting. Particularly 'hot' clinical topics included the recent passage of a law to increase organ recovery, the use of expanded criteria kidney donors, a new model for the allocation of deceased donor lungs, survival following liver transplantation and its potential effect on liver allocation and the use of novel immunosuppressive drugs. (+info)
Transfusion of RhD-incompatible blood components in RhD-negative blood marrow transplant recipients.
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BACKGROUND: Transfusion-dependent bone marrow transplant recipients are routinely transfused with ABO group and RhD-compatible blood components. However, because of the scarcity of RhD-negative blood components, particularly platelets, a policy was developed to transfuse RhD-positive blood components to RhD-negative patients during periods of shortage. METHODS: We reviewed the records of 78 RhD-negative patients with hematologic malignancies who received RhD-negative bone marrow and/or peripheral blood stem cells, from June 1995 to August 2000. The patients transfused with RhD-incompatible blood components were screened periodically for evidence of the development of red blood cell (RBC) alloimmunization. RESULTS: Three of 78 patients (4%) developed anti-D antibodies after receiving RhD-incompatible platelet transfusions. One of the patients developed evidence of anti-RhD antibodies after receiving 42 units of RhD-positive random donor platelets; the second patient developed such evidence after receiving 6 apheresis platelets and 2 infusions of intravenous immunoglobulin G (positive for anti-RhD). The third patient received 206 RhD-positive random donor platelets and 5 apheresis units. All patients were discharged from the hospital. The overall immunization rate was 4%. Six patients received Rh-incompatible packed RBCs and showed no evidence of neither anti-RhD nor any other anti-RBC antibodies. All 78 patients had received RhD-incompatible platelets throughout their engraftment period. CONCLUSION: Transfusion of RhD-positive blood components to Rh-negative patients with hematologic cancers, who have received RhD-negative bone marrow and/or peripheral blood stem cells, are at low risk of developing RhD antibodies. These findings allow for a flexible strategy of blood component therapy support for this special patient population during periods of shortage. (+info)
ABO incompatible kidney transplantations without splenectomy, using antigen-specific immunoadsorption and rituximab.
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ABO incompatible kidney transplantations have previously only been performed after several preoperative sessions of plasmapheresis and splenectomy, with the conventional triple-drug immunosuppressive protocol being reinforced with antilymphocyte globulin and B-cell-specific drugs, such as cyclophosphamide or deoxyspergualine. We have designed a protocol without splenectomy, based on antigen-specific immunoadsorption, rituximab and a conventional triple-drug immunosuppressive protocol. The protocol calls for a 10-day pretransplantation conditioning period, starting with one dosage of rituximab and followed by full dose tacrolimus, mycophenolate mofetil and prednisolone. Antigen-specific immunoadsorption was performed on pretransplantation days -6, -5, -2 and -1. After the last session, 0.5 g/kg of intravenous immunoglobulin (IVIG) was administered. Postoperatively, three more apheresis sessions were given every third day. Furthermore, if there was a significant increase in the antibody titers, extra sessions were considered. Eleven patients have received transplants with this protocol. The ABO antibodies were readily removed by the antigen-specific immunoadsorption and were kept at a low level post-transplantation by further adsorptions. There were no side effects and all patients have normal renal transplant function. We conclude that after an infusion each of rituximab and IVIG, and antigen-specific immunoadsorption; blood group-incompatible renal transplantations can be performed with excellent results using standard immunosuppression and no splenectomy. (+info)
ABO incompatible kidney transplantation (ABOINCKT) has been developed in Japan because of the shortage of cadaveric donors. We have performed 76 living-donor ABOINCKT in our center. Donor blood type antibody was removed by immunoadsorption or plasmapheresis and exchange. Immunosuppression consisted of cyclosporine or tacrolimus, steroid, and cyclophosphamide or azathioprine or mycophenolate mofetil and, recently, basiliximab. Splenectomy was routinely performed during the transplantation surgery. Donor blood type antigen was strongly expressed on the vascular endothelium at all time points and in all conditions posttransplantation. Red blood cell agglutination reaction (RBAR) was positive only in renal tissues from a patient with delayed hyperacute rejection. Donor specific antibody suppression was observed in 18 ABOINCKT recipients with blood type O from a donor with blood type A1 or B. ADCC activity was detected after pre-treatment. Acute humoral rejection in ABOINCKT can result from ADCC, as well as by antigen-antibody reaction. Five year graft and patient survival rates were 75% and 64% in 37 ABOINCKT recipients from June 1989 through December 1996, however they have been 100% in 39 ABOINCKT recipients since January 1997. Accommodation has been produced in ABOINCKT with the co-existence of blood type antigen and antibody. Currently, ABOINCKT is an alternative which should be considered, particularly for blood type O patients with extended waits for cadaveric transplantation and for pediatric patients. (+info)
Lessons learned from ABO-incompatible living donor kidney transplantation: 20 years later.
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From June 1982 to November 1989, 39 ABO-incompatible living kidney transplants were performed in 38 recipients. Pretransplant therapies included platelets donor transfusion (21/39), 2 to 5 plasmapheresis sessions (39/39), cyclosporin A with or without azathioprine (33/39) along with polyclonal Abs (36/39) and splenectomy at the time of transplantation (37/39). The last patient who received 2 ABO-incompatible transplants was previously splenectomized (end-stage renal failure due to a cortical necrosis following a traumatic spleen rupture). Three other patients who did not undergo a splenectomy at the time of transplantation were not included in that series but hyperacutely rejected their transplants during the first postoperative week. The 31 ABO-incompatible living related donor graft recipients are alive. Graft loss occurred from acute and/or hyperacute rejection in 5 cases (none below 15 years of age) and from chronic rejection in 8 cases. By contrast, among the 8 ABO-incompatible living unrelated donor graft recipients, only one renal graft is still functioning 20 years later. Graft survival rates are better in the group of patients < 15 years (100%, 89%, 78%, and 78% at 2, 5, 10, and 15 years respectively) compared with the group > 15 years (77%, 77%, 64%, and 59% respectively; NS). Today, 20 years later, prospective randomized studies testing different steps in the preparation protocol are still lacking. Plasmaphereses were replaced by double filtration plasmapheresis and immunoadsorption. Splenectomy seems to be a prerequisite for successful ABO-incompatible living kidney transplantation but IV Ig globulins and rituximab are currently being successfully used without splenectomy along with the new immunosuppressive drugs. As the procedure remains unchanged, it might be reserved to patients where cadaver graft could not be a valuable alternative, especially for recipients < 15 years of age with a living related ABO-incompatible donor. (+info)
Hemolysis of transfused group O red blood cells in minor ABO-incompatible unrelated-donor bone marrow transplants in patients receiving cyclosporine without posttransplant methotrexate.
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Hemolysis most commonly occurs following bone marrow transplant when there is "minor" ABO blood group incompatibility between donor and recipient. The hemolysis has been attributed to destruction of the patient's incompatible erythrocytes by donor-derived anti-A and/or anti-B antibody produced from "passenger" immunocompetent donor lymphocytes. Extraordinary transfusion requirements of group O erythrocytes in a series of patients receiving unrelated minor ABO-incompatible marrow grafts led us to investigate whether this mechanism could account for the extent of hemolysis observed. In seven consecutive minor ABO-incompatible unrelated-donor bone marrow transplant recipients receiving cyclosporine without posttransplant methotrexate, we observed excessive hemolysis. For cases in this index group, a strongly reactive donor-derived ABO blood group antibody was identified coincident with development of hemolysis. Transfusion requirements in the first three patients (26 U of group O erythrocytes each) greatly exceeded the recipient's volume of incompatible erythrocytes, indicating that lysis of transfused group O erythrocytes was also occurring. Pretransplant erythrocyte exchange transfusion with group O erythrocytes performed in the four subsequent patients decreased the severity of hemolysis, but did not prevent it. Among minor ABO-incompatible marrow graft recipients, an analysis of variance demonstrated effects on transfusion requirements due to donor-recipient relationship being unrelated (P less than .002) and the use of posttransplant methotrexate (P = .0001), and there was interaction between these two factors (P less than .001). Bone marrow transplants from unrelated donors resulted in an exaggerated immune response to ABO blood group antigens, which was associated with hemolysis of transfused group O erythrocytes, as well as the patient's ABO-incompatible erythrocytes. This serious complication may be prevented by posttransplant immunosuppression with methotrexate. (+info)
A case of hemolysis in ABO-unmatched liver transplantation: use of washed group O red blood cells and steroids.
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Liver transplantation is the only curative therapy for patients with end-stage liver disease. The high success rate and the increasing demand for the transplantation sometimes calls for ABO-compatible but nonidentical blood group orthotopic liver transplantation (OLT), which affords the opportunity to the production of antibody to red blood cells. Hemolytic anemia usually occurs 1 to 2 weeks after transplantation. Although mild in most patients, it can be life-threatening. Until now, a few cases showing hemolytic anemia due to donor ABO antibody formation after ABO-nonidentical OLT have been reported. In the reported cases of hemolytic anemia, most ABO-nonidentical OLT cases were O-to-A, but few reports are available on this subject with O-to-B ABO-nonidentical OLT. Herein, we report the experience with hemolysis after ABO-nonidentical OLT in a group O donor into a group B recipient and the successful treatment with transfusion of washed group O red blood cells and 60 mg dose of prednisolone for 3 days. (+info)
The Dutch national living donor kidney exchange program.
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The wait time for deceased-donor kidney transplantation has increased to 4-5 years in the Netherlands. Strategies to expand the donor pool include a living donor kidney exchange program. This makes it possible that patients who cannot directly receive a kidney from their intended living donor, due to ABO blood type incompatibility or a positive cross match, exchange donors in order to receive a compatible kidney. All Dutch kidney transplantation centers agreed on a common protocol. An independent organization is responsible for the allocation, cross matches are centrally performed and exchange takes place on an anonymous basis. Donors travel to the recipient centers. Surgical procedures are scheduled simultaneously. Sixty pairs participated within 1 year. For 9 of 29 ABO blood type incompatible and 17 of 31 cross match positive combinations, a compatible pair was found. Five times a cross match positive couple was matched to a blood type incompatible one, where the recipients were of blood type O. The living donor kidney exchange program is a successful approach that does not harm any of the candidates on the deceased donor kidney waitlist. For optimal results, both ABO blood type incompatible and cross match positive pairs should participate. (+info)